Targets for the production of radioisotopes and method of assembly

DOEpatents

Quinby, Thomas C.

1976-01-01

A target for preparation of radioisotopes by nuclear bombardment, and a method for its assembly are provided. A metallic sample to be bombarded is enclosed within a metallic support structure and the resulting target subjected to heat and pressure to effect diffusion bonds therebetween. The bonded target is capable of withstanding prolonged exposure to nuclear bombardment without thermal damage to the sample.

The origin of the diffuse background gamma radiation

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Puget, J. L.

1974-01-01

Recent observations provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV, and evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of big-bang cosmology, and connect these processes with the galaxy formation theory. A test of the theory is in future observations of the background radiation in the 100 MeK to 100 GeV energy range which are made with large orbiting spark-chamber satellite detectors. The theoretical interpretations of present data, their connection with baryon-symmetric cosmology and galaxy formation theory, and the need for future observations are discussed.

Revealing the Formation Mechanism of Ultra-Diffuse Galaxies

NASA Astrophysics Data System (ADS)

Garmire, Gordon

2017-09-01

Recently a population of large, very low optical surface brightness galaxies, so called ultra-diffuse galaxies (UDGs), were discovered in the outskirts of Coma clusters. Stellar line-of-sight velocity dispersions suggest large dark matter halo masses of 10^12 M_sun with very low baryon fractions ( 1%). The outstanding question waiting to be answered is: How do UDGs form and evolve? One theory is that UDGs are related to bright galaxies, however they are prevented from building a normal stellar population through various violent processes, such as gas stripping. We propose to observe Dragonfly 44, the most massive UDG known, for 100 ks with ACIS-I to test some of the formation theories.

A general strategy for the ultrafast surface modification of metals.

PubMed

Shen, Mingli; Zhu, Shenglong; Wang, Fuhui

2016-12-07

Surface modification is an essential step in engineering materials that can withstand the increasingly aggressive environments encountered in various modern energy-conversion systems and chemical processing industries. However, most traditional technologies exhibit disadvantages such as slow diffusion kinetics, processing difficulties or compatibility issues. Here, we present a general strategy for the ultrafast surface modification of metals inspired by electromigration, using aluminizing austenitic stainless steel as an example. Our strategy facilitates the rapid formation of a favourable ductile surface layer composed of FeCrAl or β-FeAl within only 10 min compared with several hours in conventional processes. This result indicates that electromigration can be used to achieve the ultrafast surface modification of metals and can overcome the limitations of traditional technologies. This strategy could be used to aluminize ultra-supercritical steam tubing to withstand aggressive oxidizing environments.

Massive black holes and light-element nucleosynthesis in a baryonic universe

NASA Technical Reports Server (NTRS)

Gnedin, Nickolay Y.; Ostriker, Jeremiah P.; Rees, Martin J.

1995-01-01

We reexamine the model proposed by Gnedin & Ostriker (1992) in which Jeans mass black holes (M(sub BH) approximately = 10(exp 6) solar mass) form shortly after decoupling. There is no nonbaryonic dark matter in this model, but we examine the possibility that Omega(sub b) is considerably larger than given by normal nucleosynthesis. Here we allow for the fact that much of the high baryon-to-photon ratio material will collapse leaving the universe of remaining material with light-element abundances more in accord with the residual baryonic density (approximately = 10(exp -2)) than with Omega(sub 0) and the initial baryonic density (approximately = 10(exp -1)). We find that no reasonable model can be made with random-phase density fluctuations, if the power on scales smaller than 10(exp 6) solar mass is as large as expected. However, phase-correlated models of the type that might occur in connection with topological singularities can be made with Omega(sub b) h(exp 2) = 0.013 +/- 0.001, 0.15 approximately less than Omega(sub 0) approximately less than 0.4, which are either flat (Omega(sub lambda) = 1 - Omega(sub 0)) or open (Omega(sub lambda) = 0) and which satisfy all the observational constraints which we apply, including the large baryon-to-total mass ratio found in the X-ray clusters. The remnant baryon density is thus close to that obtained in the standard picture (Omega(sub b) h(exp 2) = 0.0125 +/- 0.0025; Walker et al. 1991). The spectral index implied for fluctuations in the baryonic isocurvature scenario, -1 less than m less than 0, is in the range expected by other arguments based on large-scale structure and microwave fluctuation constraints. The dark matter in this picture is in the form of massive black holes. Accretion onto them at early epochs releases high-energy photons which significantly heat and reionize the universe. But photodissociation does not materially change light-element abundances. A typical model gives bar-y approximately = 1 x 10(exp -5), n(sub e)/n(sub H)(z = 30) approximately = 0.1, and a diffuse gamma-ray background at 100 keV near the Cosmic Background Explorer Satellite (COBE) limit of the order of 10% of that observed which originates from high-redshift quasars. Reionization in this model occurs at redshift 600 and reaches (H II/H(sub tot) approximately = 0.1-0.2.

Diffuser Test

NASA Image and Video Library

2007-09-13

Tests begun at Stennis Space Center's E Complex Sept. 13 evaluated a liquid oxygen lead for engine start performance, part of the A-3 Test Facility Subscale Diffuser Risk Mitigation Project at SSC's E-3 Test Facility. Phase 1 of the subscale diffuser project, completed Sept. 24, was a series of 18 hot-fire tests using a 1,000-pound liquid oxygen and gaseous hydrogen thruster to verify maximum duration and repeatability for steam generation supporting the A-3 Test Stand project. The thruster is a stand-in for NASA's developing J-2X engine, to validate a 6 percent scale version of A-3's exhaust diffuser. Testing the J-2X at altitude conditions requires an enormous diffuser. Engineers will generate nearly 4,600 pounds per second of steam to reduce pressure inside A-3's test cell to simulate altitude conditions. A-3's exhaust diffuser has to be able to withstand regulated pressure, temperatures and the safe discharge of the steam produced during those tests. Before the real thing is built, engineers hope to work out any issues on the miniature version. Phase 2 testing is scheduled to begin this month.

Some Like it Hot: Linking Diffuse X-Ray Luminosity, Baryonic Mass, and Star Formation Rate in Compact Groups of Galaxies

NASA Technical Reports Server (NTRS)

Desjardins, Tyler D.; Gallagher, Sarah C.; Hornschemeier, Ann E.; Mulchaey, John S.; Walker, Lisa May; Brandt, Willian N.; Charlton, Jane C.; Johnson, Kelsey E.; Tzanavaris, Panayiotis

2014-01-01

We present an analysis of the diffuse X-ray emission in 19 compact groups (CGs) of galaxies observed with Chandra. The hottest, most X-ray luminous CGs agree well with the galaxy cluster X-ray scaling relations in L(x-T) and (L(x-sigma), even in CGs where the hot gas is associated with only the brightest galaxy. Using Spitzer photometry, we compute stellar masses and classify Hickson CGs 19, 22, 40, and 42, and RSCGs 32, 44, and 86 as fossil groups using a new definition for fossil systems that includes a broader range of masses. We find that CGs with total stellar and Hi masses are great than or equal to 10(sup (11.3) solar mass are often X-ray luminous, while lower-mass CGs only sometimes exhibit faint, localized X-ray emission. Additionally, we compare the diffuse X-ray luminosity against both the total UV and 24 micron star formation rates of each CG and optical colors of the most massive galaxy in each of the CGs. The most X-ray luminous CGs have the lowest star formation rates, likely because there is no cold gas available for star formation, either because the majority of the baryons in these CGs are in stars or the X-ray halo, or due togas stripping from the galaxies in CGs with hot halos. Finally, the optical colors that trace recent star formation histories of the most massive group galaxies do not correlate with the X-ray luminosities of the CGs, indicating that perhaps the current state of the X-ray halos is independent of the recent history of stellar mass assembly in the most massive galaxies.

SAS-2 observations of celestial diffuse gamma radiation above 30 MeV

NASA Technical Reports Server (NTRS)

Thompson, D. J.; Fichtel, C. E.; Kniffen, D. A.; Hartman, R. C.

1974-01-01

The small astronomy satellite, SAS-2, used a 32-deck magnetic core digitized spark chamber to study gamma rays with energies above 30 MeV. Data for four regions of the sky away from the galactic plane were analyzed. These regions show a finite, diffuse flux of gamma rays with a steep energy spectrum, and the flux is uniform over all the regions. Represented by a power law, the differential energy spectrum shows an index of 2.5 + or - 0.4. The steep SAS-2 spectrum and the lower energy data are reasonably consistent with a neutral pion gamma-ray spectrum which was red-shifted (such as that proposed by some cosmological theories). It is concluded that the diffuse celestial gamma ray spectrum observed presents the possibility of cosmological studies and possible evidence for a residual cosmic ray density, and supports the galactic superclusters of matter and antimatter remaining from baryon-symmetric big bang.

A general strategy for the ultrafast surface modification of metals

PubMed Central

Shen, Mingli; Zhu, Shenglong; Wang, Fuhui

2016-01-01

Surface modification is an essential step in engineering materials that can withstand the increasingly aggressive environments encountered in various modern energy-conversion systems and chemical processing industries. However, most traditional technologies exhibit disadvantages such as slow diffusion kinetics, processing difficulties or compatibility issues. Here, we present a general strategy for the ultrafast surface modification of metals inspired by electromigration, using aluminizing austenitic stainless steel as an example. Our strategy facilitates the rapid formation of a favourable ductile surface layer composed of FeCrAl or β-FeAl within only 10 min compared with several hours in conventional processes. This result indicates that electromigration can be used to achieve the ultrafast surface modification of metals and can overcome the limitations of traditional technologies. This strategy could be used to aluminize ultra-supercritical steam tubing to withstand aggressive oxidizing environments. PMID:27924909

Forming supermassive black holes by accreting dark and baryon matter

NASA Astrophysics Data System (ADS)

Hu, Jian; Shen, Yue; Lou, Yu-Qing; Zhang, Shuangnan

2006-01-01

Given a large-scale mixture of self-interacting dark matter (SIDM) particles and baryon matter distributed in the early Universe, we advance here a two-phase accretion scenario for forming supermassive black holes (SMBHs) with masses around ~109Msolar at high redshifts z(>~6). The first phase is conceived to involve a rapid quasi-spherical and quasi-steady Bondi accretion of mainly SIDM particles embedded with baryon matter on to seed black holes (BHs) created at redshifts z<~ 30 by the first generation of massive Population III stars; this earlier phase rapidly gives birth to significantly enlarged seed BH masses of during z~ 20-15, where σ0 is the cross-section per unit mass of SIDM particles and Cs is the velocity dispersion in the SIDM halo referred to as an effective `sound speed'. The second phase of BH mass growth is envisaged to proceed primarily via baryon accretion, eventually leading to SMBH masses of MBH~ 109Msolar such SMBHs may form either by z~ 6 for a sustained accretion at the Eddington limit or later at lower z for sub-Eddington mean accretion rates. In between these two phases, there is a transitional yet sustained diffusively limited accretion of SIDM particles which in an eventual steady state would be much lower than the accretion rates of the two main phases. We intend to account for the reported detections of a few SMBHs at early epochs, e.g. Sloan Digital Sky Survey (SDSS) 1148+5251 and so forth, without necessarily resorting to either super-Eddington baryon accretion or very frequent BH merging processes. Only extremely massive dark SIDM haloes associated with rare peaks of density fluctuations in the early Universe may harbour such early SMBHs or quasars. Observational consequences are discussed. During the final stage of accumulating a SMBH mass, violent feedback in circumnuclear environs of a galactic nucleus leads to the central bulge formation and gives rise to the familiar empirical MBH-σb correlation inferred for nearby normal galaxies with σb being the stellar velocity dispersion in the galactic bulge; in our scenario, the central SMBH formation precedes that of the galactic bulge.

Electrodes for microfluidic applications

DOEpatents

Crocker, Robert W [Fremont, CA; Harnett, Cindy K [Livermore, CA; Rognlien, Judith L [Livermore, CA

2006-08-22

An electrode device for high pressure applications. These electrodes, designed to withstand pressure of greater than 10,000 psi, are adapted for use in microfluidic devices that employ electrokinetic or electrophoretic flow. The electrode is composed, generally, of an outer electrically insulating tubular body having a porous ceramic frit material disposed in one end of the outer body. The pores of the porous ceramic material are filled with an ion conductive polymer resin. A conductive material situated on the upper surface of the porous ceramic frit material and, thus isolated from direct contact with the electrolyte, forms a gas diffusion electrode. A metal current collector, in contact with the gas diffusion electrode, provides connection to a voltage source.

Spectroscopy of singly, doubly, and triply bottom baryons

NASA Astrophysics Data System (ADS)

Wei, Ke-Wei; Chen, Bing; Liu, Na; Wang, Qian-Qian; Guo, Xin-Heng

2017-06-01

Recently, some singly bottom baryons have been established experimentally, but none of the doubly or triply bottom baryons have been observed. Under the Regge phenomenology, the mass of an unobserved ground-state doubly or triply bottom baryon is expressed as a function of masses of the well-established light baryons and singly bottom baryons. Then, the values of Regge slopes and Regge intercepts for baryons containing one, two, or three bottom quarks are calculated. After that, the masses of the orbitally excited singly, doubly, and triply bottom baryons are estimated. Our predictions may be useful for the discovery of these baryons and their JP assignments.

Probing Circum Galactic Medium of Galaxies in Emission

NASA Astrophysics Data System (ADS)

Gupta, Anjali

Nearby late-type galaxies are missing a large fraction of their baryonic mass. Galaxies have also lost most of the metals that they produced. Cosmological simulations of galaxy formation suggest that a large fraction of the missing baryonic mass and metals should reside in the circum-galactic medium (CGM), in a warm-hot gas phase at temperatures between one million and 10 million K. Although theoretical models predict the existence of the warm-hot gas in the CGM, detecting and characterizing the diffuse CGM has been difficult. At the expected temperatures the baryons are in the form of highly ionized plasma,observable in soft X-rays. Using observations from Chandra, XMM-Newton and Suzaku, we found that there is a huge reservoir of ionized gas around the Milky Way, with a mass of over 2 billion solar masses and a radius of over 100 kpc. The baryonic mass fraction of this gas is consistent with the Universal value. Similar to the Milky Way, other spiral galaxies should also have massive, extended reservoirs of ionized hot gas in the CGM. Searches of such a warm-hot gas in CGMs of external galaxies, however, have given mixed results. There are three sets of observations which are in apparent conflict: (1) CGMs around nearby spiral galaxies are apparently not extended (this might be an observational bias which we will test with the proposed program); (2) CGMs around massive spirals are extended and massive, but given the large mass of these galaxies, about an order of magnitude higher than the Milky Way, the fraction of baryons in the CGM is still small, and the baryons are still missing; (3) the Milky Way CGM is extended and massive and may account for the missing baryons. Theoretical models suggest that CGM properties depend on galaxy properties such as the gravitational mass, stellar mass and specific star formation rate. So to understand the physics of galaxy formation and evolution and the role of the accretion and feedback mechanisms, we must probe the entire parameter space of these galaxy properties. Given that CGMs of giant massive galaxies have been studied already, in this proposed program we will study galaxies with lower, Milky Way-type masses and a range of star formation rate. Our proposed program has two parts: (1) new observations with Suzaku (now archived), and (2) archival XMM-Newton observations (1.09 Ms). We have been awarded 200ks of Suzaku time to detect and characterize the warm-hot CGM in a nearby late type galaxy NGC3221 with very high sSFR. We request support for the analysis of these observations. With our novel XMM-Newton program we will probe the relevant parameter space of stellar mass, star formation rate and gravitational mass of galaxies. XMM-Newton has the ideal combination of large field of view and large effective area at soft X-ray energies, which is crucial for faint diffuse emission studies. With the proposed program we will detect and characterize the warm-hot CGM in our targets, determine their density profiles, and measure their mass and baryon fraction. We will probe an extended parameter space of galaxy properties to understand how the properties of CGMs depend on stellar mass, halo mass, and star formation rate of galaxies. With the proposed study we will present the best and the most comprehensive phenomenological picture of the CGM of external galaxies which we will compare with theoretical models of galaxy formation. This will significantly advance our understanding of galaxy formation and evolution, feedback and metal enrichment. The proposed study is relevant to the NASA Strategic Goal to discover how the Universe works, explore how the Universe began and evolved into its present form. The PI's efforts to involve undergraduates from a Community College in her research will improve retention of students in STEM disciplines by providing opportunities and activities along the full length of the education pipeline (NASA Strategic Plan sub-goal Goal 6).

Constraints on the Sunyaev-Zel'dovich signal from the warm-hot intergalactic medium from WMAP and SPT data

NASA Astrophysics Data System (ADS)

Génova-Santos, Ricardo; Suárez-Velásquez, I.; Atrio-Barandela, F.; Mücket, J. P.

2013-07-01

The fraction of ionized gas in the warm-hot intergalactic medium induces temperature anisotropies on the cosmic microwave background similar to those of clusters of galaxies. The Sunyaev-Zel'dovich (SZ) anisotropies due to these low-density, weakly non-linear, baryon filaments cannot be distinguished from that of clusters using frequency information, but they can be separated since their angular scales are very different. To determine the relative contribution of the WHIM SZ signal to the radiation power spectrum of temperature anisotropies, we explore the parameter space of the concordance Λ cold dark matter model using Monte Carlo Markov chains and the Wilkinson Microwave Anisotropy Probe 7 yr and South Pole Telescope data. We find marginal evidence of a contribution by diffuse gas, with amplitudes of AWHIM = 10-20 μK2, but the results are also compatible with a null contribution from the WHIM, allowing us to set an upper limit of AWHIM < 43 μK2 (95.4 per cent CL). The signal produced by galaxy clusters remains at ACL = 4.5 μK2, a value similar to what is obtained when no WHIM is included. From the measured WHIM amplitude, we constrain the temperature-density phase diagram of the diffuse gas, and find it to be compatible with numerical simulations. The corresponding baryon fraction in the WHIM varies from 0.43 to 0.47, depending on model parameters. The forthcoming Planck data could set tighter constraints on the temperature-density relation.

Magnetic moments of the lowest-lying singly heavy baryons

NASA Astrophysics Data System (ADS)

Yang, Ghil-Seok; Kim, Hyun-Chul

2018-06-01

A light baryon is viewed as Nc valence quarks bound by meson mean fields in the large Nc limit. In much the same way a singly heavy baryon is regarded as Nc - 1 valence quarks bound by the same mean fields, which makes it possible to use the properties of light baryons to investigate those of the heavy baryons. A heavy quark being regarded as a static color source in the limit of the infinitely heavy quark mass, the magnetic moments of the heavy baryon are determined entirely by the chiral soliton consisting of a light-quark pair. The magnetic moments of the baryon sextet are obtained by using the parameters fixed in the light-baryon sector. In this mean-field approach, the numerical results of the magnetic moments of the baryon sextet with spin 3/2 are just 3/2 larger than those with spin 1/2. The magnetic moments of the bottom baryons are the same as those of the corresponding charmed baryons.

The origin of the diffuse background gamma-radiation

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Puget, J. L.

1974-01-01

Recent observations have now provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV. There is some evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation have been observed which provide evidence for its origin in nuclear processes in the early stages of the big-band cosmology and tie in these processes with galaxy fromation theory. A crucial test of the theory may lie in future observations of the background radiation in the 100 MeV to 100 GeV energy range which may be made with large orbiting spark-chamber satellite detectors. A discussion of the theoretical interpretations of present data, their connection with baryon symmetric cosmology and galaxy formation theory, and the need for future observations are given.

Baryonic Force for Accelerated Cosmic Expansion and Generalized U1b Gauge Symmetry in Particle-Cosmology

NASA Astrophysics Data System (ADS)

Khan, Mehbub; Hao, Yun; Hsu, Jong-Ping

2018-01-01

Based on baryon charge conservation and a generalized Yang-Mills symmetry for Abelian (and non-Abelian) groups, we discuss a new baryonic gauge field and its linear potential for two point-like baryon charges. The force between two point-like baryons is repulsive, extremely weak and independent of distance. However, for two extended baryonic systems, we have a dominant linear force α r. Thus, only in the later stage of the cosmic evolution, when two baryonic galaxies are separated by an extremely large distance, the new repulsive baryonic force can overcome the gravitational attractive force. Such a model provides a gauge-field-theoretic understanding of the late-time accelerated cosmic expansion. The baryonic force can be tested by measuring the accelerated Wu-Doppler frequency shifts of supernovae at different distances.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Espinosa-Loza, Francisco; Ross, Timothy O.; Switzer, Vernon A.

An insert for a cryogenic capable pressure vessel for storage of hydrogen or other cryogenic gases at high pressure. The insert provides the interface between a tank and internal and external components of the tank system. The insert can be used with tanks with any or all combinations of cryogenic, high pressure, and highly diffusive fluids. The insert can be threaded into the neck of a tank with an inner liner. The threads withstand the majority of the stress when the fluid inside the tank that is under pressure.

Manufacturing a Long-Period Grating with Periodic Thermal Diffusion Technology on High-NA Fiber and Its Application as a High-Temperature Sensor.

PubMed

Shen, Xiang; Dai, Bin; Xing, Yingbin; Yang, Luyun; Li, Haiqing; Li, Jinyan; Peng, Jingang

2018-05-08

We demonstrated a kind of long-period fiber grating (LPFG), which is manufactured with a thermal diffusion treatment. The LPFG was inscribed on an ultrahigh-numerical-aperture (UHNA) fiber, highly doped with Ge and P, which was able to easily diffuse at high temperatures within a few seconds. We analyzed how the elements diffused at a high temperature over 1300 °C in the UHNA fiber. Then we developed a periodically heated technology with a CO₂ laser, which was able to cause the diffusion of the elements to constitute the modulations of an LPFG. With this technology, there is little damage to the outer structure of the fiber, which is different from the traditional LPFG, as it is periodically tapered. Since the LPFG itself was manufactured under high temperature, it can withstand higher temperatures than traditional LPFGs. Furthermore, the LPFG presents a higher sensitivity to high temperature due to the large amount of Ge doping, which is approximately 100 pm/°C. In addition, the LPFG shows insensitivity to the changing of the environment’s refractive index and strain.

Baryon bags in strong coupling QCD

NASA Astrophysics Data System (ADS)

Gattringer, Christof

2018-04-01

We discuss lattice QCD with one flavor of staggered fermions and show that in the path integral the baryon contributions can be fully separated from quark and diquark contributions. The baryonic degrees of freedom (d.o.f.) are independent of the gauge field, and the corresponding free fermion action describes the baryons through the joint propagation of three quarks. The nonbaryonic dynamics is described by quark and diquark terms that couple to the gauge field. When evaluating the quark and diquark contributions in the strong coupling limit, the partition function completely factorizes into baryon bags and a complementary domain. Baryon bags are regions in space-time where the dynamics is described by a single free fermion made out of three quarks propagating coherently as a baryon. Outside the baryon bags, the relevant d.o.f. are monomers and dimers for quarks and diquarks. The partition sum is a sum over all baryon bag configurations, and for each bag, a free fermion determinant appears as a weight factor.

DETECTION OF A HOT GASEOUS HALO AROUND THE GIANT SPIRAL GALAXY NGC 1961

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Michael E.; Bregman, Joel N., E-mail: michevan@umich.edu, E-mail: jbregman@umich.edu

2011-08-10

Hot gaseous halos are predicted around all large galaxies and are critically important for our understanding of galaxy formation, but they have never been detected at distances beyond a few kpc around a spiral galaxy. We used the ACIS-I instrument on board Chandra to search for diffuse X-ray emission around an ideal candidate galaxy: the isolated giant spiral NGC 1961. We observed four quadrants around the galaxy for 30 ks each, carefully subtracting background and point-source emission, and found diffuse emission that appears to extend to 40-50 kpc. We fit {beta}-models to the emission and estimate a hot halo massmore » within 50 kpc of 5 x 10{sup 9} M{sub sun}. When this profile is extrapolated to 500 kpc (the approximate virial radius), the implied hot halo mass is 1-3 x 10{sup 11} M{sub sun}. These mass estimates assume a gas metallicity of Z = 0.5 Z{sub sun}. This galaxy's hot halo is a large reservoir of gas, but falls significantly below observational upper limits set by pervious searches, and suggests that NGC 1961 is missing 75% of its baryons relative to the cosmic mean, which would tentatively place it below an extrapolation of the baryon Tully-Fisher relationship of less massive galaxies. The cooling rate of the gas is no more than 0.4 M{sub sun} yr{sup -1}, more than an order of magnitude below the gas consumption rate through star formation. We discuss the implications of this halo for galaxy formation models.« less

Decays of excited baryons in DTU

NASA Astrophysics Data System (ADS)

Żenczykowski, P.

1981-03-01

Properties of the decays of excited strange baryons into ground state baryon and pseudoscalar meson are examined in the framework of the linear baryonic string model. The agreement between the predictions and the data is good. The single model's parameter ɛ, the deviation of which from 1 measures SU (3) breaking, is found to decrease with increasing internal orbital angular momentum of a baryon.

Beth-Uhlenbeck approach for repulsive interactions between baryons in a hadron gas

NASA Astrophysics Data System (ADS)

Vovchenko, Volodymyr; Motornenko, Anton; Gorenstein, Mark I.; Stoecker, Horst

2018-03-01

The quantum mechanical Beth-Uhlenbeck (BU) approach for repulsive hard-core interactions between baryons is applied to the thermodynamics of a hadron gas. The second virial coefficient a2—the "excluded volume" parameter—calculated within the BU approach is found to be temperature dependent, and it differs dramatically from the classical excluded volume (EV) model result. At temperatures T =100 -200 MeV, the widely used classical EV model underestimates the EV parameter for nucleons at a given value of the nucleon hard-core radius by large factors of 3-4. Previous studies, which employed the hard-core radii of hadrons as an input into the classical EV model, have to be re-evaluated using the appropriately rescaled EV parameters. The BU approach is used to model the repulsive baryonic interactions in the hadron resonance gas (HRG) model. Lattice data for the second- and fourth-order net baryon susceptibilities are described fairly well when the temperature dependent BU baryonic excluded volume parameter corresponds to nucleon hard-core radii of rc=0.25 -0.3 fm. Role of the attractive baryonic interactions is also considered. It is argued that HRG model with a constant baryon-baryon EV parameter vN N≃1 fm3 provides a simple yet efficient description of baryon-baryon interaction in the crossover temperature region.

Searching for the missing baryons in clusters

PubMed Central

Rasheed, Bilhuda; Bahcall, Neta; Bode, Paul

2011-01-01

Observations of clusters of galaxies suggest that they contain fewer baryons (gas plus stars) than the cosmic baryon fraction. This “missing baryon” puzzle is especially surprising for the most massive clusters, which are expected to be representative of the cosmic matter content of the universe (baryons and dark matter). Here we show that the baryons may not actually be missing from clusters, but rather are extended to larger radii than typically observed. The baryon deficiency is typically observed in the central regions of clusters (∼0.5 the virial radius). However, the observed gas-density profile is significantly shallower than the mass-density profile, implying that the gas is more extended than the mass and that the gas fraction increases with radius. We use the observed density profiles of gas and mass in clusters to extrapolate the measured baryon fraction as a function of radius and as a function of cluster mass. We find that the baryon fraction reaches the cosmic value near the virial radius for all groups and clusters above . This suggests that the baryons are not missing, they are simply located in cluster outskirts. Heating processes (such as shock-heating of the intracluster gas, supernovae, and Active Galactic Nuclei feedback) likely contribute to this expanded distribution. Upcoming observations should be able to detect these baryons. PMID:21321229

Introduction to temperature anisotropies of Cosmic Microwave Background radiation

NASA Astrophysics Data System (ADS)

Sugiyama, Naoshi

2014-06-01

Since its serendipitous discovery, Cosmic Microwave Background (CMB) radiation has been recognized as the most important probe of Big Bang cosmology. This review focuses on temperature anisotropies of CMB which make it possible to establish precision cosmology. Following a brief history of CMB research, the physical processes working on the evolution of CMB anisotropies are discussed, including gravitational redshift, acoustic oscillations, and diffusion dumping. Accordingly, dependencies of the angular power spectrum on various cosmological parameters, such as the baryon density, the matter density, space curvature of the universe, and so on, are examined and intuitive explanations of these dependencies are given.

Baryons and baryon resonances in nuclear matter

NASA Astrophysics Data System (ADS)

Lenske, Horst; Dhar, Madhumita; Gaitanos, Theodoros; Cao, Xu

2018-01-01

Theoretical approaches to the production of hyperons and baryon resonances in elementary hadronic reactions and heavy ion collisions are reviewed. The focus is on the production and interactions of baryons in the lowest SU(3) flavor octet and states from the next higher SU(3) flavor decuplet. Approaches using the SU(3) formalism for interactions of mesons and baryons and effective field theory for hyperons are discussed. An overview of application to free space and in-medium baryon-baryon interactions is given and the relation to a density functional theory is indicated. The intimate connection between baryon resonances and strangeness production is shown first for reactions on the nucleon. Pion-induced hypernuclear reactions are shown to proceed essentially through the excitation of intermediate nucleon resonances. Transport theory in conjunction with a statistical fragmentation model is an appropriate description of hypernuclear production in antiproton and heavy ion induced fragmentation reactions. The excitation of subnuclear degrees of freedom in peripheral heavy ion collisions at relativistic energies is reviewed. The status of in-medium resonance physics is discussed.

Cosmological simulations of dwarf galaxies with cosmic ray feedback

NASA Astrophysics Data System (ADS)

Chen, Jingjing; Bryan, Greg L.; Salem, Munier

2016-08-01

We perform zoom-in cosmological simulations of a suite of dwarf galaxies, examining the impact of cosmic rays (CRs) generated by supernovae, including the effect of diffusion. We first look at the effect of varying the uncertain CR parameters by repeatedly simulating a single galaxy. Then we fix the comic ray model and simulate five dwarf systems with virial masses range from 8 to 30 × 1010 M⊙. We find that including CR feedback (with diffusion) consistently leads to disc-dominated systems with relatively flat rotation curves and constant star formation rates. In contrast, our purely thermal feedback case results in a hot stellar system and bursty star formation. The CR simulations very well match the observed baryonic Tully-Fisher relation, but have a lower gas fraction than in real systems. We also find that the dark matter cores of the CR feedback galaxies are cuspy, while the purely thermal feedback case results in a substantial core.

Unified origin for baryonic visible matter and antibaryonic dark matter.

PubMed

Davoudiasl, Hooman; Morrissey, David E; Sigurdson, Kris; Tulin, Sean

2010-11-19

We present a novel mechanism for generating both the baryon and dark matter densities of the Universe. A new Dirac fermion X carrying a conserved baryon number charge couples to the standard model quarks as well as a GeV-scale hidden sector. CP-violating decays of X, produced nonthermally in low-temperature reheating, sequester antibaryon number in the hidden sector, thereby leaving a baryon excess in the visible sector. The antibaryonic hidden states are stable dark matter. A spectacular signature of this mechanism is the baryon-destroying inelastic scattering of dark matter that can annihilate baryons at appreciable rates relevant for nucleon decay searches.

Determination of baryon-baryon elastic scattering phase shift from finite volume spectra in elongated boxes

NASA Astrophysics Data System (ADS)

Li, Ning; Wu, Ya-Jie; Liu, Zhan-Wei

2018-01-01

The relations between the baryon-baryon elastic scattering phase shifts and the two-particle energy spectrum in the elongated box are established. We studied the cases with both the periodic boundary condition and twisted boundary condition in the center of mass frame. The framework is also extended to the system of nonzero total momentum with periodic boundary condition in the moving frame. Moreover, we discussed the sensitivity functions σ (q ) that represent the sensitivity of higher scattering phases. Our analytical results will be helpful to extract the baryon-baryon elastic scattering phase shifts in the continuum from lattice QCD data by using elongated boxes.

A Study of Double-Charm and Charm-Strange Baryons inElectron-Positron Annihilations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, Adam J.; /SLAC

2007-10-15

In this dissertation I describe a study of double-charm and charm-strange baryons based on data collected with the BABAR Detector at the Stanford Linear Accelerator Center. In this study I search for new baryons and make precise measurements of their properties and decay modes. I seek to verify and expand upon double-charm and charm-strange baryon observations made by other experiments. The BABAR Detector is used to measure subatomic particles that are produced at the PEP-II storage rings. I analyze approximately 300 million e+e- {yields} c{bar c} events in a search for the production of double-charm baryons. I search for themore » double-charm baryons {Xi}{sup +}{sub cc} (containing the quarks ccd) and {Xi}{sup ++}{sub cc} (ccu) in decays to {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +} and {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +}{pi}{sup +}, respectively. No statistically significant signals for their production are found, and upper limits on their production are determined. Statistically significant signals for excited charm-strange baryons are observed with my analysis of approximately 500 million e+e- {yields} c{bar c} events. The charged charm-strange baryons {Xi}{sub c}(2970){sup +}, {Xi}{sub c}(3055){sup +}, {Xi}{sub c}(3123){sup +} are found in decays to {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +}, the same decay mode used in the {Xi}{sup +}{sub cc} search. The neutral charm-strange baryon {Xi}{sub c}(3077){sup 0} is observed in decays to {Lambda}{sup +}{sub c}K{sub 8}{pi}{sup -}. I also search for excited charm-strange baryon decays to {Lambda}{sup +}{sub c}K{sub 8}, {Lambda}{sup +}{sub c}K{sup -}, {Lambda}{sup +}{sub c}K{sub 8}{pi}{sup -}{pi}{sup +}, and {Lambda}{sup +}{sub c}K{sup -}{pi}{sup -}{pi}{sup +}. No significant charm-strange baryon signals a f h these decay modes. For each excited charm-strange baryon state that I observe, I measure its mass, natural width (lifetime), and production rate. The properties of these excited charm-strange baryons and their decay modes provide constraints for phenomenological models of quark interactions through quantum chromodynamics. My discovery of the two new charm-strange baryons {Xi}{sub c}(3055){sup +} and {Xi}{sub c}(3123){sup +} influences our theoretical understanding of charm-strange baryon states.« less

Diffuse X-ray emission from the NGC 2300 group of galaxies - Implications for dark matter and galaxy evolution in small groups

NASA Technical Reports Server (NTRS)

Mulchaey, John S.; Davis, David S.; Mushotzky, Richard F.; Burstein, David

1993-01-01

The discovery of diffuse X-ray emission from the NGC 2300 group of galaxies using the ROSAT Position Sensitive Proportional Counter is reported. The gas distributions is roughly symmetric and extends to a radius of at least 0.2/h(50) Mpc. A Raymond-Smith hot plasma model provides an excellent fit the X-ray spectrum with a best-fit value temperature of 0.9 + -/15 or - 0.14 keV and abundance 0.06 + 0/.12 or - 0.05 solar. The assumption of gravitational confinement leads to a total mass of the group of 3.0 + 0.4 or - 0.5 x 10 exp 13 solar. Baryons can reasonably account for 4 percent of this mass, and errors could push this number not higher than 10-15 percent. This is one of the strongest pieces of evidence that dark matter dominates small groups such as this one. The intragroup medium in this system has the lowest metal abundance yet found in diffuse gas in a group or cluster.

Baryonic contributions to the dilepton spectra in relativistic heavy ion collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bleicher, M.; Dutt-mazumder, A. K.; Gale, C.

2017-05-09

We investigate the baryonic contributions to the dilepton yield in high energy heavy ion collisions within the context of a transport model. The relative contribution of the baryonic and mesonic sources are examined. It is observed that most dominant among the baryonic channels is the decay of N*(1520) and mostly confined in the region below the rho peak. In a transport theory implementation we find the baryonic contribution to the lepton pair yield to be small.

Chiral Lagrangian with Heavy Quark-Diquark Symmetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jie Hu; Thomas Mehen

2005-11-29

We construct a chiral Lagrangian for doubly heavy baryons and heavy mesons that is invariant under heavy quark-diquark symmetry at leading order and includes the leading O(1/m{sub Q}) symmetry violating operators. The theory is used to predict the electromagnetic decay width of the J=3/2 member of the ground state doubly heavy baryon doublet. Numerical estimates are provided for doubly charm baryons. We also calculate chiral corrections to doubly heavy baryon masses and strong decay widths of low lying excited doubly heavy baryons.

The Circumgalactic Medium of Andromeda

NASA Astrophysics Data System (ADS)

Lehner, Nicolas; Project AMIGA Team

2017-03-01

Our view of galaxies has been transformed in recent years with diffuse halo gas surrounding galaxies that contains at least as many metals and baryons as their disks. While single sight lines through galaxy halos seen in absorption have provided key new constraints, they provide only average properties. Our massive neighbor, the Andromeda (M31) galaxy, provides an unique way to study its circumgalactic medium whereby we can study it using not one or two, but ~36 sightlines thanks to its proximity. With our Large HST program - Project AMIGA (Absorption Maps In the Gas of Andromeda), our goals are to determine the spatial distribution of the halo properties of a L* galaxy using 36 background targets at different radii and azimuths. In this brief paper, I discuss briefly the scientific rationale of Project AMIGA and some early science results. In particular, for the first time we have demonstrated that M31 has a gaseous halo that extends to R vir with as much as metal and baryonic masses than in its disk and has substantial change in its ionization properties with more highly ionized gas found at R ~ R vir than cooler gas found near the disk.

Exotic triple-charm deuteronlike hexaquarks

NASA Astrophysics Data System (ADS)

Chen, Rui; Wang, Fu-Lai; Hosaka, Atsushi; Liu, Xiang

2018-06-01

Adopting the one-boson-exchange model, we perform a systematic investigation of interactions between a doubly charmed baryon (Ξc c) and an S -wave charmed baryon (Λc, Σc(*), and Ξc(',*)). Both the S - D mixing effect and coupled-channel effect are considered in this work. Our results suggest that there may exist several possible triple-charm deuteronlike hexaquarks. Meanwhile, we further study the interactions between a doubly charmed baryon and an S -wave anticharmed baryon. We find that a doubly charmed baryon and an S -wave anticharmed baryon can be easily bound together to form shallow molecular hexaquarks. These heavy flavor hexaquarks predicted here can be accessible at future experiment like LHCb.

Mass and residue of Λ (1405) as hybrid and excited ordinary baryon

NASA Astrophysics Data System (ADS)

Azizi, K.; Barsbay, B.; Sundu, H.

2018-03-01

The nature of the Λ (1405) has been a puzzle for decades, whether it is a standard three-quark baryon, a hybrid baryon or a baryon-meson molecule. More information on the decay channels of this particle and its strong, weak and electromagnetic interactions with other hadrons is needed to clarify its internal organization. The residue of this particle is one of the main inputs in investigation of its decay properties in many approaches. We calculate the mass and residue of the Λ (1405) state in the context of QCD sum rules considering it as a hybrid baryon with three-quark-one-gluon content as well as an excited ordinary baryon with quantum numbers I(JP)=0(1/2-). The comparison of the obtained results on the mass with the average experimental value presented in PDG allows us to interpret this state as a hybrid baryon.

Electromagnetic form factors of singly heavy baryons in the self-consistent SU(3) chiral quark-soliton model

NASA Astrophysics Data System (ADS)

Kim, June-Young; Kim, Hyun-Chul

2018-06-01

The self-consistent chiral quark-soliton model is a relativistic pion mean-field approach in the large Nc limit, which describes both light and heavy baryons on an equal footing. In the limit of the infinitely heavy mass of the heavy quark, a heavy baryon can be regarded as Nc-1 valence quarks bound by the pion mean fields, leaving the heavy quark as a color static source. The structure of the heavy baryon in this scheme is mainly governed by the light-quark degrees of freedom. Based on this framework, we evaluate the electromagnetic form factors of the lowest-lying heavy baryons. The rotational 1 /Nc and strange current quark mass corrections in linear order are considered. We discuss the electric charge and magnetic densities of heavy baryons in comparison with those of the nucleons. The results of the electric charge radii of the positive-charged heavy baryons show explicitly that the heavy baryon is a compact object. The electric form factors are presented. The form factor of Σc++ is compared with that from a lattice QCD. We also discuss the results of the magnetic form factors. The magnetic moments of the baryon sextet with spin 1 /2 and the magnetic radii are compared with other works and the lattice data.

Dissecting the thermal Sunyaev-Zeldovich-gravitational lensing cross-correlation with hydrodynamical simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hojjati, Alireza; Harnois-Deraps, Joachim; Waerbeke, Ludovic Van

2015-10-01

We use the cosmo-OWLS suite of cosmological hydrodynamical simulations, which includes different galactic feedback models, to predict the cross-correlation signal between weak gravitational lensing and the thermal Sunyaev-Zeldovich (tSZ) y-parameter. The predictions are compared to the recent detection reported by van Waerbeke and collaborators. The simulations reproduce the weak lensing-tSZ cross-correlation, ξ{sub yκ}(θ), well. The uncertainty arising from different possible feedback models appears to be important on small scales only (0θ ∼< 1 arcmin), while the amplitude of the correlation on all scales is sensitive to cosmological parameters that control the growth rate of structure (such as σ{sub 8}, Ω{sub m} andmore » Ω{sub b}). This study confirms our previous claim (in Ma et al.) that a significant proportion of the signal originates from the diffuse gas component in low-mass (M{sub halo} ∼< 10{sup 14} M{sub ⊙}) clusters as well as from the region beyond the virial radius. We estimate that approximately 20% of the detected signal comes from low-mass clusters, which corresponds to about 30% of the baryon density of the Universe. The simulations also suggest that more than half of the baryons in the Universe are in the form of diffuse gas outside halos (∼> 5 times the virial radius) which is not hot or dense enough to produce a significant tSZ signal or be observed by X-ray experiments. Finally, we show that future high-resolution tSZ-lensing cross-correlation observations will serve as a powerful tool for discriminating between different galactic feedback models.« less

Evolution of the baryon asymmetry through the electroweak crossover in the presence of a helical magnetic field

NASA Astrophysics Data System (ADS)

Kamada, Kohei; Long, Andrew J.

2016-12-01

We elaborate upon the model of baryogenesis from decaying magnetic helicity by focusing on the evolution of the baryon number and magnetic field through the Standard Model electroweak crossover. The baryon asymmetry is determined by a competition between the helical hypermagnetic field, which sources baryon number, and the electroweak sphaleron, which tends to wash out baryon number. At the electroweak crossover, both of these processes become inactive; the hypermagnetic field is converted into an electromagnetic field, which does not source baryon number, and the weak gauge boson masses grow, suppressing the electroweak sphaleron reaction. An accurate prediction of the relic baryon asymmetry requires a careful treatment of the crossover. We extend our previous study [K. Kamada and A. J. Long, Phys. Rev. D 94, 063501 (2016)], taking into account the gradual conversion of the hypermagnetic into the electromagnetic field. If the conversion is not completed by the time of sphaleron freeze-out, as both analytic and numerical studies suggest, the relic baryon asymmetry is enhanced compared to previous calculations. The observed baryon asymmetry of the Universe can be obtained for a primordial magnetic field that has a present-day field strength and coherence length of B0˜10-17 G and λ0˜10-3 pc and a positive helicity. For larger B0 the baryon asymmetry is overproduced, which may be in conflict with blazar observations that provide evidence for an intergalactic magnetic field of strength B0≳10-14 - 16 G .

The role of the baryon junction in relativistic heavy-ion collisions

NASA Astrophysics Data System (ADS)

Vance, Stephen Earl

The non-perturbative nature of the conserved baryon number of nuclei is investigated by studying the role of the baryon junction in relativistic heavy-ion collisions. The junction, J, of a baryon originates in the Standard Model of Strong Interactions (QCD) and is the vertex which connects the color flux (Wilson) lines flowing from the three valence quarks. In high energy interactions, the baryon junction can play a dynamical role through the Regge exchange of junction states. We show that the junction exchange provides a natural mechanism for the transport of baryon number into the central rapidity region and has the remarkable ability to produce valence hyperons, including W- baryons. This mechanism is used to describe the observed baryon stopping and associated hyperon production in nucleus-nucleus collisions at the CERN SPS. We also show that junction - antijunction excitations or JJ loops provide a new mechanism for baryon pair production and lead to enhanced hyperon and antihyperon production. The combination of these two mechanisms is able to explain part of the anomalous hyperon production observed in Pb + Pb collisions at the SPS. Using the junction initial state dynamics, final state strangeness exchange interactions are shown to further enhance hyperon production and are proposed as an explanation of the remaining anomalous hyperon production. With larger phase space (higher energy) accessible at the newly constructed BNL RHIC facility, we propose that the observation of valence W- baryons in pp collisions will be a decisive observable to confirm the junction exchange picture of baryon number transport. In addition, we note that novel rapidity correlations between baryons and antibaryons of completely different quark flavors, like D++(uuu) and W+( ss s) , are predicted by the JJ loop mechanism. For numerical calculations of multiparticle observables associated with these junction mechanisms, we developed the HIJING/BB¯ nuclear event generator. HIJING/BB¯ was then coupled to the General Cascade Program (GCP) to study the role of the final state flavor changing interactions.

Atomic diffusion in metal-poor stars. II. Predictions for the Spite plateau

NASA Astrophysics Data System (ADS)

Salaris, M.; Weiss, A.

2001-09-01

We have computed a grid of up-to-date stellar evolutionary models including atomic diffusion, in order to study the evolution with time of the surface Li abundance in low-mass metal-poor stars. We discuss in detail the dependence of the surface Li evolution on the initial metallicity and stellar mass, and compare the abundances obtained from our models with the available Li measurements in Pop II stars. While it is widely accepted that the existence of the Spite Li-plateau for these stars is a strong evidence that diffusion is inhibited, we show that, when taking into account observational errors, uncertainties in the Li abundance determinations, in the T_eff scale, and in particular the size of the observed samples of stars, the Spite plateau and the Li abundances in subgiant branch stars can be reproduced also by models including fully efficient diffusion, provided that the most metal-poor field halo objects are between 13.5 and 14 Gyr old. We provide the value of the minimum number of plateau stars to observe, for discriminating between efficient or inhibited diffusion. {From} our models with diffusion we derive that the average Li abundance along the Spite plateau is about a factor of 2 lower than the primordial one. As a consequence, the derived primordial Li abundance would be consistent with a high helium and low deuterium Big Bang Nucleosynthesis; this implies a high cosmological baryon density as inferred from the analyses of the cosmic microwave background.

Insight into particle production mechanisms via angular correlations of identified particles in pp collisions at √{s}=7 TeV

NASA Astrophysics Data System (ADS)

Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; An, M.; Andrei, C.; Andrews, H. A.; Andronic, A.; Anguelov, V.; Anson, C.; Antičić, T.; Antinori, F.; Antonioli, P.; Anwar, R.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barioglio, L.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Beltran, L. G. E.; Belyaev, V.; Bencedi, G.; Beole, S.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Blair, J. T.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Boldizsár, L.; Bombara, M.; Bonora, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buhler, P.; Buitron, S. A. I.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Caines, H.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Capon, A. A.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Ceballos Sanchez, C.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, S.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; del Valle, Z. Conesa; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crkovská, J.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; De Caro, A.; de Cataldo, G.; de Conti, C.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Souza, R. D.; Degenhardt, H. F.; Deisting, A.; Deloff, A.; Deplano, C.; Dhankher, P.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Di Ruzza, B.; Corchero, M. A. Diaz; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Duggal, A. K.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erhardt, F.; Espagnon, B.; Esumi, S.; Eulisse, G.; Eum, J.; Evans, D.; Evdokimov, S.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Francisco, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Girard, M. Fusco; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gajdosova, K.; Gallio, M.; Galvan, C. D.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Garg, K.; Garg, P.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Ducati, M. B. Gay; Germain, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, A. S.; Gonzalez, V.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Graham, K. L.; Greiner, L.; Grelli, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grion, N.; Gronefeld, J. M.; Grosa, F.; Grosse-Oetringhaus, J. F.; Grosso, R.; Gruber, L.; Grull, F. R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Guzman, I. B.; Haake, R.; Hadjidakis, C.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Harris, J. W.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Hellbär, E.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Herrmann, F.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hippolyte, B.; Hladky, J.; Horak, D.; Hosokawa, R.; Hristov, P.; Hughes, C.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Inaba, M.; Ippolitov, M.; Irfan, M.; Isakov, V.; Islam, M. S.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacak, B.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovska, S.; Jadlovsky, J.; Jahnke, C.; Jakubowska, M. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jercic, M.; Bustamante, R. T. Jimenez; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kang, J. H.; Kaplin, V.; Kar, S.; Uysal, A. Karasu; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Mohisin Khan, M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Khatun, A.; Khuntia, A.; Kielbowicz, M. M.; Kileng, B.; Kim, D. W.; Kim, D. J.; Kim, D.; Kim, H.; Kim, J. S.; Kim, J.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kopcik, M.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.; Meethaleveedu, G. Koyithatta; Králik, I.; Kravčáková, A.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kuhn, C.; Kuijer, P. G.; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kundu, S.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lapidus, K.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lavicka, R.; Lazaridis, L.; Lea, R.; Leardini, L.; Lee, S.; Lehas, F.; Lehner, S.; Lehrbach, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Litichevskyi, V.; Ljunggren, H. M.; Llope, W. J.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Loncar, P.; Lopez, X.; Torres, E. López; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.; Lupi, M.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Cervantes, I. Maldonado; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martin, N. A.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Pedreira, M. Martinez; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Mastroserio, A.; Mathis, A. M.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzilli, M.; Mazzoni, M. A.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Mhlanga, S.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Mishra, T.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montes, E.; De Godoy, D. A. Moreira; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Münning, K.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Myers, C. J.; Naik, B.; Nair, R.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Natal da Luz, H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Negrao De Oliveira, R. A.; Nellen, L.; Nesbo, S. V.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Ohlson, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pacik, V.; Pagano, D.; Pagano, P.; Paić, G.; Pal, S. K.; Palni, P.; Pan, J.; Pandey, A. K.; Panebianco, S.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, J.; Park, W. J.; Parmar, S.; Passfeld, A.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Peng, X.; Pereira, L. G.; Pereira Da Costa, H.; Peresunko, D.; Perez Lezama, E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Pezzi, R. P.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Poppenborg, H.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Pozdniakov, V.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Rana, D. B.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Ratza, V.; Ravasenga, I.; Read, K. F.; Redlich, K.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rodríguez Cahuantzi, M.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Saarinen, S.; Sadhu, S.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sandoval, A.; Sarkar, D.; Sarkar, N.; Sarma, P.; Sas, M. H. P.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schmidt, M. O.; Schmidt, M.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Šefčík, M.; Seger, J. E.; Sekiguchi, Y.; Sekihata, D.; Selyuzhenkov, I.; Senosi, K.; Senyukov, S.; Serradilla, E.; Sett, P.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, A.; Sharma, M.; Sharma, M.; Sharma, N.; Sheikh, A. I.; Shigaki, K.; Shou, Q.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Song, J.; Song, M.; Soramel, F.; Sorensen, S.; Sozzi, F.; Spiriti, E.; Sputowska, I.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stankus, P.; Stenlund, E.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Suljic, M.; Sultanov, R.; Šumbera, M.; Sumowidagdo, S.; Suzuki, K.; Swain, S.; Szabo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Tabassam, U.; Takahashi, J.; Tambave, G. J.; Tanaka, N.; Tarhini, M.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Muñoz, G. Tejeda; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thakur, D.; Thomas, D.; Tieulent, R.; Tikhonov, A.; Timmins, A. R.; Toia, A.; Tripathy, S.; Trogolo, S.; Trombetta, G.; Trubnikov, V.; Trzaska, W. H.; Trzeciak, B. A.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Umaka, E. N.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vala, M.; Van Der Maarel, J.; Van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vázquez Doce, O.; Vechernin, V.; Veen, A. M.; Velure, A.; Vercellin, E.; Limón, S. Vergara; Vernet, R.; Vértesi, R.; Vickovic, L.; Vigolo, S.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Villatoro Tello, A.; Vinogradov, A.; Vinogradov, L.; Virgili, T.; Vislavicius, V.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Voscek, D.; Vranic, D.; Vrláková, J.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wessels, J. P.; Westerhoff, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Willems, G. A.; Williams, M. C. S.; Windelband, B.; Witt, W. E.; Yalcin, S.; Yang, P.; Yano, S.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yoon, J. H.; Yurchenko, V.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zimmermann, S.; Zinovjev, G.; Zmeskal, J.

2017-08-01

Two-particle angular correlations were measured in pp collisions at √{s} = 7 TeV for pions, kaons, protons, and lambdas, for all particle/anti-particle combinations in the pair. Data for mesons exhibit an expected peak dominated by effects associated with mini-jets and are well reproduced by general purpose Monte Carlo generators. However, for baryon-baryon and anti-baryon-anti-baryon pairs, where both particles have the same baryon number, a near-side anti-correlation structure is observed instead of a peak. This effect is interpreted in the context of baryon production mechanisms in the fragmentation process. It currently presents a challenge to Monte Carlo models and its origin remains an open question.

A DIRECT MEASUREMENT OF THE BARYONIC MASS FUNCTION OF GALAXIES AND IMPLICATIONS FOR THE GALACTIC BARYON FRACTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papastergis, Emmanouil; Huang, Shan; Giovanelli, Riccardo

We use both an H I-selected and an optically selected galaxy sample to directly measure the abundance of galaxies as a function of their 'baryonic' mass (stars + atomic gas). Stellar masses are calculated based on optical data from the Sloan Digital Sky Survey and atomic gas masses are calculated using atomic hydrogen (H I) emission line data from the Arecibo Legacy Fast ALFA survey. By using the technique of abundance matching, we combine the measured baryonic function of galaxies with the dark matter halo mass function in a {Lambda}CDM universe, in order to determine the galactic baryon fraction asmore » a function of host halo mass. We find that the baryon fraction of low-mass halos is much smaller than the cosmic value, even when atomic gas is taken into account. We find that the galactic baryon deficit increases monotonically with decreasing halo mass, in contrast with previous studies which suggested an approximately constant baryon fraction at the low-mass end. We argue that the observed baryon fractions of low-mass halos cannot be explained by reionization heating alone, and that additional feedback mechanisms (e.g., supernova blowout) must be invoked. However, the outflow rates needed to reproduce our result are not easily accommodated in the standard picture of galaxy formation in a {Lambda}CDM universe.« less

Large-Nc sum rules for charmed baryons at subleading orders

NASA Astrophysics Data System (ADS)

Heo, Yonggoo; Lutz, Matthias F. M.

2018-05-01

Sum rules for the low-energy constants of the chiral SU(3) Lagrangian with charmed baryons of spin JP=1 /2+ and JP=3 /2+ baryons are derived from large-Nc QCD. We consider the large-Nc operator expansion at subleading orders for current-current correlation functions in the charmed baryon-ground states for two scalar and two axial-vector currents.

Symétries et nomenclature des baryons: Proposition d'une nouvelle nomenclature

NASA Astrophysics Data System (ADS)

Landry, Gaëtan

Baryons, such as protons and neutrons, are matter particles made of three quarks. Their current nomenclature is based on the concept of isospin, introduced by Werner Heisenberg in 1932 to explain the similarity between the masses of protons and neutrons, as well as the similarity of their behaviour under the strong interaction. It is a refinement of a nomenclature designed in 1964, before the acceptance of the quark model, for light baryons. A historical review of baryon physics before the advent of the quark model is given to understand the motivations behind the light baryon nomenclature. Then, an overview of the quark model is given to understand the extensions done to this nomenclature in 1986, as well as to understand the physics of baryons and of properties such as isospin and flavour quantum numbers. Since baryon properties are in general explained by the quark model, a nomenclature based on isospin leads to several issues of physics and of clarity. To resolve these issues, the concepts of isospin and mass groups are generalized to all flavours of quarks, the Gell-Mann--Okubo formalism is extended to generalized mass groups, and a baryon nomenclature based on the quark model, reflecting modern knowledge, is proposed.

Baryonic matter perturbations in decaying vacuum cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marttens, R.F. vom; Zimdahl, W.; Hipólito-Ricaldi, W.S., E-mail: rodrigovonmarttens@gmail.com, E-mail: wiliam.ricaldi@ufes.br, E-mail: winfried.zimdahl@pq.cnpq.br

2014-08-01

We consider the perturbation dynamics for the cosmic baryon fluid and determine the corresponding power spectrum for a Λ(t)CDM model in which a cosmological term decays into dark matter linearly with the Hubble rate. The model is tested by a joint analysis of data from supernovae of type Ia (SNIa) (Constitution and Union 2.1), baryonic acoustic oscillations (BAO), the position of the first peak of the anisotropy spectrum of the cosmic microwave background (CMB) and large-scale-structure (LSS) data (SDSS DR7). While the homogeneous and isotropic background dynamics is only marginally influenced by the baryons, there are modifications on the perturbativemore » level if a separately conserved baryon fluid is included. Considering the present baryon fraction as a free parameter, we reproduce the observed abundance of the order of 5% independently of the dark-matter abundance which is of the order of 32% for this model. Generally, the concordance between background and perturbation dynamics is improved if baryons are explicitly taken into account.« less

Baryon spin-flavor structure from an analysis of lattice QCD results of the baryon spectrum

DOE PAGES

Fernando, I. P.; Goity, J. L.

2015-02-01

The excited baryon masses are analyzed in the framework of the 1/Nc expansion using the available physical masses and also the masses obtained in lattice QCD for different quark masses. The baryon states are organized into irreducible representations of SU(6) x O(3), where the [56,l P=0⁺] ground state and excited baryons, and the [56,2 +] and [70}},1 -] excited states are analyzed. The analyses are carried out to order O(1/N c) and first order in the quark masses. The issue of state identifications is discussed. Numerous parameter independent mass relations result at those orders, among them the well known Gell-Mann-Okubomore » and Equal Spacing relations, as well as additional relations involving baryons with different spins. It is observed that such relations are satisfied at the expected level of precision. The main conclusion of the analysis is that qualitatively the dominant physical effects are similar for the physical and the lattice QCD baryons.« less

Hadron resonance gas with repulsive interactions and fluctuations of conserved charges

DOE PAGES

Huovinen, Pasi; Petreczky, Peter

2017-12-11

We discuss the role of repulsive baryon-baryon interactions in a hadron gas using relativistic virial expansion and repulsive mean field approaches. The fluctuations of the baryon number as well as strangeness-baryon correlations are calculated in the hadron resonance gas with repulsive interactions and compared with the recent lattice QCD results. In particular, we calculate the difference between the second and fourth order fluctuations and correlations of baryon number and strangeness, that have been proposed as probes of deconfinement. We show that for not too high temperatures these differences could be understood in terms of repulsive interactions.

A Search for Hot, Diffuse Gas in Superclusters

NASA Technical Reports Server (NTRS)

Boughn, Stephen P.

1998-01-01

The HEA01 A2 full sky, 2-10 keV X-ray map was searched for diffuse emission correlated with the plane of the local supercluster of galaxies and a positive correlation was found at the 99% confidence level. The most obvious interpretation is that the local supercluster contains a substantial amount of hot (10(exp 8) OK), diffuse gas, i.e. ionized hydrogen, with a density on the order of 2 - 3 x 10(exp -6) ions per cubic centimeter. This density is about an order of magnitude larger than the average baryon density of the universe and is consistent with a supercluster collapse factor of 10. The implied total mass is of the order of 10(exp 16) times the mass of the sun and would constitute a large fraction of the baryonic matter in the local universe. This result supports current thinking that most of the ordinary matter in the universe is in the form of ionized hydrogen; however, the high temperature implied by the X-ray emission is at the top of the range predicted by most theories. The presence of a large amount of hot gas would leave its imprint on the Cosmic Microwave Background (CMB) via the Sunyaev-Zel'dovich (SZ) effect. A marginal decrement (-17 muK) was found in the COBE 4-year 53 GHz CMB map coincident with the plane of the local supercluster. Although the detection is only 1beta, the level is consistent with the SZ effect predicted from the hot gas. If these results are confirmed by future observations they will have important implications for the formation of large-scale structure in the universe. Three other projects related directly to the HEAO 1 map or the X-ray background in general benefited from this NASA grant. They are: (1) "Correlations between the Cosmic X-ray and Microwave Backgrounds: Constraints on a Cosmological Constant"; (2) "Cross-correlation of the X-ray Background with Radio Sources: Constraining the Large-Scale Structure of the X-ray Background"; and (3) "Radio and X-ray Emission Mechanisms in Advection Dominated Accretion Flow".

A new method to quantify the effects of baryons on the matter power spectrum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, Aurel; Teyssier, Romain, E-mail: aurel@physik.uzh.ch, E-mail: teyssier@physik.uzh.ch

2015-12-01

Future large-scale galaxy surveys have the potential to become leading probes for cosmology provided the influence of baryons on the total mass distribution is understood well enough. As hydrodynamical simulations strongly depend on details in the feedback implementations, no unique and robust predictions for baryonic effects currently exist. In this paper we propose a baryonic correction model that modifies the density field of dark-matter-only N-body simulations to mimic the effects of baryons from any underlying adopted feedback recipe. The model assumes haloes to consist of 4 components: 1- hot gas in hydrostatical equilibrium, 2- ejected gas from feedback processes, 3-more » central galaxy stars, and 4- adiabatically relaxed dark matter, which all modify the initial dark-matter-only density profiles. These altered profiles allow to define a displacement field for particles in N-body simulations and to modify the total density field accordingly. The main advantage of the baryonic correction model is to connect the total matter density field to the observable distribution of gas and stars in haloes, making it possible to parametrise baryonic effects on the matter power spectrum. We show that the most crucial quantities are the mass fraction of ejected gas and its corresponding ejection radius. The former controls how strongly baryons suppress the power spectrum, while the latter provides a measure of the scale where baryonic effects become important. A comparison with X-ray and Sunyaev-Zel'dovich cluster observations suggests that baryons suppress wave modes above k∼0.5 h/Mpc with a maximum suppression of 10-25 percent around k∼ 2 h/Mpc. More detailed observations of the gas in the outskirts of groups and clusters are required to decrease the large uncertainties of these numbers.« less

Flux-ratio anomalies from discs and other baryonic structures in the Illustris simulation

NASA Astrophysics Data System (ADS)

Hsueh, Jen-Wei; Despali, Giulia; Vegetti, Simona; Xu, Dandan; Fassnacht, Christopher D.; Metcalf, R. Benton

2018-04-01

The flux ratios in the multiple images of gravitationally lensed quasars can provide evidence for dark matter substructure in the halo of the lensing galaxy if the flux ratios differ from those predicted by a smooth model of the lensing galaxy mass distribution. However, it is also possible that baryonic structures in the lensing galaxy, such as edge-on discs, can produce flux-ratio anomalies. In this work, we present the first statistical analysis of flux-ratio anomalies due to baryons from a numerical simulation perspective. We select galaxies with various morphological types in the Illustris simulation and ray trace through the simulated haloes, which include baryons in the main lensing galaxies but exclude any substructures, in order to explore the pure baryonic effects. Our ray-tracing results show that the baryonic components can be a major contribution to the flux-ratio anomalies in lensed quasars and that edge-on disc lenses induce the strongest anomalies. We find that the baryonic components increase the probability of finding high flux-ratio anomalies in the early-type lenses by about 8 per cent and by about 10-20 per cent in the disc lenses. The baryonic effects also induce astrometric anomalies in 13 per cent of the mock lenses. Our results indicate that the morphology of the lens galaxy becomes important in the analysis of flux-ratio anomalies when considering the effect of baryons, and that the presence of baryons may also partially explain the discrepancy between the observed (high) anomaly frequency and what is expected due to the presence of subhaloes as predicted by the cold dark matter simulations.

An Investigation into the Effects of Process Conditions on the Tribological Performance of Pack Carburized Titanium with Limited Oxygen Diffusion

NASA Astrophysics Data System (ADS)

Bailey, R.; Sun, Y.

2018-04-01

In the present study, a new pack carburization technique for titanium has been investigated. The aim of this treatment is to produce a titanium carbide/oxycarbide layer atop of an extended oxygen diffusion zone [α-Ti(O)]. The effects of treatment temperature and pack composition have been investigated in order to determine the optimal conditions required to grant the best tribological response. The resulting structural features were investigated with particular interest in the carbon and oxygen concentrations across the samples cross section. The optimization showed that a temperature of 925 °C with a pack composition of 1 part carbon to 1 part energizer produced surface capable of withstanding a contact pressure of ≈ 1.5 GPa for 1 h. The process resulted in TiC surface structure which offers enhanced hardness (2100 HV) and generates a low friction coefficient (μ ≈ 0.2) when in dry sliding contact with an alumina (Al2O3) ball. The process also produced an extended oxygen diffusion zone that helps to improve the load bearing capacity of the substrate.

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se2 Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing.

PubMed

Wi, Jae-Hyung; Kim, Tae Gun; Kim, Jeong Won; Lee, Woo-Jung; Cho, Dae-Hyung; Han, Won Seok; Chung, Yong-Duck

2015-08-12

We selected a sputtered-Zn(O,S) film as a buffer material and fabricated a Cu(In,Ga)Se2 (CIGS) solar cell for use in monolithic tandem solar cells. A thermally stable buffer layer was required because it should withstand heat treatment during processing of top cell. Postannealing treatment was performed on a CIGS solar cell in vacuum at temperatures from 300-500 °C to examine its thermal stability. Serious device degradation particularly in VOC was observed, which was due to the diffusion of thermally activated constituent elements. The elements In and Ga tend to out-diffuse to the top surface of the CIGS, while Zn diffuses into the interface of Zn(O,S)/CIGS. Such rearrangement of atomic fractions modifies the local energy band gap and band alignment at the interface. The notch-shape induced at the interface after postannealing could function as an electrical trap during electron transport, which would result in the reduction of solar cell efficiency.

Mass formulas for {Xi}{sub c} and {Xi}{sub b} baryons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aliev, T. M.; Zamiralov, V. S.; Ozpineci, A.

The importance of taking into account the mixing of the heavy cascade baryons {Xi} and {Xi}' that have new quantum numbers in analyzing their properties is shown. The Ono quark model is considered by way of example. The masses of the new baryons and the {Xi}-{Xi}' mixing angles are obtained. The same approach is applied to the interpolating currents of these baryons within QCD sum rules.

Weak decays of triply heavy baryons

NASA Astrophysics Data System (ADS)

Wang, Wei; Xu, Ji

2018-05-01

After the experimental establishment of doubly heavy baryons, baryons with three quarks are the last missing pieces of the lowest-lying baryon multiplets in the quark model. In this work, we study semileptonic and nonleptonic weak decays of triply heavy baryons, Ωcc c ++, Ωcc b +, Ωcb b 0, and Ωbb b -. Decay amplitudes for various channels are parametrized in terms of a few SU(3) irreducible amplitudes. We point out that branching fractions for Cabibbo-allowed processes, Ωcc c ++→(Ξcc ++K¯0,Ξcc ++K-π+,Ωcc +π+,Ξc+D+,Ξc'D+,ΛcD+K¯0,Ξc+D0π+,Ξc0D+π+), may reach a few percent. We suggest our experimental colleagues to perform a search at hadron colliders and the electron and positron collisions in the future, which will presumably lead to discoveries of triply heavy baryons and complete the baryon multiplets. Using the expanded amplitudes, we derive a number of relations for the partial widths that can be examined in the future.

Towards Precision Spectroscopy of Baryonic Resonances

NASA Astrophysics Data System (ADS)

Döring, Michael; Mai, Maxim; Rönchen, Deborah

2017-01-01

Recent progress in baryon spectroscopy is reviewed. In a common effort, various groups have analyzed a set of new high-precision polarization observables from ELSA. The Jülich-Bonn group has finalized the analysis of pion-induced meson-baryon production, the potoproduction of pions and eta mesons, and (almost) the KΛ final state. As data become preciser, statistical aspects in the analysis of excited baryons become increasingly relevant and several advances in this direction are proposed.

Strangeness Production in 19.6 GeV Collisions at the Relativistic Heavy Ion Collider

DTIC Science & Technology

2010-05-12

Baryons Figure 1.3: Well known Mesons Figure 1.4: Phase Diagram of Nuclear Matter Figure 1.5: The author and his advisor together with MIDN 3/C...7. Conclusions and Outlook Acknowledgements 3 List of Figures Figure 1.1: Nucleus Breakdown Figure 1.2: Well known Baryons and Anti...AntiBaryon/ Baryon Ration from experiments around the globe 6 List of Symbols and Acronyms AGS – Alternating

Towards precision spectroscopy of baryonic resonances

DOE PAGES

Doring, Michael; Mai, Maxim; Ronchen, Deborah

2017-01-26

Recent progress in baryon spectroscopy is reviewed. In a common effort, various groups have analyzed a set of new high-precision polarization observables from ELSA. The Julich-Bonn group has finalized the analysis of pion-induced meson-baryon production, the potoproduction of pions and eta mesons, and (almost) the KΛ final state. Lastly, as data become preciser, statistical aspects in the analysis of excited baryons become increasingly relevant and several advances in this direction are proposed.

Hybrid baryons in QCD

DOE PAGES

Dudek, Jozef J.; Edwards, Robert G.

2012-03-21

In this study, we present the first comprehensive study of hybrid baryons using lattice QCD methods. Using a large basis of composite QCD interpolating fields we extract an extensive spectrum of baryon states and isolate those of hybrid character using their relatively large overlap onto operators which sample gluonic excitations. We consider the spectrum of Nucleon and Delta states at several quark masses finding a set of positive parity hybrid baryons with quantum numbersmore » $$N_{1/2^+},\\,N_{1/2^+},\\,N_{3/2^+},\\, N_{3/2^+},\\,N_{5/2^+},\\,$$ and $$\\Delta_{1/2^+},\\, \\Delta_{3/2^+}$$ at an energy scale above the first band of `conventional' excited positive parity baryons. This pattern of states is compatible with a color octet gluonic excitation having $$J^{P}=1^{+}$$ as previously reported in the hybrid meson sector and with a comparable energy scale for the excitation, suggesting a common bound-state construction for hybrid mesons and baryons.« less

The link between the baryonic mass distribution and the rotation curve shape

NASA Astrophysics Data System (ADS)

Swaters, R. A.; Sancisi, R.; van der Hulst, J. M.; van Albada, T. S.

2012-09-01

The observed rotation curves of disc galaxies, ranging from late-type dwarf galaxies to early-type spirals, can be fitted remarkably well simply by scaling up the contributions of the stellar and H I discs. This 'baryonic scaling model' can explain the full breadth of observed rotation curves with only two free parameters. For a small fraction of galaxies, in particular early-type spiral galaxies, H I scaling appears to fail in the outer parts, possibly due to observational effects or ionization of H I. The overall success of the baryonic scaling model suggests that the well-known global coupling between the baryonic mass of a galaxy and its rotation velocity (known as the baryonic Tully-Fisher relation) applies at a more local level as well, and it seems to imply a link between the baryonic mass distribution and the distribution of total mass (including dark matter).

A probable stellar solution to the cosmological lithium discrepancy.

PubMed

Korn, A J; Grundahl, F; Richard, O; Barklem, P S; Mashonkina, L; Collet, R; Piskunov, N; Gustafsson, B

2006-08-10

The measurement of the cosmic microwave background has strongly constrained the cosmological parameters of the Universe. When the measured density of baryons (ordinary matter) is combined with standard Big Bang nucleosynthesis calculations, the amounts of hydrogen, helium and lithium produced shortly after the Big Bang can be predicted with unprecedented precision. The predicted primordial lithium abundance is a factor of two to three higher than the value measured in the atmospheres of old stars. With estimated errors of 10 to 25%, this cosmological lithium discrepancy seriously challenges our understanding of stellar physics, Big Bang nucleosynthesis or both. Certain modifications to nucleosynthesis have been proposed, but found experimentally not to be viable. Diffusion theory, however, predicts atmospheric abundances of stars to vary with time, which offers a possible explanation of the discrepancy. Here we report spectroscopic observations of stars in the metal-poor globular cluster NGC 6397 that reveal trends of atmospheric abundance with evolutionary stage for various elements. These element-specific trends are reproduced by stellar-evolution models with diffusion and turbulent mixing. We thus conclude that diffusion is predominantly responsible for the low apparent stellar lithium abundance in the atmospheres of old stars by transporting the lithium deep into the star.

CMB anisotropies from patchy reionisation and diffuse Sunyaev-Zel'dovich effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fidler, Christian; Ringeval, Christophe, E-mail: christophe.ringeval@uclouvain.be, E-mail: christian.fidler@uclouvain.be

Anisotropies in the Cosmic Microwave Background (CMB) can be induced during the later stages of cosmic evolution, and in particular during and after the Epoch of Reionisation. Inhomogeneities in the ionised fraction, but also in the baryon density, in the velocity fields and in the gravitational potentials are expected to generate correlated CMB perturbations. We present a complete relativistic treatment of all these effects, up to second order in perturbation theory, that we solve using the numerical Boltzmann code (\\SONG). The physical origin and relevance of all second order terms are carefully discussed. In addition to collisional and gravitational contributions,more » we identify the diffuse analogue of the blurring and kinetic Sunyaev-Zel'dovich (SZ) effects. Our approach naturally includes the correlations between the imprint from patchy reionisation and the diffuse SZ effects thereby allowing us to derive reliable estimates of the induced temperature and polarisation CMB angular power spectra. In particular, we show that the B -modes generated at intermediate length-scales (ℓ ≅ 100) have the same amplitude as the B -modes coming from primordial gravitational waves with a tensor-to-scalar ratio r =10{sup −4}.« less

Locating the QCD critical end point through peaked baryon number susceptibilities along the freeze-out line

NASA Astrophysics Data System (ADS)

Li, Zhibin; Chen, Yidian; Li, Danning; Huang, Mei

2018-01-01

We investigate the baryon number susceptibilities up to fourth order along different freeze-out lines in a holographic QCD model with a critical end point (CEP), and we propose that the peaked baryon number susceptibilities along the freeze-out line can be used as a clean signature to locate the CEP in the QCD phase diagram. On the temperature and baryon chemical potential plane, the cumulant ratio of the baryon number susceptibilities (up to fourth order) forms a ridge along the phase boundary, and develops a sword-shaped “mountain” standing upright around the CEP in a narrow and oblate region. The measurement of baryon number susceptibilities from heavy-ion collision experiments is along the freeze-out line. If the freeze-out line crosses the foot of the CEP mountain, then one can observe the peaked baryon number susceptibilities along the freeze-out line, and the kurtosis of the baryon number distributions has the highest magnitude. The data from the first phase of the beam energy scan program at the Relativistic Heavy Ion Collider indicates that there should be a peak of the kurtosis of the baryon number distribution at a collision energy of around 5 GeV, which suggests that the freeze-out line crosses the foot of the CEP mountain and the summit of the CEP should be located nearby, around a collision energy of 3-7 GeV. Supported by NSFC (11275213, and 11261130311) (CRC 110 by DFG and NSFC), CAS key project KJCX2-EW-N01, and Youth Innovation Promotion Association of CAS

Discovery potentials of doubly charmed baryons

NASA Astrophysics Data System (ADS)

Yu, Fu-Sheng; Jiang, Hua-Yu; Li, Run-Hui; Lü, Cai-Dian; Wang, Wei; Zhao, Zhen-Xing

2018-05-01

The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, {{{\\Xi }}}{{cc}}++ and {{{\\Xi }}}{{cc}}+, which should be helpful for experimental searches for these particles. The long-distance contributions are first studied in the doubly heavy baryon decays, and found to be significantly enhanced. Comparing all the processes, {{{\\Xi }}}{{cc}}++\\to {{{Λ }}}{{c}}+{{{K}}}-{{{π }}}+{{{π }}}+ and {{{\\Xi }}}{{c}}+{{{π }}}+ are the most favorable decay modes for experiments to search for doubly heavy baryons. Supported by National Natural Science Foundation of China (11505083, 11505098, 11647310, 11575110, 11375208, 11521505, 11621131001, 11235005, 11447032, U1732101) and Natural Science Foundation of Shanghai (15DZ2272100)

Octet baryons in large magnetic fields

NASA Astrophysics Data System (ADS)

Deshmukh, Amol; Tiburzi, Brian C.

2018-01-01

Magnetic properties of octet baryons are investigated within the framework of chiral perturbation theory. Utilizing a power counting for large magnetic fields, the Landau levels of charged mesons are treated exactly giving rise to baryon energies that depend nonanalytically on the strength of the magnetic field. In the small-field limit, baryon magnetic moments and polarizabilities emerge from the calculated energies. We argue that the magnetic polarizabilities of hyperons provide a testing ground for potentially large contributions from decuplet pole diagrams. In external magnetic fields, such contributions manifest themselves through decuplet-octet mixing, for which possible results are compared in a few scenarios. These scenarios can be tested with lattice QCD calculations of the octet baryon energies in magnetic fields.

Evolutionary Strategies of Viruses, Bacteria and Archaea in Hydrothermal Vent Ecosystems Revealed through Metagenomics

PubMed Central

Anderson, Rika E.; Sogin, Mitchell L.; Baross, John A.

2014-01-01

The deep-sea hydrothermal vent habitat hosts a diverse community of archaea and bacteria that withstand extreme fluctuations in environmental conditions. Abundant viruses in these systems, a high proportion of which are lysogenic, must also withstand these environmental extremes. Here, we explore the evolutionary strategies of both microorganisms and viruses in hydrothermal systems through comparative analysis of a cellular and viral metagenome, collected by size fractionation of high temperature fluids from a diffuse flow hydrothermal vent. We detected a high enrichment of mobile elements and proviruses in the cellular fraction relative to microorganisms in other environments. We observed a relatively high abundance of genes related to energy metabolism as well as cofactors and vitamins in the viral fraction compared to the cellular fraction, which suggest encoding of auxiliary metabolic genes on viral genomes. Moreover, the observation of stronger purifying selection in the viral versus cellular gene pool suggests viral strategies that promote prolonged host integration. Our results demonstrate that there is great potential for hydrothermal vent viruses to integrate into hosts, facilitate horizontal gene transfer, and express or transfer genes that manipulate the hosts’ functional capabilities. PMID:25279954

On the relevance of chaos for halo stars in the solar neighbourhood II

NASA Astrophysics Data System (ADS)

Maffione, Nicolas P.; Gómez, Facundo A.; Cincotta, Pablo M.; Giordano, Claudia M.; Grand, Robert J. J.; Marinacci, Federico; Pakmor, Rüdiger; Simpson, Christine M.; Springel, Volker; Frenk, Carlos S.

2018-05-01

In a previous paper based on dark matter only simulations we show that, in the approximation of an analytic and static potential describing the strongly triaxial and cuspy shape of Milky Way-sized haloes, diffusion due to chaotic mixing in the neighbourhood of the Sun does not efficiently erase phase space signatures of past accretion events. In this second paper we further explore the effect of chaotic mixing using multicomponent Galactic potential models and solar neighbourhood-like volumes extracted from fully cosmological hydrodynamic simulations, thus naturally accounting for the gravitational potential associated with baryonic components, such as the bulge and disc. Despite the strong change in the global Galactic potentials with respect to those obtained in dark matter only simulations, our results confirm that a large fraction of halo particles evolving on chaotic orbits exhibit their chaotic behaviour after periods of time significantly larger than a Hubble time. In addition, significant diffusion in phase space is not observed on those particles that do exhibit chaotic behaviour within a Hubble time.

The Stormy Life of Galaxy Clusters

NASA Astrophysics Data System (ADS)

Rudnick, Lawrence

2018-01-01

Galaxy clusters, the largest gravitationally bound structures, hold the full history of their baryonic evolution, serve as important cosmological tools and allow us to probe unique physical regimes in their diffuse plasmas. With characteristic dynamical timescales of 107-109 years, these diffuse thermal and relativistic media continue to evolve, as dark matter drives major mergers and more gentle continuing accretion. The history of this assembly is encoded in the plasmas, and a wide range of observational and theoretical investigations are aimed at decoding their signatures. X-ray temperature and density variations, low Mach number shocks, and "cold front" discontinuities all illuminate clusters' continued evolution. Radio structures and spectra are passive indicators of merger shocks, while radio galaxy distortions reveal the complex motions in the intracluster medium. Deep in cluster cores, AGNs associated with brightest cluster galaxies provide ongoing energy, and perhaps even stabilize the intracluster medium. In this talk, we will recount this evolving picture of the stormy ICM, and suggest areas of likely advance in the coming years.

Cosmological baryon number domain structure from symmetry-breaking in grand unified field theories

NASA Technical Reports Server (NTRS)

Brown, R. W.; Stecker, F. W.

1979-01-01

It is suggested that grand unified field theories with spontaneous symmetry breaking in the very early big-bang can lead more naturally to a baryon symmetric cosmology with a domain structure than to a totally baryon asymmetric cosmology. The symmetry is broken in a randomized manner in causally independent domains, favoring neither a baryon nor an antibaryon excess on a universal scale. Arguments in favor of this cosmology and observational tests are discussed.

Baryons as Fock states of 3,5,... Quarks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dmitri Diakonov; Victor Petrov

2004-09-01

We present a generating functional producing quark wave functions of all Fock states in the octet, decuplet and antidecuplet baryons in the mean field approximation, both in the rest and infinite momentum frames. In particular, for the usual octet and decuplet baryons we get the SU(6)-symmetric wave functions for their 3-quark component but with specific corrections from relativism and from additional quark-antiquark pairs. For the exotic antidecuplet baryons we obtain the 5-quark wave function.

Beauty Baryons at CDF and DO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kryemadhi, Abaz

The results from Tevatron in the baryonic sector are presented. The lifetime of {lambda}b {yields} J/{psi}{lambda}, the observation of hadronic decay of {lambda}b {yields} {lambda}c{pi}, the semileptonic decays of {lambda}b {yields} {lambda}c{mu}{nu}, the hadronization of the b-baryons, and the {lambda}b decays to {lambda}b {yields} p{pi} and {lambda}b {yields} pK are discussed. These measurements paint a nice picture of our understanding of the beauty baryons.

Cosmological baryon-number domain structure from symmetry breaking in grand unified field theories

NASA Technical Reports Server (NTRS)

Brown, R. W.; Stecker, F. W.

1979-01-01

It is suggested that grand unified field theories with spontaneous symmetry breaking in the very early big bang can lead more naturally to a baryon-symmetric cosmology with a domain structure than to a totally baryon-asymmetric cosmology. The symmetry is broken in a randomized manner in causally independent domains, favoring neither a baryon nor an antibaryon excess on a universal scale. Arguments in favor of this cosmology and observational tests are discussed.

The Baryonic Collapse Efficiency of Galaxy Groups in the RESOLVE and ECO Surveys

NASA Astrophysics Data System (ADS)

Eckert, Kathleen D.; Kannappan, Sheila J.; Lagos, Claudia del P.; Baker, Ashley D.; Berlind, Andreas A.; Stark, David V.; Moffett, Amanda J.; Nasipak, Zachary; Norris, Mark A.

2017-11-01

We examine the z = 0 group-integrated stellar and cold baryonic (stars + cold atomic gas) mass functions (group SMF and CBMF) and the baryonic collapse efficiency (group cold baryonic to dark matter halo mass ratio) using the RESOLVE and ECO survey galaxy group catalogs and a galform semi-analytic model (SAM) mock catalog. The group SMF and CBMF fall off more steeply at high masses and rise with a shallower low-mass slope than the theoretical halo mass function (HMF). The transition occurs at the group-integrated cold baryonic mass {M}{bary}{cold} ˜ 1011 {M}⊙ . The SAM, however, has significantly fewer groups at the transition mass ˜1011 {M}⊙ and a steeper low-mass slope than the data, suggesting that feedback is too weak in low-mass halos and conversely too strong near the transition mass. Using literature prescriptions to include hot halo gas and potential unobservable galaxy gas produces a group BMF with a slope similar to the HMF even below the transition mass. Its normalization is lower by a factor of ˜2, in agreement with estimates of warm-hot gas making up the remaining difference. We compute baryonic collapse efficiency with the halo mass calculated two ways, via halo abundance matching (HAM) and via dynamics (extended all the way to three-galaxy groups using stacking). Using HAM, we find that baryonic collapse efficiencies reach a flat maximum for groups across the halo mass range of {M}{halo}˜ {10}11.4-12 {M}⊙ , which we label “nascent groups.” Using dynamics, however, we find greater scatter in baryonic collapse efficiencies, likely indicating variation in group hot-to-cold baryon ratios. Similarly, we see higher scatter in baryonic collapse efficiencies in the SAM when using its true groups and their group halo masses as opposed to friends-of-friends groups and HAM masses.

Hybrid baryons [alpha].

DOE Office of Scientific and Technical Information (OSTI.GOV)

Page, P. R.

The authors review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modeled by both the bag and flux tube models. The low lying hybrid baryon is N 1/2{sup +} with a mass of 1.5 - 1.8 GeV. Hybrid baryons can be produced in the glue rich processes of diffractive {gamma}N and {pi}N production, {Psi} decays and p{bar p} annihilation. We review the current status of research on three quarks with a gluonic excitation, called a hybrid baryon. The excitation is not an orbital or radial excitation betweenmore » the quarks. Hybrid baryons have also been reviewed elsewhere. The Mercedes-Benz logl in Figure 1 indicates two possible views of the confining interaction of three quarks, an essential issue in the study of hybrid baryons. In the logo the three points where the Y shape meets the boundary circle should be identified with the three quarks. There are two possibilities fo rthe interaction of the quarks: (1) a pairwise interaction of the quarks represented by the circle, or (2) a Y shaped interaction between the quarks, represented by the Y-shape in the logo.« less

Holographic heavy ion collisions with baryon charge

DOE PAGES

Casalderrey-Solana, Jorge; Mateos, David; van der Schee, Wilke; ...

2016-09-19

We numerically simulate collisions of charged shockwaves in Einstein-Maxwell theory in anti-de Sitter space as a toy model of heavy ion collisions with non-zero baryon charge. The stress tensor and the baryon current become well described by charged hydrodynamics at roughly the same time. The effect of the charge density on generic observables is typically no larger than 15%. Finally, we find significant stopping of the baryon charge and compare our results with those in heavy ion collision experiments.

Measurement of the forward-backward asymmetries in the production of Ξ and Ω baryons in $$p\\overline{p}$$ collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abazov, Victor Mukhamedovich

Here, we measure the forward-backward asymmetries AFB of charged Ξ and Ω baryons produced inmore » $$p\\overline{p}$$ collisions recorded by the D0 detector at the Fermilab Tevatron collider at √s = 1.96 TeV as a function of the baryon rapidity y. We find that the asymmetries AFB for charged Ξ and Ω baryons are consistent with zero within statistical uncertainties.« less

Measurement of the forward-backward asymmetries in the production of Ξ and Ω baryons in $$p\\overline{p}$$ collisions

DOE PAGES

Abazov, Victor Mukhamedovich

2016-06-01

Here, we measure the forward-backward asymmetries AFB of charged Ξ and Ω baryons produced inmore » $$p\\overline{p}$$ collisions recorded by the D0 detector at the Fermilab Tevatron collider at √s = 1.96 TeV as a function of the baryon rapidity y. We find that the asymmetries AFB for charged Ξ and Ω baryons are consistent with zero within statistical uncertainties.« less

Dark matter and the baryon asymmetry of the universe.

PubMed

Farrar, Glennys R; Zaharijas, Gabrijela

2006-02-03

We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the big bang. If dark matter particles carry baryon number Bx, and sigmaxannih

New narrow baryons and dibaryons observed in inelastic pp scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tatischeff, B.; Willis, N.; Comets, M. P.

Several narrow exotic baryonic states have been recently observed at 1004, 1044, and possibly at 1094 MeV, from the study of pp{yields}p{pi}{sup +}X reaction at different energies (T{sub p}=1520, 1805 and 2100 MeV) and angles from 0 deg. up to 17 deg. (lab.). The small widths: a few MeV, indicate a possible interpretation within multiquark baryons or baryonic resonances. A phenomonological mass formula for two clusters of quarks, predicts masses, quite close to the experimental ones.

Calm Multi-Baryon Operators

NASA Astrophysics Data System (ADS)

Berkowitz, Evan; Nicholson, Amy; Chang, Chia Cheng; Rinaldi, Enrico; Clark, M. A.; Joó, Bálint; Kurth, Thorsten; Vranas, Pavlos; Walker-Loud, André

2018-03-01

There are many outstanding problems in nuclear physics which require input and guidance from lattice QCD calculations of few baryons systems. However, these calculations suffer from an exponentially bad signal-to-noise problem which has prevented a controlled extrapolation to the physical point. The variational method has been applied very successfully to two-meson systems, allowing for the extraction of the two-meson states very early in Euclidean time through the use of improved single hadron operators. The sheer numerical cost of using the same techniques in two-baryon systems has so far been prohibitive. We present an alternate strategy which offers some of the same advantages as the variational method while being significantly less numerically expensive. We first use the Matrix Prony method to form an optimal linear combination of single baryon interpolating fields generated from the same source and different sink interpolating fields. Very early in Euclidean time this optimal linear combination is numerically free of excited state contamination, so we coin it a calm baryon. This calm baryon operator is then used in the construction of the two-baryon correlation functions. To test this method, we perform calculations on the WM/JLab iso-clover gauge configurations at the SU(3) flavor symmetric point with mπ 800 MeV — the same configurations we have previously used for the calculation of two-nucleon correlation functions. We observe the calm baryon significantly removes the excited state contamination from the two-nucleon correlation function to as early a time as the single-nucleon is improved, provided non-local (displaced nucleon) sources are used. For the local two-nucleon correlation function (where both nucleons are created from the same space-time location) there is still improvement, but there is significant excited state contamination in the region the single calm baryon displays no excited state contamination.

Diagrammatic representation of scalar QCD and sign problem at nonzero chemical potential

NASA Astrophysics Data System (ADS)

Bruckmann, Falk; Wellnhofer, Jacob

2018-01-01

We consider QCD at strong coupling with scalar quarks coupled to a chemical potential. Performing the link integrals we present a diagrammatic representation of the path integral weight. It is based on mesonic and baryonic building blocks, in close analogy to fermionic QCD. Likewise, the baryon loops are subject to a manifest conservation of the baryon number. The sign problem is expected to disappear in this representation and we do confirm this for three flavors, where a scalar baryon can be built and, thus, a dependence on the chemical potential occurs. For higher flavor number, we analyze examples for a potential sign problem in the baryon sector and conjecture that all weights are positive upon exploring the current conservation of each flavor.

Diffuse hot gas in the NGC 4261 group of galaxies

NASA Technical Reports Server (NTRS)

Davis, David S.; Mushotzky, Richard F.; Mulchaey, John S.; Worrall, D. M.; Birkinshaw, M.; Burstein, David

1995-01-01

We have found diffuse X-ray gas in the group of galaxies containing the elliptical galaxy NGC 4261. This galaxy along with its associated companions are behind the Virgo cluster in the W-cloud. A recent analysis of the velocity structure in the Virgo region indicates that the W-cloud has approximately 30 members, most of which are low luminosity dwarfs. The hot X-ray emitting gas is centered about halfway between NGC 4261 and NGC 4264 and extends out to a radius of approximately 40 min(620 kpc). The spectral data for the diffuse component are well fitted with a Raymond-Smith plasma model with a temperature of 0.85(sup +0.21)(sub -0.16) keV and abundance less than 0.08 times the solar value. Under the assumption that the diffuse gas is in hydrostatic equilibrium the total mass within 40 min is 1.9 x 10(exp 13) solar mass. We estimate that the total baryonic mass of the hot gas and the galaxies is 20%-34% of the total mass in the central 40 min radius of this group. This group of galaxies contains NGC 4273 which exhibits a 'bow shock' morphology similar to that of NGC 2276. This is thought to occur when the ram pressure from the intragroup gas significantly perturbs the interstellar medium in a late-type galaxy. We show that this is unlikely in this group.

Diffuse hot gas in the NGC 4261 group of galaxies

NASA Astrophysics Data System (ADS)

Davis, David S.; Mushotzky, Richard F.; Mulchaey, John S.; Worrall, D. M.; Birkinshaw, M.; Burstein, David

1995-05-01

We have found diffuse X-ray gas in the group of galaxies containing the elliptical galaxy NGC 4261. This galaxy along with its associated companions are behind the Virgo cluster in the W-cloud. A recent analysis of the velocity structure in the Virgo region indicates that the W-cloud has approximately 30 members, most of which are low luminosity dwarfs. The hot X-ray emitting gas is centered about halfway between NGC 4261 and NGC 4264 and extends out to a radius of approximately 40 min(620 kpc). The spectral data for the diffuse component are well fitted with a Raymond-Smith plasma model with a temperature of 0.85+0.21-0.16 keV and abundance less than 0.08 times the solar value. Under the assumption that the diffuse gas is in hydrostatic equilibrium the total mass within 40 min is 1.9 x 1013 solar mass. We estimate that the total baryonic mass of the hot gas and the galaxies is 20%-34% of the total mass in the central 40 min radius of this group. This group of galaxies contains NGC 4273 which exhibits a 'bow shock' morphology similar to that of NGC 2276. This is thought to occur when the ram pressure from the intragroup gas significantly perturbs the interstellar medium in a late-type galaxy. We show that this is unlikely in this group.

On the search for the electric dipole moment of strange and charm baryons at LHC

NASA Astrophysics Data System (ADS)

Botella, F. J.; Garcia Martin, L. M.; Marangotto, D.; Martinez Vidal, F.; Merli, A.; Neri, N.; Oyanguren, A.; Ruiz Vidal, J.

2017-03-01

Permanent electric dipole moments (EDMs) of fundamental particles provide powerful probes for physics beyond the Standard Model. We propose to search for the EDM of strange and charm baryons at LHC, extending the ongoing experimental program on the neutron, muon, atoms, molecules and light nuclei. The EDM of strange Λ baryons, selected from weak decays of charm baryons produced in p p collisions at LHC, can be determined by studying the spin precession in the magnetic field of the detector tracking system. A test of CPT symmetry can be performed by measuring the magnetic dipole moment of Λ and \\overline{Λ} baryons. For short-lived {Λ} ^+c and {Ξ} ^+c baryons, to be produced in a fixed-target experiment using the 7 TeV LHC beam and channeled in a bent crystal, the spin precession is induced by the intense electromagnetic field between crystal atomic planes. The experimental layout based on the LHCb detector and the expected sensitivities in the coming years are discussed.

Critical point in the phase diagram of primordial quark-gluon matter from black hole physics

NASA Astrophysics Data System (ADS)

Critelli, Renato; Noronha, Jorge; Noronha-Hostler, Jacquelyn; Portillo, Israel; Ratti, Claudia; Rougemont, Romulo

2017-11-01

Strongly interacting matter undergoes a crossover phase transition at high temperatures T ˜1012 K and zero net-baryon density. A fundamental question in the theory of strong interactions, QCD, is whether a hot and dense system of quarks and gluons displays critical phenomena when doped with more quarks than antiquarks, where net-baryon number fluctuations diverge. Recent lattice QCD work indicates that such a critical point can only occur in the baryon dense regime of the theory, which defies a description from first principles calculations. Here we use the holographic gauge/gravity correspondence to map the fluctuations of baryon charge in the dense quark-gluon liquid onto a numerically tractable gravitational problem involving the charge fluctuations of holographic black holes. This approach quantitatively reproduces ab initio results for the lowest order moments of the baryon fluctuations and makes predictions for the higher-order baryon susceptibilities and also for the location of the critical point, which is found to be within the reach of heavy-ion collision experiments.

High baryon and energy densities achievable in heavy-ion collisions at √{sN N}=39 GeV

NASA Astrophysics Data System (ADS)

Ivanov, Yu. B.; Soldatov, A. A.

2018-02-01

Baryon and energy densities, which are reached in central Au+Au collisions at collision energy of √{sN N}= 39 GeV, are estimated within the model of three-fluid dynamics. It is shown that the initial thermalized mean proper baryon and energy densities in a sizable central region approximately are nB/n0≈ 10 and ɛ ≈ 40 GeV/fm3, respectively. The study indicates that the deconfinement transition at the stage of interpenetration of colliding nuclei makes the system quite opaque. The final fragmentation regions in these collisions are formed not only by primordial fragmentation fireballs, i.e., the baryon-rich matter passed through the interaction region (containing approximately 30% of the total baryon charge), but also by the baryon-rich regions of the central fireball pushed out to peripheral rapidities by the subsequent almost one-dimensional expansion of the central fireball along the beam direction.

Cloistered Baryogenesis

NASA Astrophysics Data System (ADS)

Fong, Chee Sheng

2015-10-01

The cosmic matter-antimatter asymmetry can be generated through baryon number conserving decays of heavy particles that produce asymmetries in the two final states that carry equal and opposite baryon number in which one of them couples directly or indirectly to electroweak sphalerons. The final state that participates in electroweak sphalerons will have its baryon asymmetry partly reprocessed to a lepton asymmetry while the other remains chemically decoupled from the thermal bath or cloistered with its baryon content frozen. The key condition for this mechanism to work is for the decoupled particles to remain cloistered until after electroweak sphalerons freeze out and then the subsequent decays of the particles will inject an unbalanced baryon asymmetry in the thermal bath giving rise to a net nonzero baryon asymmetry. Such a condition implies weakly coupled particles and if produced in a collider could give signatures of long-lived (on a collider timescale) particles. We discuss such a scenario with a type-I seesaw model extended by a new colored scalar.

Possible dark matter origin of the gamma ray emission from the Galactic Center observed by HESS

NASA Astrophysics Data System (ADS)

Cembranos, J. A. R.; Gammaldi, V.; Maroto, A. L.

2012-11-01

We show that the gamma ray spectrum observed with the HESS array of Cherenkov telescopes coming from the Galactic Center region and identified with the source HESS J1745-290 is well fitted by the secondary photons coming from dark matter (DM) annihilation over a diffuse power law background. The amount of photons and morphology of the signal localized within a region of few parsecs, require compressed DM profiles as those resulting from baryonic contraction, which offer ˜103 enhancements in the signal over DM alone simulations. The fitted background from HESS data is consistent with recent Fermi-LAT observations of the same region.

The baryon content of groups and clusters of galaxies

NASA Astrophysics Data System (ADS)

Roussel, H.; Sadat, R.; Blanchard, A.

2000-09-01

We have analyzed the properties of a sample of 33 groups and clusters of galaxies for which both optical and X-ray data were available in the literature. This sample was built to examine the baryon content and to check for trends over a decade in temperature down to 1 keV. We examine the relative contribution of galaxies and ICM to baryons in clusters through the gas-to-stellar mass ratio (Mgas/M*). We find that the typical stellar contribution to the baryonic mass is between 5 and 20%, at the virial radius. The ratio (Mgas/M*) is found to be roughly independent of temperature. Therefore, we do not confirm the trend of increasing gas-to-stellar mass ratio with increasing temperature as previously claimed. We also determine the absolute values and the distribution of the baryon fraction with the density contrast delta with respect to the critical density. Virial masses are estimated from two different mass estimators: one based on the isothermal hydrostatic equation (IHE), the other based on scaling law models (SLM), the calibration being taken from numerical simulations. Comparing the two methods, we find that SLM lead to less dispersed baryon fractions over all density contrasts and that the derived mean absolute values are significantly lower than IHE mean values: at delta =500, the baryon fractions (gas fractions) are 11.5-13.4% (10.3-12%) and ~ 20% (17%) respectively. We show that this is not due to the uncertainties on the outer slope beta of the gas density profile but is rather indicating that IHE masses are less reliable. Examining the shape of the baryon fraction profiles, we find that cluster baryon fractions estimated from SLM follow a scaling law. Moreover, we do not find any strong evidence of increasing baryon (gas) fraction with temperature: hotter clusters do not have a higher baryon fraction than colder ones, neither do we find the slope beta to increase with temperature. The absence of clear trends between fb and Mgas/M* with temperature is consistent with the similarity of baryon fraction profiles and suggests that non-gravitational processes such as galaxy feedback, necessary to explain the observed luminosity-temperature relationship, do not play a dominant rôle in heating the intra-cluster gas on the virial scale. Tables~1 to 6 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

Oxygen-Permeable, Hydrophobic Membranes of Silanized alpha-Al2O3

NASA Technical Reports Server (NTRS)

Atwater, James E.; Akse, James R.

2006-01-01

Membranes made of silanized alumina have been prepared and tested as prototypes of derivatized ceramic membranes that are both highly permeable to oxygen and hydrophobic. Improved oxygen-permeable, hydrophobic membranes would be attractive for use in several technological disciplines, including supporting high-temperature aqueousphase oxidation in industrial production of chemicals, oxygenation of aqueous streams for bioreactors, and oxygenation of blood during open-heart surgery and in cases of extreme pulmonary dysfunction. In comparison with organic polymeric oxygen-permeable membranes now commercially available, the derivatized ceramic membranes are more chemically robust, are capable of withstanding higher temperatures, and exhibit higher oxygen-diffusion coefficients.

Baryon chiral perturbation theory combined with the 1 /Nc expansion in SU(3): Framework

NASA Astrophysics Data System (ADS)

Fernando, I. P.; Goity, J. L.

2018-03-01

Baryon chiral perturbation theory combined with the 1 /Nc expansion is implemented for three flavors. Baryon masses, vector charges and axial vector couplings are studied to one-loop and organized according to the ξ -expansion, in which the 1 /Nc and the low-energy power countings are linked according to 1 /Nc=O (ξ )=O (p ). The renormalization to O (ξ3) necessary for the mentioned observables is provided, along with applications to the baryon masses and axial couplings as obtained in lattice QCD calculations.

Magnetic properties of confined holographic QCD

NASA Astrophysics Data System (ADS)

Bergman, Oren; Lifschytz, Gilad; Lippert, Matthew

2013-12-01

We investigate the Sakai-Sugimoto model at nonzero baryon chemical potential in a background magnetic field in the confined phase where chiral symmetry is broken. The D8-brane Chern-Simons term holographically encodes the axial anomaly and generates a gradient of the η' meson, which carries a non-vanishing baryon charge. Above a critical value of the chemical potential, there is a second-order phase transition to a mixed phase which includes also ordinary baryonic matter. However, at fixed baryon charge density, the matter is purely η'-gradient above a critical magnetic field.

Light baryon spectroscopy

NASA Astrophysics Data System (ADS)

Crede, Volker

2013-03-01

The spectrum of excited baryons serves as an excellent probe of quantum chromodynamics (QCD). In particular, highly-excited baryon resonances are sensitive to the details of quark confinement which is only poorly understood within QCD. Facilities worldwide such as Jefferson Lab, ELSA, and MAMI, which study the systematics of hadron spectra in photo- and electroproduction experiments, have accumulated a large amount of data in recent years including unpolarized cross section and polarization data for a large variety of meson-production reactions. These are important steps toward complete experiments that will allow us to unambiguously determine the scattering amplitude in the underlying reactions and to identify the broad and overlapping baryon resonance contributions. Several new nucleon resonances have been proposed and changes to the baryon listing in the 2012 Review of Particle Physics reflect the progress in the field.

Baryon spectra and antiparticle-to-particle ratios from the improved AMPT model

NASA Astrophysics Data System (ADS)

He, Yuncun; Lin, Zi-Wei

2018-02-01

The current version of a multi-phase transport (AMPT) model with string melting can reasonably describe the dN/dy yields, pT spectra and anisotropic flows of pions and kaons at low pT in heavy ion collisions at RHIC and LHC energies, although it failed to reproduce the dN/dy and pT spectra of baryons. In this work, we improve the quark coalescence mechanism in AMPT by removing the forced separate number conservations of mesons, baryons and antibaryons in each event. We find that the improved AMPT model can better describe the yields at midrapidity, the pT spectra and elliptic flow of low-pT baryons in comparison with the experimental data. Antiparticle-to-particle ratios of strange baryons are also significantly improved.

Baryon asymmetry from primordial black holes

NASA Astrophysics Data System (ADS)

Hamada, Yuta; Iso, Satoshi

2017-03-01

We propose a new scenario of the baryogenesis from primordial black holes (PBH). Assuming the presence of microscopic baryon (or lepton) number violation, and the presence of an effective CP-violating operator such as ∂αF (R…)Jα , where F (R…) is a scalar function of the Riemann tensor and Jα is a baryonic (leptonic) current, the time evolution of an evaporating black hole generates baryonic (leptonic) chemical potential at the horizon; consequently PBH emanates asymmetric Hawking radiation between baryons (leptons) and antibaryons (leptons). Though the operator is higher-dimensional and largely suppressed by a high mass scale M* , we show that a sufficient amount of asymmetry can be generated for a wide range of parameters of the PBH mass MPBH , its abundance ΩPBH , and the scale M*.

Baryons in the relativistic jets of the stellar-mass black-hole candidate 4U 1630-47.

PubMed

Trigo, María Díaz; Miller-Jones, James C A; Migliari, Simone; Broderick, Jess W; Tzioumis, Tasso

2013-12-12

Accreting black holes are known to power relativistic jets, both in stellar-mass binary systems and at the centres of galaxies. The power carried away by the jets, and, hence, the feedback they provide to their surroundings, depends strongly on their composition. Jets containing a baryonic component should carry significantly more energy than electron-positron jets. Energetic considerations and circular-polarization measurements have provided conflicting circumstantial evidence for the presence or absence of baryons in jets, and the only system in which they have been unequivocally detected is the peculiar X-ray binary SS 433 (refs 4, 5). Here we report the detection of Doppler-shifted X-ray emission lines from a more typical black-hole candidate X-ray binary, 4U 1630-47, coincident with the reappearance of radio emission from the jets of the source. We argue that these lines arise from baryonic matter in a jet travelling at approximately two-thirds the speed of light, thereby establishing the presence of baryons in the jet. Such baryonic jets are more likely to be powered by the accretion disk than by the spin of the black hole, and if the baryons can be accelerated to relativistic speeds, the jets should be strong sources of γ-rays and neutrino emission.

Baryonic distributions in galaxy dark matter haloes - II. Final results

NASA Astrophysics Data System (ADS)

Richards, Emily E.; van Zee, L.; Barnes, K. L.; Staudaher, S.; Dale, D. A.; Braun, T. T.; Wavle, D. C.; Dalcanton, J. J.; Bullock, J. S.; Chandar, R.

2018-06-01

Re-creating the observed diversity in the organization of baryonic mass within dark matter haloes represents a key challenge for galaxy formation models. To address the growth of galaxy discs in dark matter haloes, we have constrained the distribution of baryonic and non-baryonic matter in a statistically representative sample of 44 nearby galaxies defined from the Extended Disk Galaxy Exploration Science (EDGES) Survey. The gravitational potentials of each galaxy are traced using rotation curves derived from new and archival radio synthesis observations of neutral hydrogen (H I). The measured rotation curves are decomposed into baryonic and dark matter halo components using 3.6 μm images for the stellar content, the H I observations for the atomic gas component, and, when available, CO data from the literature for the molecular gas component. The H I kinematics are supplemented with optical integral field spectroscopic (IFS) observations to measure the central ionized gas kinematics in 26 galaxies, including 13 galaxies that are presented for the first time in this paper. Distributions of baryonic-to-total mass ratios are determined from the rotation curve decompositions under different assumptions about the contribution of the stellar component and are compared to global and radial properties of the dominant stellar populations extracted from optical and near-infrared photometry. Galaxies are grouped into clusters of similar baryonic-to-total mass distributions to examine whether they also exhibit similar star and gas properties. The radial distribution of baryonic-to-total mass in a galaxy does not appear to correlate with any characteristics of its star formation history.

PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ON BARYON DYNAMICS AT RHIC, MARCH 28-30, 2002, BROOKHAVEN NATIONAL LABORATORY.

DOE Office of Scientific and Technical Information (OSTI.GOV)

GYULASSY,M.; KHARZEEV,D.; XU,N.

2002-03-28

One of the striking observations at RHIC is the large valence baryon rapidity density observed at mid rapidity in central Au+Au at 130 A GeV. There are about twice as many valence protons at mid-rapidity than predicted based on extrapolation from p+p collisions. Even more striking PHENIX observed that the high pt spectrum is dominated by baryons and anti-baryons. The STAR measured event anisotropy parameter v2 for lambdas are as high as charged particles at pt {approx} 2.5 GeV/c. These are completely unexpected based on conventional pQCD parton fragmentation phenomenology. One exciting possibility is that these observables reveal the topologicalmore » gluon field origin of baryon number transport referred to as baryon junctions. Another is that hydrodynamics may apply up to high pt in A+A. There is no consensus on what are the correct mechanisms for producing baryons and hyperons at high pt and large rapidity shifts and the new RHIC data provide a strong motivation to hold a meeting focusing on this class of observables. The possible role of junctions in forming CP violating domain walls and novel nuclear bucky-ball configurations would also be discussed. In this workshop, we focused on all measured baryon distributions at RHIC energies and related theoretical considerations. To facilitate the discussions, results of heavy ion collisions at lower beam energies, results from p+A /p+p/e+e collisions were included. Some suggestions for future measurements have been made at the workshop.« less

The role of baryons in creating statistically significant planes of satellites around Milky Way-mass galaxies

NASA Astrophysics Data System (ADS)

Ahmed, Sheehan H.; Brooks, Alyson M.; Christensen, Charlotte R.

2017-04-01

We investigate whether the inclusion of baryonic physics influences the formation of thin, coherently rotating planes of satellites such as those seen around the Milky Way and Andromeda. For four Milky Way-mass simulations, each run both as dark matter-only and with baryons included, we are able to identify a planar configuration that significantly maximizes the number of plane satellite members. The maximum plane member satellites are consistently different between the dark matter-only and baryonic versions of the same run due to the fact that satellites are both more likely to be destroyed and to infall later in the baryonic runs. Hence, studying satellite planes in dark matter-only simulations is misleading, because they will be composed of different satellite members than those that would exist if baryons were included. Additionally, the destruction of satellites in the baryonic runs leads to less radially concentrated satellite distributions, a result that is critical to making planes that are statistically significant compared to a random distribution. Since all planes pass through the centre of the galaxy, it is much harder to create a plane of a given height from a random distribution if the satellites have a low radial concentration. We identify Andromeda's low radial satellite concentration as a key reason why the plane in Andromeda is highly significant. Despite this, when corotation is considered, none of the satellite planes identified for the simulated galaxies are as statistically significant as the observed planes around the Milky Way and Andromeda, even in the baryonic runs.

Mean-field theory of baryonic matter for QCD in the large Nc and heavy quark mass limits

NASA Astrophysics Data System (ADS)

Adhikari, Prabal; Cohen, Thomas D.

2013-11-01

We discuss theoretical issues pertaining to baryonic matter in the combined heavy-quark and large Nc limits of QCD. Witten's classic argument that baryons and interacting systems of baryons can be described in a mean-field approximation with each of the quarks moving in an average potential due to the remaining quarks is heuristic. It is important to justify this heuristic description for the case of baryonic matter since systems of interacting baryons are intrinsically more complicated than single baryons due to the possibility of hidden color states—states in which the subsystems making up the entire baryon crystal are not color-singlet nucleons but rather colorful states coupled together to make a color-singlet state. In this work, we provide a formal justification of this heuristic prescription. In order to do this, we start by taking the heavy quark limit, thus effectively reducing the problem to a many-body quantum mechanical system. This problem can be formulated in terms of integrals over coherent states, which for this problem are simple Slater determinants. We show that for the many-body problem, the support region for these integrals becomes narrow at large Nc, yielding an energy which is well approximated by a single coherent state—that is a mean-field description. Corrections to the energy are of relative order 1/Nc. While hidden color states are present in the exact state of the heavy quark system, they only influence the interaction energy below leading order in 1/Nc.

Warm-hot baryons comprise 5-10 per cent of filaments in the cosmic web.

PubMed

Eckert, Dominique; Jauzac, Mathilde; Shan, HuanYuan; Kneib, Jean-Paul; Erben, Thomas; Israel, Holger; Jullo, Eric; Klein, Matthias; Massey, Richard; Richard, Johan; Tchernin, Céline

2015-12-03

Observations of the cosmic microwave background indicate that baryons account for 5 per cent of the Universe's total energy content. In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two. Cosmological simulations indicate that the missing baryons have not condensed into virialized haloes, but reside throughout the filaments of the cosmic web (where matter density is larger than average) as a low-density plasma at temperatures of 10(5)-10(7) kelvin, known as the warm-hot intergalactic medium. There have been previous claims of the detection of warm-hot baryons along the line of sight to distant blazars and of hot gas between interacting clusters. These observations were, however, unable to trace the large-scale filamentary structure, or to estimate the total amount of warm-hot baryons in a representative volume of the Universe. Here we report X-ray observations of filamentary structures of gas at 10(7) kelvin associated with the galaxy cluster Abell 2744. Previous observations of this cluster were unable to resolve and remove coincidental X-ray point sources. After subtracting these, we find hot gas structures that are coherent over scales of 8 megaparsecs. The filaments coincide with over-densities of galaxies and dark matter, with 5-10 per cent of their mass in baryonic gas. This gas has been heated up by the cluster's gravitational pull and is now feeding its core. Our findings strengthen evidence for a picture of the Universe in which a large fraction of the missing baryons reside in the filaments of the cosmic web.

Dark matter annihilation at the galactic center

NASA Astrophysics Data System (ADS)

Linden, Tim

Observations by the WMAP and PLANCK satellites have provided extraordinarily accurate observations on the densities of baryonic matter, dark matter, and dark energy in the universe. These observations indicate that our universe is composed of approximately five times as much dark matter as baryonic matter. However, efforts to detect a particle responsible for the energy density of dark matter have been unsuccessful. Theoretical models have indicated that a leading candidate for the dark matter is the lightest supersymmetric particle, which may be stable due to a conserved R-parity. This dark matter particle would still be capable of interacting with baryons via weak-force interactions in the early universe, a process which was found to naturally explain the observed relic abundance of dark matter today. These residual annihilations can persist, albeit at a much lower rate, in the present universe, providing a detectable signal from dark matter annihilation events which occur throughout the universe. Simulations calculating the distribution of dark matter in our galaxy almost universally predict the galactic center of the Milky Way Galaxy (GC) to provide the brightest signal from dark matter annihilation due to its relative proximity and large simulated dark matter density. Recent advances in telescope technology have allowed for the first multiwavelength analysis of the GC, with suitable effective exposure, angular resolution, and energy resolution in order to detect dark matter particles with properties similar to those predicted by the WIMP miracle. In this work, I describe ongoing efforts which have successfully detected an excess in gamma-ray emission from the region immediately surrounding the GC, which is difficult to describe in terms of standard diffuse emission predicted in the GC region. While the jury is still out on any dark matter interpretation of this excess, I describe several related observations which may indicate a dark matter origin. Finally, I discuss the role of future telescopes in differentiating a dark matter model from astrophysical emission.

Baryon spectroscopy and the omega minus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samios, N.P.

1994-12-31

In this report, I will mainly discuss baryon resonances with emphasis on the discovery of the {Omega}{sup {minus}}. However, for completeness, I will also present some data on the meson resonances which together with the baryons led to the uncovering of the SU(3) symmetry of particles and ultimately to the concept of quarks.

Dark matter and cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schramm, D.N.

1992-03-01

The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ``cold`` and ``hot`` non-baryonic candidates is shown to depend on the assumed ``seeds`` that stimulate structure formation. Gaussian density fluctuations,more » such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.« less

Dark matter and cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schramm, D.N.

1992-03-01

The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between cold'' and hot'' non-baryonic candidates is shown to depend on the assumed seeds'' that stimulate structure formation. Gaussian density fluctuations,more » such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.« less

Dark matter and cosmology

NASA Astrophysics Data System (ADS)

Schramm, David N.

1992-07-01

The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the Ω = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ``cold'' and ``hot'' non-baryonic candidates is shown to depend on the assumed ``seeds'' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

Dark matter and cosmology

NASA Astrophysics Data System (ADS)

Schramm, D. N.

1992-03-01

The cosmological dark matter problem is reviewed. The Big Bang nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the omega = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between 'cold' and 'hot' non-baryonic candidates is shown to depend on the assumed 'seeds' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages, and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

Finite volume effects in the chiral extrapolation of baryon masses

NASA Astrophysics Data System (ADS)

Lutz, M. F. M.; Bavontaweepanya, R.; Kobdaj, C.; Schwarz, K.

2014-09-01

We perform an analysis of the QCD lattice data on the baryon octet and decuplet masses based on the relativistic chiral Lagrangian. The baryon self-energies are computed in a finite volume at next-to-next-to-next-to-leading order (N3LO), where the dependence on the physical meson and baryon masses is kept. The number of free parameters is reduced significantly down to 12 by relying on large-Nc sum rules. Altogether we describe accurately more than 220 data points from six different lattice groups, BMW, PACS-CS, HSC, LHPC, QCDSF-UKQCD and NPLQCD. Values for all counterterms relevant at N3LO are predicted. In particular we extract a pion-nucleon sigma term of 39-1+2 MeV and a strangeness sigma term of the nucleon of σsN=84-4+28 MeV. The flavor SU(3) chiral limit of the baryon octet and decuplet masses is determined with (802±4) and (1103±6) MeV. Detailed predictions for the baryon masses as currently evaluated by the ETM lattice QCD group are made.

Baryogenesis via particle-antiparticle oscillations

DOE PAGES

Ipek, Seyda; March-Russell, John

2016-06-29

CP violation, which is crucial for producing the baryon asymmetry of the Universe, is enhanced in particle-antiparticle oscillations. We study particle-antiparticle oscillations [of a particle with mass O(100GeV)] with CP violation in the early Universe in the presence of interactions with O(ab-fb) cross sections. We show that if baryon-number-violating interactions exist, a baryon asymmetry can be produced via out-of-equilibrium decays of oscillating particles. As a concrete example we study a U(1)R-symmetric, R-parity-violating supersymmetry model with pseudo-Dirac gauginos, which undergo particle-antiparticle oscillations. Hence, taking bino to be the lightest U(1) R-symmetric particle, and assuming it decays via baryon-number-violating interactions, we showmore » that bino-antibino oscillations can produce the baryon asymmetry of the Universe.« less

Flavor-singlet baryons in the graded symmetry approach to partially quenched QCD

NASA Astrophysics Data System (ADS)

Hall, Jonathan M. M.; Leinweber, Derek B.

2016-11-01

Progress in the calculation of the electromagnetic properties of baryon excitations in lattice QCD presents new challenges in the determination of sea-quark loop contributions to matrix elements. A reliable estimation of the sea-quark loop contributions represents a pressing issue in the accurate comparison of lattice QCD results with experiment. In this article, an extension of the graded symmetry approach to partially quenched QCD is presented, which builds on previous theory by explicitly including flavor-singlet baryons in its construction. The formalism takes into account the interactions among both octet and singlet baryons, octet mesons, and their ghost counterparts; the latter enables the isolation of the quark-flow disconnected sea-quark loop contributions. The introduction of flavor-singlet states enables systematic studies of the internal structure of Λ -baryon excitations in lattice QCD, including the topical Λ (1405 ).

A simple testable model of baryon number violation: Baryogenesis, dark matter, neutron-antineutron oscillation and collider signals

NASA Astrophysics Data System (ADS)

Allahverdi, Rouzbeh; Dev, P. S. Bhupal; Dutta, Bhaskar

2018-04-01

We study a simple TeV-scale model of baryon number violation which explains the observed proximity of the dark matter and baryon abundances. The model has constraints arising from both low and high-energy processes, and in particular, predicts a sizable rate for the neutron-antineutron (n - n bar) oscillation at low energy and the monojet signal at the LHC. We find an interesting complementarity among the constraints arising from the observed baryon asymmetry, ratio of dark matter and baryon abundances, n - n bar oscillation lifetime and the LHC monojet signal. There are regions in the parameter space where the n - n bar oscillation lifetime is found to be more constraining than the LHC constraints, which illustrates the importance of the next-generation n - n bar oscillation experiments.

Multistrange Baryon elliptic flow in Au+Au collisions at square root of sNN=200 GeV.

PubMed

Adams, J; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Berger, J; Bezverkhny, B I; Bharadwaj, S; Bhasin, A; Bhati, A K; Bhatia, V S; Bichsel, H; Bielcik, J; Bielcikova, J; Billmeier, A; Bland, L C; Blyth, C O; Blyth, S L; Bonner, B E; Botje, M; Boucham, A; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Daugherity, M; de Moura, M M; Dedovich, T G; DePhillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fornazier, K S F; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Gos, H; Grachov, O; Grebenyuk, O; Grosnick, D; Guertin, S M; Guo, Y; Gupta, A; Gupta, N; Gutierrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Jedynak, M; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kowalik, K L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Miller, M L; Minaev, N G; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Reinnarth, J; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimanskiy, S S; Sichtermann, E; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van der Kolk, N; van Leeuwen, M; Vander Molen, A M; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, G; Wang, X L; Wang, Y; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zborovsky, I; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

2005-09-16

We report on the first measurement of elliptic flow v2(pT) of multistrange baryons Xi- +Xi+ and Omega- + Omega+ in heavy-ion collisions. In minimum-bias Au+Au collisions at square root of s(NN)=200 GeV, a significant amount of elliptic flow, comparable to other nonstrange baryons, is observed for multistrange baryons which are expected to be particularly sensitive to the dynamics of the partonic stage of heavy-ion collisions. The pT dependence of v2 of the multistrange baryons confirms the number of constituent quark scaling previously observed for lighter hadrons. These results support the idea that a substantial fraction of the observed collective motion is developed at the early partonic stage in ultrarelativistic nuclear collisions at the Relativistic Heavy Ion Collider.

Light baryon spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crede, Volker

The spectrum of excited baryons serves as an excellent probe of quantum chromodynamics (QCD). In particular, highly-excited baryon resonances are sensitive to the details of quark confinement which is only poorly understood within QCD. Facilities worldwide such as Jefferson Lab, ELSA, and MAMI, which study the systematics of hadron spectra in photo- and electroproduction experiments, have accumulated a large amount of data in recent years including unpolarized cross section and polarization data for a large variety of meson-production reactions. These are important steps toward complete experiments that will allow us to unambiguously determine the scattering amplitude in the underlying reactionsmore » and to identify the broad and overlapping baryon resonance contributions. Several new nucleon resonances have been proposed and changes to the baryon listing in the 2012 Review of Particle Physics reflect the progress in the field.« less

High baryon densities in heavy ion collisions at energies attainable at the BNL Relativistic Heavy-Ion Collider and the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

Li, Ming; Kapusta, Joseph I.

2017-01-01

In very high-energy collisions nuclei are practically transparent to each other but produce very hot nearly baryon-free matter in the so-called central rapidity region. The energy in the central rapidity region comes from the kinetic energy of the colliding nuclei. We calculate the energy and rapidity loss of the nuclei using the color glass condensate model. This model also predicts the excitation energy of the nuclear fragments. Using a space-time picture of the collision we calculate the baryon and energy densities of the receding baryonic fireballs. For central collisions of gold nuclei at the highest energy attainable at the Relativistic Heavy-Ion Collider, for example, we find baryon densities more than ten times that of atomic nuclei over a large volume.

Search for Baryon-Number Violating Ξb0 Oscillations

NASA Astrophysics Data System (ADS)

Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Archilli, F.; d'Argent, P.; Arnau Romeu, J.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baker, S.; Balagura, V.; Baldini, W.; Baranov, A.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Baryshnikov, F.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Beiter, A.; Bel, L. J.; Beliy, N.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Beranek, S.; Berezhnoy, A.; Bernet, R.; Berninghoff, D.; Bertholet, E.; Bertolin, A.; Betancourt, C.; Betti, F.; Bettler, M.-O.; van Beuzekom, M.; Bezshyiko, Ia.; Bifani, S.; Billoir, P.; Birnkraut, A.; Bitadze, A.; Bizzeti, A.; Bjørn, M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bonivento, W.; Bordyuzhin, I.; Borgheresi, A.; Borghi, S.; Borisyak, M.; Borsato, M.; Bossu, F.; Boubdir, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britton, T.; Brodzicka, J.; Brundu, D.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Byczynski, W.; Cadeddu, S.; Cai, H.; Calabrese, R.; Calladine, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D. H.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cavallero, G.; Cenci, R.; Chamont, D.; Charles, M.; Charpentier, Ph.; Chatzikonstantinidis, G.; Chefdeville, M.; Chen, S.; Cheung, S. F.; Chitic, S.-G.; Chobanova, V.; Chrzaszcz, M.; Chubykin, A.; Ciambrone, P.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collins, P.; Colombo, T.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombs, G.; Coquereau, S.; Corti, G.; Corvo, M.; Costa Sobral, C. M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Currie, R.; D'Ambrosio, C.; Da Cunha Marinho, F.; Dall'Occo, E.; Dalseno, J.; Davis, A.; De Aguiar Francisco, O.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Serio, M.; De Simone, P.; Dean, C. T.; Decamp, D.; Del Buono, L.; Dembinski, H.-P.; Demmer, M.; Dendek, A.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Nezza, P.; Dijkstra, H.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Douglas, L.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Durante, P.; Dzhelyadin, R.; Dziewiecki, M.; Dziurda, A.; Dzyuba, A.; Easo, S.; Ebert, M.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Farley, N.; Farry, S.; Fazzini, D.; Federici, L.; Ferguson, D.; Fernandez, G.; Fernandez Declara, P.; Fernandez Prieto, A.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fini, R. A.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fleuret, F.; Fohl, K.; Fontana, M.; Fontanelli, F.; Forshaw, D. C.; Forty, R.; Franco Lima, V.; Frank, M.; Frei, C.; Fu, J.; Funk, W.; Furfaro, E.; Färber, C.; Gabriel, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Martin, L. M.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Garsed, P. J.; Gascon, D.; Gaspar, C.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianı, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gorelov, I. V.; Gotti, C.; Govorkova, E.; Grabowski, J. P.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greim, R.; Griffith, P.; Grillo, L.; Gruber, L.; Gruberg Cazon, B. R.; Grünberg, O.; Gushchin, E.; Guz, Yu.; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hamilton, B.; Han, X.; Hancock, T. H.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hasse, C.; Hatch, M.; He, J.; Hecker, M.; Heinicke, K.; Heister, A.; Hennessy, K.; Henrard, P.; Henry, L.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hombach, C.; Hopchev, P. H.; Huard, Z. C.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hutchcroft, D.; Ibis, P.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jalocha, J.; Jans, E.; Jawahery, A.; Jiang, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Karacson, M.; Kariuki, J. M.; Karodia, S.; Kazeev, N.; Kecke, M.; Kelsey, M.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.; Klimaszewski, K.; Klimkovich, T.; Koliiev, S.; Kolpin, M.; Komarov, I.; Kopecna, R.; Koppenburg, P.; Kosmyntseva, A.; Kotriakhova, S.; Kozeiha, M.; Kravchuk, L.; Kreps, M.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Lemos Cid, E.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, P.-R.; Li, T.; Li, Y.; Li, Z.; Likhomanenko, T.; Lindner, R.; Lionetto, F.; Lisovskyi, V.; Liu, X.; Loh, D.; Loi, A.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Macko, V.; Mackowiak, P.; Maddrell-Mander, S.; Maev, O.; Maguire, K.; Maisuzenko, D.; Majewski, M. W.; Malde, S.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Manning, P.; Marangotto, D.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marinangeli, M.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massacrier, L. M.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurice, E.; Maurin, B.; Mazurov, A.; McCann, M.; McNab, A.; McNulty, R.; Mead, J. V.; Meadows, B.; Meaux, C.; Meier, F.; Meinert, N.; Melnychuk, D.; Merk, M.; Merli, A.; Michielin, E.; Milanes, D. A.; Millard, E.; Minard, M.-N.; Minzoni, L.; Mitzel, D. S.; Mogini, A.; Molina Rodriguez, J.; Mombacher, T.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morello, M. J.; Morgunova, O.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mulder, M.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, T. D.; Nguyen-Mau, C.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Nogay, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J. G.; Ossowska, A.; Otalora Goicochea, J. M.; Owen, P.; Oyanguren, A.; Pais, P. R.; Palano, A.; Palutan, M.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parker, W.; Parkes, C.; Passaleva, G.; Pastore, A.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pikies, M.; Pinci, D.; Pistone, A.; Piucci, A.; Placinta, V.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poli Lener, M.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Ponce, S.; Popov, A.; Popov, D.; Poslavskii, S.; Potterat, C.; Price, E.; Prisciandaro, J.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Pullen, H.; Punzi, G.; Qian, W.; Quagliani, R.; Quintana, B.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Ramos Pernas, M.; Rangel, M. S.; Raniuk, I.; Ratnikov, F.; Raven, G.; Ravonel Salzgeber, M.; Reboud, M.; Redi, F.; Reichert, S.; dos Reis, A. C.; Remon Alepuz, C.; Renaudin, V.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Robert, A.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Rogozhnikov, A.; Roiser, S.; Rollings, A.; Romanovskiy, V.; Romero Vidal, A.; Ronayne, J. W.; Rotondo, M.; Rudolph, M. S.; Ruf, T.; Ruiz Valls, P.; Ruiz Vidal, J.; Saborido Silva, J. J.; Sadykhov, E.; Sagidova, N.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarpis, G.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schreiner, H. F.; Schubert, K.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepulveda, E. S.; Sergi, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Simone, S.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, E.; Smith, I. T.; Smith, J.; Smith, M.; Soares Lavra, l.; Sokoloff, M. D.; Soler, F. J. P.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stemmle, S.; Stenyakin, O.; Stepanova, M.; Stevens, H.; Stone, S.; Storaci, B.; Stracka, S.; Stramaglia, M. E.; Straticiuc, M.; Straumann, U.; Sun, J.; Sun, L.; Sutcliffe, W.; Swientek, K.; Syropoulos, V.; Szczekowski, M.; Szumlak, T.; Szymanski, M.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Thomas, E.; van Tilburg, J.; Tilley, M. J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Toriello, F.; Tourinho Jadallah Aoude, R.; Tournefier, E.; Traill, M.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tully, A.; Tuning, N.; Ukleja, A.; Usachov, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagner, A.; Vagnoni, V.; Valassi, A.; Valat, S.; Valenti, G.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; van Veghel, M.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Verlage, T. A.; Vernet, M.; Vesterinen, M.; Viana Barbosa, J. V.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Viemann, H.; Vilasis-Cardona, X.; Vitti, M.; Volkov, V.; Vollhardt, A.; Voneki, B.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Vázquez Sierra, C.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wang, J.; Ward, D. R.; Wark, H. M.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Winn, M.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wraight, K.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yang, Z.; Yao, Y.; Yin, H.; Yu, J.; Yuan, X.; Yushchenko, O.; Zarebski, K. A.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zheng, Y.; Zhu, X.; Zhukov, V.; Zonneveld, J. B.; Zucchelli, S.; LHCb Collaboration

2017-11-01

A search for baryon-number violating Ξb0 oscillations is performed with a sample of p p collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3 fb-1 . The baryon number at the moment of production is identified by requiring that the Ξb0 come from the decay of a resonance Ξb*-→Ξb0π- or Ξb'-→Ξb0π-, and the baryon number at the moment of decay is identified from the final state using the decays Ξb0→Ξc+π-,Ξc+→p K-π+. No evidence of baryon-number violation is found, and an upper limit at the 95% confidence level is set on the oscillation rate of ω <0.08 ps-1, where ω is the associated angular frequency.

The diverse density profiles of galaxy clusters with self-interacting dark matter plus baryons

NASA Astrophysics Data System (ADS)

Robertson, Andrew; Massey, Richard; Eke, Vincent; Tulin, Sean; Yu, Hai-Bo; Bahé, Yannick; Barnes, David J.; Bower, Richard G.; Crain, Robert A.; Dalla Vecchia, Claudio; Kay, Scott T.; Schaller, Matthieu; Schaye, Joop

2018-05-01

We present the first simulated galaxy clusters (M200 > 1014 M⊙) with both self-interacting dark matter (SIDM) and baryonic physics. They exhibit a greater diversity in both dark matter and stellar density profiles than their counterparts in simulations with collisionless dark matter (CDM), which is generated by the complex interplay between dark matter self-interactions and baryonic physics. Despite variations in formation history, we demonstrate that analytical Jeans modelling predicts the SIDM density profiles remarkably well, and the diverse properties of the haloes can be understood in terms of their different final baryon distributions.

The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample: anisotropic Baryon Acoustic Oscillations measurements in Fourier-space with optimal redshift weights

NASA Astrophysics Data System (ADS)

Wang, Dandan; Zhao, Gong-Bo; Wang, Yuting; Percival, Will J.; Ruggeri, Rossana; Zhu, Fangzhou; Tojeiro, Rita; Myers, Adam D.; Chuang, Chia-Hsun; Baumgarten, Falk; Zhao, Cheng; Gil-Marín, Héctor; Ross, Ashley J.; Burtin, Etienne; Zarrouk, Pauline; Bautista, Julian; Brinkmann, Jonathan; Dawson, Kyle; Brownstein, Joel R.; de la Macorra, Axel; Schneider, Donald P.; Shafieloo, Arman

2018-06-01

We present a measurement of the anisotropic and isotropic Baryon Acoustic Oscillations (BAO) from the extended Baryon Oscillation Spectroscopic Survey Data Release 14 quasar sample with optimal redshift weights. Applying the redshift weights improves the constraint on the BAO dilation parameter α(zeff) by 17 per cent. We reconstruct the evolution history of the BAO distance indicators in the redshift range of 0.8 < z < 2.2. This paper is part of a set that analyses the eBOSS DR14 quasar sample.

Nucleon and Delta axial-vector couplings in 1/N{sub c}-Baryon Chiral Perturbation Theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goity, Jose Luis; Calle Cordon, Alvaro

In this contribution, baryon axial-vector couplings are studied in the framework of the combined 1/N{sub c} and chiral expansions. This framework is implemented on the basis of the emergent spin-flavor symmetry in baryons at large N{sub c} and HBChPT, and linking both expansions ({xi}-expansion), where 1/N{sub c} is taken to be a quantity order p. The study is carried out including one-loop contributions, which corresponds to order xi to the third for baryon masses and order {xi} square for the axial couplings.

Hydrodynamic collimation of gamma-ray-burst fireballs

PubMed

Levinson; Eichler

2000-07-10

Analytic solutions are presented for the hydrodynamic collimation of a relativistic fireball by a surrounding baryonic wind emanating from a torus. The opening angle is shown to be the ratio of the power output of the inner fireball to that of the exterior baryonic wind. The gamma ray burst 990123 might thus be interpreted as a baryon-poor jet (BPJ) with an energy output of order 10(50) erg or less, collimated by a baryonic wind from a torus with an energy output of order 10(52.5) erg, roughly the geometric mean of the BPJ and its isotropic equivalent.

The simultaneous enhancement of photorefraction and optical damage resistance in MgO and Bi2O3 co-doped LiNbO3 crystals

PubMed Central

Zheng, Dahuai; Kong, Yongfa; Liu, Shiguo; Chen, Muling; Chen, Shaolin; Zhang, Ling; Rupp, Romano; Xu, Jingjun

2016-01-01

For a long time that optical damage was renamed as photorefraction, here we find that the optical damage resistance and photorefraction can be simultaneously enhanced in MgO and Bi2O3 co-doped LiNbO3 (LN:Bi,Mg). The photorefractive response time of LN:Bi,Mg was shortened to 170 ms while the photorefractive sensitivity reached up to 21 cm2/J. Meanwhile, LN:Bi,Mg crystals could withstand a light intensity higher than 106  W/cm2 without apparent optical damage. Our experimental results indicate that photorefraction doesn’t equal to optical damage. The underground mechanism was analyzed and attributed to that diffusion dominates the transport process of charge carriers, that is to say photorefraction causes only slight optical damage under diffusion mechanism, which is very important for the practical applications of photorefractive crystals, such as in holographic storage, integrated optics and 3D display. PMID:26837261

Masses and sigma terms of doubly charmed baryons up to O (p4) in manifestly Lorentz-invariant baryon chiral perturbation theory

NASA Astrophysics Data System (ADS)

Yao, De-Liang

2018-02-01

We calculate the masses and sigma terms of the doubly charmed baryons up to next-to-next-to-next-to-leading order [i.e., O (p4) ] in a covariant baryon chiral perturbation theory by using the extended-on-mass-shell renormalization scheme. Their expressions both in infinite and finite volumes are provided for chiral extrapolation in lattice QCD. As a first application, our chiral results of the masses are confronted with the existing lattice QCD data in the presence of finite-volume corrections. Up to O (p3) , all relevant low-energy constants can be well determined. As a consequence, we obtain the physical values for the masses of Ξc c and Ωc c baryons by extrapolating to the physical limit. Our determination of the Ξc c mass is consistent with the recent experimental value by LHCb Collaboration, however, larger than the one by SELEX Collaboration. In addition, we predict the pion-baryon and strangeness-baryon sigma terms, as well as the mass splitting between the Ξc c and Ωc c states. Their quark mass dependences are also discussed. The numerical procedure can be applied to the chiral results of O (p4) order, where more unknown constants are involved, when more data are available for unphysical pion masses.

The baryonic mass function of galaxies.

PubMed

Read, J I; Trentham, Neil

2005-12-15

In the Big Bang about 5% of the mass that was created was in the form of normal baryonic matter (neutrons and protons). Of this about 10% ended up in galaxies in the form of stars or of gas (that can be in molecules, can be atomic, or can be ionized). In this work, we measure the baryonic mass function of galaxies, which describes how the baryonic mass is distributed within galaxies of different types (e.g. spiral or elliptical) and of different sizes. This can provide useful constraints on our current cosmology, convolved with our understanding of how galaxies form. This work relies on various large astronomical surveys, e.g. the optical Sloan Digital Sky Survey (to observe stars) and the HIPASS radio survey (to observe atomic gas). We then perform an integral over our mass function to determine the cosmological density of baryons in galaxies: Omega(b,gal)=0.0035. Most of these baryons are in stars: Omega(*)=0.0028. Only about 20% are in gas. The error on the quantities, as determined from the range obtained between different methods, is ca 10%; systematic errors may be much larger. Most (ca 90%) of the baryons in the Universe are not in galaxies. They probably exist in a warm/hot intergalactic medium. Searching for direct observational evidence and deeper theoretical understanding for this will form one of the major challenges for astronomy in the next decade.

The baryon content of the Cosmic Web

PubMed Central

Eckert, Dominique; Jauzac, Mathilde; Shan, HuanYuan; Kneib, Jean-Paul; Erben, Thomas; Israel, Holger; Jullo, Eric; Klein, Matthias; Massey, Richard; Richard, Johan; Tchernin, Céline

2015-01-01

Big-Bang nucleosynthesis indicates that baryons account for 5% of the Universe’s total energy content[1]. In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two[2,3]. Cosmological simulations indicate that the missing baryons have not yet condensed into virialised halos, but reside throughout the filaments of the cosmic web: a low-density plasma at temperature 105–107 K known as the warm-hot intergalactic medium (WHIM)[3,4,5,6]. There have been previous claims of the detection of warm baryons along the line of sight to distant blazars[7,8,9,10] and hot gas between interacting clusters[11,12,13,14]. These observations were however unable to trace the large-scale filamentary structure, or to estimate the total amount of warm baryons in a representative volume of the Universe. Here we report X-ray observations of filamentary structures of ten-million-degree gas associated with the galaxy cluster Abell 2744. Previous observations of this cluster[15] were unable to resolve and remove coincidental X-ray point sources. After subtracting these, we reveal hot gas structures that are coherent over 8 Mpc scales. The filaments coincide with over-densities of galaxies and dark matter, with 5-10% of their mass in baryonic gas. This gas has been heated up by the cluster's gravitational pull and is now feeding its core. PMID:26632589

PROSPECTS FOR PENTAQUARK SEARCHES IN E+D- ANNIHILATIONS AND VV COLLISIONS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

ARMSTRONG,S.; MELLADO,B.; WU,S.L.

2004-06-28

Recent strong experimental evidence of a narrow exotic S = +1 baryon resonance, {Theta}{sup +}, suggests the existence of other exotic baryons. We discuss the prospects of confirming earlier experimental evidence of {Theta}{sup +} and the observation of additional hypothetical exotic baryons in e{sup +}e{sup -} annihilations and {gamma}{gamma} collisions at LEP and B Factories.

Spectroscopy of the Ωccb baryon in the hypercentral constituent quark model

NASA Astrophysics Data System (ADS)

Shah, Zalak; Rai, Ajay Kumar

2018-05-01

We extract the mass spectrum of the triply heavy baryon {{{Ω }}}{{ccb}} using the hypercentral constituent quark model. The first order correction is also added to the potential term of the Hamiltonian. The radial and orbital excited state masses are determined, and the Regge trajectories and magnetic moments for this baryon are also given.

A small amount of mini-charged dark matter could cool the baryons in the early Universe.

PubMed

Muñoz, Julian B; Loeb, Abraham

2018-05-01

The dynamics of our Universe is strongly influenced by pervasive-albeit elusive-dark matter, with a total mass about five times the mass of all the baryons 1,2 . Despite this, its origin and composition remain a mystery. All evidence for dark matter relies on its gravitational pull on baryons, and thus such evidence does not require any non-gravitational coupling between baryons and dark matter. Nonetheless, some small coupling would explain the comparable cosmic abundances of dark matter and baryons 3 , as well as solving structure-formation puzzles in the pure cold-dark-matter models 4 . A vast array of observations has been unable to find conclusive evidence for any non-gravitational interactions of baryons with dark matter 5-9 . Recent observations by the EDGES collaboration, however, suggest that during the cosmic dawn, roughly 200 million years after the Big Bang, the baryonic temperature was half of its expected value 10 . This observation is difficult to reconcile with the standard cosmological model but could be explained if baryons are cooled down by interactions with dark matter, as expected if their interaction rate grows steeply at low velocities 11 . Here we report that if a small fraction-less than one per cent-of the dark matter has a mini-charge, a million times smaller than the charge on the electron, and a mass in the range of 1-100 times the electron mass, then the data 10 from the EDGES experiment can be explained while remaining consistent with all other observations. We also show that the entirety of the dark matter cannot have a mini-charge.

ASSESSING ASTROPHYSICAL UNCERTAINTIES IN DIRECT DETECTION WITH GALAXY SIMULATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sloane, Jonathan D.; Buckley, Matthew R.; Brooks, Alyson M.

2016-11-01

We study the local dark matter velocity distribution in simulated Milky Way-mass galaxies, generated at high resolution with both dark matter and baryons. We find that the dark matter in the solar neighborhood is influenced appreciably by the inclusion of baryons, increasing the speed of dark matter particles compared to dark matter-only simulations. The gravitational potential due to the presence of a baryonic disk increases the amount of high velocity dark matter, resulting in velocity distributions that are more similar to the Maxwellian Standard Halo Model than predicted from dark matter-only simulations. Furthermore, the velocity structures present in baryonic simulationsmore » possess a greater diversity than expected from dark matter-only simulations. We show that the impact on the direct detection experiments LUX, DAMA/Libra, and CoGeNT using our simulated velocity distributions, and explore how resolution and halo mass within the Milky Way’s estimated mass range impact the results. A Maxwellian fit to the velocity distribution tends to overpredict the amount of dark matter in the high velocity tail, even with baryons, and thus leads to overly optimistic direct detection bounds on models that are dependent on this region of phase space for an experimental signal. Our work further demonstrates that it is critical to transform simulated velocity distributions to the lab frame of reference, due to the fact that velocity structure in the solar neighborhood appears when baryons are included. There is more velocity structure present when baryons are included than in dark matter-only simulations. Even when baryons are included, the importance of the velocity structure is not as apparent in the Galactic frame of reference as in the Earth frame.« less

Scaling Laws for Dark Matter Halos in Late-type and Dwarf Spheroidal Galaxies

NASA Astrophysics Data System (ADS)

Kormendy, John; Freeman, K. C.

2016-02-01

Dark matter (DM) halos of Sc-Im and dwarf spheroidal (dSph) galaxies satisfy scaling laws: halos in lower-luminosity galaxies have smaller core radii, higher central densities, and smaller velocity dispersions. These results are based on maximum-disk rotation curve decompositions for giant galaxies and Jeans equation analysis for dwarfs. (1) We show that spiral, Im, and Sph galaxies with absolute magnitudes MV > -18 form a sequence of decreasing baryon-to-DM surface density with decreasing luminosity. We suggest that this is a sequence of decreasing baryon retention versus supernova-driven losses or decreasing baryon capture after cosmological reionization. (2) The structural differences between S+Im and Sph galaxies are small. Both are affected mostly by the physics that controls baryon depletion. (3) There is a linear correlation between the maximum rotation velocities of baryonic disks and the outer circular velocities Vcirc of test particles in their DM halos. Baryons become unimportant at Vcirc = 42 ± 4 km s-1. Smaller galaxies are dim or dark. (4) We find that, absent baryon “depletion” and with all baryons converted into stars, dSph galaxies would be brighter by ˜4.6 mag and dIm galaxies would be brighter by ˜3.5 mag. Both have DM halos that are massive enough to help to solve the “too big to fail” problem with DM galaxy formation. (5) We suggest that there exist many galaxies that are too dark to be discovered by current techniques, as required by cold DM theory. (6) Central surface densities of DM halos are constant from MB ˜ -5 to -22. This implies a Faber-Jackson law with halo mass M ∝ (halo dispersion)4.

Parity partners in the baryon resonance spectrum

DOE PAGES

Lu, Ya; Chen, Chen; Roberts, Craig D.; ...

2017-07-28

Here, we describe a calculation of the spectrum of flavor-SU(3) octet and decuplet baryons, their parity partners, and the radial excitations of these systems, made using a symmetry-preserving treatment of a vector x vector contact interaction as the foundation for the relevant few-body equations. Dynamical chiral symmetry breaking generates nonpointlike diquarks within these baryons and hence, using the contact interaction, flavor-antitriplet scalar, pseudoscalar, vector, and flavor-sextet axial-vector quark-quark correlations can all play active roles. The model yields reasonable masses for all systems studied and Faddeev amplitudes for ground states and associated parity partners that sketch a realistic picture of theirmore » internal structure: ground-state, even-parity baryons are constituted, almost exclusively, from like-parity diquark correlations, but orbital angular momentum plays an important role in the rest-frame wave functions of odd-parity baryons, whose Faddeev amplitudes are dominated by odd-parity diquarks.« less

Σ--antihyperon correlations in Z0 decay and investigation of the baryon production mechanism

NASA Astrophysics Data System (ADS)

Abbiendi, G.; Ainsley, C.; Åkesson, P. F.; Alexander, G.; Anagnostou, G.; Anderson, K. J.; Asai, S.; Axen, D.; Bailey, I.; Barberio, E.; Barillari, T.; Barlow, R. J.; Batley, R. J.; Bechtle, P.; Behnke, T.; Bell, K. W.; Bell, P. J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brown, R. M.; Burckhart, H. J.; Campana, S.; Capiluppi, P.; Carnegie, R. K.; Carter, A. A.; Carter, J. R.; Chang, C. Y.; Charlton, D. G.; Ciocca, C.; Csilling, A.; Cuffiani, M.; Dado, S.; Dallavalle, M.; de Roeck, A.; de Wolf, E. A.; Desch, K.; Dienes, B.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I. P.; Etzion, E.; Fabbri, F.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Gagnon, P.; Gary, J. W.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, M.; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwé, M.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G. G.; Harel, A.; Hauschild, M.; Hawkes, C. M.; Hawkings, R.; Herten, G.; Heuer, R. D.; Hill, J. C.; Horváth, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T. R.; Kanzaki, J.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R. K.; Kellogg, R. G.; Kennedy, B. W.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Krämer, T.; Krasznahorkay, A.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kupper, M.; Lafferty, G. D.; Landsman, H.; Lanske, D.; Lellouch, D.; Letts, J.; Levinson, L.; Lillich, J.; Lloyd, S. L.; Loebinger, F. K.; Lu, J.; Ludwig, A.; Ludwig, J.; Mader, W.; Marcellini, S.; Martin, A. J.; Mashimo, T.; Mättig, P.; McKenna, J.; McPherson, R. A.; Meijers, F.; Menges, W.; Merritt, F. S.; Mes, H.; Meyer, N.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D. J.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H. A.; O'Neale, S. W.; Oh, A.; Oreglia, M. J.; Orito, S.; Pahl, C.; Pásztor, G.; Pater, J. R.; Pilcher, J. E.; Pinfold, J.; Plane, D. E.; Pooth, O.; Przybycień, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J. M.; Rossi, A. M.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E. K. G.; Schaile, A. D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schörner-Sadenius, T.; Schröder, M.; Schumacher, M.; Seuster, R.; Shears, T. G.; Shen, B. C.; Sherwood, P.; Skuja, A.; Smith, A. M.; Sobie, R.; Söldner-Rembold, S.; Spano, F.; Stahl, A.; Strom, D.; Ströhmer, R.; Tarem, S.; Tasevsky, M.; Teuscher, R.; Thomson, M. A.; Torrence, E.; Toya, D.; Trigger, I.; Trócsányi, Z.; Tsur, E.; Turner-Watson, M. F.; Ueda, I.; Ujvári, B.; Vollmer, C. F.; Vannerem, P.; Vértesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Ward, C. P.; Ward, D. R.; Watkins, P. M.; Watson, A. T.; Watson, N. K.; Wells, P. S.; Wengler, T.; Wermes, N.; Wetterling, D.; Wilson, G. W.; Wilson, J. A.; Wolf, G.; Wyatt, T. R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, L.

2009-12-01

Data collected around sqrt{s}=91 GeV by the OPAL experiment at the LEP e+e- collider are used to study the mechanism of baryon formation. As the signature, the fraction of Σ- hyperons whose baryon number is compensated by the production of a overline{Σ-},overline{Λ} or overline{Ξ-} antihyperon is determined. The method relies entirely on quantum number correlations of the baryons, and not rapidity correlations, making it more model independent than previous studies. Within the context of the JETSET implementation of the string hadronization model, the diquark baryon production model without the popcorn mechanism is strongly disfavored with a significance of 3.8 standard deviations including systematic uncertainties. It is shown that previous studies of the popcorn mechanism with Λ overline{Λ} and p\\uppi overline{p} correlations are not conclusive, if parameter uncertainties are considered.

Parity partners in the baryon resonance spectrum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Ya; Chen, Chen; Roberts, Craig D.

Here, we describe a calculation of the spectrum of flavor-SU(3) octet and decuplet baryons, their parity partners, and the radial excitations of these systems, made using a symmetry-preserving treatment of a vector x vector contact interaction as the foundation for the relevant few-body equations. Dynamical chiral symmetry breaking generates nonpointlike diquarks within these baryons and hence, using the contact interaction, flavor-antitriplet scalar, pseudoscalar, vector, and flavor-sextet axial-vector quark-quark correlations can all play active roles. The model yields reasonable masses for all systems studied and Faddeev amplitudes for ground states and associated parity partners that sketch a realistic picture of theirmore » internal structure: ground-state, even-parity baryons are constituted, almost exclusively, from like-parity diquark correlations, but orbital angular momentum plays an important role in the rest-frame wave functions of odd-parity baryons, whose Faddeev amplitudes are dominated by odd-parity diquarks.« less

On the nature of the newly discovered Ω states

NASA Astrophysics Data System (ADS)

Agaev, S. S.; Azizi, K.; Sundu, H.

2017-06-01

The mass and residue of the ground-state, as well as the first orbital and radial excitations of the heavy ΩQ baryons with Q being b or c quark, for both J=1/2 and J=3/2 are calculated by means of the QCD two-point sum rule method using the general forms for the interpolating currents. In the calculations the quark, gluon and mixed vacuum condensates up to ten dimensions are taken into account. We compare our results for the masses of Ω_b- and Ω_c0 baryons with the existing predictions of other theoretical works. Our results for the charmed baryons are confronted with the experimental data of the LHCb Collaboration to understand the nature of the recently observed narrow Ω_c0 resonances. The predictions for the masses of the Ω_b- baryons with the same quantum numbers may shed light on future experimental searches for the corresponding bottom baryons.

Search for Baryon-Number Violating Ξ_{b}^{0} Oscillations.

PubMed

Aaij, R; Adeva, B; Adinolfi, M; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Alfonso Albero, A; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Andreassi, G; Andreotti, M; Andrews, J E; Appleby, R B; Archilli, F; d'Argent, P; Arnau Romeu, J; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Babuschkin, I; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baker, S; Balagura, V; Baldini, W; Baranov, A; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Baryshnikov, F; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Beiter, A; Bel, L J; Beliy, N; Bellee, V; Belloli, N; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Beranek, S; Berezhnoy, A; Bernet, R; Berninghoff, D; Bertholet, E; Bertolin, A; Betancourt, C; Betti, F; Bettler, M-O; van Beuzekom, M; Bezshyiko, Ia; Bifani, S; Billoir, P; Birnkraut, A; Bitadze, A; Bizzeti, A; Bjørn, M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Boettcher, T; Bondar, A; Bondar, N; Bonivento, W; Bordyuzhin, I; Borgheresi, A; Borghi, S; Borisyak, M; Borsato, M; Bossu, F; Boubdir, M; Bowcock, T J V; Bowen, E; Bozzi, C; Braun, S; Britton, T; Brodzicka, J; Brundu, D; Buchanan, E; Burr, C; Bursche, A; Buytaert, J; Byczynski, W; Cadeddu, S; Cai, H; Calabrese, R; Calladine, R; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D H; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carniti, P; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cavallero, G; Cenci, R; Chamont, D; Charles, M; Charpentier, Ph; Chatzikonstantinidis, G; Chefdeville, M; Chen, S; Cheung, S F; Chitic, S-G; Chobanova, V; Chrzaszcz, M; Chubykin, A; Ciambrone, P; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collins, P; Colombo, T; Comerma-Montells, A; Contu, A; Cook, A; Coombs, G; Coquereau, S; Corti, G; Corvo, M; Costa Sobral, C M; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A; Cruz Torres, M; Currie, R; D'Ambrosio, C; Da Cunha Marinho, F; Dall'Occo, E; Dalseno, J; Davis, A; De Aguiar Francisco, O; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Serio, M; De Simone, P; Dean, C T; Decamp, D; Del Buono, L; Dembinski, H-P; Demmer, M; Dendek, A; Derkach, D; Deschamps, O; Dettori, F; Dey, B; Di Canto, A; Di Nezza, P; Dijkstra, H; Dordei, F; Dorigo, M; Dosil Suárez, A; Douglas, L; Dovbnya, A; Dreimanis, K; Dufour, L; Dujany, G; Durante, P; Dzhelyadin, R; Dziewiecki, M; Dziurda, A; Dzyuba, A; Easo, S; Ebert, M; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; Ely, S; Esen, S; Evans, H M; Evans, T; Falabella, A; Farley, N; Farry, S; Fazzini, D; Federici, L; Ferguson, D; Fernandez, G; Fernandez Declara, P; Fernandez Prieto, A; Ferrari, F; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fini, R A; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fleuret, F; Fohl, K; Fontana, M; Fontanelli, F; Forshaw, D C; Forty, R; Franco Lima, V; Frank, M; Frei, C; Fu, J; Funk, W; Furfaro, E; Färber, C; Gabriel, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; Garcia Martin, L M; García Pardiñas, J; Garra Tico, J; Garrido, L; Garsed, P J; Gascon, D; Gaspar, C; Gavardi, L; Gazzoni, G; Gerick, D; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianì, S; Gibson, V; Girard, O G; Giubega, L; Gizdov, K; Gligorov, V V; Golubkov, D; Golutvin, A; Gomes, A; Gorelov, I V; Gotti, C; Govorkova, E; Grabowski, J P; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Greim, R; Griffith, P; Grillo, L; Gruber, L; Gruberg Cazon, B R; Grünberg, O; Gushchin, E; Guz, Yu; Gys, T; Göbel, C; Hadavizadeh, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hamilton, B; Han, X; Hancock, T H; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hasse, C; Hatch, M; He, J; Hecker, M; Heinicke, K; Heister, A; Hennessy, K; Henrard, P; Henry, L; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hombach, C; Hopchev, P H; Huard, Z C; Hulsbergen, W; Humair, T; Hushchyn, M; Hutchcroft, D; Ibis, P; Idzik, M; Ilten, P; Jacobsson, R; Jalocha, J; Jans, E; Jawahery, A; Jiang, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Karacson, M; Kariuki, J M; Karodia, S; Kazeev, N; Kecke, M; Kelsey, M; Kenzie, M; Ketel, T; Khairullin, E; Khanji, B; Khurewathanakul, C; Kirn, T; Klaver, S; Klimaszewski, K; Klimkovich, T; Koliiev, S; Kolpin, M; Komarov, I; Kopecna, R; Koppenburg, P; Kosmyntseva, A; Kotriakhova, S; Kozeiha, M; Kravchuk, L; Kreps, M; Krokovny, P; Kruse, F; Krzemien, W; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kuonen, A K; Kurek, K; Kvaratskheliya, T; Lacarrere, D; Lafferty, G; Lai, A; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; Leflat, A; Lefrançois, J; Lefèvre, R; Lemaitre, F; Lemos Cid, E; Leroy, O; Lesiak, T; Leverington, B; Li, P-R; Li, T; Li, Y; Li, Z; Likhomanenko, T; Lindner, R; Lionetto, F; Lisovskyi, V; Liu, X; Loh, D; Loi, A; Longstaff, I; Lopes, J H; Lucchesi, D; Lucio Martinez, M; Luo, H; Lupato, A; Luppi, E; Lupton, O; Lusiani, A; Lyu, X; Machefert, F; Maciuc, F; Macko, V; Mackowiak, P; Maddrell-Mander, S; Maev, O; Maguire, K; Maisuzenko, D; Majewski, M W; Malde, S; Malinin, A; Maltsev, T; Manca, G; Mancinelli, G; Manning, P; Marangotto, D; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marinangeli, M; Marino, P; Marks, J; Martellotti, G; Martin, M; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massacrier, L M; Massafferri, A; Matev, R; Mathad, A; Mathe, Z; Matteuzzi, C; Mauri, A; Maurice, E; Maurin, B; Mazurov, A; McCann, M; McNab, A; McNulty, R; Mead, J V; Meadows, B; Meaux, C; Meier, F; Meinert, N; Melnychuk, D; Merk, M; Merli, A; Michielin, E; Milanes, D A; Millard, E; Minard, M-N; Minzoni, L; Mitzel, D S; Mogini, A; Molina Rodriguez, J; Mombacher, T; Monroy, I A; Monteil, S; Morandin, M; Morello, M J; Morgunova, O; Moron, J; Morris, A B; Mountain, R; Muheim, F; Mulder, M; Müller, D; Müller, J; Müller, K; Müller, V; Naik, P; Nakada, T; Nandakumar, R; Nandi, A; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, T D; Nguyen-Mau, C; Nieswand, S; Niet, R; Nikitin, N; Nikodem, T; Nogay, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Ogilvy, S; Oldeman, R; Onderwater, C J G; Ossowska, A; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pais, P R; Palano, A; Palutan, M; Papanestis, A; Pappagallo, M; Pappalardo, L L; Parker, W; Parkes, C; Passaleva, G; Pastore, A; Patel, M; Patrignani, C; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perret, P; Pescatore, L; Petridis, K; Petrolini, A; Petrov, A; Petruzzo, M; Picatoste Olloqui, E; Pietrzyk, B; Pikies, M; Pinci, D; Pistone, A; Piucci, A; Placinta, V; Playfer, S; Plo Casasus, M; Polci, F; Poli Lener, M; Poluektov, A; Polyakov, I; Polycarpo, E; Pomery, G J; Ponce, S; Popov, A; Popov, D; Poslavskii, S; Potterat, C; Price, E; Prisciandaro, J; Prouve, C; Pugatch, V; Puig Navarro, A; Pullen, H; Punzi, G; Qian, W; Quagliani, R; Quintana, B; Rachwal, B; Rademacker, J H; Rama, M; Ramos Pernas, M; Rangel, M S; Raniuk, I; Ratnikov, F; Raven, G; Ravonel Salzgeber, M; Reboud, M; Redi, F; Reichert, S; Dos Reis, A C; Remon Alepuz, C; Renaudin, V; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Robert, A; Rodrigues, A B; Rodrigues, E; Rodriguez Lopez, J A; Rodriguez Perez, P; Rogozhnikov, A; Roiser, S; Rollings, A; Romanovskiy, V; Romero Vidal, A; Ronayne, J W; Rotondo, M; Rudolph, M S; Ruf, T; Ruiz Valls, P; Ruiz Vidal, J; Saborido Silva, J J; Sadykhov, E; Sagidova, N; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santimaria, M; Santovetti, E; Sarpis, G; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrina, D; Schael, S; Schellenberg, M; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmelzer, T; Schmidt, B; Schneider, O; Schopper, A; Schreiner, H F; Schubert, K; Schubiger, M; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Semennikov, A; Sepulveda, E S; Sergi, A; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Siddi, B G; Silva Coutinho, R; Silva de Oliveira, L; Simi, G; Simone, S; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, E; Smith, I T; Smith, J; Smith, M; Soares Lavra, L; Sokoloff, M D; Soler, F J P; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Stefko, P; Stefkova, S; Steinkamp, O; Stemmle, S; Stenyakin, O; Stepanova, M; Stevens, H; Stone, S; Storaci, B; Stracka, S; Stramaglia, M E; Straticiuc, M; Straumann, U; Sun, J; Sun, L; Sutcliffe, W; Swientek, K; Syropoulos, V; Szczekowski, M; Szumlak, T; Szymanski, M; T'Jampens, S; Tayduganov, A; Tekampe, T; Tellarini, G; Teubert, F; Thomas, E; van Tilburg, J; Tilley, M J; Tisserand, V; Tobin, M; Tolk, S; Tomassetti, L; Tonelli, D; Toriello, F; Tourinho Jadallah Aoude, R; Tournefier, E; Traill, M; Tran, M T; Tresch, M; Trisovic, A; Tsaregorodtsev, A; Tsopelas, P; Tully, A; Tuning, N; Ukleja, A; Usachov, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagner, A; Vagnoni, V; Valassi, A; Valat, S; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; van Veghel, M; Velthuis, J J; Veltri, M; Veneziano, G; Venkateswaran, A; Verlage, T A; Vernet, M; Vesterinen, M; Viana Barbosa, J V; Viaud, B; Vieira, D; Vieites Diaz, M; Viemann, H; Vilasis-Cardona, X; Vitti, M; Volkov, V; Vollhardt, A; Voneki, B; Vorobyev, A; Vorobyev, V; Voß, C; de Vries, J A; Vázquez Sierra, C; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wang, J; Ward, D R; Wark, H M; Watson, N K; Websdale, D; Weiden, A; Whitehead, M; Wicht, J; Wilkinson, G; Wilkinson, M; Williams, M; Williams, M P; Williams, M; Williams, T; Wilson, F F; Wimberley, J; Winn, M; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wraight, K; Wyllie, K; Xie, Y; Xu, Z; Yang, Z; Yang, Z; Yao, Y; Yin, H; Yu, J; Yuan, X; Yushchenko, O; Zarebski, K A; Zavertyaev, M; Zhang, L; Zhang, Y; Zhelezov, A; Zheng, Y; Zhu, X; Zhukov, V; Zonneveld, J B; Zucchelli, S

2017-11-03

A search for baryon-number violating Ξ_{b}^{0} oscillations is performed with a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3  fb^{-1}. The baryon number at the moment of production is identified by requiring that the Ξ_{b}^{0} come from the decay of a resonance Ξ_{b}^{*-}→Ξ_{b}^{0}π^{-} or Ξ_{b}^{'-}→Ξ_{b}^{0}π^{-}, and the baryon number at the moment of decay is identified from the final state using the decays Ξ_{b}^{0}→Ξ_{c}^{+}π^{-},Ξ_{c}^{+}→pK^{-}π^{+}. No evidence of baryon-number violation is found, and an upper limit at the 95% confidence level is set on the oscillation rate of ω<0.08  ps^{-1}, where ω is the associated angular frequency.

The Universe Adventure - What is Dark Matter?

Science.gov Websites

scientists today believe to be Dark Matter (DM). In fact, DM is most probably non-baryonic, meaning it does , scientists are convinced that 70-90% of matter in The Universe is non-baryonic DM and that ordinary luminous the Universe's matter must be non-baryonic dark matter. The degree to which light is bent by galaxies

D-Wave Heavy Baryons from QCD Sum Rules

NASA Astrophysics Data System (ADS)

Mao, Qiang; Chen, Hua-Xing; Hosaka, Atsushi; Liu, Xiang; Zhu, Shi-Lin

We study the D-wave heavy baryons using the method of QCD sum rules in the framework of heavy quark effective theory. Our results suggest that the Λc(2860), Λc(2880), Ξc(3055) and Ξc(3080) complete two D-wave SU(3) flavor 3¯F charmed baryon doublets of JP = 3/2+ and 5/2+.

String junction as a baryonic constituent

NASA Astrophysics Data System (ADS)

Kalashnikova, Yu. S.; Nefediev, A. V.

1996-02-01

We extend the model for QCD string with quarks to consider the Mercedes Benz string configuration describing the three-quark baryon. Under the assumption of adiabatic separation of quark and string junction motion we formulate and solve the classical equation of motion for the junction. We dare to quantize the motion of the junction, and discuss the impact of these modes on the baryon spectra.

Triple product asymmetries in Λ b and Ξ 0 b decays

DOE PAGES

Gronau, Michael; Rosner, Jonathan L.

2015-07-28

In this study, the LHCb experiment is capable of studying four-body decays of the b-flavored baryons Λ b and Ξ 0 b to charmless final states consisting of charged pions, kaons, and baryons. We remark on the search in such modes for CP-violating triple product asymmetries and for CP rate asymmetries relative to decays involving charmed baryons.

Second feature of the matter two-point function

NASA Astrophysics Data System (ADS)

Tansella, Vittorio

2018-05-01

We point out the existence of a second feature in the matter two-point function, besides the acoustic peak, due to the baryon-baryon correlation in the early Universe and positioned at twice the distance of the peak. We discuss how the existence of this feature is implied by the well-known heuristic argument that explains the baryon bump in the correlation function. A standard χ2 analysis to estimate the detection significance of the second feature is mimicked. We conclude that, for realistic values of the baryon density, a SKA-like galaxy survey will not be able to detect this feature with standard correlation function analysis.

Modelling baryonic effects on galaxy cluster mass profiles

NASA Astrophysics Data System (ADS)

Shirasaki, Masato; Lau, Erwin T.; Nagai, Daisuke

2018-06-01

Gravitational lensing is a powerful probe of the mass distribution of galaxy clusters and cosmology. However, accurate measurements of the cluster mass profiles are limited by uncertainties in cluster astrophysics. In this work, we present a physically motivated model of baryonic effects on the cluster mass profiles, which self-consistently takes into account the impact of baryons on the concentration as well as mass accretion histories of galaxy clusters. We calibrate this model using the Omega500 hydrodynamical cosmological simulations of galaxy clusters with varying baryonic physics. Our model will enable us to simultaneously constrain cluster mass, concentration, and cosmological parameters using stacked weak lensing measurements from upcoming optical cluster surveys.

Baryon chiral perturbation theory combined with the 1 / N c expansion in SU(3): Framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernando, I. P.; Goity, J. L.

Baryon Chiral Perturbation Theory combined with themore » $$1/N_c$$ expansion is implemented for three flavors. Here, Baryon masses, vector charges and axial vector couplings are studied to one-loop and organized according to the $$\\xi$$-expansion, in which the $$1/N_c$$ and the low energy power countings are linked according to $$1/N_c={\\cal{O}}(\\xi)={\\cal{O}}(p)$$. The renormalization to $${\\cal{O}}(\\xi^3)$$ necessary for the mentioned observables is provided, along with applications to the baryon masses and axial couplings as obtained in lattice QCD calculations.« less

Baryon chiral perturbation theory combined with the 1 / N c expansion in SU(3): Framework

DOE PAGES

Fernando, I. P.; Goity, J. L.

2018-03-14

Baryon Chiral Perturbation Theory combined with themore » $$1/N_c$$ expansion is implemented for three flavors. Here, Baryon masses, vector charges and axial vector couplings are studied to one-loop and organized according to the $$\\xi$$-expansion, in which the $$1/N_c$$ and the low energy power countings are linked according to $$1/N_c={\\cal{O}}(\\xi)={\\cal{O}}(p)$$. The renormalization to $${\\cal{O}}(\\xi^3)$$ necessary for the mentioned observables is provided, along with applications to the baryon masses and axial couplings as obtained in lattice QCD calculations.« less

Searches for the baryon- and lepton-number violating decays B0→Λc+l-, B-→Λl-, and B-→Λ¯l-

NASA Astrophysics Data System (ADS)

Del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Osipenkov, I. L.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Curry, S.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Meadows, B. T.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Jasper, H.; Petzold, A.; Spaan, B.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Fioravanti, E.; Franchini, P.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Marks, J.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Volk, A.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Crawley, H. B.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Firmino da Costa, J.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Perez, A.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wang, L.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Anderson, J.; Cenci, R.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Sciolla, G.; Zhao, M.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; de Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; Losecco, J. M.; Wang, W. F.; Corwin, L. A.; Honscheid, K.; Kass, R.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Prendki, J.; Sitt, S.; Biasini, M.; Manoni, E.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Baracchini, E.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Renga, F.; Buenger, C.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Allen, M. T.; Aston, D.; Bard, D. J.; Bartoldus, R.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Li, S.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; Macfarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; O'Grady, C. P.; Ofte, I.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Santoro, V.; Schindler, R. H.; Schwiening, J.; Snyder, A.; Su, D.; Sullivan, M. K.; Sun, S.; Suzuki, K.; Thompson, J. M.; Va'Vra, J.; Wagner, A. P.; Weaver, M.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Yarritu, A. K.; Young, C. C.; Ziegler, V.; Chen, X. R.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Miyashita, T. S.; Ahmed, S.; Alam, M. S.; Ernst, J. A.; Pan, B.; Saeed, M. A.; Zain, S. B.; Guttman, N.; Soffer, A.; Lund, P.; Spanier, S. M.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Schilling, C. J.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; Gamba, D.; Pelliccioni, M.; Lanceri, L.; Vitale, L.; Lopez-March, N.; Martinez-Vidal, F.; Oyanguren, A.; Ahmed, H.; Albert, J.; Banerjee, Sw.; Choi, H. H. F.; Hamano, K.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Lindsay, C.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Puccio, E. M. T.; Band, H. R.; Dasu, S.; Flood, K. T.; Pan, Y.; Prepost, R.; Vuosalo, C. O.; Wu, S. L.

2011-05-01

Searches for B mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either Λc or Λ and the lepton is a muon or an electron. These decays violate both baryon and lepton number and would be a signature of physics beyond the standard model. No significant signal is observed in any of the decay modes, and upper limits in the range (3.2-520)×10-8 are set on the branching fractions at the 90% confidence level.

QCD sum rules study of meson-baryon sigma terms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erkol, Gueray; Oka, Makoto; Turan, Guersevil

2008-11-01

The pion-baryon sigma terms and the strange-quark condensates of the octet and the decuplet baryons are calculated by employing the method of QCD sum rules. We evaluate the vacuum-to-vacuum transition matrix elements of two baryon interpolating fields in an external isoscalar-scalar field and use a Monte Carlo-based approach to systematically analyze the sum rules and the uncertainties in the results. We extract the ratios of the sigma terms, which have rather high accuracy and minimal dependence on QCD parameters. We discuss the sources of uncertainties and comment on possible strangeness content of the nucleon and the Delta.

Coupled-channel approach to strangeness S = -2 baryon-bayron interactions in lattice QCD

NASA Astrophysics Data System (ADS)

Sasaki, Kenji; Aoki, Sinya; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Ishii, Noriyoshi; Murano, Keiko

2015-11-01

Baryon-baryon interactions with strangeness S=-2 with flavor SU(3) breaking are calculated for the first time by using the HAL QCD method extended to the coupled-channel system in lattice QCD. The potential matrices are extracted from the Nambu-Bethe-Salpeter wave functions obtained by the 2+1-flavor gauge configurations of the CP-PACS/JLQCD Collaborations with a physical volume of (1.93 fm)^3 and with m_{π }/m_K=0.96, 0.90, 0.86. The spatial structure and the quark mass dependence of the potential matrix in the baryon basis and in the SU(3) basis are investigated.

Color breaking baryogenesis

NASA Astrophysics Data System (ADS)

Ramsey-Musolf, Michael J.; White, Graham; Winslow, Peter

2018-06-01

We propose a scenario that generates the observed baryon asymmetry of the Universe through a multistep phase transition in which SU(3) color symmetry is first broken and then restored. A spontaneous violation of B -L conservation leads to a contribution to the baryon asymmetry that becomes negligible in the final phase. The baryon asymmetry is therefore produced exclusively through the electroweak mechanism in the intermediate phase. We illustrate this scenario with a simple model that reproduces the observed baryon asymmetry. We discuss how future electric dipole moment and collider searches may probe this scenario, though future electric dipole moment searches would require an improved sensitivity of several orders of magnitude.

Baryon asymmetry from hypermagnetic helicity in dilaton hypercharge electromagnetism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bamba, Kazuharu

2006-12-15

The generation of the baryon asymmetry of the Universe from the hypermagnetic helicity, the physical interpretation of which is given in terms of hypermagnetic knots, is studied in inflationary cosmology, taking into account the breaking of the conformal invariance of hypercharge electromagnetic fields through both a coupling with the dilaton and with a pseudoscalar field. It is shown that, if the electroweak phase transition is strongly first order and the present amplitude of the generated magnetic fields on the horizon scale is sufficiently large, a baryon asymmetry with a sufficient magnitude to account for the observed baryon-to-entropy ratio can bemore » generated.« less

Regge Trajectories of triply heavy baryons

NASA Astrophysics Data System (ADS)

Rai, Ajay Kumar; Shah, Zalak

2017-12-01

Ω ccc , Ω bbb , Ω bcc and Ω ccb baryons are considerable theoretical interest in a baryonic analogue of heavy quarkonium because of the color-singlet bound state of three heavy quark (c,b) combination inside. Regge trajectories are concerned with the mass spectrum of the particles so that the present study exhibits the regge trajectories obtained from excited states of four experimentally unknown triply heavy Ω baryons. The trajectories are plotted in (n, M 2) and (J, M 2) planes which are helpful to determine the unknown quantum number and JP values. The calculations have computed in Hypercentral Constituent Quark Model with hyper coulomb plus linear potential.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crede, Volker; Roberts, Winston

The composite nature of baryons manifests itself in the existence of a rich spectrum of excited states, in particular in the important mass region 1?2 GeV for the light-flavoured baryons. The properties of these resonances can be identified by systematic investigations using electromagnetic and strong probes, primarily with beams of electrons, photons, and pions. After decades of research, the fundamental degrees of freedom underlying the baryon excitation spectrum are still poorly understood. The search for hitherto undiscovered but predicted resonances continues at many laboratories around the world. Recent results from photo- and electroproduction experiments provide intriguing indications for new statesmore » and shed light on the structure of some of the known nucleon excitations. The continuing study of available data sets with consideration of new observables and improved analysis tools have also called into question some of the earlier findings in baryon spectroscopy. Other breakthrough measurements have been performed in the heavy-baryon sector, which has seen a fruitful period in recent years, in particular at the B factories and the Tevatron. First results from the large hadron collider indicate rapid progress in the field of bottom baryons. In this review, we discuss the recent experimental progress and give an overview of theoretical approaches.« less

The impact of baryonic discs on the shapes and profiles of self-interacting dark matter halos

NASA Astrophysics Data System (ADS)

Sameie, Omid; Creasey, Peter; Yu, Hai-Bo; Sales, Laura V.; Vogelsberger, Mark; Zavala, Jesús

2018-06-01

We employ isolated N-body simulations to study the response of self-interacting dark matter (SIDM) halos in the presence of the baryonic potentials. Dark matter self-interactions lead to kinematic thermalization in the inner halo, resulting in a tight correlation between the dark matter and baryon distributions. A deep baryonic potential shortens the phase of SIDM core expansion and triggers core contraction. This effect can be further enhanced by a large self-scattering cross section. We find the final SIDM density profile is sensitive to the baryonic concentration and the strength of dark matter self-interactions. Assuming a spherical initial halo, we also study evolution of the SIDM halo shape together with the density profile. The halo shape at later epochs deviates from spherical symmetry due to the influence of the non-spherical disc potential, and its significance depends on the baryonic contribution to the total gravitational potential, relative to the dark matter one. In addition, we construct a multi-component model for the Milky Way, including an SIDM halo, a stellar disc and a bulge, and show it is consistent with observations from stellar kinematics and streams.

Spectrum and Structure of Excited Baryons with CLAS

NASA Astrophysics Data System (ADS)

Burkert, Volker D.

2017-01-01

In this contribution I discuss recent results in light quark baryon spectroscopy involving CLAS data and higher level analysis results from the partial wave analysis by the Bonn-Gatchina group. New baryon states were discovered largely based on the open strangeness production channels γp → K+Λ and γp → K+Σ0. The data illustrate the great potential of the kaon-hyperon channel in the discovery of higher mass baryon resonances in s-channel production. Other channels with discovery potential, such as γp → pω and γp → ϕp are also discussed. In the second part I will demonstrate on data the sensitivity of meson electroproduction to expose the active degrees of freedom underlying resonance transitions as a function of the probed distance scale. For several of the prominent excited states in the lower mass range the short distance behavior is described by a core of three dressed-quarks with running quark mass, and meson-baryon contributions make up significant parts of the excitation strength at large distances. Finally, I give an outlook of baryon resonance physics at the 12 GeV CEBAF electron accelerator. Talk presented at the CRC-16 Symposium, Bonn University, June 6-9, 2016.

Peripheral transverse densities of the baryon octet from chiral effective field theory and dispersion analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alarcón, J. M.; Hiller Blin, A. N.; Vicente Vacas, M. J.

2017-05-08

The baryon electromagnetic form factors are expressed in terms of two-dimensional densities describing the distribution of charge and magnetization in transverse space at fixed light-front time. In this paper, we calculate the transverse densities of the spin-1/2 flavor-octet baryons at peripheral distances b=O(Mmore » $$-1\\atop{π}$$) using methods of relativistic chiral effective field theory (χ EFT) and dispersion analysis. The densities are represented as dispersive integrals over the imaginary parts of the form factors in the timelike region (spectral functions). The isovector spectral functions on the two-pion cut t > 4 M$$2\\atop{π}$$ are calculated using relativistic χEFT including octet and decuplet baryons. The χEFT calculations are extended into the ρ meson mass region using an N/D method that incorporates the pion electromagnetic form factor data. The isoscalar spectral functions are modeled by vector meson poles. We compute the peripheral charge and magnetization densities in the octet baryon states, estimate the uncertainties, and determine the quark flavor decomposition. Finally, the approach can be extended to baryon form factors of other operators and the moments of generalized parton distributions.« less

Freeze-out of baryon number in low-scale leptogenesis

NASA Astrophysics Data System (ADS)

Eijima, S.; Shaposhnikov, M.; Timiryasov, I.

2017-11-01

Low-scale leptogenesis provides an economic and testable description of the origin of the baryon asymmetry of the Universe. In this scenario, the baryon asymmetry of the Universe is reprocessed from the lepton asymmetry by electroweak sphaleron processes. Provided that sphalerons are fast enough to maintain equilibrium, the values of the baryon and lepton asymmetries are related to each other. Usually, this relation is used to find the value of the baryon asymmetry at the time of the sphaleron freeze-out. To put in other words, the formula which is valid only when the sphalerons are fast, is applied at the moment when they are actually switched off. In this paper, we examine the validity of such a treatment. To this end, we solve the full system of kinetic equations for low-scale leptogenesis. This system includes equations describing the production of the lepton asymmetry in oscillations of right-handed neutrinos, as well as a separate kinetic equation for the baryon asymmetry. We show that for some values of the model parameters, the corrections to the standard approach are sizeable. We also present a feasible improvement to the ordinary procedure, which accounts for these corrections.

Baryon masses and axial couplings in the combined 1/N{sub c} and Chiral expansions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alvaro Calle Cordon, Jose Goity

The effective theory for baryons with a combined 1/N{sub c} and chiral expansions is analyzed for non-strange baryons. Results for baryon masses and axial couplings are obtained in the small scale expansion, to be coined as the {xi}-expansion, in which the 1/N{sub c} and the low energy power countings are linked according to 1/N{sub c}=O({xi})=O(p). Masses and axial couplings are analyzed to O({xi}{sup 3}) and O({xi}{sup 2}) respectively, which correspond to next-to-next to leading order evaluations, and require one-loop contributions in the effective theory. The role of the spin-flavor approximate symmetry in baryons, consequence of the large N{sub c} limit,more » is manifested in the physical world with N{sub c}=3 in a significant way, as the analysis of its breaking in the masses and the axial couplings show. Applications to the recent lattice QCD results on baryon masses and the nucleon's axial coupling are presented. It is shown that those results are naturally described within the effective theory at the order considered in the {xi}-expansion.« less

Galaxy Clusters: A Novel Look at Diffuse Baryons Withstanding Dark Matter Gravity

NASA Astrophysics Data System (ADS)

Cavaliere, A.; Lapi, A.; Fusco-Femiano, R.

2009-06-01

In galaxy clusters, the equilibria of the intracluster plasma (ICP) and of the gravitationally dominant dark matter (DM) are governed by the hydrostatic equation and by the Jeans equation, respectively; in either case gravity is withstood by the corresponding, entropy-modulated pressure. Jeans, with the DM "entropy" set to K vprop r α and α ≈ 1.25-1.3 applying from groups to rich clusters, yields our radial α-profiles these, compared to the empirical Navarro-Frenk-White distribution, are flatter at the center and steeper in the outskirts as required by recent gravitational lensing data. In the ICP, on the other hand, the entropy run k(r) is mainly shaped by shocks, as steadily set by supersonic accretion of gas at the cluster boundary, and intermittently driven from the center by merging events or by active galactic nuclei (AGNs); the resulting equilibrium is described by the exact yet simple formalism constituting our ICP Supermodel. With two parameters, this accurately represents the runs of density n(r) and temperature T(r) as required by up-to-date X-ray data on surface brightness and spectroscopy for both cool core (CC) and non-cool core (NCC) clusters; the former are marked by a middle temperature peak, whose location is predicted from rich clusters to groups. The Supermodel inversely links the inner runs of n(r) and T(r), and highlights their central scaling with entropy nc vprop k -1 c and Tc vprop k 0.35 c , to yield radiative cooling times tc ≈ 0.3(kc /15 keV cm2)1.2 Gyr. We discuss the stability of the central values so focused: against radiative erosion of kc in the cool dense conditions of CC clusters, that triggers recurrent AGN activities resetting it back; or against energy inputs from AGNs and mergers whose effects are saturated by the hot central conditions of NCC clusters. From the Supermodel, we also derive as limiting cases the classic polytropic β-models, and the "mirror" model with T(r) vprop σ2(r) suitable for NCC and CC clusters, respectively; these limiting cases highlight how the ICP temperature T(r) strives to mirror the DM velocity dispersion σ2(r) away from energy and entropy injections. Finally, we discuss how the Supermodel connects information derived from X-ray and gravitational lensing observations.

ROSAT observations of compact groups of galaxies

NASA Technical Reports Server (NTRS)

Pildis, Rachel A.; Bregman, Joel N.; Evrard, August E.

1995-01-01

We have systematically analyzed a sample of 13 new and archival ROSAT Position Sensitive Proportional Counter (PSPC) observations of compact groups of galaxies: 12 Hickson compact groups plus the NCG 2300 group. We find that approximately two-thirds of the groups have extended X-ray emission and, in four of these, the emission is resolved into diffuse emission from gas at a temperature of kT approximately 1 keV in the group potential. All but one of the groups with extended emission have a spiral fraction of less than 50%. The baryon fraction of groups with diffuse emission is 5%-19%, similar to the values in clusters of galaxies. However, with a single exception (HCG 62), the gas-to-stellar mass ratio in our groups has a median value near 5%, somewhat greater than the values for individual early-type galaxies and two orders of magnitude than in clusters of galaxies. The X-ray luminosities of individual group galaxies are comparable to those of similar field galaxies, although the L(sub X)-L(sub B) relation for early-type galaxies may be flatter in compact groups than in the field.

Investigation of microstructural changes in polyetherether-ketone films at cryogenic temperatures by positron lifetime spectroscopy

NASA Technical Reports Server (NTRS)

Singh, Jag J.; Eftekhari, Abe; St.clair, Terry L.; Sprinkle, Danny R.

1991-01-01

Microstructural changes in Polyetherether-ketone (PEEK) films were investigated in the temperature ranges of 23 to -196 C, using Positron Lifetime Spectroscopy (PLS) technique. It was determined that the total free volume decreases by about 46 percent in amorphous PEEK samples and about 36 percent in semicrystalline PEEK samples when they are cooled down from room temperature to liquid nitrogen (LN2) temperature. If this trend in reduction in free volume with decreasing temperature continues, as expected, it is surmised that PEEK will be able to withstand cooling down to liquid hydrogen (LH2) temperature without any detrimental effect on its diffusivity for liquid hydrogen.

Can a large neutron excess help solve the baryon loading problem in gamma-Ray burst fireballs?

PubMed

Fuller; Pruet; Abazajian

2000-09-25

We point out that the baryon loading problem in gamma-ray burst (GRB) models can be ameliorated if a significant fraction of the baryons which inertially confine the fireball is converted to neutrons. A high neutron fraction can result in a reduced transfer of energy from relativistic light particles in the fireball to baryons. The energy needed to produce the required relativistic flow in the GRB is consequently reduced, in some cases by orders of magnitude. A high neutron-to-proton ratio has been calculated in neutron star-merger fireball environments. Significant neutron excess also could occur near compact objects with high neutrino fluxes.

Establishing low-lying doubly charmed baryons

NASA Astrophysics Data System (ADS)

Chen, Hua-Xing; Mao, Qiang; Chen, Wei; Liu, Xiang; Zhu, Shi-Lin

2017-08-01

We systematically study the S -wave doubly charmed baryons using the method of QCD sum rules. Our results suggest that the Ξcc ++ recently observed by LHCb can be well identified as the S -wave Ξc c state of JP=1 /2+. We study its relevant Ωc c state, the mass of which is predicted to be around 3.7 GeV. We also systematically study the P -wave doubly charmed baryons, the masses of which are predicted to be around 4.1 GeV. Especially, there can be several excited doubly charmed baryons in this energy region, and we suggest searching for them in order to study the fine structure of the strong interaction.

Gravitational baryogenesis in running vacuum models

NASA Astrophysics Data System (ADS)

Oikonomou, V. K.; Pan, Supriya; Nunes, Rafael C.

2017-08-01

We study the gravitational baryogenesis mechanism for generating baryon asymmetry in the context of running vacuum models. Regardless of whether these models can produce a viable cosmological evolution, we demonstrate that they produce a nonzero baryon-to-entropy ratio even if the universe is filled with conformal matter. This is a sound difference between the running vacuum gravitational baryogenesis and the Einstein-Hilbert one, since in the latter case, the predicted baryon-to-entropy ratio is zero. We consider two well known and most used running vacuum models and show that the resulting baryon-to-entropy ratio is compatible with the observational data. Moreover, we also show that the mechanism of gravitational baryogenesis may constrain the running vacuum models.

Large Nc equivalence and baryons

NASA Astrophysics Data System (ADS)

Blake, Mike; Cherman, Aleksey

2012-09-01

In the large Nc limit, gauge theories with different gauge groups and matter content sometimes turn out to be “large Nc equivalent,” in the sense of having a set of coincident correlation functions. Large Nc equivalence has mainly been explored in the glueball and meson sectors. However, a recent proposal to dodge the fermion sign problem of QCD with a quark number chemical potential using large Nc equivalence motivates investigating the applicability of large Nc equivalence to correlation functions involving baryon operators. Here we present evidence that large Nc equivalence extends to the baryon sector, under the same type of symmetry realization assumptions as in the meson sector, by adapting the classic Witten analysis of large Nc baryons.

Baryonic Higgs at the LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duerr, Michael; Perez, Pavel Fileviez; Smirnov, Juri

We investigate the possible collider signatures of a new Higgs in simple extensions of the Standard Model where baryon number is a local symmetry spontaneously broken at the low scale. Here, we refer to this new Higgs as “Baryonic Higgs”. This Higgs has peculiar properties since it can decay into all Standard Model particles, the leptophobic gauge boson, and the vector-like quarks present in these theories to ensure anomaly cancellation. We investigate in detail the constraints from the γγ, Zγ, ZZ, and W W searches at the Large Hadron Collider, needed to find a lower bound on the scale atmore » which baryon number is spontaneously broken. The di-photon channel turns out to be a very sensitive probe in the case of small scalar mixing and can severely constrain the baryonic scale. Finally, we also study the properties of the leptophobic gauge boson in order to understand the testability of these theories at the LHC.« less

Fluid dynamic propagation of initial baryon number perturbations on a Bjorken flow background

DOE PAGES

Floerchinger, Stefan; Martinez, Mauricio

2015-12-11

Baryon number density perturbations offer a possible route to experimentally measure baryon number susceptibilities and heat conductivity of the quark gluon plasma. We study the fluid dynamical evolution of local and event-by-event fluctuations of baryon number density, flow velocity, and energy density on top of a (generalized) Bjorken expansion. To that end we use a background-fluctuation splitting and a Bessel-Fourier decomposition for the fluctuating part of the fluid dynamical fields with respect to the azimuthal angle, the radius in the transverse plane, and rapidity. Here, we examine how the time evolution of linear perturbations depends on the equation of statemore » as well as on shear viscosity, bulk viscosity, and heat conductivity for modes with different azimuthal, radial, and rapidity wave numbers. Finally we discuss how this information is accessible to experiments in terms of the transverse and rapidity dependence of correlation functions for baryonic particles in high energy nuclear collisions.« less

Effect of finite particle number sampling on baryon number fluctuations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinheimer, Jan; Koch, Volker

The effects of finite particle number sampling on the net baryon number cumulants, extracted from fluid dynamical simulations, are studied. The commonly used finite particle number sampling procedure introduces an additional Poissonian (or multinomial if global baryon number conservation is enforced) contribution which increases the extracted moments of the baryon number distribution. If this procedure is applied to a fluctuating fluid dynamics framework, one severely overestimates the actual cumulants. We show that the sampling of so-called test particles suppresses the additional contribution to the moments by at least one power of the number of test particles. We demonstrate this methodmore » in a numerical fluid dynamics simulation that includes the effects of spinodal decomposition due to a first-order phase transition. Furthermore, in the limit where antibaryons can be ignored, we derive analytic formulas which capture exactly the effect of particle sampling on the baryon number cumulants. These formulas may be used to test the various numerical particle sampling algorithms.« less

Baryon inhomogeneity generation in the quark-gluon plasma phase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Layek, Biswanath; Mishra, Ananta P.; Srivastava, Ajit M.

2006-05-15

We discuss the possibility of generation of baryon inhomogeneities in a quark-gluon plasma phase due to moving Z(3) interfaces. By modeling the dependence of effective mass of the quarks on the Polyakov loop order parameter, we study the reflection of quarks from collapsing Z(3) interfaces and estimate resulting baryon inhomogeneities in the context of the early universe. We argue that in the context of certain low energy scale inflationary models, it is possible that large Z(3) walls arise at the end of the reheating stage. Collapse of such walls could lead to baryon inhomogeneities which may be separated by largemore » distances near the QCD scale. Importantly, the generation of these inhomogeneities is insensitive to the order, or even the existence, of the quark-hadron phase transition. We also briefly discuss the possibility of formation of quark nuggets in this model, as well as baryon inhomogeneity generation in relativistic heavy-ion collisions.« less

Particle formation and ordering in strongly correlated fermionic systems: Solving a model of quantum chromodynamics

DOE PAGES

Azaria, P.; Konik, R. M.; Lecheminant, P.; ...

2016-08-03

In our paper we study a (1+1)-dimensional version of the famous Nambu–Jona-Lasinio model of quantum chromodynamics (QCD2) both at zero and at finite baryon density. We use nonperturbative techniques (non-Abelian bosonization and the truncated conformal spectrum approach). When the baryon chemical potential, μ, is zero, we describe the formation of fermion three-quark (nucleons and Δ baryons) and boson (two-quark mesons, six-quark deuterons) bound states. We also study at μ=0 the formation of a topologically nontrivial phase. When the chemical potential exceeds the critical value and a finite baryon density appears, the model has a rich phase diagram which includes phasesmore » with a density wave and superfluid quasi-long-range (QLR) order, as well as a phase of a baryon Tomonaga-Luttinger liquid (strange metal). Finally, the QLR order results in either a condensation of scalar mesons (the density wave) or six-quark bound states (deuterons).« less

Effect of finite particle number sampling on baryon number fluctuations

DOE PAGES

Steinheimer, Jan; Koch, Volker

2017-09-28

The effects of finite particle number sampling on the net baryon number cumulants, extracted from fluid dynamical simulations, are studied. The commonly used finite particle number sampling procedure introduces an additional Poissonian (or multinomial if global baryon number conservation is enforced) contribution which increases the extracted moments of the baryon number distribution. If this procedure is applied to a fluctuating fluid dynamics framework, one severely overestimates the actual cumulants. We show that the sampling of so-called test particles suppresses the additional contribution to the moments by at least one power of the number of test particles. We demonstrate this methodmore » in a numerical fluid dynamics simulation that includes the effects of spinodal decomposition due to a first-order phase transition. Furthermore, in the limit where antibaryons can be ignored, we derive analytic formulas which capture exactly the effect of particle sampling on the baryon number cumulants. These formulas may be used to test the various numerical particle sampling algorithms.« less

Modified Baryonic Dynamics: two-component cosmological simulations with light sterile neutrinos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Angus, G.W.; Gentile, G.; Diaferio, A.

2014-10-01

In this article we continue to test cosmological models centred on Modified Newtonian Dynamics (MOND) with light sterile neutrinos, which could in principle be a way to solve the fine-tuning problems of the standard model on galaxy scales while preserving successful predictions on larger scales. Due to previous failures of the simple MOND cosmological model, here we test a speculative model where the modified gravitational field is produced only by the baryons and the sterile neutrinos produce a purely Newtonian field (hence Modified Baryonic Dynamics). We use two-component cosmological simulations to separate the baryonic N-body particles from the sterile neutrinomore » ones. The premise is to attenuate the over-production of massive galaxy cluster halos which were prevalent in the original MOND plus light sterile neutrinos scenario. Theoretical issues with such a formulation notwithstanding, the Modified Baryonic Dynamics model fails to produce the correct amplitude for the galaxy cluster mass function for any reasonable value of the primordial power spectrum normalisation.« less

Observation of an Exotic Baryon with S=+1 in Photoproduction from the Proton

NASA Astrophysics Data System (ADS)

Kubarovsky, V.; Guo, L.; Weygand, D. P.; Stoler, P.; Battaglieri, M.; Devita, R.; Adams, G.; Li, Ji; Nozar, M.; Salgado, C.; Ambrozewicz, P.; Anciant, E.; Anghinolfi, M.; Asavapibhop, B.; Audit, G.; Auger, T.; Avakian, H.; Bagdasaryan, H.; Ball, J. P.; Barrow, S.; Beard, K.; Bektasoglu, M.; Bellis, M.; Benmouna, N.; Berman, B. L.; Bianchi, N.; Biselli, A. S.; Boiarinov, S.; Bouchigny, S.; Bradford, R.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Butuceanu, C.; Calarco, J. R.; Carman, D. S.; Carnahan, B.; Cetina, C.; Chen, S.; Ciciani, L.; Cole, P. L.; Connelly, J.; Cords, D.; Corvisiero, P.; Crabb, D.; Crannell, H.; Cummings, J. P.; de Sanctis, E.; Degtyarenko, P. V.; Denizli, H.; Dennis, L.; Dharmawardane, K. V.; Djalali, C.; Dodge, G. E.; Doughty, D.; Dragovitsch, P.; Dugger, M.; Dytman, S.; Dzyubak, O. P.; Egiyan, H.; Egiyan, K. S.; Elouadrhiri, L.; Empl, A.; Eugenio, P.; Farhi, L.; Fatemi, R.; Feuerbach, R. J.; Ficenec, J.; Forest, T. A.; Frolov, V.; Funsten, H.; Gaff, S. J.; Garçon, M.; Gavalian, G.; Gilfoyle, G. P.; Giovanetti, K. L.; Girard, P.; Gothe, R.; Gordon, C. I.; Griffioen, K.; Guidal, M.; Guillo, M.; Gyurjyan, V.; Hadjidakis, C.; Hakobyan, R. S.; Hancock, D.; Hardie, J.; Heddle, D.; Heimberg, P.; Hersman, F. W.; Hicks, K.; Holtrop, M.; Hu, J.; Ilieva, Y.; Ito, M. M.; Jenkins, D.; Joo, K.; Juengst, H. G.; Kelley, J. H.; Khandaker, M.; Kim, K. Y.; Kim, K.; Kim, W.; Klein, F. J.; Klimenko, A. V.; Klusman, M.; Kossov, M.; Kramer, L. H.; Kuhn, S. E.; Kuhn, J.; Lachniet, J.; Laget, J. M.; Langheinrich, J.; Lawrence, D.; Longhi, A.; Lukashin, K.; Major, R. W.; Manak, J. J.; Marchand, C.; McAleer, S.; McNabb, J. W.; Mecking, B. A.; Mehrabyan, S.; Melone, J. J.; Mestayer, M. D.; Meyer, C. A.; Mikhailov, K.; Minehart, R.; Mirazita, M.; Miskimen, R.; Mokeev, V.; Morand, L.; Morrow, S. A.; Mozer, M. U.; Muccifora, V.; Mueller, J.; Mutchler, G. S.; Napolitano, J.; Nasseripour, R.; Nelson, S. O.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niczyporuk, B. B.; Niyazov, R. A.; O'Brien, J. T.; O'Rielly, G. V.; Opper, A. K.; Osipenko, M.; Park, K.; Pasyuk, E.; Peterson, G.; Philips, S. A.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Polli, E.; Pozdniakov, S.; Preedom, B. M.; Price, J. W.; Prok, Y.; Protopopescu, D.; Qin, L. M.; Raue, B. A.; Riccardi, G.; Ripani, M.; Ritchie, B. G.; Ronchetti, F.; Rossi, P.; Rowntree, D.; Rubin, P. D.; Sabatié, F.; Sabourov, K.; Santoro, J. P.; Sapunenko, V.; Sargsyan, M.; Schumacher, R. A.; Serov, V. S.; Shafi, A.; Sharabian, Y. G.; Shaw, J.; Simionatto, S.; Skabelin, A. V.; Smith, E. S.; Smith, T.; Smith, L. C.; Sober, D. I.; Spraker, M.; Stavinsky, A.; Stepanyan, S.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Taylor, S.; Tedeschi, D. J.; Thoma, U.; Thompson, R.; Todor, L.; Tur, C.; Ungaro, M.; Vineyard, M. F.; Vlassov, A. V.; Wang, K.; Weinstein, L. B.; Weisberg, A.; Whisnant, C. S.; Wolin, E.; Wood, M. H.; Yegneswaran, A.; Yun, J.

2004-01-01

The reaction γp→π+K-K+n was studied at Jefferson Laboratory using a tagged photon beam with an energy range of 3 5.47GeV. A narrow baryon state with strangeness S=+1 and mass M=1555±10 MeV/c2 was observed in the nK+ invariant mass spectrum. The peak’s width is consistent with the CLAS resolution (FWHM=26 MeV/c2), and its statistical significance is (7.8±1.0)σ. A baryon with positive strangeness has exotic structure and cannot be described in the framework of the naive constituent quark model. The mass of the observed state is consistent with the mass predicted by the chiral soliton model for the Θ+ baryon. In addition, the pK+ invariant mass distribution was analyzed in the reaction γp→K-K+p with high statistics in search of doubly charged exotic baryon states. No resonance structures were found in this spectrum.

Baryonic Higgs at the LHC

DOE PAGES

Duerr, Michael; Perez, Pavel Fileviez; Smirnov, Juri

2017-09-20

We investigate the possible collider signatures of a new Higgs in simple extensions of the Standard Model where baryon number is a local symmetry spontaneously broken at the low scale. Here, we refer to this new Higgs as “Baryonic Higgs”. This Higgs has peculiar properties since it can decay into all Standard Model particles, the leptophobic gauge boson, and the vector-like quarks present in these theories to ensure anomaly cancellation. We investigate in detail the constraints from the γγ, Zγ, ZZ, and W W searches at the Large Hadron Collider, needed to find a lower bound on the scale atmore » which baryon number is spontaneously broken. The di-photon channel turns out to be a very sensitive probe in the case of small scalar mixing and can severely constrain the baryonic scale. Finally, we also study the properties of the leptophobic gauge boson in order to understand the testability of these theories at the LHC.« less

The baryon vector current in the combined chiral and 1/Nc expansions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flores-Mendieta, Ruben; Goity, Jose L

2014-12-01

The baryon vector current is computed at one-loop order in large-Nc baryon chiral perturbation theory, where Nc is the number of colors. Loop graphs with octet and decuplet intermediate states are systematically incorporated into the analysis and the effects of the decuplet-octet mass difference and SU(3) flavor symmetry breaking are accounted for. There are large-Nc cancellations between different one-loop graphs as a consequence of the large-Nc spin-flavor symmetry of QCD baryons. The results are compared against the available experimental data through several fits in order to extract information about the unknown parameters. The large-Nc baryon chiral perturbation theory predictions aremore » in very good agreement both with the expectations from the 1/Nc expansion and with the experimental data. The effect of SU(3) flavor symmetry breaking for the |Delta S|=1 vector current form factors f1(0) results in a reduction by a few percent with respect to the corresponding SU(3) symmetric values.« less

Chiral symmetry and pentaquarks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dmitri Diakonov

2004-07-01

Spontaneous chiral symmetry breaking, mesons and baryons are illustrated in the language of the Dirac theory. Various forces acting between quarks inside baryons are discussed. I explain why the naive quark models typically overestimate pentaquark masses by some 500 MeV and why in the fully relativistic approach to baryons pentaquarks turn out to be light. I discuss briefly why it can be easier to produce pentaquarks at low than at high energies.

Baryon isocurvature scenario in inflationary cosmology - A particle physics model and its astrophysical implications

NASA Technical Reports Server (NTRS)

Yokoyama, Jun'ichi; Suto, Yasushi

1991-01-01

A phenomenological model to produce isocurvature baryon-number fluctuations is proposed in the framework of inflationary cosmology. The resulting spectrum of density fluctuation is very different from the conventional Harrison-Zel'dovich shape. The model, with the parameters satisfying several requirements from particle physics and cosmology, provides an appropriate initial condition for the minimal baryon isocurvature scenario of galaxy formation discussed by Peebles.

Balance of baryon number in the quark coalescence model

NASA Astrophysics Data System (ADS)

Bialas, A.; Rafelski, J.

2006-02-01

The charge and baryon balance functions are studied in the coalescence hadronization mechanism of quark-gluon plasma. Assuming that in the plasma phase the qqbar pairs form uncorrelated clusters whose decay is also uncorrelated, one can understand the observed small width of the charge balance function in the Gaussian approximation. The coalescence model predicts even smaller width of the baryon-antibaryon balance function: σBBbar /σ+ - =√{ 2 / 3 }.

Non-conservation of global charges in the Brane Universe and baryogenesis

NASA Astrophysics Data System (ADS)

Dvali, Gia; Gabadadze, Gregory

1999-08-01

We argue that global charges, such as baryon or lepton number, are not conserved in theories with the Standard Model fields localized on the brane which propagates in higher-dimensional space-time. The global-charge non-conservation is due to quantum fluctuations of the brane surface. These fluctuations create ``baby branes'' that can capture some global charges and carry them away into the bulk of higher-dimensional space. Such processes are exponentially suppressed at low-energies, but can be significant at high enough temperatures or energies. These effects can lead to a new, intrinsically high-dimensional mechanism of baryogenesis. Baryon asymmetry might be produced due either to ``evaporation'' into the baby branes, or creation of the baryon number excess in collisions of two Brane Universes. As an example we discuss a possible cosmological scenario within the recently proposed ``Brane Inflation'' framework. Inflation is driven by displaced branes which slowly fall on top of each other. When the branes collide inflation stops and the Brane Universe reheats. During this non-equilibrium collision baryon number can be transported from one brane to another one. This results in the baryon number excess in our Universe which exactly equals to the hidden ``baryon number'' deficit in the other Brane Universe. © 1999

Skewness and kurtosis of net baryon-number distributions at small values of the baryon chemical potential

DOE PAGES

Bazavov, A.; Ding, H. -T.; Hegde, P.; ...

2017-10-27

In this paper, we present results for the ratios of mean (M B), variance (σmore » $$2\\atop{B}$$), skewness (S B) and kurtosis (κ B) of net baryon-number fluctuations obtained in lattice QCD calculations with physical values of light and strange quark masses. Using next-to-leading order Taylor expansions in baryon chemical potential we find that qualitative features of these ratios closely resemble the corresponding experimentally measured cumulants ratios of net proton-number fluctuations for beam energies down to √sNN ≥ 19.6 GeV. We show that the difference in cumulant ratios for the mean net baryon-number, M B/σ$$2\\atop{B}$$ = χ$$B\\atop{1}$$ (T, µ B)/χ$$B\\atop{2}$$ (T, µ B) and the normalized skewness, S Bσ B = χ$$B\\atop{3}$$ (T, µB)/χ2 (T, µB ), nat-urally arises in QCD thermodynamics. Moreover, we establish a close relation between skewness and kurtosis ratios, S Bσ$$B\\atop{3}$$/M B = χ$$B\\atop{3}$$ (T, µ B)/χ$$B\\atop{1}$$ (T,µ B) and κ Bσ$$2\\atop{B}$$ = χ$$B\\atop{4}$$ (T,μ B)/χ$$B\\atop{2}$$ (T,μ B), valid at small values of the baryon chemical potential.« less

Skewness and kurtosis of net baryon-number distributions at small values of the baryon chemical potential

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bazavov, A.; Ding, H. -T.; Hegde, P.

In this paper, we present results for the ratios of mean (M B), variance (σmore » $$2\\atop{B}$$), skewness (S B) and kurtosis (κ B) of net baryon-number fluctuations obtained in lattice QCD calculations with physical values of light and strange quark masses. Using next-to-leading order Taylor expansions in baryon chemical potential we find that qualitative features of these ratios closely resemble the corresponding experimentally measured cumulants ratios of net proton-number fluctuations for beam energies down to √sNN ≥ 19.6 GeV. We show that the difference in cumulant ratios for the mean net baryon-number, M B/σ$$2\\atop{B}$$ = χ$$B\\atop{1}$$ (T, µ B)/χ$$B\\atop{2}$$ (T, µ B) and the normalized skewness, S Bσ B = χ$$B\\atop{3}$$ (T, µB)/χ2 (T, µB ), nat-urally arises in QCD thermodynamics. Moreover, we establish a close relation between skewness and kurtosis ratios, S Bσ$$B\\atop{3}$$/M B = χ$$B\\atop{3}$$ (T, µ B)/χ$$B\\atop{1}$$ (T,µ B) and κ Bσ$$2\\atop{B}$$ = χ$$B\\atop{4}$$ (T,μ B)/χ$$B\\atop{2}$$ (T,μ B), valid at small values of the baryon chemical potential.« less

Counts of galaxy clusters as cosmological probes: the impact of baryonic physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balaguera-Antolínez, Andrés; Porciani, Cristiano, E-mail: abalan@astro.uni-bonn.de, E-mail: porciani@astro.uni-bonn.de

2013-04-01

The halo mass function from N-body simulations of collisionless matter is generally used to retrieve cosmological parameters from observed counts of galaxy clusters. This neglects the observational fact that the baryonic mass fraction in clusters is a random variable that, on average, increases with the total mass (within an overdensity of 500). Considering a mock catalog that includes tens of thousands of galaxy clusters, as expected from the forthcoming generation of surveys, we show that the effect of a varying baryonic mass fraction will be observable with high statistical significance. The net effect is a change in the overall normalizationmore » of the cluster mass function and a milder modification of its shape. Our results indicate the necessity of taking into account baryonic corrections to the mass function if one wants to obtain unbiased estimates of the cosmological parameters from data of this quality. We introduce the formalism necessary to accomplish this goal. Our discussion is based on the conditional probability of finding a given value of the baryonic mass fraction for clusters of fixed total mass. Finally, we show that combining information from the cluster counts with measurements of the baryonic mass fraction in a small subsample of clusters (including only a few tens of objects) will nearly optimally constrain the cosmological parameters.« less

The mass discrepancy acceleration relation in a ΛCDM context

NASA Astrophysics Data System (ADS)

Di Cintio, Arianna; Lelli, Federico

2016-02-01

The mass discrepancy acceleration relation (MDAR) describes the coupling between baryons and dark matter (DM) in galaxies: the ratio of total-to-baryonic mass at a given radius anticorrelates with the acceleration due to baryons. The MDAR has been seen as a challenge to the Λ cold dark matter (ΛCDM) galaxy formation model, while it can be explained by Modified Newtonian Dynamics. In this Letter, we show that the MDAR arises in a ΛCDM cosmology once observed galaxy scaling relations are taken into account. We build semi-empirical models based on ΛCDM haloes, with and without the inclusion of baryonic effects, coupled to empirically motivated structural relations. Our models can reproduce the MDAR: specifically, a mass-dependent density profile for DM haloes can fully account for the observed MDAR shape, while a universal profile shows a discrepancy with the MDAR of dwarf galaxies with M⋆ < 109.5 M⊙, a further indication suggesting the existence of DM cores. Additionally, we reproduce slope and normalization of the baryonic Tully-Fisher relation (BTFR) with 0.17 dex scatter. These results imply that in ΛCDM (I) the MDAR is driven by structural scaling relations of galaxies and DM density profile shapes, and (II) the baryonic fractions determined by the BTFR are consistent with those inferred from abundance-matching studies.

Analytic prediction of baryonic effects from the EFT of large scale structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewandowski, Matthew; Perko, Ashley; Senatore, Leonardo, E-mail: mattlew@stanford.edu, E-mail: perko@stanford.edu, E-mail: senatore@stanford.edu

2015-05-01

The large scale structures of the universe will likely be the next leading source of cosmological information. It is therefore crucial to understand their behavior. The Effective Field Theory of Large Scale Structures provides a consistent way to perturbatively predict the clustering of dark matter at large distances. The fact that baryons move distances comparable to dark matter allows us to infer that baryons at large distances can be described in a similar formalism: the backreaction of short-distance non-linearities and of star-formation physics at long distances can be encapsulated in an effective stress tensor, characterized by a few parameters. Themore » functional form of baryonic effects can therefore be predicted. In the power spectrum the leading contribution goes as ∝ k{sup 2} P(k), with P(k) being the linear power spectrum and with the numerical prefactor depending on the details of the star-formation physics. We also perform the resummation of the contribution of the long-wavelength displacements, allowing us to consistently predict the effect of the relative motion of baryons and dark matter. We compare our predictions with simulations that contain several implementations of baryonic physics, finding percent agreement up to relatively high wavenumbers such as k ≅ 0.3 hMpc{sup −1} or k ≅ 0.6 hMpc{sup −1}, depending on the order of the calculation. Our results open a novel way to understand baryonic effects analytically, as well as to interface with simulations.« less

Baryon Budget of the Hot Circumgalactic Medium of Massive Spiral Galaxies

NASA Astrophysics Data System (ADS)

Li, Jiang-Tao; Bregman, Joel N.; Wang, Q. Daniel; Crain, Robert A.; Anderson, Michael E.

2018-03-01

The baryon content around local galaxies is observed to be much less than is needed in Big Bang nucleosynthesis. Simulations indicate that a significant fraction of these “missing baryons” may be stored in a hot tenuous circumgalactic medium (CGM) around massive galaxies extending to or even beyond the virial radius of their dark matter halos. Previous observations in X-ray and Sunyaev–Zel’dovich (SZ) signals claimed that ∼(1–50)% of the expected baryons are stored in a hot CGM within the virial radius. The large scatter is mainly caused by the very uncertain extrapolation of the hot gas density profile based on the detection in a small radial range (typically within 10%–20% of the virial radius). Here, we report stacking X-ray observations of six local isolated massive spiral galaxies from the CGM-MASS sample. We find that the mean density profile can be characterized by a single power law out to a galactocentric radius of ≈200 kpc (or ≈130 kpc above the 1σ background uncertainty), about half the virial radius of the dark matter halo. We can now estimate that the hot CGM within the virial radius accounts for (8 ± 4)% of the baryonic mass expected for the halos. Including the stars, the baryon fraction is (27 ± 16)%, or (39 ± 20)% by assuming a flattened density profile at r ≳ 130 kpc. We conclude that the hot baryons within the virial radius of massive galaxy halos are insufficient to explain the “missing baryons.”

Localized N, {lambda}, {sigma}, and {xi} single-particle potentials in finite nuclei calculated with SU{sub 6} quark-model baryon-baryon interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohno, M.; Fujiwara, Y.

Localized single-particle potentials for all octet baryons, N, {lambda}, {sigma}, and {xi}, in finite nuclei, {sup 12}C, {sup 16}O, {sup 28}Si, {sup 40}Ca, {sup 56}Fe, and {sup 90}Zr, are calculated using the quark-model baryon-baryon interactions. G matrices evaluated in symmetric nuclear matter in the lowest order Brueckner theory (LOBT) are applied to finite nuclei in local density approximation. Nonlocal potentials are localized by a zero-momentum Wigner transformation. Empirical single-particle properties of the nucleon and the {lambda} hyperon in a nuclear medium have been known to be explained semiquantitatively in the LOBT framework. Attention is focused in the present consideration onmore » predictions for the {sigma} and {xi} hyperons. The unified description for the octet baryon-baryon interactions by the SU{sub 6} quark model enables us to obtain less ambiguous extrapolation to the S=-1 and S=-2 sectors based on the knowledge in the NN sector than other potential models. The {sigma} mean field is shown to be weakly attractive at the surface, but turns out to be repulsive inside, which is consistent with the experimental evidence. The {xi} hyperon s.p. potential is also attractive at the nuclear surface region, and inside it fluctuates around zero. Hence {xi} hypernuclear bound states are unlikely. We also evaluate energy shifts of the {sigma}{sup -} and {xi}{sup -} atomic levels in {sup 28}Si and {sup 56}Fe, using the calculated s.p. potentials.« less

Emergence of the mass discrepancy-acceleration relation from dark matter-baryon interactions

NASA Astrophysics Data System (ADS)

Famaey, Benoit; Khoury, Justin; Penco, Riccardo

2018-03-01

The observed tightness of the mass discrepancy-acceleration relation (MDAR) poses a fine-tuning challenge to current models of galaxy formation. We propose that this relation could arise from collisional interactions between baryons and dark matter (DM) particles, without the need for modification of gravity or ad hoc feedback processes. We assume that these interactions satisfy the following three conditions: (i) the relaxation time of DM particles is comparable to the dynamical time in disk galaxies; (ii) DM exchanges energy with baryons due to elastic collisions; (iii) the product between the baryon-DM cross section and the typical energy exchanged in a collision is inversely proportional to the DM number density. As a proof of principle, we present an example of a particle physics model that gives a DM-baryon cross section with the desired density and velocity dependence. For consistency with direct detection constraints, our DM particles must be either very light (m ll mb) or very heavy (mgg mb), corresponding respectively to heating and cooling of DM by baryons. In both cases, our mechanism applies and an equilibrium configuration can in principle be reached. In this exploratory paper, we focus on the heavy DM/cooling case because it is technically simpler, since the average energy exchanged turns out to be approximately constant throughout galaxies. Under these assumptions, we find that rotationally-supported disk galaxies could naturally settle to equilibrium configurations satisfying a MDAR at all radii without invoking finely tuned feedback processes. We also discuss issues related to the small scale clumpiness of baryons, as well as predictions for pressure-supported systems. We argue in particular that galaxy clusters do not follow the MDAR despite being DM-dominated because they have not reached their equilibrium configuration. Finally, we revisit existing phenomenological, astrophysical and cosmological constraints on baryon-DM interactions in light of the unusual density dependence of the cross section of DM particles.

SCALING LAWS FOR DARK MATTER HALOS IN LATE-TYPE AND DWARF SPHEROIDAL GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kormendy, John; Freeman, K. C., E-mail: kormendy@astro.as.utexas.edu, E-mail: kenneth.freeman@anu.edu.au

2016-02-01

Dark matter (DM) halos of Sc–Im and dwarf spheroidal (dSph) galaxies satisfy scaling laws: halos in lower-luminosity galaxies have smaller core radii, higher central densities, and smaller velocity dispersions. These results are based on maximum-disk rotation curve decompositions for giant galaxies and Jeans equation analysis for dwarfs. (1) We show that spiral, Im, and Sph galaxies with absolute magnitudes M{sub V} > −18 form a sequence of decreasing baryon-to-DM surface density with decreasing luminosity. We suggest that this is a sequence of decreasing baryon retention versus supernova-driven losses or decreasing baryon capture after cosmological reionization. (2) The structural differences betweenmore » S+Im and Sph galaxies are small. Both are affected mostly by the physics that controls baryon depletion. (3) There is a linear correlation between the maximum rotation velocities of baryonic disks and the outer circular velocities V{sub circ} of test particles in their DM halos. Baryons become unimportant at V{sub circ} = 42 ± 4 km s{sup −1}. Smaller galaxies are dim or dark. (4) We find that, absent baryon “depletion” and with all baryons converted into stars, dSph galaxies would be brighter by ∼4.6 mag and dIm galaxies would be brighter by ∼3.5 mag. Both have DM halos that are massive enough to help to solve the “too big to fail” problem with DM galaxy formation. (5) We suggest that there exist many galaxies that are too dark to be discovered by current techniques, as required by cold DM theory. (6) Central surface densities of DM halos are constant from M{sub B} ∼ −5 to −22. This implies a Faber–Jackson law with halo mass M ∝ (halo dispersion){sup 4}.« less

Thin coatings in packaging: Fundamental and practical aspects

NASA Astrophysics Data System (ADS)

Thorne, N. A.

1996-01-01

A beverage or food can is very much a functionalized product, the overall performance characteristics being achieved by the use of several materials each of which provides a specific property. Schematically, the metal substrate provides the mechanical and barrier properties, whereby the chemical resistance is provided by specific surface treatments to the metal surface and the application of a thin organic coating. Between about 4-15 μm in thickness, this organic coating has a double protective role, as it must protect the substrate from the foodstuff (corrosion) and the foodstuff from the substrate (taste..) over the required shelflife of the product. To give an idea of the industrial importance of this application, over 100 billion beverage cans per year are produced worldwide, each being individually sprayed with a protective organic layer. To perform correctly these coatings need to possess the following characteristics: —ability to be applied in thin, homogeneous layers without macroscopic or microscopic defects, —sufficient adhesion with the substrate and possess considerable interface stability —mechanical properties sufficient to withstand the can forming operations —intrinsic diffusion barrier properties necessary to prevent significant interaction with the substrate —sufficient chemical resistance to withstand any significant modification of the coating structure and hence intrinsic properties induced by the foodstuff Whereas a considerable amount of scientific attention has been applied to ``bulk'' systems, such as the mechanical properties of epoxies used for composite materials, diffusion in polymer packaging..., little published work is available concerning the specific properties of these thin coatings. The task is not helped by the commercial nature of the resin formulations used, the need to adapt these formulations to the multitude of industrial operations and the physical size of the coatings. The above coating properties will be discussed in relation to the ability to understand the underlying mechanisms involved, to measure the required properties and in the long term predict coating performance.

Mixing {Xi}--{Xi}' Effects and Static Properties of Heavy {Xi}'s

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aliev, T. M.; Ozpineci, A.; Zamiralov, V. S.

It is shown the importance of mixing of heavy baryons {Xi}--{Xi}' with the new quantum numbers for analysis of its characteristics. The quark model of Ono is used as an example. Masses of new baryons as well as mixing angles of the states {Xi}--{Xi}' are obtained. The same reasoning is shown to be valid for the interpolating currents of these baryons in the framework of the QCD sum rules.

Massive graviton dark matter with environment dependent mass: A natural explanation of the dark matter-baryon ratio

NASA Astrophysics Data System (ADS)

Aoki, Katsuki; Mukohyama, Shinji

2017-11-01

We propose a scenario that can naturally explain the observed dark matter-baryon ratio in the context of bimetric theory with a chameleon field. We introduce two additional gravitational degrees of freedom, the massive graviton and the chameleon field, corresponding to dark matter and dark energy, respectively. The chameleon field is assumed to be nonminimally coupled to dark matter, i.e., the massive graviton, through the graviton mass terms. We find that the dark matter-baryon ratio is dynamically adjusted to the observed value due to the energy transfer by the chameleon field. As a result, the model can explain the observed dark matter-baryon ratio independently from the initial abundance of them.

Search for baryon-number and lepton-number violating decays of Λ hyperons using the CLAS detector at Jefferson Laboratory

NASA Astrophysics Data System (ADS)

McCracken, M. E.; Bellis, M.; Adhikari, K. P.; Adikaram, D.; Akbar, Z.; Pereira, S. Anefalos; Badui, R. A.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Cao, T.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G. E.; Dupre, R.; Alaoui, A. El; Fassi, L. El; Elouadrhiri, E.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fersch, R.; Filippi, A.; Fleming, J. A.; Garillon, B.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; Jiang, H.; Jo, H. S.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Mayer, M.; McKinnon, B.; Mestayer, M. D.; Meyer, C. A.; Mirazita, M.; Mokeev, V.; Moody, C. I.; Moriya, K.; Camacho, C. Munoz; Nadel-Turonski, P.; Net, L. A.; Niccolai, S.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Raue, B. A.; Ripani, M.; Rizzo, A.; Rosner, G.; Roy, P.; Sabatié, F.; Salgado, C.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Skorodumina, Iu.; Sokhan, D.; Sparveris, N.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Tian, Ye; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration

2015-10-01

We present a search for ten baryon number violating decay modes of Λ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state (Λ →m ℓ) and conserve either the sum or the difference of baryon and lepton number (B ±L ). The tenth decay mode (Λ →p ¯ π+ ) represents a difference in baryon number of two units and no difference in lepton number. We observe no significant signal and set upper limits on the branching fractions of these reactions in the range (4 - 200 )×10-7 at the 90% confidence level.

Halo density profiles and baryon physics

NASA Astrophysics Data System (ADS)

Del Popolo, A.; Li, Xi-Guo

2017-08-01

The radial dependence of the pseudo phase-space density, ρ( r)/ σ 3( r) is studied. We find that the pseudo phase-space density for halos consisting both of dark matter and baryons is approximately a power-law only down to 0.1% of the virial radius while it has a non-power law behavior below the quoted scale, with inner profiles changing with mass. Halos consisting just of dark matter, as the one in dark matter only simulations, are characterized by an approximately power-law behavior. The results argue against universality of the pseudo phase-space density, when the baryons effect are included, and as a consequence argue against universality of density profiles constituted by dark matter and baryons as also discussed in [1].

Matrix theory for baryons: an overview of holographic QCD for nuclear physics.

PubMed

Aoki, Sinya; Hashimoto, Koji; Iizuka, Norihiro

2013-10-01

We provide, for non-experts, a brief overview of holographic QCD (quantum chromodynamics) and a review of the recent proposal (Hashimoto et al 2010 (arXiv:1003.4988[hep-th])) of a matrix-like description of multi-baryon systems in holographic QCD. Based on the matrix model, we derive the baryon interaction at short distances in multi-flavor holographic QCD. We show that there is a very universal repulsive core of inter-baryon forces for a generic number of flavors. This is consistent with a recent lattice QCD analysis for Nf = 2, 3 where the repulsive core looks universal. We also provide a comparison of our results with the lattice QCD and the operator product expansion analysis.

The Nc dependencies of baryon masses: Analysis with Lattice QCD and Effective Theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calle Cordon, Alvaro C.; DeGrand, Thomas A.; Goity, Jose L.

Baryon masses at varying values of Nc and light quark masses are studied with Lattice QCD and the results are analyzed in a low energy effective theory based on a combined framework of the 1/Nc and Heavy Baryon Chiral Perturbation Theory expansions. Lattice QCD results for Nc=3, 5 and 7 obtained in quenched calculations, as well as results for unquenched calculations for Nc=3, are used for the analysis. The results are consistent with a previous analysis of Nc=3 LQCD results, and in addition permit the determination of sub-leading in 1/Nc effects in the spin-flavor singlet component of the baryon massesmore » as well as in the hyperfine splittings.« less

Dios: The Dark Baryon Exploring Mission

NASA Technical Reports Server (NTRS)

T.Ohashi; Ishisaki, Y.; Yamada, S.; Kuromaru, G.; Suzuki, S.; Tawara, Y.; Mitsuishi, I.; Babazaki, Y.; Mitsuda, K.; Yamasaki, N. Y.;

Lynx mission concept study

NASA Astrophysics Data System (ADS)

Vikhlinin, Alexey

2018-01-01

Lynx is an observatory-class mission, featuring high throughput, exquisite angular resolution over a substantial field of view, and high spectral resolution for point and extended X-ray sources. The design requirements provide a tremendous leap in capabilities relative to missions such as Chandra and Athena. Lynx will observe the dawn of supermassive black holes through detection of very faint X-ray sources in the early universe and will reveal the "invisible drivers" of galaxy and structure formation through observations of hot, diffuse baryons in and around the galaxies. Lynx will enable breakthroughs across all of astrophysics, ranging from detailed understanding of stellar activity including effects on habitability of associated planets to population statistics of neutron stars and black holes in the Local Group galaxies, to earliest groups and clusters of galaxies, and to cosmology

Bosonic-seesaw portal dark matter

NASA Astrophysics Data System (ADS)

Ishida, Hiroyuki; Matsuzaki, Shinya; Yamaguchi, Yuya

2017-10-01

We discuss a new type of Higgs-portal dark matter (DM) production mechanism, called the bosonic-seesaw portal (BSP) scenario. The BS provides the dynamical origin of the electroweak symmetry breaking, triggered by mixing between the elementary Higgs and a composite Higgs generated by a new-color strong dynamics, hypercolor (HC). At the HC strong coupling scale, the classical-scale invariance assumed in the model is dynamically broken, as well as the "chiral" symmetry present in the HC sector. In addition to the composite Higgs, HC baryons emerge to potentially be stable because of the unbroken HC baryon number symmetry. Hence the lightest HC baryon can be a DM candidate. Of interest in the present scenario is that HC pions can be as heavy as the HC baryon due to the possibly enhanced explicit "chiral"-breaking effect triggered after the BS mechanism, so the HC baryon pair cannot annihilate into HC pions. As in the standard setup of the freeze-in scenario, it is assumed that the DM was never in the thermal equilibrium, which ends up with no thermal abundance. It is then the non-thermal BSP process that crucially comes into the game below the HC scale: the HC baryon significantly couples to the standard-model Higgs via the BS mechanism, and can non-thermally be produced from the thermal plasma below the HC scale, which turns out to allow the TeV mass scale for the composite baryonic DM, much smaller than the generic bound placed in the conventional thermal freeze-out scenario, to account for the observed relic abundance. Thus the DM can closely be related to the mechanism of the electroweak symmetry breaking.

Baryonic effects in cosmic shear tomography: PCA parametrization and importance of extreme baryonic models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohammed, Irshad; Gnedin, Nickolay Y.

Baryonic effects are amongst the most severe systematics to the tomographic analysis of weak lensing data which is the principal probe in many future generations of cosmological surveys like LSST, Euclid etc.. Modeling or parameterizing these effects is essential in order to extract valuable constraints on cosmological parameters. In a recent paper, Eifler et al. (2015) suggested a reduction technique for baryonic effects by conducting a principal component analysis (PCA) and removing the largest baryonic eigenmodes from the data. In this article, we conducted the investigation further and addressed two critical aspects. Firstly, we performed the analysis by separating the simulations into training and test sets, computing a minimal set of principle components from the training set and examining the fits on the test set. We found that using only four parameters, corresponding to the four largest eigenmodes of the training set, the test sets can be fitted thoroughly with an RMSmore » $$\\sim 0.0011$$. Secondly, we explored the significance of outliers, the most exotic/extreme baryonic scenarios, in this method. We found that excluding the outliers from the training set results in a relatively bad fit and degraded the RMS by nearly a factor of 3. Therefore, for a direct employment of this method to the tomographic analysis of the weak lensing data, the principle components should be derived from a training set that comprises adequately exotic but reasonable models such that the reality is included inside the parameter domain sampled by the training set. The baryonic effects can be parameterized as the coefficients of these principle components and should be marginalized over the cosmological parameter space.« less

Baryon Effective Theories and Phenomenology in the 1/N c Expansion

NASA Astrophysics Data System (ADS)

Fernando, Ishara Priyasad

Chiral perturbation theory (ChPT) and the 1/Nc expansion provide systematic frameworks to investigate the strong interaction at low energy. There are two main focuses of this dissertation. First, analyzing the masses of baryons in the framework of the 1/Nc expansion, using the available physical masses and masses calculated in lattice QCD. Second, combining both ChPT and the 1/Nc expansion into a single framework and applying it to the phenomenology of baryons with three light-quark flavors. In the first focus, the baryon states are organized into irreducible representa- tions of SU(6) x O(3), where the [56, ℓ P = 0+] contains the ground state and radially excited baryons, and the [56, 2+] and [70, 1 -] contain orbitally excited states are analyzed. The analyses are carried out to O(1/Nc) and first order in the quark masses. The issue of state identifications is discussed. Numerous parameter independent mass relations and the famous Gell-Mann-Okubo (GMO) and Equal-Spacing (ES) relations are tested. Also, the quark mass dependence of the operator coefficients for baryon mass is discussed. In the second focus, a small scale expansion of the combined approach is defined as the xi-expansion, in which the power counting of 1/Nc and chiral expansions are linked as O(p) = O(1/Nc) = O(xi). A calculation of one-loop corrections to the ground state baryon masses, vector and axial-vector currents up to O(xi 3) is presented. Moreover, the physical and lattice QCD masses are considered in order to understand the quark mass dependence, along with an analysis of the violations to GMO, ES and Gursey-Radicati (GR) mass relations, and their dependence on Nc.

The Detection of Faint Space Objects Using Solid State Imaging Detectors.

DTIC Science & Technology

1983-12-31

are con.iposed of baryonic matter . New arguments were presented against halos being composed of planets or asteroids. D. Hegyi was also invited to...being made up of baryonic matter . 5.0 THE CHARGE-COUPLED DEVICE IMAGING SYSTEM Our major hardware improvement during the past year is a stainless steel...Hegyi Department of Physics University of Michigan Ann Arbor, Michigan ABSIR:CT The problems with massive halos being composed of baryonic matter are

Study of compressed baryonic matter at FAIR: JINR participation

NASA Astrophysics Data System (ADS)

Derenovskaya, O.; Kurilkin, P.; Gusakov, Yu.; Ivanov, V.; Ladygin, V.; Ladygina, N.; Malakhov, A.; Peshekhonov, V.; Zinchenko, A.

2017-11-01

The scientific goal of the CBM (Compressed Baryonic Matter) experiment at FAIR (Darmstadt) is to explore the phase diagram of strongly interacting matter at highest baryon densities. The physics program of the CBM experiment is complimentary to the programs to be realized at MPD and BMN facilities at NICA and will start with beam derived by the SIS100 synchrotron. The results of JINR participation in the development of different sub-projects of the CBM experiment are presented.

Multistrange Meson-Baryon Dynamics and Resonance Generation

NASA Astrophysics Data System (ADS)

Khemchandani, K. P.; Martínez Torres, A.; Hosaka, A.; Nagahiro, H.; Navarra, F. S.; Nielsen, M.

2018-05-01

In this talk I review our recent studies on meson-baryon systems with strangeness - 1 and - 2. The motivation of our works is to find resonances generated as a consequence of coupled channel meson-baryon interactions. The coupled channels are all meson-baryon systems formed by combining a pseudoscalar or a vector meson with an octet baryon such that the system has the strange quantum number equal to - 1 or - 2. The lowest order meson-baryon interaction amplitudes are obtained from Lagrangians based on the chiral and the hidden local symmetries related to the vector mesons working as the gauge bosons. These lowest order amplitudes are used as an input to solve the Bethe-Salpeter equation and a search for poles is made in the resulting amplitudes, in the complex plane. In case of systems with strangeness - 1, we find evidence for the existence of some hyperons such as: Λ(2000), Σ(1750), Σ(1940), Σ(2000). More recently, in the study of strangeness - 2 systems we have found two narrow resonances which can be related to Ξ (1690) and Ξ(2120). In this latter work, we have obtained the lowest order amplitudes relativistically as well as in the nonrelativistic approximation to solve the scattering equations. We find that the existence of the poles in the complex plane does not get affected by the computation of the scattering equation with the lowest order amplitudes obtained in the nonrelativistic approximation.

XMM-NEWTON DETECTS A HOT GASEOUS HALO IN THE FASTEST ROTATING SPIRAL GALAXY UGC 12591

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai Xinyu; Anderson, Michael E.; Bregman, Joel N.

2012-08-20

We present our XMM-Newton observation of the fastest rotating spiral galaxy UGC 12591. We detect hot gas halo emission out to 80 kpc from the galaxy center, and constrain the halo gas mass to be smaller than 4.5 Multiplication-Sign 10{sup 11} M{sub Sun }. We also measure the temperature of the hot gas as T = 0.64 {+-} 0.03 keV. Combining our x-ray constraints and the near-infrared and radio measurements in the literature, we find a baryon mass fraction of 0.03-0.05 in UGC 12591, suggesting a missing baryon mass of 70% compared with the cosmological mean value. Combined with anothermore » recent measurement in NGC 1961, the result strongly argues that the majority of missing baryons in spiral galaxies do not reside in their hot halos. We also find that UGC 12591 lies significantly below the baryonic Tully-Fisher relationship. Finally, we find that the baryon fractions of massive spiral galaxies are similar to those of galaxy groups with similar masses, indicating that the baryon loss is ultimately controlled by the gravitational potential well. The cooling radius of this gas halo is small, similar to NGC 1961, which argues that the majority of the stellar mass of this galaxy is not assembled as a result of cooling of this gas halo.« less

The segregation of baryons and dark matter during halo assembly

NASA Astrophysics Data System (ADS)

Liao, Shihong; Gao, Liang; Frenk, Carlos S.; Guo, Qi; Wang, Jie

2017-09-01

The standard galaxy formation theory assumes that baryons and dark matter are initially well mixed before becoming segregated due to radiative cooling. We use non-radiative hydrodynamical simulations to explicitly examine this assumption and find that baryons and dark matter can also be segregated due to different characteristics of gas and dark matter during the buildup of the halo. As a result, baryons in many haloes do not originate from the same Lagrangian region as the dark matter. When using the fraction of corresponding dark matter and gas particles in the initial conditions (the 'paired fraction') as a proxy of the dark matter and gas segregation strength of a halo, on average about 25 per cent of the baryonic and dark matter of the final halo are segregated in the initial conditions. This is at odds with the assumption of the standard galaxy formation model. A consequence of this effect is that the baryons and dark matter of the same halo initially experience different tidal torques and thus their angular momentum vectors are often misaligned. The degree of the misalignment is largely preserved during later halo assembly and can be understood with the tidal torque theory. The result challenges the precision of some semi-analytical approaches that utilize dark matter halo merger trees to infer properties of gas associated with dark matter haloes.

Performance Specification for the Battery Monitoring System of the Program Executive Office Ground Combat Systems (PEO GCS)

DTIC Science & Technology

2009-10-26

14 3.3.4 Dielectric Withstanding Voltage and Insulation Resistance. ............................. 14...Grounding. .................................................................................................. 32 4.6.2.3 Dielectric Withstanding Voltage ...shall accommodate a non-painted 0.38” 8-32 screw. 3.3.4 Dielectric Withstanding Voltage and Insulation Resistance. Electrical connections

Baryon anomaly and strong color fields in Pb + Pb collisions at 2.76A TeV at the CERN Large Hadron Collider

NASA Astrophysics Data System (ADS)

Topor Pop, V.; Gyulassy, M.; Barrette, J.; Gale, C.

2011-10-01

With the HIJING/B¯B v2.0 heavy ion event generator, we explore the phenomenological consequences of several high parton density dynamical effects predicted in central Pb+Pb collisions at the Large Hadron Collider (LHC) energies. These include (1) jet quenching due to parton energy loss (dE/dx), (2) strangeness and hyperon enhancement due to strong longitudinal color field (SCF), and (3) enhancement of baryon-to-meson ratios due to baryon-antibaryon junction (J¯J) loops and SCF effects. The saturation/minijet cutoff scale p0(s,A) and effective string tension κ(s,A) are constrained by our previous analysis of LHC p+p data and recent data on the charged multiplicity for Pb+Pb collisions reported by the ALICE collaboration. We predict the hadron flavor dependence (mesons and baryons) of the nuclear modification factor RAA(pT) and emphasize the possibility that the baryon anomaly could persist at the LHC up to pT˜10 GeV, well beyond the range observed in central Au+Au collisions at RHIC energies.

Omega-Omega interaction on the Lattice

NASA Astrophysics Data System (ADS)

Yamada, Masanori; Halqcd Collaboration

2014-09-01

We report our results of central potential between two Omega baryons from 2+1 flavor full Lattice QCD simulation. In the past studies, there is a possibility that some decouplet baryons have a bound state. However, almost all decuplet baryons are unstable due to decays via the strong interaction. An exception is the Omega decuplte baryon, which is stable against the strong decays, so its interaction is suitable to be investigated. It is, however, still difficult to investigate the Omega-Omega interaction experimentally due to its short-life time via weak decays. Therefore, the lattice QCD study for the Omega-Omega interaction is necessary and important. We present results obtained by the extension of the HAL QCD method to the system of two decuplet baryons. Our numerical results are obtained from 2+1 flavor full QCD gauge configurations at L ~ 2 . 9 fm mπ ~ 701 MeV and mΩ ~ 1966 MeV, generated by the PACS-CS Collaboration. We find that the Omega-Omega interaction is strong attractive, but it's not strong enough to make a bound state at out simulation set up.

Analysis of a dusty wall jet

NASA Technical Reports Server (NTRS)

Lim, Hock-Bin; Roberts, Leonard

1991-01-01

An analysis is given for the entrainment of dust into a turbulent radial wall jet. Equations are solved based on incompressible flow of a radial wall jet into which dust is entrained from the wall and transported by turbulent diffusion and convection throughout the flow. It is shown that the resulting concentration of dust particles in the flow depends on the difference between the applied shear stress at the surface and the maximum level of shear stress that the surface can withstand (varies as rho(sub d)a(sub g)D) i.e., the pressure due to the weight of a single layer of dust. The analysis is expected to have application to the downflow that results from helicopter and VTOL aircraft.

Insight into particle production mechanisms via angular correlations of identified particles in pp collisions at $$\\sqrt{\\mathrm{s}}=7$$ TeV

DOE PAGES

Adam, J.; Adamová, D.; Aggarwal, M. M.; ...

2017-08-24

We measured two-particle angular correlations in pp collisions at √s=7 TeV for pions, kaons, protons, and lambdas, for all particle/anti-particle combinations in the pair. Data for mesons exhibit an expected peak dominated by effects associated with mini-jets and are well reproduced by general purpose Monte Carlo generators. However, for baryon–baryon and anti-baryon–anti-baryon pairs, where both particles have the same baryon number, a near-side anti-correlation structure is observed instead of a peak. This effect is interpreted in the context of baryon production mechanisms in the fragmentation process. It currently presents a challenge to Monte Carlo models and its origin remains an openmore » question.« less

Semileptonic decays of Λ _c baryons in the relativistic quark model

NASA Astrophysics Data System (ADS)

Faustov, R. N.; Galkin, V. O.

2016-11-01

Motivated by recent experimental progress in studying weak decays of the Λ _c baryon we investigate its semileptonic decays in the framework of the relativistic quark model based on the quasipotential approach with the QCD-motivated potential. The form factors of the Λ _c→ Λ lν _l and Λ _c→ nlν _l decays are calculated in the whole accessible kinematical region without extrapolations and additional model assumptions. Relativistic effects are systematically taken into account including transformations of baryon wave functions from the rest to moving reference frame and contributions of the intermediate negative-energy states. Baryon wave functions found in the previous mass spectrum calculations are used for the numerical evaluation. Comprehensive predictions for decay rates, asymmetries and polarization parameters are given. They agree well with available experimental data.

Baryon spectrum of SU(4) composite Higgs theory with two distinct fermion representations

NASA Astrophysics Data System (ADS)

Ayyar, Venkitesh; DeGrand, Thomas; Hackett, Daniel C.; Jay, William I.; Neil, Ethan T.; Shamir, Yigal; Svetitsky, Benjamin

2018-06-01

We use lattice simulations to compute the baryon spectrum of SU(4) lattice gauge theory coupled to dynamical fermions in the fundamental and two-index antisymmetric (sextet) representations simultaneously. This model is closely related to a composite Higgs model in which the chimera baryon made up of fermions from both representations plays the role of a composite top-quark partner. The dependence of the baryon masses on each underlying fermion mass is found to be generally consistent with a quark-model description and large-Nc scaling. We combine our numerical results with experimental bounds on the scale of the new strong sector to estimate a lower bound on the mass of the top-quark partner. We discuss some theoretical uncertainties associated with this estimate.

Search for baryon-number and lepton-number violating decays of Λ hyperons using the CLAS detector at Jefferson Laboratory

DOE PAGES

McCracken, Michael E.

2015-10-09

We present a search for ten baryon-number violating decay modes of Λ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state (Λ → mΙ) and conserve either the sum or the difference of baryon and lepton number (Β ± L). The tenth decay mode (Λ → p¯π +) represents a difference in baryon number of two units and no difference in lepton number. Furthermore, we observe no significant signal and set upper limits on the branching fractions of these reactions in the range (4more » – 200) x 10 7 at the 90% confidence level.« less

Phenomenology of nonperturbative charm in the nucleon

DOE PAGES

Hobbs, T. J.; Londergan, J. T.; Melnitchouk, W.

2014-04-02

We perform a comprehensive analysis of the role of nonperturbative (or intrinsic) charm in the nucleon, generated through Fock state expansions of the nucleon wave function involving five-quark virtual states represented by charmed mesons and baryons. We consider contributions from a variety of charmed meson-baryon states and find surprisingly dominant effects from the D¯ *0 Λ c + configuration. We pay particular attention to the existence and persistence of high-x structure for intrinsic charm, and the x dependence of the c-c¯ asymmetry predicted in meson-baryon models. We discuss how studies of charmed baryons and mesons in hadronic reactions can bemore » used to constrain models, and outline future measurements that could further illuminate the intrinsic charm component of the nucleon.« less

The Voltage Distribution Characteristics of a Hybrid Circuit Breaker During High Current Interruption

NASA Astrophysics Data System (ADS)

Cheng, Xian; Duan, Xiongying; Liao, Minfu; Huang, Zhihui; Luo, Yan; Zou, Jiyan

2013-08-01

Hybrid circuit breaker (HCB) technology based on a vacuum interrupter and a SF6 interrupter in series has become a new research direction because of the low-carbon requirements for high voltage switches. The vacuum interrupter has an excellent ability to deal with the steep rising part of the transient recovery voltage (TRV), while the SF6 interrupter can withstand the peak part of the voltage easily. An HCB can take advantage of the interrupters in the current interruption process. In this study, an HCB model based on the vacuum ion diffusion equations, ion density equation, and modified Cassie-Mayr arc equation is explored. A simulation platform is constructed by using a set of software called the alternative transient program (ATP). An HCB prototype is also designed, and the short circuit current is interrupted by the HCB under different action sequences of contacts. The voltage distribution of the HCB is analyzed through simulations and tests. The results demonstrate that if the vacuum interrupter withstands the initial TRV and interrupts the post-arc current first, then the recovery speed of the dielectric strength of the SF6 interrupter will be fast. The voltage distribution between two interrupters is determined by their post-arc resistance, which happens after current-zero, and subsequently, it is determined by the capacitive impedance after the post-arc current decays to zero.

Reversible Redox Effect on Gas Permeation of Cobalt Doped Ethoxy Polysiloxane (ES40) Membranes

PubMed Central

Miller, Christopher R.; Wang, David K.; Smart, Simon; Diniz da Costa, João C.

2013-01-01

This work reports the remarkable effect of reversible gas molecular sieving for high temperature gas separation from cobalt doped ethoxy polysiloxane (CoES40) membranes. This effect stemmed from alternating the reducing and oxidising (redox) state of the cobalt particles embedded in the ES40 matrix. The reduced membranes gave the best H2 permeances of 1 × 10−6 mol m−2 s−1 Pa−1 and H2/N2 permselectivities of 65. The reduction process tailored a molecular gap attributed to changes in the specific volume between the reduced cobalt (Co(OH)2 and CoO) particles in the ES40 structure, thus allowing for the increased diffusion of gases. Upon re-oxidation, the tailored molecular gap became constricted as the particles reversed to Co3O4 resulting a lower gas diffusion, particularly for the larger gases ie. CO2 and N2. The ES40 matrix proved to be structurally rigid enough to withstand the reversible redox effect of cobalt particles across multiple cycles. PMID:23571730

Design of a variable area diffuser for a 15-inch Mach 6 open-jet tunnel

NASA Technical Reports Server (NTRS)

Loney, Norman W.

1994-01-01

The Langley 15-inch Mach 6 High Temperature Tunnel was recently converted from a Mach 10 Hypersonic Flow Apparatus. This conversion was effected to improve the capability of testing in Mach 6 air at relatively high reservoir temperatures not previously possible at Langley. Elevated temperatures allow the matching of the Mach numbers, Reynolds numbers, and ratio of wall-to-adiabatic-wall temperatures (TW/Taw) between this and the Langley 20-inch Mach 6 CF4 Tunnel. This ratio is also matched for Langley's 31-inch Mach 10 Tunnel and is an important parameter useful in the simulation of slender bodies such as National Aerospace Plane (NASP) configurations currently being studied. Having established the nozzle's operating characteristics, the decision was made to install another test section to provide model injection capability. This test section is an open-jet type, with an injection system capable of injecting a model from retracted position to nozzle centerline between 0.5 and 2 seconds. Preliminary calibrations with the new test section resulted in Tunnel blockage. This blockage phenomenon was eliminated when the conical center body in the diffuser was replaced. The issue then, is to provide a new and more efficient variable area diffuser configuration with the capability to withstand testing of larger models without sending the Tunnel into an unstart condition. Use of the 1-dimensional steady flow equation with due regard to friction and heat transfer was employed to estimate the required area ratios (exit area / throat area) in a variable area diffuser. Correlations between diffuser exit Mach number and area ratios, relative to the stagnation pressure ratios and diffuser inlet Mach number were derived. From these correlations, one can set upper and lower operating pressures and temperatures for a given diffuser throat area. In addition, they will provide appropriate input conditions for the full 3-dimensional computational fluid dynamics (CFD) code for further simulation studies.

Cold Antimatter Plasmas, and Aspirations for Cold Antihydrogen

DTIC Science & Technology

2002-06-24

comparison of any baryon and antibaryon by almost a factor of CP606, Non-Neutral Plasma Physics IV, edited by F. Anderegg et al. © 2002 American...antiprotons 3 _one-electron .1 eV quantum cyclotron 0.001 K FIGURE 1. Particle energies a million. An improved baryon CPT test (e.g. involving cold...more precise tests of CPT invariance with baryons and leptons than have been realized so far. The pursuit of cold antihydrogen thus began some time ago

Spectroscopy of triply charmed baryons from lattice QCD

DOE PAGES

Padmanath, M.; Edwards, Robert G.; Mathur, Nilmani; ...

2014-10-14

The spectrum of excitations of triply-charmed baryons is computed using lattice QCD including dynamical light quark fields. The spectrum obtained has baryonic states with well-defined total spin up to 7/2 and the low-lying states closely resemble the expectation from models with an SU(6) x O(3) symmetry. As a result, energy splittings between extracted states, including those due to spin-orbit coupling in the heavy quark limit are computed and compared against data at other quark masses.

Lattice QCD studies on baryon interactions in the strangeness -2 sector with physical quark masses

NASA Astrophysics Data System (ADS)

Sasaki, Kenji; Aoki, Sinya; Doi, Takumi; Gongyo, Shinya; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Iritani, Takumi; Ishii, Noriyoshi; Miyamoto, Takaya

2018-03-01

We investigate baryon-baryon (BB) interactions in the strangeness S = -2 sector via the coupled-channel HAL QCD method which enables us to extract the scattering observables from Nambu-Bethe-Salpeter (NBS) wave function on the lattice. The simulations are performed with (almost) physical quark masses (mπ = 146MeV) and a huge lattice volume of La = 8.1fm. We discuss the fate of H-dibaryon state through the ΛΛ and NΞ coupled-channel scatterings

Baryon symmetric big-bang cosmology. [matter-antimatter symmetry

NASA Technical Reports Server (NTRS)

Stecker, F. W.

1978-01-01

The framework of baryon-symmetric big-bang cosmology offers the greatest potential for deducing the evolution of the universe as a consequence of physical laws and processes with the minimum number of arbitrary assumptions as to initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the universe and how galaxies and galaxy clusters are formed, and also provides the only acceptable explanation at present for the origin of the cosmic gamma ray background radiation.

Multicharmed Baryon Production in High Energy Nuclear Collisions

NASA Astrophysics Data System (ADS)

Zhao, Jiaxing; Zhuang, Pengfei

2017-03-01

We study nuclear medium effect on multicharmed baryon production in relativistic heavy ion collisions. By solving the three-quark Schroedinger equation at finite temperature, we calculate the wave functions and Wigner functions for doubly and triply charmed baryons Ξ_{cc} and Ω_{ccc}. Their production in nuclear collisions is largely enhanced due to the combination of uncorrelated charm quarks in the quark-gluon plasma. It is most probable to discover these new particles in heavy ion collisions at the RHIC and LHC energies.

Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago

NASA Astrophysics Data System (ADS)

Genzel, R.; Schreiber, N. M. Förster; Übler, H.; Lang, P.; Naab, T.; Bender, R.; Tacconi, L. J.; Wisnioski, E.; Wuyts, S.; Alexander, T.; Beifiori, A.; Belli, S.; Brammer, G.; Burkert, A.; Carollo, C. M.; Chan, J.; Davies, R.; Fossati, M.; Galametz, A.; Genel, S.; Gerhard, O.; Lutz, D.; Mendel, J. T.; Momcheva, I.; Nelson, E. J.; Renzini, A.; Saglia, R.; Sternberg, A.; Tacchella, S.; Tadaki, K.; Wilman, D.

2017-03-01

In the cold dark matter cosmology, the baryonic components of galaxies—stars and gas—are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius—a hallmark of the dark-matter model. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early (high-redshift) Universe efficiently condensed at the centres of dark-matter haloes when gas fractions were high and dark matter was less concentrated.

Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago.

PubMed

Genzel, R; Schreiber, N M Förster; Übler, H; Lang, P; Naab, T; Bender, R; Tacconi, L J; Wisnioski, E; Wuyts, S; Alexander, T; Beifiori, A; Belli, S; Brammer, G; Burkert, A; Carollo, C M; Chan, J; Davies, R; Fossati, M; Galametz, A; Genel, S; Gerhard, O; Lutz, D; Mendel, J T; Momcheva, I; Nelson, E J; Renzini, A; Saglia, R; Sternberg, A; Tacchella, S; Tadaki, K; Wilman, D

2017-03-15

In the cold dark matter cosmology, the baryonic components of galaxies-stars and gas-are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius-a hallmark of the dark-matter model. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early (high-redshift) Universe efficiently condensed at the centres of dark-matter haloes when gas fractions were high and dark matter was less concentrated.

Evolution of the baryon fraction in the Local Group: accretion versus feedback at low and high z

NASA Astrophysics Data System (ADS)

Peirani, Sébastien; Jung, Intae; Silk, Joseph; Pichon, Christophe

2012-12-01

Using hydrodynamical zoom simulations in the standard Λ cold dark matter cosmology, we investigate the evolution of the distribution of baryons (gas and stars) in a Local Group-type universe. First, with standard star formation and supernova feedback prescriptions, we find that the mean baryonic fraction value estimated at the virial radius of the two main central objects (i.e. the Milky Way and Andromeda) is decreasing over time and is 10-15 per cent lower than the universal value 0.166, at z = 0. This decrease is mainly due to the fact that the amount of accretion of dissipative gas on to the halo, especially at low redshift, is in general much lower than that of the dissipationless dark matter. Indeed, a significant part of the baryons does not collapse on to the haloes and remains in their outskirts, mainly in the form of warm hot intergalactic medium (WHIM). Moreover, during the formation of each object, some dark matter and baryons are also expelled through merger events via tidal disruption. In contrast to baryons, expelled dark matter can be more efficiently re-accreted on to the halo, enhancing both the reduction of fb inside Rv and the increase of the mass of WHIM outside Rv. Varying the efficiency of supernova feedback at low redshift does not seem to significantly affect these trends. Alternatively, when a significant fraction of the initial gas in the main objects is released at high redshifts by more powerful sources of feedback, such as active galactic nuclei from intermediate-mass black holes in lower mass galaxies, the baryonic fraction at the virial radius can have a lower value (fb˜0.12) at low redshift. Hence, physical mechanisms able to drive the gas out of the virial radius at high redshifts will have a stronger impact on the deficit of baryons in the mass budget of Milky Way-type galaxies at present times than those that expel the gas in the longer, late phases of galaxy formation.

Searching for the missing baryons with the VSA and WMAP

NASA Astrophysics Data System (ADS)

Genova-Santos, Ricardo

2004-12-01

The hot diffuse gas in the local Universe which could host the missing baryons, could produce detectable thermal Sunyaev-Zel’dovich effect (tSZE). With this aim, in this work, I present the discussion of the search of this gas, via two different ways. Both takes into account this fact: Firstly, the search for the imprint of the tSZE in the first year data of the WMAP satellite, by applying a pixel to pixel correlation method between this data and a template constructed from the Two Micron All Sky Survey (2MASS) Extended Source Catalogue, which it has been assumed that trace the distribution of this hot gas. This analysis has yielded a detection of 35 7 µK in ¢ ¡ the 26 d eg2 of the sky containing the largest projected galaxy density. Nevertheless, this signal is mostly due to the contribution from galaxy clusters subtending an angular size of 20 30 . When ¡ £ the regions affected by the clusters are removed from the analysis, it is found a decrement of 96 37 µK in 0 8 d eg2 of the sky. Nevertheless, most of this signal comes from five different ¢ ¡ ¤ cluster candidates in the Zone of Avoidance (ZoA), present in the Clusters in the ZoA catalogue (CIZA). Hence, it is not found any clear evidence of structures larger than clusters, as it would be the case of this hot gas, contributing to the tSZE signal in the WMAP data. Secondly, interferometric imaging at 33 GH z of the well known Corona Borealis supercluster with the Very Small Array (VSA). The maps built up from these observations, apart from the common Cosmic Microwave Background (CMB) primordial fluctuations, show the presence of two intriguing strong negative features near the centre of the core of the supercluster [1]. It is discussed the possibility of being caused by CMB fluctuations, or by tSZ signals related to either unknown distant galaxy clusters or to diffuse extended warm/hot gas.

Measurements of the properties of Λ c ( 2595 ) , Λ c ( 2625 ) , Σ c ( 2455 ) , and Σ c ( 2520 ) baryons

DOE PAGES

Aaltonen, T.; Álvarez González, B.; Amerio, S.; ...

2011-07-13

We report measurements of the resonance properties of Λ c(2595) + and Λ c(2595) + baryons in their decays to Λ c +π +π - as well as Σ c(2455) ++,0 and Σ c(2455) ++,0 baryons in their decays to Λ c +π ± final states. These measurements are performed using data corresponding to 5.2 fb -1 of integrated luminosity from pp̄ collisions at √s = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. In addition, exploiting the largest available charmed baryon sample, we measure masses and decay widths with uncertainties comparable to the world averagesmore » for Σ c states, and significantly smaller uncertainties than the world averages for excited Λ c + states.« less

Baryon spectrum from superconformal quantum mechanics and its light-front holographic embedding

DOE PAGES

de Teramond, Guy F.; Dosch, Hans Gunter; Brodsky, Stanley J.

2015-02-27

We describe the observed light-baryon spectrum by extending superconformal quantum mechanics to the light front and its embedding in AdS space. This procedure uniquely determines the confinement potential for arbitrary half-integer spin. To this end, we show that fermionic wave equations in AdS space are dual to light-front supersymmetric quantum-mechanical bound-state equations in physical space-time. The specific breaking of conformal invariance explains hadronic properties common to light mesons and baryons, such as the observed mass pattern in the radial and orbital excitations, from the spectrum generating algebra. Lastly, the holographic embedding in AdS also explains distinctive and systematic features, suchmore » as the spin-J degeneracy for states with the same orbital angular momentum, observed in the light-baryon spectrum.« less

Inference from the small scales of cosmic shear with current and future Dark Energy Survey data

DOE PAGES

MacCrann, N.; Aleksić, J.; Amara, A.; ...

2016-11-05

Cosmic shear is sensitive to fluctuations in the cosmological matter density field, including on small physical scales, where matter clustering is affected by baryonic physics in galaxies and galaxy clusters, such as star formation, supernovae feedback and AGN feedback. While muddying any cosmological information that is contained in small scale cosmic shear measurements, this does mean that cosmic shear has the potential to constrain baryonic physics and galaxy formation. We perform an analysis of the Dark Energy Survey (DES) Science Verification (SV) cosmic shear measurements, now extended to smaller scales, and using the Mead et al. 2015 halo model tomore » account for baryonic feedback. While the SV data has limited statistical power, we demonstrate using a simulated likelihood analysis that the final DES data will have the statistical power to differentiate among baryonic feedback scenarios. We also explore some of the difficulties in interpreting the small scales in cosmic shear measurements, presenting estimates of the size of several other systematic effects that make inference from small scales difficult, including uncertainty in the modelling of intrinsic alignment on nonlinear scales, `lensing bias', and shape measurement selection effects. For the latter two, we make use of novel image simulations. While future cosmic shear datasets have the statistical power to constrain baryonic feedback scenarios, there are several systematic effects that require improved treatments, in order to make robust conclusions about baryonic feedback.« less

The relative impact of baryons and cluster shape on weak lensing mass estimates of galaxy clusters

NASA Astrophysics Data System (ADS)

Lee, B. E.; Le Brun, A. M. C.; Haq, M. E.; Deering, N. J.; King, L. J.; Applegate, D.; McCarthy, I. G.

2018-05-01

Weak gravitational lensing depends on the integrated mass along the line of sight. Baryons contribute to the mass distribution of galaxy clusters and the resulting mass estimates from lensing analysis. We use the cosmo-OWLS suite of hydrodynamic simulations to investigate the impact of baryonic processes on the bias and scatter of weak lensing mass estimates of clusters. These estimates are obtained by fitting NFW profiles to mock data using MCMC techniques. In particular, we examine the difference in estimates between dark matter-only runs and those including various prescriptions for baryonic physics. We find no significant difference in the mass bias when baryonic physics is included, though the overall mass estimates are suppressed when feedback from AGN is included. For lowest-mass systems for which a reliable mass can be obtained (M200 ≈ 2 × 1014M⊙), we find a bias of ≈-10 per cent. The magnitude of the bias tends to decrease for higher mass clusters, consistent with no bias for the most massive clusters which have masses comparable to those found in the CLASH and HFF samples. For the lowest mass clusters, the mass bias is particularly sensitive to the fit radii and the limits placed on the concentration prior, rendering reliable mass estimates difficult. The scatter in mass estimates between the dark matter-only and the various baryonic runs is less than between different projections of individual clusters, highlighting the importance of triaxiality.

Decays of J/psi (3100) to baryon final states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eaton, M.W.

We present results for the decays of psi(3100) into baryon and hyperon final states. The sample studied here consists of 1.3 million produced psi decays. The decays into nonstrange baryons agree well with currently established results, but with better statistics. In addition, significant resonance formation in multibody final states is observed. The decay psi ..-->.. anti pp..gamma.., the first direct photon decay of the psi involving baryons in the final state, is presented and the theoretical implications of the decays are briefly explored. Several new decays of the psi involving strange baryons are explored, including the first observations of threemore » body final states involving hyperons. The I-spin symmetry of the strong decay psi ..-->.. baryons has clearly been observed. The reduced matrix elements for psi ..-->.. B anti B are presented for final states of different SU(3) content. The B/sub 8/ anti B/sub 8/ results are in excellent agreement with the psi being an SU(3) singlet as are the results for psi ..-->.. B/sub 10/ anti B/sub 10/. We present the first evidence for the SU(3) violating decays of the type psi ..-->.. B/sub 8/ anti B/sub 10/ + c.c.. Angular distributions for psi ..-->.. B/sub 8/ anti B/sub 8/ are presented and compared with theoretical predictions. Statistics are limited, but the data tends to prefer other than a 1 + Cos/sup 2/theta distribution.« less

Xenia: A Probe of Cosmic Chemical Evolution

NASA Technical Reports Server (NTRS)

Kouveliotou, Chryssa; Piro, L.

2008-01-01

Xenia is a concept study for a medium-size astrophysical cosmology mission addressing the Cosmic Origins key objective of NASA's Science Plan. The fundamental goal of this objective is to understand the formation and evolution of structures on various scales from the early Universe to the present time (stars, galaxies and the cosmic web). Xenia will use X-and y-ray monitoring and wide field X-ray imaging and high-resolution spectroscopy to collect essential information from three major tracers of these cosmic structures: the Warm Hot Intergalactic Medium (WHIM), Galaxy Clusters and Gamma Ray Bursts (GRBs). Our goal is to trace the chemo-dynamical history of the ubiquitous warm hot diffuse baryon component in the Universe residing in cosmic filaments and clusters of galaxies up to its formation epoch (at z =0-2) and to map star formation and galaxy metal enrichment into the re-ionization era beyond z 6. The concept of Xenia (Greek for "hospitality") evolved in parallel with the Explorer of Diffuse Emission and GRB Explosions (EDGE), a mission proposed by a multinational collaboration to the ESA Cosmic Vision 2015. Xenia incorporates the European and Japanese collaborators into a U.S. led mission that builds on the scientific objectives and technological readiness of EDGE.

Xenia: A Probe of Cosmic Chemical Evolution

NASA Astrophysics Data System (ADS)

Kouveliotou, Chryssa; Piro, L.; Xenia Collaboration

2008-03-01

Xenia is a concept study for a medium-size astrophysical cosmology mission addressing the Cosmic Origins key objective of NASA's Science Plan. The fundamental goal of this objective is to understand the formation and evolution of structures on various scales from the early Universe to the present time (stars, galaxies and the cosmic web). Xenia will use X-and γ-ray monitoring and wide field X-ray imaging and high-resolution spectroscopy to collect essential information from three major tracers of these cosmic structures: the Warm Hot Intergalactic Medium (WHIM), Galaxy Clusters and Gamma Ray Bursts (GRBs). Our goal is to trace the chemo-dynamical history of the ubiquitous warm hot diffuse baryon component in the Universe residing in cosmic filaments and clusters of galaxies up to its formation epoch (at z =0-2) and to map star formation and galaxy metal enrichment into the re-ionization era beyond z 6. The concept of Xenia (Greek for "hospitality") evolved in parallel with the Explorer of Diffuse Emission and GRB Explosions (EDGE), a mission proposed by a multinational collaboration to the ESA Cosmic Vision 2015. Xenia incorporates the European and Japanese collaborators into a U.S. led mission that builds on the scientific objectives and technological readiness of EDGE.

Production du baryon Sigma+ dans les collisions e+e- au LEP

NASA Astrophysics Data System (ADS)

Joly, Andre

Les mécanismes de production des baryons dans les interactions e+e- font l'objet de nombreuses études. De plus, les modes de production des baryons étranges semblent faire appel A des processus spécifiques, qui sont encore mal compris. Notre étude de la production des baryons Σ+ dans les interactions e+e- nous permet de formuler certaines remarques sur l'état des connaîssances acquises sur le sujet. Une methode de reconstruction originale et des critères de sélection spécifiques ont été développés afin d'identifier des baryons Σ+ de haute Energie ( ES+ > 5 GeV), partir de leur canal de désintégration en un proton et un π0 (S+-->p+p0 ). Trois mesures principales sont réalisées à partir de notre échantillon de baryons reconstruits. Le nombre mesuré de baryons Σ+ produits par événement e +e- à 91 GeV est de: =0.102+/-0.006(stat.) +/-0.008(syst.) +/-0.003(extrap.) où les erreurs sont dues à la statistique, aux systématiques et à la procédure d'extrapolation. Ce résultat est en accord avec ceux obtenus précédemment, mais avec des erreurs réduites. La section efficace différentielle en fonction de l'energie est mesurée et comparée aux prédictions des principaux générateurs Monte-Carlo (JETSET7.4(MOPS), JETSET7.4 et HERWIG5.9). A haute énergie, HERWIG ne semble pas reproduire les mesures, aussi bien que les deux versions de JETSET. Enfin, la position du maximum de la section efficace différentielle de production des baryons Σ+ en fonction de l'impulsion est mesurée. On trouve: overlinexoverlineS+=2.32+/- 0.47 Une étude spécifique du générateur JETSET7.4(MOPS) est réalisee, afin de mieux comprendre les mécanismes de production de l'étrangeté et du spin dans la production des baryons. Aucun générateur ne semble capable de décrire de manière simultanée la production du spin et de l'étrangeté.

Neutrino assisted GUT baryogenesis revisited

NASA Astrophysics Data System (ADS)

Huang, Wei-Chih; Päs, Heinrich; Zeißner, Sinan

2018-03-01

Many grand unified theory (GUT) models conserve the difference between the baryon and lepton number, B -L . These models can create baryon and lepton asymmetries from heavy Higgs or gauge boson decays with B +L ≠0 but with B -L =0 . Since the sphaleron processes violate B +L , such GUT-generated asymmetries will finally be washed out completely, making GUT baryogenesis scenarios incapable of reproducing the observed baryon asymmetry of the Universe. In this work, we revisit the idea to revive GUT baryogenesis, proposed by Fukugita and Yanagida, where right-handed neutrinos erase the lepton asymmetry before the sphaleron processes can significantly wash out the original B +L asymmetry, and in this way one can prevent a total washout of the initial baryon asymmetry. By solving the Boltzmann equations numerically for baryon and lepton asymmetries in a simplified 1 +1 flavor scenario, we can confirm the results of the original work. We further generalize the analysis to a more realistic scenario of three active and two right-handed neutrinos to highlight flavor effects of the right-handed neutrinos. Large regions in the parameter space of the Yukawa coupling and the right-handed neutrino mass featuring successful baryogenesis are identified.

Tracing the Angular Dependence of the CGM

NASA Astrophysics Data System (ADS)

Nattinger, Michael; Christensen, Charlotte

2017-01-01

The circumgalactic media (CGM) is enriched with metals through a process called the baryon cycle, which may play a significant role in the regulation of star formation. While the relationship between the CGM’s baryonic makeup and impact parameter is well documented, the relationship between the baryonic distribution of the CGM and the azimuthal angle out of the plane of the galaxy remains an open question. We investigated the angular distribution of baryons in the CGM by creating mock-absorption line spectra for a high-resolution simulation of a Milky Way-like galaxy at redshift zero. By comparison with data from the Cosmic Origins Spectrograph-Halos survey, we determined that our equivalent widths of HI, MgII, CIII, SiII, and SiIII are consistent with observations. Using our data, we found that low ionization state material is more prevalent at low azimuthal angles and that high ionization state material is more prevalent at high angles within the virial radius. We attributed this increased ionization to higher temperatures at high angles. We also found that the highest metallicity levels appear at high and low azimuthal angles, with lower metallicities at middle angles. This evidence supports the recycled accretion model of CGM baryon flow.

Exploration of particle production mechanisms via angular correlations of π, K, p, Λ with ALICE in pp collisions at √S = 7 TeV

NASA Astrophysics Data System (ADS)

Janik, Małgorzata Anna

2018-02-01

Two-particle correlations as a function of Δη and Δφ are used in many colliding systems to study a wide range of physical phenomena. Examples include the collective behavior of the quark-gluon plasma medium, jets, quantum statistics or Coulomb effects, conservation laws, and resonance decays. In this work, measurements of the correlations of identified particles and their antiparticles (for π, K, p, Λ) are reported in pp collisions at √s = 7 TeV at low transverse momenta. The analysis reveals differences in particle production between baryons and mesons. The correlation functions for mesons exhibit the expected peak dominated by the effects of mini-jet fragmentation and are reproduced well by general purpose Monte Carlo generators. For baryon pairs where both particles have the same baryon number, an anti-correlation structure is observed instead of a peak centered at (Δη, Δφ) = (0, 0); an observation which presents a challenge to models typically used to describe pp data (PYTHIA, PHOJET). This baryon anti-correlation is further interpreted in the context of baryon production mechanisms in the fragmentation processes.

A BARYONIC EFFECT ON THE MERGER TIMESCALE OF GALAXY CLUSTERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Congyao; Yu, Qingjuan; Lu, Youjun, E-mail: yuqj@pku.edu.cn

2016-04-01

Accurate estimation of the merger timescales of galaxy clusters is important for understanding the cluster merger process and further understanding the formation and evolution of the large-scale structure of the universe. In this paper, we explore a baryonic effect on the merger timescale of galaxy clusters by using hydrodynamical simulations. We find that the baryons play an important role in accelerating the merger process. The merger timescale decreases upon increasing the gas fraction of galaxy clusters. For example, the merger timescale is shortened by a factor of up to 3 for merging clusters with gas fractions of 0.15, compared withmore » the timescale obtained with 0 gas fractions. The baryonic effect is significant for a wide range of merger parameters and is particularly more significant for nearly head-on mergers and high merging velocities. The baryonic effect on the merger timescale of galaxy clusters is expected to have an impact on the structure formation in the universe, such as the cluster mass function and massive substructures in galaxy clusters, and a bias of “no-gas” may exist in the results obtained from the dark matter-only cosmological simulations.« less

The baryonic self similarity of dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alard, C., E-mail: alard@iap.fr

2014-06-20

The cosmological simulations indicates that dark matter halos have specific self-similar properties. However, the halo similarity is affected by the baryonic feedback. By using momentum-driven winds as a model to represent the baryon feedback, an equilibrium condition is derived which directly implies the emergence of a new type of similarity. The new self-similar solution has constant acceleration at a reference radius for both dark matter and baryons. This model receives strong support from the observations of galaxies. The new self-similar properties imply that the total acceleration at larger distances is scale-free, the transition between the dark matter and baryons dominatedmore » regime occurs at a constant acceleration, and the maximum amplitude of the velocity curve at larger distances is proportional to M {sup 1/4}. These results demonstrate that this self-similar model is consistent with the basics of modified Newtonian dynamics (MOND) phenomenology. In agreement with the observations, the coincidence between the self-similar model and MOND breaks at the scale of clusters of galaxies. Some numerical experiments show that the behavior of the density near the origin is closely approximated by a Einasto profile.« less

Pattern of (Multi)strange (Anti)baryon Production and Search for Deconfinement

NASA Astrophysics Data System (ADS)

Rafelski, Johann

1998-04-01

We study (multi)strange particle abundances obtained recently in relativistic heavy ion collisions and determine thermal and chemical source parameters(J. Letessier et al., Phys. Lett. B410 (1997) 315--322 hep-ph/9710310 and: Acta Physica Polonica in press, hep- ph/9710340). These are primarily constrained by (multi)strange (anti)baryon relative abundances, which have been measured for Pb--Pb 158 A GeV interactions(I. Kralik, for WA97 collaboration, QM97 Tsukuba, to appear in Nucl. Phys. A) and S-S/W/Pb 200 A GeV interactions(See: proceedings of S'96-Budapest, APH N.S., Heavy Ion Physics 4 (1996) vii--x). We have extended our analysis and have now determined the properties of the particle source using the fitted macro canonical parameters, allowing as required for non-equilibrium dynamics of the locally thermal fireball. We find that in the 158 A GeV Pb--Pb collisions the entropy per baryon, energy per baryon, strangeness per baryon implied by particle spectra are all in the range of values associated commonly with the deconfined QGP phase.

Quark seesaw mechanism, dark U (1 ) symmetry, and the baryon-dark matter coincidence

NASA Astrophysics Data System (ADS)

Gu, Pei-Hong; Mohapatra, Rabindra N.

2017-09-01

We attempt to understand the baryon-dark matter coincidence problem within the quark seesaw extension of the standard model where parity invariance is used to solve the strong C P problem. The S U (2 )L×S U (2 )R×U (1 )B -L gauge symmetry of this model is extended by a dark U (1 )X group plus inclusion of a heavy neutral vector-like fermion χL ,R charged under the dark group which plays the role of dark matter. All fermions are Dirac type in this model. Decay of heavy scalars charged under U (1 )X leads to simultaneous asymmetry generation of the dark matter and baryons after sphaleron effects are included. The U (1 )X group not only helps to stabilize the dark matter but also helps in the elimination of the symmetric part of the dark matter via χ -χ ¯ annihilation. For dark matter mass near the proton mass, it explains why the baryon and dark matter abundances are of similar magnitude (the baryon-dark matter coincidence problem). This model is testable in low threshold (sub-keV) direct dark matter search experiments.

Prospects of detecting baryon and quark superfluidity from cooling neutron stars

PubMed

Page; Prakash; Lattimer; Steiner

2000-09-04

Baryon and quark superfluidity in the cooling of neutron stars are investigated. Future observations will allow us to constrain combinations of the neutron or Lambda-hyperon pairing gaps and the star's mass. However, in a hybrid star with a mixed phase of hadrons and quarks, quark gaps larger than a few tenths of an MeV render quark matter virtually invisible for cooling. If the quark gap is smaller, quark superfluidity could be important, but its effects will be nearly impossible to distinguish from those of other baryonic constituents.

Future prospects of baryon istability search in p-decay and n n(bar) oscillation experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ball, S.J.; Kamyshkov, Y.A.

1996-11-01

These proceedings contain thirty-one papers which review both the theoretical and the experimental status and near future of baryon instability research. Baryon instability is investigated from the vantage point of supersymmetric and unified theories. The interplay between baryogenesis and antimatter is examined. Double beta decay experiments are discussed. The huge Icarus experiment is described with its proton decay capabilities. Neutron-antineutron oscillations investigations are presented, especially efforts with ultra-cold neutrons. Individual papers are indexed separately on the Energy Data Base.

Probing the Big Bang with LEP

NASA Technical Reports Server (NTRS)

Schramm, David N.

1990-01-01

It is shown that LEP probes the Big Bang in two significant ways: (1) nucleosynthesis, and (2) dark matter constraints. In the first case, LEP verifies the cosmological standard model prediction on the number of neutrino types, thus strengthening the conclusion that the cosmological baryon density is approximately 6 percent of the critical value. In the second case, LEP shows that the remaining non-baryonic cosmological matter must be somewhat more massive and/or more weakly interacting than the favorite non-baryonic dark matter candidates of a few years ago.

Evolution of the distribution of baryons in a simulated Local Group Universe

NASA Astrophysics Data System (ADS)

Peirani, S.

2012-12-01

Using hydrodynamical zoom simulations in the standard ΛCDM cosmology, we have investigated the evolution of the distribution of baryons (gas and stars) in a local group-type universe. We found that physical mechanisms able to drive the gas out of the virial radius at high redshifts (such as AGN) will have a stronger impact on the deficit of baryons in the mass budget of Milky Way type-galaxies at present times than those that expel the gas in the longer, late phases of galaxy formation.

Masses and Regge trajectories of triply heavy Ω_{ccc} and Ω_{bbb} baryons

NASA Astrophysics Data System (ADS)

Shah, Zalak; Rai, Ajay Kumar

2017-10-01

The excited state masses of triply charm and triply bottom Ω baryons are exhibited in the present study. The masses are computed for 1 S-5 S, 1 P-5 P, 1 D-4 D and 1 F-2 F states in the Hypercentral Constituent Quark Model (hCQM) with the hyper Coulomb plus linear potential. The triply charm/bottom baryon masses are experimentally unknown so that the Regge trajectories are plotted using computed masses to assign the quantum numbers of these unknown states.

Baryon Content in a Sample of 91 Galaxy Clusters Selected by the South Pole Telescope at 0.2 < z < 1.25

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, I.; et al.

2017-11-02

We estimate total mass (more » $$M_{500}$$), intracluster medium (ICM) mass ($$M_{\\mathrm{ICM}}$$) and stellar mass ($$M_{\\star}$$) in a Sunyaev-Zel'dovich effect (SZE) selected sample of 91 galaxy clusters with masses $$M_{500}\\gtrsim2.5\\times10^{14}M_{\\odot}$$ and redshift $0.2 < z < 1.25$ from the 2500 deg$^2$ South Pole Telescope SPT-SZ survey. The total masses $$M_{500}$$ are estimated from the SZE observable, the ICM masses $$M_{\\mathrm{ICM}}$$ are obtained from the analysis of $Chandra$ X-ray observations, and the stellar masses $$M_{\\star}$$ are derived by fitting spectral energy distribution templates to Dark Energy Survey (DES) $griz$ optical photometry and $WISE$ or $Spitzer$ near-infrared photometry. We study trends in the stellar mass, the ICM mass, the total baryonic mass and the cold baryonic fraction with cluster mass and redshift. We find significant departures from self-similarity in the mass scaling for all quantities, while the redshift trends are all statistically consistent with zero, indicating that the baryon content of clusters at fixed mass has changed remarkably little over the past $$\\approx9$$ Gyr. We compare our results to the mean baryon fraction (and the stellar mass fraction) in the field, finding that these values lie above (below) those in cluster virial regions in all but the most massive clusters at low redshift. Using a simple model of the matter assembly of clusters from infalling groups with lower masses and from infalling material from the low density environment or field surrounding the parent halos, we show that the measured mass trends without strong redshift trends in the stellar mass scaling relation could be explained by a mass and redshift dependent fractional contribution from field material. Similar analyses of the ICM and baryon mass scaling relations provide evidence for the so-called "missing baryons" outside cluster virial regions.« less

Baryon-baryon interactions and spin-flavor symmetry from lattice quantum chromodynamics

NASA Astrophysics Data System (ADS)

Wagman, Michael L.; Winter, Frank; Chang, Emmanuel; Davoudi, Zohreh; Detmold, William; Orginos, Kostas; Savage, Martin J.; Shanahan, Phiala E.; Nplqcd Collaboration

2017-12-01

Lattice quantum chromodynamics is used to constrain the interactions of two octet baryons at the S U (3 ) flavor-symmetric point, with quark masses that are heavier than those in nature (equal to that of the physical strange quark mass and corresponding to a pion mass of ≈806 MeV ). Specifically, the S -wave scattering phase shifts of two-baryon systems at low energies are obtained with the application of Lüscher's formalism, mapping the energy eigenvalues of two interacting baryons in a finite volume to the two-particle scattering amplitudes below the relevant inelastic thresholds. The leading-order low-energy scattering parameters in the two-nucleon systems that were previously obtained at these quark masses are determined with a refined analysis, and the scattering parameters in two other channels containing the Σ and Ξ baryons are constrained for the first time. It is found that the values of these parameters are consistent with an approximate S U (6 ) spin-flavor symmetry in the nuclear and hypernuclear forces that is predicted in the large-Nc limit of QCD. The two distinct S U (6 )-invariant interactions between two baryons are constrained for the first time at this value of the quark masses, and their values indicate an approximate accidental S U (16 ) symmetry. The S U (3 ) irreps containing the N N (1S0), N N (3S1) and 1/√{2 } (Ξ0n +Ξ-p )(3S1) channels unambiguously exhibit a single bound state, while the irrep containing the Σ+p (3S1) channel exhibits a state that is consistent with either a bound state or a scattering state close to threshold. These results are in agreement with the previous conclusions of the NPLQCD collaboration regarding the existence of two-nucleon bound states at this value of the quark masses.

Baryon Content in a Sample of 91 Galaxy Clusters Selected by the South Pole Telescope at 0.2 < z < 1.25

DOE PAGES

Chiu, I.; Mohr, J. J.; McDonald, M.; ...

2018-05-16

Here, we estimate total mass (more » $$M_{500}$$), intracluster medium (ICM) mass ($$M_{\\mathrm{ICM}}$$) and stellar mass ($$M_{\\star}$$) in a Sunyaev-Zel'dovich effect (SZE) selected sample of 91 galaxy clusters with masses $$M_{500}\\gtrsim2.5\\times10^{14}M_{\\odot}$$ and redshift $0.2 < z < 1.25$ from the 2500 deg$^2$ South Pole Telescope SPT-SZ survey. The total masses $$M_{500}$$ are estimated from the SZE observable, the ICM masses $$M_{\\mathrm{ICM}}$$ are obtained from the analysis of $Chandra$ X-ray observations, and the stellar masses $$M_{\\star}$$ are derived by fitting spectral energy distribution templates to Dark Energy Survey (DES) $griz$ optical photometry and $WISE$ or $Spitzer$ near-infrared photometry. We study trends in the stellar mass, the ICM mass, the total baryonic mass and the cold baryonic fraction with cluster mass and redshift. We find significant departures from self-similarity in the mass scaling for all quantities, while the redshift trends are all statistically consistent with zero, indicating that the baryon content of clusters at fixed mass has changed remarkably little over the past $$\\approx9$$ Gyr. We compare our results to the mean baryon fraction (and the stellar mass fraction) in the field, finding that these values lie above (below) those in cluster virial regions in all but the most massive clusters at low redshift. Using a simple model of the matter assembly of clusters from infalling groups with lower masses and from infalling material from the low density environment or field surrounding the parent halos, we show that the measured mass trends without strong redshift trends in the stellar mass scaling relation could be explained by a mass and redshift dependent fractional contribution from field material. Similar analyses of the ICM and baryon mass scaling relations provide evidence for the so-called "missing baryons" outside cluster virial regions.« less

Baryon Content in a Sample of 91 Galaxy Clusters Selected by the South Pole Telescope at 0.2 < z < 1.25

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, I.; et al.

2017-11-02

We estimate total mass (more » $$M_{500}$$), intracluster medium (ICM) mass ($$M_{\\mathrm{ICM}}$$) and stellar mass ($$M_{\\star}$$) in a Sunyaev-Zel'dovich effect (SZE) selected sample of 91 galaxy clusters with masses $$M_{500}\\gtrsim2.5\\times10^{14}M_{\\odot}$$ and redshift $0.2 < z < 1.25$ from the 2500 deg$^2$ South Pole Telescope SPT-SZ survey. The total masses $$M_{500}$$ are estimated from the SZE observable, the ICM masses $$M_{\\mathrm{ICM}}$$ are obtained from the analysis of $Chandra$ X-ray observations, and the stellar masses $$M_{\\star}$$ are derived by fitting spectral energy distribution templates to Dark Energy Survey (DES) $griz$ optical photometry and $WISE$ or $Spitzer$ near-infrared photometry. We study trends in the stellar mass, the ICM mass, the total baryonic mass and the cold baryonic fraction with cluster mass and redshift. We find significant departures from self-similarity in the mass scaling for all quantities, while the redshift trends are all statistically consistent with zero, indicating that the baryon content of clusters at fixed mass has changed remarkably little over the past $$\\approx9$$ Gyr. We compare our results to the mean baryon fraction (and the stellar mass fraction) in the field, finding that these values lie above (below) those in cluster virial regions in all but the most massive clusters at low redshift. Using a simple model of the matter assembly of clusters from infalling groups with lower masses and from infalling material from the low density environment or field surrounding the parent halos, we show that the strong mass and weak redshift trends in the stellar mass scaling relation suggest a mass and redshift dependent fractional contribution from field material. Similar analyses of the ICM and baryon mass scaling relations provide evidence for the so-called 'missing baryons' outside cluster virial regions.« less

Baryon Content in a Sample of 91 Galaxy Clusters Selected by the South Pole Telescope at 0.2 < z < 1.25

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, I.; Mohr, J. J.; McDonald, M.

Here, we estimate total mass (more » $$M_{500}$$), intracluster medium (ICM) mass ($$M_{\\mathrm{ICM}}$$) and stellar mass ($$M_{\\star}$$) in a Sunyaev-Zel'dovich effect (SZE) selected sample of 91 galaxy clusters with masses $$M_{500}\\gtrsim2.5\\times10^{14}M_{\\odot}$$ and redshift $0.2 < z < 1.25$ from the 2500 deg$^2$ South Pole Telescope SPT-SZ survey. The total masses $$M_{500}$$ are estimated from the SZE observable, the ICM masses $$M_{\\mathrm{ICM}}$$ are obtained from the analysis of $Chandra$ X-ray observations, and the stellar masses $$M_{\\star}$$ are derived by fitting spectral energy distribution templates to Dark Energy Survey (DES) $griz$ optical photometry and $WISE$ or $Spitzer$ near-infrared photometry. We study trends in the stellar mass, the ICM mass, the total baryonic mass and the cold baryonic fraction with cluster mass and redshift. We find significant departures from self-similarity in the mass scaling for all quantities, while the redshift trends are all statistically consistent with zero, indicating that the baryon content of clusters at fixed mass has changed remarkably little over the past $$\\approx9$$ Gyr. We compare our results to the mean baryon fraction (and the stellar mass fraction) in the field, finding that these values lie above (below) those in cluster virial regions in all but the most massive clusters at low redshift. Using a simple model of the matter assembly of clusters from infalling groups with lower masses and from infalling material from the low density environment or field surrounding the parent halos, we show that the measured mass trends without strong redshift trends in the stellar mass scaling relation could be explained by a mass and redshift dependent fractional contribution from field material. Similar analyses of the ICM and baryon mass scaling relations provide evidence for the so-called "missing baryons" outside cluster virial regions.« less

Baryon Content in a Sample of 91 Galaxy Clusters Selected by the South Pole Telescope at 0.2 < z < 1.25

NASA Astrophysics Data System (ADS)

Chiu, I.; Mohr, J. J.; McDonald, M.; Bocquet, S.; Desai, S.; Klein, M.; Israel, H.; Ashby, M. L. N.; Stanford, A.; Benson, B. A.; Brodwin, M.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Annis, J.; Bayliss, M.; Benoit-Lévy, A.; Bertin, E.; Bleem, L.; Brooks, D.; Buckley-Geer, E.; Bulbul, E.; Capasso, R.; Carlstrom, J. E.; Rosell, A. Carnero; Carretero, J.; Castander, F. J.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; Davis, C.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Drlica-Wagner, A.; Eifler, T. F.; Evrard, A. E.; Flaugher, B.; García-Bellido, J.; Garmire, G.; Gaztanaga, E.; Gerdes, D. W.; Gonzalez, A.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gupta, N.; Gutierrez, G.; Hlavacek-L, J.; Honscheid, K.; James, D. J.; Jeltema, T.; Kraft, R.; Krause, E.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Lahav, O.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Miquel, R.; Murray, S.; Nord, B.; Ogando, R. L. C.; Plazas, A. A.; Rapetti, D.; Reichardt, C. L.; Romer, A. K.; Roodman, A.; Sanchez, E.; Saro, A.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sharon, K.; Smith, R. C.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Stalder, B.; Stern, C.; Strazzullo, V.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Vikram, V.; Walker, A. R.; Weller, J.; Zhang, Y.

2018-05-01

We estimate total mass (M500), intracluster medium (ICM) mass (MICM) and stellar mass (M⋆) in a Sunyaev-Zel'dovich effect (SZE) selected sample of 91 galaxy clusters with masses M500 ≳ 2.5 × 1014M⊙ and redshift 0.2 < z < 1.25 from the 2500 ° ^2 South Pole Telescope SPT-SZ survey. The total masses M500 are estimated from the SZE observable, the ICM masses MICM are obtained from the analysis of Chandra X-ray observations, and the stellar masses M⋆ are derived by fitting spectral energy distribution templates to Dark Energy Survey (DES) griz optical photometry and WISE or Spitzer near-infrared photometry. We study trends in the stellar mass, the ICM mass, the total baryonic mass and the cold baryonic fraction with cluster halo mass and redshift. We find significant departures from self-similarity in the mass scaling for all quantities, while the redshift trends are all statistically consistent with zero, indicating that the baryon content of clusters at fixed mass has changed remarkably little over the past ≈9 Gyr. We compare our results to the mean baryon fraction (and the stellar mass fraction) in the field, finding that these values lie above (below) those in cluster virial regions in all but the most massive clusters at low redshift. Using a simple model of the matter assembly of clusters from infalling groups with lower masses and from infalling material from the low density environment or field surrounding the parent halos, we show that the measured mass trends without strong redshift trends in the stellar mass scaling relation could be explained by a mass and redshift dependent fractional contribution from field material. Similar analyses of the ICM and baryon mass scaling relations provide evidence for the so-called "missing baryons" outside cluster virial regions.

Outskirts of Distant Galaxies in Absorption

NASA Astrophysics Data System (ADS)

Chen, Hsiao-Wen

QSO absorption spectroscopy provides a sensitive probe of both the neutral medium and diffuse ionized gas in the distant Universe. It extends 21 cm maps of gaseous structures around low-redshift galaxies both to lower gas column densities and to higher redshifts. Combining galaxy surveys with absorption-line observations of gas around galaxies enables comprehensive studies of baryon cycles in galaxy outskirts over cosmic time. This chapter presents a review of the empirical understanding of the cosmic neutral gas reservoir from studies of damped Lyα absorbers (DLAs). It describes the constraints on the star formation relation and chemical enrichment history in the outskirts of distant galaxies from DLA studies. A brief discussion of available constraints on the ionized circumgalactic gas from studies of lower column density Lyα absorbers and associated ionic absorption transitions is presented at the end.

Measurement of matter-antimatter differences in beauty baryon decays

NASA Astrophysics Data System (ADS)

Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; , A. A. Alves, Jr.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Archilli, F.; D'Argent, P.; Romeu, J. Arnau; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baker, S.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Baszczyk, M.; Batozskaya, V.; Batsukh, B.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Betti, F.; Bettler, M.-O.; Beuzekom, M. Van; Bezshyiko, I.; Bifani, S.; Billoir, P.; Bird, T.; Birnkraut, A.; Bitadze, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bonivento, W.; Borgheresi, A.; Borghi, S.; Borisyak, M.; Borsato, M.; Bossu, F.; Boubdir, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britsch, M.; Britton, T.; Brodzicka, J.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Gomez, M. Calvo; Camboni, A.; Campana, P.; Perez, D. Campora; Perez, D. H. Campora; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Akiba, K. Carvalho; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chatzikonstantinidis, G.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chobanova, V.; Chrzaszcz, M.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coquereau, S.; Corti, G.; Corvo, M.; Sobral, C. M. Costa; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Marinho, F. Da Cunha; Dall'Occo, E.; Dalseno, J.; David, P. N. Y.; Davis, A.; Francisco, O. De Aguiar; Bruyn, K. De; Capua, S. De; Cian, M. De; Miranda, J. M. De; Paula, L. De; Serio, M. De; Simone, P. De; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Buono, L. Del; Demmer, M.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Canto, A. Di; Dijkstra, H.; Dordei, F.; Dorigo, M.; Suárez, A. Dosil; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dungs, K.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Déléage, N.; Easo, S.; Ebert, M.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Farley, N.; Farry, S.; Fay, R.; Fazzini, D.; Ferguson, D.; Albor, V. Fernandez; Prieto, A. Fernandez; Ferrari, F.; Rodrigues, F. Ferreira; Ferro-Luzzi, M.; Filippov, S.; Fini, R. A.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fleuret, F.; Fohl, K.; Fontana, M.; Fontanelli, F.; Forshaw, D. C.; Forty, R.; Lima, V. Franco; Frank, M.; Frei, C.; Fu, J.; Furfaro, E.; Färber, C.; Torreira, A. Gallas; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Martin, L. M. Garcia; Pardiñas, J. Garcıa; Tico, J. Garra; Garrido, L.; Garsed, P. J.; Gascon, D.; Gaspar, C.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianì, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gorelov, I. V.; Gotti, C.; Gándara, M. Grabalosa; Diaz, R. Graciani; Cardoso, L. A. Granado; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Griffith, P.; Grillo, L.; Cazon, B. R. Gruberg; Grünberg, O.; Gushchin, E.; Guz, Yu.; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hatch, M.; He, J.; Head, T.; Heister, A.; Hennessy, K.; Henrard, P.; Henry, L.; Morata, J. A. Hernando; Herwijnen, E. Van; Heß, M.; Hicheur, A.; Hill, D.; Hombach, C.; Hopchev, H.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hussain, N.; Hutchcroft, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jiang, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Kariuki, J. M.; Karodia, S.; Kecke, M.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.; Klimaszewski, K.; Koliiev, S.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kozachuk, A.; Kozeiha, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Gac, R. Le; Leerdam, J. Van; Lees, J.-P.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Cid, E. Lemos; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Liu, X.; Loh, D.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Martinez, M. Lucio; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Maev, O.; Maguire, K.; Malde, S.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Manning, P.; Maratas, J.; Marchand, J. F.; Marconi, U.; Benito, C. Marin; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Santos, D. Martinez; Vidal, F. Martinez; Tostes, D. Martins; Massacrier, L. M.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Melnychuk, D.; Merk, M.; Merli, A.; Michielin, E.; Milanes, D. A.; Minard, M.-N.; Mitzel, D. S.; Mogini, A.; Rodriguez, J. Molina; Monroy, I. A.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mulder, M.; Mussini, M.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen-Mau, C.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J. G.; Goicochea, J. M. Otalora; Otto, A.; Owen, P.; Oyanguren, A.; Pais, P. R.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parker, W.; Parkes, C.; Passaleva, G.; Pastore, A.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Altarelli, M. Pepe; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Olloqui, E. Picatoste; Pietrzyk, B.; Pikies, M.; Pinci, D.; Pistone, A.; Piucci, A.; Playfer, S.; Casasus, M. Plo; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Popov, A.; Popov, D.; Popovici, B.; Poslavskii, S.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Pernas, M. Ramos; Rangel, M. S.; Raniuk, I.; Raven, G.; Redi, F.; Reichert, S.; Reis, A. C. Dos; Alepuz, C. Remon; Renaudin, V.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Molina, V. Rives; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Lopez, J. A. Rodriguez; Perez, P. Rodriguez; Rogozhnikov, A.; Roiser, S.; Romanovskiy, V.; Vidal, A. Romero; Ronayne, J. W.; Rotondo, M.; Rudolph, M. S.; Ruf, T.; Valls, P. Ruiz; Silva, J. J. Saborido; Sadykhov, E.; Sagidova, N.; Saitta, B.; Guimaraes, V. Salustino; Mayordomo, C. Sanchez; Sedes, B. Sanmartin; Santacesaria, R.; Rios, C. Santamarina; Santimaria, M.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schubert, K.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sergi, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Siddi, B. G.; Coutinho, R. Silva; de Oliveira, L. Silva; Simi, G.; Simone, S.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, E.; Smith, I. T.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; de Paula, B. Souza; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stemmle, S.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Sun, L.; Sutcliffe, W.; Swientek, K.; Syropoulos, V.; Szczekowski, M.; Szumlak, T.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Thomas, E.; Tilburg, J. Van; Tilley, M. J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Toriello, F.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Traill, M.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tully, A.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valassi, A.; Valat, S.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Regueiro, P. Vazquez; Vecchi, S.; Veghel, M. Van; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Vernet, M.; Vesterinen, M.; Viaud, B.; Vieira, D.; Diaz, M. Vieites; Vilasis-Cardona, X.; Volkov, V.; Vollhardt, A.; Voneki, B.; Vorobyev, A.; Vorobyev, V.; Voß, C.; Vries, J. A. De; Sierra, C. Vázquez; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wang, J.; Ward, D. R.; Wark, H. M.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wraight, K.; Wright, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yin, H.; Yu, J.; Yuan, X.; Yushchenko, O.; Zarebski, K. A.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhang, Y.; Zhelezov, A.; Zheng, Y.; Zhokhov, A.; Zhu, X.; Zhukov, V.; Zucchelli, S.

2017-04-01

Differences in the behaviour of matter and antimatter have been observed in K and B meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as CP violation. Here, using data from the LHCb experiment at the Large Hadron Collider, we search for CP-violating asymmetries in the decay angle distributions of Λb0 baryons decaying to pπ-π+π- and pπ-K+K- final states. These four-body hadronic decays are a promising place to search for sources of CP violation both within and beyond the standard model of particle physics. We find evidence for CP violation in Λb0 to pπ-π+π- decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for CP violation in the baryon sector.

Production cross sections of hyperons and charmed baryons from e+e- annihilation near √{s }=10.52 GeV

NASA Astrophysics Data System (ADS)

Niiyama, M.; Sumihama, M.; Nakano, T.; Adachi, I.; Aihara, H.; Al Said, S.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Ayad, R.; Babu, V.; Badhrees, I.; Bakich, A. M.; Bansal, V.; Barberio, E.; Berger, M.; Bhardwaj, V.; Bhuyan, B.; Biswal, J.; Bobrov, A.; Bonvicini, G.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chang, M.-C.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, K.; Choi, Y.; Cinabro, D.; Dash, N.; Di Carlo, S.; Doležal, Z.; Drásal, Z.; Dutta, D.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Fulsom, B. G.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gillard, R.; Goldenzweig, P.; Haba, J.; Hara, T.; Hayasaka, K.; Hayashii, H.; Iijima, T.; Inami, K.; Ishikawa, A.; Itoh, R.; Iwasaki, Y.; Jacobs, W. W.; Jaegle, I.; Jin, Y.; Joffe, D.; Joo, K. K.; Julius, T.; Karyan, G.; Kato, Y.; Katrenko, P.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, K. T.; Kim, M. J.; Kim, S. H.; Kim, Y. J.; Kinoshita, K.; Kodyš, P.; Kotchetkov, D.; Križan, P.; Krokovny, P.; Kulasiri, R.; Kuzmin, A.; Kwon, Y.-J.; Lange, J. S.; Lee, I. S.; Li, C. H.; Li, L.; Li, Y.; Li Gioi, L.; Libby, J.; Liventsev, D.; Luo, T.; Masuda, M.; Matsuda, T.; Matvienko, D.; Merola, M.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Moon, H. K.; Mori, T.; Mussa, R.; Nakano, E.; Nakao, M.; Nanut, T.; Nath, K. J.; Natkaniec, Z.; Nayak, M.; Nisar, N. K.; Nishida, S.; Ogawa, S.; Ono, H.; Pakhlov, P.; Pakhlova, G.; Pal, B.; Pardi, S.; Park, H.; Pedlar, T. K.; Piilonen, L. E.; Pulvermacher, C.; Ritter, M.; Sahoo, H.; Sakai, Y.; Sandilya, S.; Santelj, L.; Sato, Y.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Seidl, R.; Seino, Y.; Senyo, K.; Sevior, M. E.; Shebalin, V.; Shen, C. P.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Simon, F.; Sokolov, A.; Solovieva, E.; Starič, M.; Sumiyoshi, T.; Takizawa, M.; Tanida, K.; Tenchini, F.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Van Hulse, C.; Varner, G.; Vossen, A.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Watanabe, Y.; Widmann, E.; Williams, K. M.; Won, E.; Yamashita, Y.; Ye, H.; Yuan, C. Z.; Yusa, Y.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.; Belle Collaboration

2018-04-01

We measure the inclusive production cross sections of hyperons and charmed baryons from e+e- annihilation using a 800 fb-1 data sample taken near the ϒ (4 S ) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. The feed-down contributions from heavy particles are subtracted using our data, and the direct production cross sections are presented for the first time. The production cross sections divided by the number of spin states for S =-1 hyperons follow an exponential function with a single slope parameter except for the Σ (1385 )+resonance. Suppression for Σ (1385 )+ and Ξ (1530 )0 hyperons is observed. Among the production cross sections of charmed baryons, a factor of 3 difference for Λc+ states over Σc states is observed. This observation suggests a diquark structure for these baryons.

Mass spectra and radiative transitions of doubly heavy baryons in a relativized quark model

NASA Astrophysics Data System (ADS)

Lü, Qi-Fang; Wang, Kai-Lei; Xiao, Li-Ye; Zhong, Xian-Hui

2017-12-01

We study the mass spectra and radiative decays of doubly heavy baryons within the diquark picture in a relativized quark model. The mass of the JP=1 /2+ Ξc c ground state is predicted to be 3606 MeV, which is consistent with the mass of Ξcc ++(3621 ) newly observed by the LHCb Collaboration. The predicted mass gap between two S -wave states, Ξcc * (JP=3 /2+) and Ξc c (JP=1 /2+), is 69 MeV. Furthermore, the radiative transitions of doubly heavy baryons are also estimated by using the realistic wave functions obtained from relativized quark model. The radiative decay widths of Ξcc *++→Ξcc ++γ and Ξcc *+→Ξcc +γ are predicted to be about 7 and 4 keV, respectively. These predictions of doubly heavy baryons can provide helpful information for future experimental searches.

Octet baryon masses and sigma terms from an SU(3) chiral extrapolation

NASA Astrophysics Data System (ADS)

Young, R. D.; Thomas, A. W.

2010-01-01

We report an analysis of the impressive new lattice simulation results for octet baryon masses in 2+1-flavor QCD. The analysis is based on a low-order expansion about the chiral SU(3) limit in which the symmetry breaking arises from terms linear in the quark masses plus the variation of the Goldstone boson masses in the leading chiral loops. The baryon masses evaluated at the physical light-quark masses are in remarkable agreement with the experimental values, with a model dependence considerably smaller than the rather small statistical uncertainty. From the mass formulas one can evaluate the sigma commutators for all octet baryons. This yields an accurate value for the pion-nucleon sigma commutator. It also yields the first determination of the strangeness sigma term based on 2+1-flavor lattice QCD and, in general, the sigma commutators provide a resolution to the difficult issue of fine-tuning the strange-quark mass.

Life Outside the Golden Window: Statistical Angles on the Signal-to-Noise Problem

NASA Astrophysics Data System (ADS)

Wagman, Michael

2018-03-01

Lattice QCD simulations of multi-baryon correlation functions can predict the structure and reactions of nuclei without encountering the baryon chemical potential sign problem. However, they suffer from a signal-to-noise problem where Monte Carlo estimates of observables have quantum fluctuations that are exponentially larger than their average values. Recent lattice QCD results demonstrate that the complex phase of baryon correlations functions relates the baryon signal-to-noise problem to a sign problem and exhibits unexpected statistical behavior resembling a heavy-tailed random walk on the unit circle. Estimators based on differences of correlation function phases evaluated at different Euclidean times are discussed that avoid the usual signal-to-noise problem, instead facing a signal-to-noise problem as the time interval associated with the phase difference is increased, and allow hadronic observables to be determined from arbitrarily large-time correlation functions.

QCD inequalities for the nucleon mass and the free energy of baryonic matter.

PubMed

Cohen, Thomas D

2003-07-18

The positivity of the integrand of certain Euclidean space functional integrals for two flavor QCD with degenerate quark masses implies that the free energy per unit volume for QCD with a baryon chemical potential mu(B) (and zero isospin chemical potential) is greater than the free energy with an isospin chemical potential mu(I)=(2 mu(B)/N(c)) (and zero baryon chemical potential). The same result applies to QCD with any number of heavy flavors in addition to the two light flavors so long as the chemical potential is understood as applying to the light quark contributions to the baryon number. This relation implies a bound on the nucleon mass: there exists a particle X in QCD (presumably the pion) such that M(N)> or =(N(c) m(X)/2 I(X)) where m(X) is the mass of the particle and I(X) is its isospin.

Big-bang nucleosynthesis and the baryon density of the universe.

PubMed

Copi, C J; Schramm, D N; Turner, M S

1995-01-13

For almost 30 years, the predictions of big-bang nucleosynthesis have been used to test the big-bang model to within a fraction of a second of the bang. The agreement between the predicted and observed abundances of deuterium, helium-3, helium-4, and lithium-7 confirms the standard cosmology model and allows accurate determination of the baryon density, between 1.7 x 10(-31) and 4.1 x 10(-31) grams per cubic centimeter (corresponding to about 1 to 15 percent of the critical density). This measurement of the density of ordinary matter is pivotal to the establishment of two dark-matter problems: (i) most of the baryons are dark, and (ii) if the total mass density is greater than about 15 percent of the critical density, as many determinations indicate, the bulk of the dark matter must be "non-baryonic," composed of elementary particles left from the earliest moments.

Production cross sections of hyperons and charmed baryons from e + e - annihilation near s = 10.52 GeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niiyama, M.; Sumihama, M.; Nakano, T.

Here, we measure the inclusive production cross sections of hyperons and charmed baryons from e +e - annihilation using a 800 fb -1 data sample taken near the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e +e - collider. The feed-down contributions from heavy particles are subtracted using our data, and the direct production cross sections are presented for the first time. The production cross sections divided by the number of spin states for S = -1 hyperons follow an exponential function with a single slope parameter except for the Σ(1385) + resonance. Suppression for Σ(1385) + and Ξ(1530) 0 hyperons is observed. Among the production cross sections of charmed baryons, a factor of 3 difference for Λmore » $$+\\atop{c}$$ states over Σ c states is observed. This observation suggests a diquark structure for these baryons.« less

Production cross sections of hyperons and charmed baryons from e + e - annihilation near s = 10.52 GeV

DOE PAGES

Niiyama, M.; Sumihama, M.; Nakano, T.; ...

2018-04-09

Here, we measure the inclusive production cross sections of hyperons and charmed baryons from e +e - annihilation using a 800 fb -1 data sample taken near the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e +e - collider. The feed-down contributions from heavy particles are subtracted using our data, and the direct production cross sections are presented for the first time. The production cross sections divided by the number of spin states for S = -1 hyperons follow an exponential function with a single slope parameter except for the Σ(1385) + resonance. Suppression for Σ(1385) + and Ξ(1530) 0 hyperons is observed. Among the production cross sections of charmed baryons, a factor of 3 difference for Λmore » $$+\\atop{c}$$ states over Σ c states is observed. This observation suggests a diquark structure for these baryons.« less

Report on the ESO and Excellence Cluster Universe Workshop "Galaxy Ecosystem: Flow of Baryons through Galaxies"

NASA Astrophysics Data System (ADS)

Mainieri, V.; Popesso, P.

2017-12-01

This conference focussed on the "baryon cycle", namely the flow of baryons through galaxies. The following aspects were discussed: a) the gas inflow into systems through streams of pristine gas or as drizzles of recycled material; b) the conversion of this gas into stars; and c) the ejection of gas enriched with heavy elements through powerful outflows. Understanding these different but mutually connected phases is of fundamental importance when studying the details of galaxy formation and evolution through cosmic time. This conference was held following the month-long workshop of the Munich Institute for Astro- and Particle Physics (MIAPP) entitled: "In & out: What rules the galaxy baryon cycle?" It therefore provided an opportunity to share the main outcomes of the MIAPP workshop with a larger audience, including many young outstanding scientists who could not attend the MIAPP workshop.

Preliminary Diffusive Clearance of Silicon Nanopore Membranes in a Parallel Plate Configuration for Renal Replacement Therapy

PubMed Central

Kim, Steven; Heller, James; Iqbal, Zohora; Kant, Rishi; Kim, Eun Jung; Durack, Jeremy; Saeed, Maythem; Do, Loi; Hetts, Steven; Wilson, Mark; Brakeman, Paul; Fissell, William H.; Roy, Shuvo

2015-01-01

Silicon nanopore membranes (SNM) with compact geometry and uniform pore size distribution have demonstrated a remarkable capacity for hemofiltration. These advantages could potentially be used for hemodialysis. Here we present an initial evaluation of the SNM’s mechanical robustness, diffusive clearance, and hemocompatibility in a parallel plate configuration. Mechanical robustness of the SNM was demonstrated by exposing membranes to high flows (200ml/min) and pressures (1,448mmHg). Diffusive clearance was performed in an albumin solution and whole blood with blood and dialysate flow rates of 25ml/min. Hemocompatibility was evaluated using scanning electron microscopy and immunohistochemistry after 4-hours in an extra-corporeal porcine model. The pressure drop across the flow cell was 4.6mmHg at 200ml/min. Mechanical testing showed that SNM could withstand up to 775.7mmHg without fracture. Urea clearance did not show an appreciable decline in blood versus albumin solution. Extra-corporeal studies showed blood was successfully driven via the arterial-venous pressure differential without thrombus formation. Bare silicon showed increased cell adhesion with a 4.1 fold increase and 1.8 fold increase over polyethylene-glycol (PEG)-coated surfaces for tissue plasminogen factor (t-PA) and platelet adhesion (CD-41), respectively. These initial results warrant further design and development of a fully scaled SNM-based parallel plate dialyzer for renal replacement therapy. PMID:26692401

Sol-Gel Glass Holographic Light-Shaping Diffusers

NASA Technical Reports Server (NTRS)

Yu, Kevin; Lee, Kang; Savant, Gajendra; Yin, Khin Swe (Lillian)

2005-01-01

Holographic glass light-shaping diffusers (GLSDs) are optical components for use in special-purpose illumination systems (see figure). When properly positioned with respect to lamps and areas to be illuminated, holographic GLSDs efficiently channel light from the lamps onto specified areas with specified distributions of illumination for example, uniform or nearly uniform irradiance can be concentrated with intensity confined to a peak a few degrees wide about normal incidence, over a circular or elliptical area. Holographic light diffusers were developed during the 1990s. The development of the present holographic GLSDs extends the prior development to incorporate sol-gel optical glass. To fabricate a holographic GLSD, one records a hologram on a sol-gel silica film formulated specially for this purpose. The hologram is a quasi-random, micro-sculpted pattern of smoothly varying changes in the index of refraction of the glass. The structures in this pattern act as an array of numerous miniature lenses that refract light passing through the GLSD, such that the transmitted light beam exhibits a precisely tailored energy distribution. In comparison with other light diffusers, holographic GLSDs function with remarkably high efficiency: they typically transmit 90 percent or more of the incident lamp light onto the designated areas. In addition, they can withstand temperatures in excess of 1,000 C. These characteristics make holographic GLSDs attractive for use in diverse lighting applications that involve high temperatures and/or requirements for high transmission efficiency for ultraviolet, visible, and near-infrared light. Examples include projectors, automobile headlights, aircraft landing lights, high-power laser illuminators, and industrial and scientific illuminators.

Subhalo demographics in the Illustris simulation: effects of baryons and halo-to-halo variation

NASA Astrophysics Data System (ADS)

Chua, Kun Ting Eddie; Pillepich, Annalisa; Rodriguez-Gomez, Vicente; Vogelsberger, Mark; Bird, Simeon; Hernquist, Lars

2017-12-01

We study the abundance of subhaloes in the hydrodynamical cosmological simulation Illustris, which includes both baryons and dark matter in a cold dark matter volume 106.5 Mpc a side. We compare Illustris to its dark-matter only (DMO) analogue, Illustris-Dark and quantify the effects of baryonic processes on the demographics of subhaloes in the host mass range 1011-3 × 1014 M⊙. We focus on both the evolved (z = 0) subhalo cumulative mass functions (SHMF) and the statistics of subhaloes ever accreted, i.e. infall SHMF. We quantify the variance in subhalo abundance at fixed host mass and investigate the physical reasons responsible for such scatter. We find that in Illustris, baryonic physics impacts both the infall and z = 0 subhalo abundance by tilting the DMO function and suppressing the abundance of low-mass subhaloes. The breaking of self-similarity in the subhalo abundance at z = 0 is enhanced by the inclusion of baryonic physics. The non-monotonic alteration of the evolved subhalo abundances can be explained by the modification of the concentration-mass relation of Illustris hosts compared to Illustris-Dark. Interestingly, the baryonic implementation in Illustris does not lead to an increase in the halo-to-halo variation compared to Illustris-Dark. In both cases, the normalized intrinsic scatter today is larger for Milky Way-like haloes than for cluster-sized objects. For Milky Way-like haloes, it increases from about eight per cent at infall to about 25 per cent at the current epoch. In both runs, haloes of fixed mass formed later host more subhaloes than early formers.

Spreading out and staying sharp - creating diverse rotation curves via baryonic and self-interaction effects

NASA Astrophysics Data System (ADS)

Creasey, Peter; Sameie, Omid; Sales, Laura V.; Yu, Hai-Bo; Vogelsberger, Mark; Zavala, Jesús

2017-06-01

Galactic rotation curves are a fundamental constraint for any cosmological model. We use controlled N-body simulations of galaxies to study the gravitational effect of baryons in a scenario with collisionless cold dark matter (CDM) versus one with a self-interacting dark matter (SIDM) component. In particular, we examine the inner profiles of the rotation curves in the velocity range Vmax = [30-250] km s-1, whose diversity has been found to be greater than predicted by the ΛCDM scenario. We find that the scatter in the observed rotation curves exceeds that predicted by dark matter only mass-concentration relations in either the CDM nor SIDM models. Allowing for realistic baryonic content and spatial distributions, however, helps create a large variety of rotation curve shapes, which is in a better agreement with observations in the case of self-interactions due to the characteristic cored profiles being more accommodating to the slowly rising rotation curves than CDM. We find individual fits to model two of the most remarkable outliers of similar Vmax, UGC 5721 and IC 2574 - the former a cusp-like rotation curve and the latter a seemingly 8-kpc-cored profile. This diversity in SIDM arises as permutations of overly concentrated haloes with compact baryonic distributions versus underdense haloes with extended baryonic discs. The SIDM solution is promising and its feasibility ultimately depends on the sampling of the halo mass-concentration relation and its interplay with the baryonic profiles, emphasizing the need for a better understanding of the frequency of extreme outliers present in current observational samples.

Baryon-baryon interactions and spin-flavor symmetry from lattice quantum chromodynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagman, Michael L.; Winter, Frank; Chang, Emmanuel

Lattice quantum chromodynamics is used to constrain the interactions of two octet baryons at the SU(3) flavor-symmetric point, with quark masses that are heavier than those in nature (equal to that of the physical strange quark mass and corresponding to a pion mass ofmore » $$\\approx 806~\\tt{MeV}$$). Specifically, the S-wave scattering phase shifts of two-baryon systems at low energies are obtained with the application of L\\"uscher's formalism, mapping the energy eigenvalues of two interacting baryons in a finite volume to the two-particle scattering amplitudes below the relevant inelastic thresholds. The values of the leading-order low-energy scattering parameters in the irreducible representations of SU(3) are consistent with an approximate SU(6) spin-flavor symmetry in the nuclear and hypernuclear forces that is predicted in the large-$$N_c$$ limit of QCD. The two distinct SU(6)-invariant interactions between two baryons are constrained at this value of the quark masses, and their values indicate an approximate accidental SU(16) symmetry. The SU(3) irreducible representations containing the $$NN~({^1}S_0)$$, $$NN~({^3}S_1)$$ and $$\\frac{1}{\\sqrt{2}}(\\Xi^0n+\\Xi^-p)~({^3}S_1)$$ channels unambiguously exhibit a single bound state, while the irreducible representation containing the $$\\Sigma^+ p~({^3}S_1)$$ channel exhibits a state that is consistent with either a bound state or a scattering state close to threshold. These results are in agreement with the previous conclusions of the NPLQCD collaboration regarding the existence of two-nucleon bound states at this value of the quark masses.« less

Flavor structure of Λ baryons from lattice QCD: From strange to charm quarks

NASA Astrophysics Data System (ADS)

Gubler, Philipp; Takahashi, Toru T.; Oka, Makoto

2016-12-01

We study Λ baryons of spin-parity 1/2± with either a strange or charm valence quark in full 2 +1 flavor lattice QCD. Multiple S U (3 ) singlet and octet operators are employed to generate the desired single baryon states on the lattice. Via the variational method, the couplings of these states to the different operators provide information about the flavor structure of the Λ baryons. We make use of the gauge configurations of the PACS-CS Collaboration and chirally extrapolate the results for the masses and S U (3 ) flavor components to the physical point. We furthermore gradually change the hopping parameter of the heaviest quark from strange to charm to study how the properties of the Λ baryons evolve as a function of the heavy quark mass. It is found that the baryon energy levels increase almost linearly with the quark mass. Meanwhile, the flavor structure of most of the states remains stable, with the exception of the lowest 1/2- state, which changes from a flavor singlet Λ to a Λc state with singlet and octet components of comparable size. Finally, we discuss whether our findings can be interpreted with the help of a simple quark model and find that the negative-parity Λc states can be naturally explained as diquark excitations of the light u and d quarks. On the other hand, the quark-model picture does not appear to be adequate for the negative-parity Λ states, suggesting the importance of other degrees of freedom to describe them.

Baryon-baryon interactions and spin-flavor symmetry from lattice quantum chromodynamics

DOE PAGES

Wagman, Michael L.; Winter, Frank; Chang, Emmanuel; ...

2017-12-28

Lattice quantum chromodynamics is used to constrain the interactions of two octet baryons at the SU(3) flavor-symmetric point, with quark masses that are heavier than those in nature (equal to that of the physical strange quark mass and corresponding to a pion mass ofmore » $$\\approx 806~\\tt{MeV}$$). Specifically, the S-wave scattering phase shifts of two-baryon systems at low energies are obtained with the application of L\\"uscher's formalism, mapping the energy eigenvalues of two interacting baryons in a finite volume to the two-particle scattering amplitudes below the relevant inelastic thresholds. The values of the leading-order low-energy scattering parameters in the irreducible representations of SU(3) are consistent with an approximate SU(6) spin-flavor symmetry in the nuclear and hypernuclear forces that is predicted in the large-$$N_c$$ limit of QCD. The two distinct SU(6)-invariant interactions between two baryons are constrained at this value of the quark masses, and their values indicate an approximate accidental SU(16) symmetry. The SU(3) irreducible representations containing the $$NN~({^1}S_0)$$, $$NN~({^3}S_1)$$ and $$\\frac{1}{\\sqrt{2}}(\\Xi^0n+\\Xi^-p)~({^3}S_1)$$ channels unambiguously exhibit a single bound state, while the irreducible representation containing the $$\\Sigma^+ p~({^3}S_1)$$ channel exhibits a state that is consistent with either a bound state or a scattering state close to threshold. These results are in agreement with the previous conclusions of the NPLQCD collaboration regarding the existence of two-nucleon bound states at this value of the quark masses.« less

The baryonic Tully-Fisher relationship for S{sup 4}G galaxies and the 'condensed' baryon fraction of galaxies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaritsky, Dennis; Courtois, Helene; Sorce, Jenny

We combine data from the Spitzer Survey for Stellar Structure in Galaxies, a recently calibrated empirical stellar mass estimator from Eskew et al., and an extensive database of H I spectral line profiles to examine the baryonic Tully-Fisher (BTF) relation. We find (1) that the BTF has lower scatter than the classic Tully-Fisher (TF) relation and is better described as a linear relationship, confirming similar previous results, (2) that the inclusion of a radial scale in the BTF decreases the scatter but only modestly, as seen previously for the TF relation, and (3) that the slope of the BTF, whichmore » we find to be 3.5 ± 0.2 (Δlog M {sub baryon}/Δlog v{sub c} ), implies that on average a nearly constant fraction (∼0.4) of all baryons expected to be in a halo are 'condensed' onto the central region of rotationally supported galaxies. The condensed baryon fraction, M {sub baryon}/M {sub total}, is, to our measurement precision, nearly independent of galaxy circular velocity (our sample spans circular velocities, v {sub c} , between 60 and 250 km s{sup –1}, but is extended to v{sub c} ∼ 10 km s{sup –1} using data from the literature). The observed galaxy-to-galaxy scatter in this fraction is generally ≤ a factor of 2 despite fairly liberal selection criteria. These results imply that cooling and heating processes, such as cold versus hot accretion, mass loss due to stellar winds, and active galactic nucleus driven feedback, to the degree that they affect the global galactic properties involved in the BTF, are independent of halo mass for galaxies with 10 < v{sub c} < 250 km s{sup –1} and typically introduce no more than a factor of two range in the resulting M {sub baryon}/M {sub total}. Recent simulations by Aumer et al. of a small sample of disk galaxies are in excellent agreement with our data, suggesting that current simulations are capable of reproducing the global properties of individual disk galaxies. More detailed comparison to models using the BTF holds great promise, but awaits improved determinations of the stellar masses.« less

76 FR 38074 - Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-200B, 747-200C, 747...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-29

... withstand fail-safe loads. DATES: We must receive comments on this proposed AD by August 15, 2011. ADDRESSES... pressurization and the inability of the airplane fuselage to withstand fail-safe loads. Actions Since Existing AD... withstand fail-safe loads. Compliance (f) You are responsible for having the actions required by this AD...

Strangeness S =-1 hyperon-nucleon scattering in covariant chiral effective field theory

NASA Astrophysics Data System (ADS)

Li, Kai-Wen; Ren, Xiu-Lei; Geng, Li-Sheng; Long, Bingwei

2016-07-01

Motivated by the successes of covariant baryon chiral perturbation theory in one-baryon systems and in heavy-light systems, we study relevance of relativistic effects in hyperon-nucleon interactions with strangeness S =-1 . In this exploratory work, we follow the covariant framework developed by Epelbaum and Gegelia to calculate the Y N scattering amplitude at leading order. By fitting the five low-energy constants to the experimental data, we find that the cutoff dependence is mitigated, compared with the heavy-baryon approach. Nevertheless, the description of the experimental data remains quantitatively similar at leading order.

Meson and baryon dispersion relations with Brillouin fermions

NASA Astrophysics Data System (ADS)

Dürr, Stephan; Koutsou, Giannis; Lippert, Thomas

2012-12-01

We study the dispersion relations of mesons and baryons built from Brillouin quarks on one Nf=2 gauge ensemble provided by QCDSF. For quark masses up to the physical strange quark mass, there is hardly any improvement over the Wilson discretization, if either action is link-smeared and tree-level clover improved. For quark masses in the range of the physical charm quark mass, the Brillouin action still shows a perfect relativistic behavior, while the Wilson action induces severe cutoff effects. As an application we determine the masses of the Ωc0, Ωcc+ and Ωccc++ baryons on that ensemble.

Strangeness driven phase transitions in compressed baryonic matter and their relevance for neutron stars and core collapsing supernovae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raduta, Ad. R.; Gulminelli, F.; Oertel, M.

2015-02-24

We discuss the thermodynamics of compressed baryonic matter with strangeness within non-relativistic mean-field models with effective interactions. The phase diagram of the full baryonic octet under strangeness equilibrium is built and discussed in connection with its relevance for core-collapse supernovae and neutron stars. A simplified framework corresponding to (n, p, Λ)(+e)-mixtures is employed in order to test the sensitivity of the existence of a phase transition on the (poorely constrained) interaction coupling constants and the compatibility between important hyperonic abundances and 2M{sub ⊙} neutron stars.

Dense cold baryonic matter

NASA Astrophysics Data System (ADS)

Stavinskiy, A. V.

2017-09-01

A possibility of studying cold nuclear matter on the Nuclotron-NICA facility at baryonic densities characteristic of and higher than at the center of a neutron star is considered based on the data from cumulative processes. A special rare-event kinematic trigger for collisions of relativistic ions is proposed for effective selection of events accompanied by production of dense baryonic systems. Possible manifestations of new matter states under these unusual conditions and an experimental program for their study are discussed. Various experimental setups are proposed for these studies, and a possibility of using experimental setups at the Nuclotron-NICA facility for this purpose is considered.

BM@N and MPD experiments at NICA

NASA Astrophysics Data System (ADS)

Kekelidze, Vladimir; Kolesnikov, Vadim; Sorin, Alexander

2018-02-01

The project NICA (Nuclotron-based Ion Collider fAcility) aims to study hot and baryon rich QCD matter in heavy ion collisions in the energy range = 4 - 11 GeV. The rich heavy-ion physics program will be performed at two experiments, BM@N (Baryonic Matter at Nuclotron) at beams extracted from the Nuclotron, and at MPD (Multi-Purpose Detector) at the NICA collider. This program covers a variety of phenomena in strongly interacting matter of the highest baryonic density, which includes study of collective effects, production of hyperon and hypernuclei, in-medium modification of meson properties, and event-by-event fluctuations.

Chiral gravitational waves and baryon superfluid dark matter

NASA Astrophysics Data System (ADS)

Alexander, Stephon; McDonough, Evan; Spergel, David N.

2018-05-01

We develop a unified model of darkgenesis and baryogenesis involving strongly interacting dark quarks, utilizing the gravitational anomaly of chiral gauge theories. In these models, both the visible and dark baryon asymmetries are generated by the gravitational anomaly induced by the presence of chiral primordial gravitational waves. We provide a concrete model of an SU(2) gauge theory with two massless quarks. In this model, the dark quarks condense and form a dark baryon charge superfluid (DBS), in which the Higgs-mode acts as cold dark matter. We elucidate the essential features of this dark matter scenario and discuss its phenomenological prospects.

Globally baryon symmetric cosmology, GUT spontaneous symmetry breaking, and the structure of the universe

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Brown, R. W.

1979-01-01

Grand unified theories (GUT) such as SU(5), with spontaneous symmetry breaking, can lead more naturally to a globally baryon symmetric big bang cosmology with a domain structure than to a totally asymmetric cosmology. The symmetry is broken at random in causally independent domains, favoring neither a baryon nor an antibaryon excess on a universal scale. Because of the additional freedom in the high-energy physics allowed by such GUT gauge theories, new observational tests may be possible. Arguments in favor of this cosmology and various observational tests are discussed.

Cosmological baryon and lepton number in the presence of electroweak fermion-number violation

NASA Technical Reports Server (NTRS)

Harvey, Jeffrey A.; Turner, Michael S.

1990-01-01

In the presence of rapid fermion-number violation due to nonperturbative electroweak effects certain relations between the baryon number of the Universe and the lepton numbers of the Universe are predicted. In some cases the electron-neutrino asymmetry is exactly specified in terms of the baryon asymmetry. Without introducing new particles, beyond the usual quarks and leptons, it is necessary that the Universe possess a nonzero value of B - L prior to the epoch of fermion-number violation if baryon and lepton asymmetries are to survive. Contrary to intuition, even though electroweak processes violate B + L, a nonzero value of B + L persists after the epoch of rapid fermion-number violation. If the standard model is extended to include lepton-number violation, for example through Majorana neutrino masses, then electroweak processes will reduce the baryon number to zero even in the presence of an initial B - L unless 20 M(sub L) approximately greater than the square root of (T(sub B - L) m(sub P1)) where M(sub L) sets the scale of lepton number violation and T(sub B - L) is the temperature at which a B - L asymmetry is produced. In many models this implies that neutrinos must be so light that they cannot contribute appreciably to the mass density of the Universe.

Low-lying baryon spectrum with two dynamical twisted mass fermions

NASA Astrophysics Data System (ADS)

Alexandrou, C.; Baron, R.; Carbonell, J.; Drach, V.; Guichon, P.; Jansen, K.; Korzec, T.; Pène, O.

2009-12-01

The masses of the low-lying baryons are evaluated using two degenerate flavors of twisted mass sea quarks corresponding to pseudoscalar masses in the range of about 270-500 MeV. The strange valence quark mass is tuned to reproduce the mass of the kaon in the physical limit. The tree-level Symanzik improved gauge action is employed. We use lattices of spatial size 2.1 and 2.7 fm at two values of the lattice spacing with r0/a=5.22(2) and r0/a=6.61(3). We check for both finite volume and cutoff effects on the baryon masses. We performed a detailed study of the chiral extrapolation of the octet and decuplet masses using SU(2) χPT. The lattice spacings determined using the nucleon mass at the physical point are consistent with the values extracted using the pion decay constant. We examine the issue of isospin symmetry breaking for the octet and decuplet baryons and its dependence on the lattice spacing. We show that in the continuum limit isospin breaking is consistent with zero, as expected. The baryon masses that we find after taking the continuum limit and extrapolating to the physical limit are in good agreement with experiment.

Baryon spectrum with Nf=2+1+1 twisted mass fermions

NASA Astrophysics Data System (ADS)

Alexandrou, C.; Drach, V.; Jansen, K.; Kallidonis, C.; Koutsou, G.

2014-10-01

The masses of the low-lying baryons are evaluated using a total of ten ensembles of dynamical twisted mass fermion gauge configurations. The simulations are performed using two degenerate flavors of light quarks, and a strange and a charm quark fixed to approximately their physical values. The light sea quarks correspond to pseudo scalar masses in the range of about 210 to 430 MeV. We use the Iwasaki improved gluonic action at three values of the coupling constant corresponding to lattice spacing a=0.094, 0.082 and 0.065 fm determined from the nucleon mass. We check for both finite volume and cutoff effects on the baryon masses. We examine the issue of isospin symmetry breaking for the octet and decuplet baryons and its dependence on the lattice spacing. We show that in the continuum limit isospin breaking is consistent with zero, as expected. We performed a chiral extrapolation of the forty baryon masses using SU(2) χPT. After taking the continuum limit and extrapolating to the physical pion mass our results are in good agreement with experiment. We provide predictions for the mass of the doubly charmed Ξcc*, as well as of the doubly and triply charmed Ωs that have not yet been determined experimentally.

CP asymmetries in Strange Baryon Decays

NASA Astrophysics Data System (ADS)

Bigi, I. I.; Kang, Xian-Wei; Li, Hai-Bo

2018-01-01

While indirect and direct CP violation (CPV) has been established in the decays of strange and beauty mesons, no CPV has yet been found for baryons. There are different paths to finding CP asymmetry in the decays of strange baryons; they are all highly non-trivial. The HyperCP Collaboration has probed CPV in the decays of single Ξ and Λ [1]. We discuss future lessons from {{{e}}}+{{{e}}}- collisions at BESIII/BEPCII: probing decays of pairs of strange baryons, namely Λ, Σ and Ξ. Realistic goals are to learn about non-perturbative QCD. One can hope to find CPV in the decays of strange baryons; one can also dream of finding the impact of New Dynamics. We point out that an important new era will start with the BESIII/BEPCII data accumulated by the end of 2018. This also supports new ideas to trigger {{J}}/{{\\psi }}\\to \\bar{{{Λ }}}{{Λ }} at the LHCb collaboration. Supported by National Science Foundation (PHY-1520966), National Natural Science Foundation of China (11335009, 11125525), Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U1532257), the National Key Basic Research Program of China (2015CB856700), Key Research Program of Frontier Sciences, CAS, (QYZDJ-SSW-SLH003), XWK’s work is also supported by MOST (Taiwan) (104-2112-M-001-022)

Quark-level analogue of nuclear fusion with doubly heavy baryons.

PubMed

Karliner, Marek; Rosner, Jonathan L

2017-11-01

The essence of nuclear fusion is that energy can be released by the rearrangement of nucleons between the initial- and final-state nuclei. The recent discovery of the first doubly charmed baryon , which contains two charm quarks (c) and one up quark (u) and has a mass of about 3,621 megaelectronvolts (MeV) (the mass of the proton is 938 MeV) also revealed a large binding energy of about 130 MeV between the two charm quarks. Here we report that this strong binding enables a quark-rearrangement, exothermic reaction in which two heavy baryons (Λ c ) undergo fusion to produce the doubly charmed baryon and a neutron n (), resulting in an energy release of 12 MeV. This reaction is a quark-level analogue of the deuterium-tritium nuclear fusion reaction (DT → 4 He n). The much larger binding energy (approximately 280 MeV) between two bottom quarks (b) causes the analogous reaction with bottom quarks () to have a much larger energy release of about 138 MeV. We suggest some experimental setups in which the highly exothermic nature of the fusion of two heavy-quark baryons might manifest itself. At present, however, the very short lifetimes of the heavy bottom and charm quarks preclude any practical applications of such reactions.

Pion-nucleon scattering in covariant baryon chiral perturbation theory with explicit Delta resonances

NASA Astrophysics Data System (ADS)

Yao, De-Liang; Siemens, D.; Bernard, V.; Epelbaum, E.; Gasparyan, A. M.; Gegelia, J.; Krebs, H.; Meißner, Ulf-G.

2016-05-01

We present the results of a third order calculation of the pion-nucleon scattering amplitude in a chiral effective field theory with pions, nucleons and delta resonances as explicit degrees of freedom. We work in a manifestly Lorentz invariant formulation of baryon chiral perturbation theory using dimensional regularization and the extended on-mass-shell renormalization scheme. In the delta resonance sector, the on mass-shell renormalization is realized as a complex-mass scheme. By fitting the low-energy constants of the effective Lagrangian to the S- and P -partial waves a satisfactory description of the phase shifts from the analysis of the Roy-Steiner equations is obtained. We predict the phase shifts for the D and F waves and compare them with the results of the analysis of the George Washington University group. The threshold parameters are calculated both in the delta-less and delta-full cases. Based on the determined low-energy constants, we discuss the pion-nucleon sigma term. Additionally, in order to determine the strangeness content of the nucleon, we calculate the octet baryon masses in the presence of decuplet resonances up to next-to-next-to-leading order in SU(3) baryon chiral perturbation theory. The octet baryon sigma terms are predicted as a byproduct of this calculation.

Semileptonic decays of charmed and beauty baryons with heavy sterile neutrinos in the final state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramazanov, Sabir; Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect 7a, Moscow 117312

We obtain tree-level estimates of various differential branching ratios of heavy baryon decays with massive sterile neutrinos {nu}{sub x} in the final state. Generally, charmed baryons are found to be less promising than charmed mesons, in contrast to b hadrons. In the latter case, branching ratios of beauty mesons and baryons into sterile neutrinos are of the same order. As a consequence, at high energies beauty baryons give contribution to sterile neutrino production comparable to the contribution of beauty mesons (up to about 15%). Experimental limits on active-to-sterile mixing are quite strong for neutrinos lighter than D mesons but formore » heavier neutrinos they are weaker. As an example, for neutrino masses in the range 2 GeV < or approx. m{sub {nu}{sub x}} < or approx. 2.5 GeV, current data imply that the bounds on {lambda}{sub b}-hyperon branching ratios into sterile neutrinos are Br({lambda}{sub b}{yields}{lambda}{sub c}+e{sup -}+{nu}{sub x}) < or approx. 1.3x10{sup -5}-1.7x10{sup -6} and Br({lambda}{sub b}{yields}{lambda}{sub c}+{mu}{sup -}+{nu}{sub x}) < or approx. 3.9x10{sup -7}-1.4x10{sup -7}.« less

Cross-section measurement for quasi-elastic production of charmed baryons in νN interactions

NASA Astrophysics Data System (ADS)

Kayis-Topaksu, A.; Onengüt, G.; van Dantzig, R.; de Jong, M.; Melzer, O.; Oldeman, R. G. C.; Pesen, E.; Spada, F. R.; Visschers, J. L.; Güler, M.; Köse, U.; Serin-Zeyrek, M.; Sever, R.; Tolun, P.; Zeyrek, M. T.; Catanesi, M. G.; de Serio, M.; Ieva, M.; Muciaccia, M. T.; Radicioni, E.; Simone, S.; Bülte, A.; Winter, K.; van de Vyver, B.; Vilain, P.; Wilquet, G.; Pittoni, G. L.; Saitta, B.; di Capua, E.; Ogawa, S.; Shibuya, H.; Artamonov, A.; Chizhov, M.; Doucet, M.; Hristova, I. R.; Kawamura, T.; Kolev, D.; Meinhard, H.; Panman, J.; Papadopoulos, I. M.; Ricciardi, S.; Rozanov, A.; Tsenov, R.; Uiterwijk, J. W. E.; Zucchelli, P.; Goldberg, J.; Chikawa, M.; Arik, E.; Song, J. S.; Yoon, C. S.; Kodama, K.; Ushida, N.; Aoki, S.; Hara, T.; Delbar, T.; Favart, D.; Grégoire, G.; Kalinin, S.; Maklioueva, I.; Gorbunov, P.; Khovansky, V.; Shamanov, V.; Tsukerman, I.; Bruski, N.; Frekers, D.; Hoshino, K.; Kawada, J.; Komatsu, M.; Miyanishi, M.; Nakamura, M.; Nakano, T.; Narita, K.; Niu, K.; Niwa, K.; Nonaka, N.; Sato, O.; Toshito, T.; Buontempo, S.; Cocco, A. G.; D'Ambrosio, N.; de Lellis, G.; De Rosa, G.; di Capua, F.; Ereditato, A.; Fiorillo, G.; Marotta, A.; Messina, M.; Migliozzi, P.; Pistillo, C.; Scotto Lavina, L.; Strolin, P.; Tioukov, V.; Nakamura, K.; Okusawa, T.; Dore, U.; Loverre, P. F.; Ludovici, L.; Righini, P.; Rosa, G.; Santacesaria, R.; Satta, A.; Barbuto, E.; Bozza, C.; Grella, G.; Romano, G.; Sirignano, C.; Sorrentino, S.; Sato, Y.; Tezuka, I.; CHORUS Collaboration

2003-11-01

A study of quasi-elastic production of charmed baryons in charged-current interactions of neutrinos with the nuclear emulsion target of CHORUS is presented. In a sample of about 46 000 interactions located in the emulsion, candidates for decays of short-lived particles were identified by using new automatic scanning systems and later confirmed through visual inspection. Criteria based both on the topological and kinematical characteristics of quasi-elastic charm production allowed a clear separation between events of this type and those in which charm is produced in deep inelastic processes. A final sample containing 13 candidates consistent with quasi-elastic production of a charmed baryon with an estimated background of 1.7 events was obtained. At the average neutrino energy of 27 GeV the cross-section for the total quasi-elastic production of charmed baryons relative to the νN charged-current cross-section was measured to be σ(QE)/σ(CC)=(0.23+0.12-0.06(stat)+0.02-0.03(syst))×10-2. Through an analysis of the topology at the production and decay vertices the relative cross-sections were measured separately for singly (Λc+,Σc+,Σc+∗) and doubly (Σc++,Σc++∗) charged baryons.

The qqqqq components and hidden flavor contributions to the baryon magnetic moments

DOE Office of Scientific and Technical Information (OSTI.GOV)

An, C. S.; Li, Q. B.; Riska, D. O.

2006-11-15

The contributions from the qqqqq components to the magnetic moments of the octet as well as the {delta}{sup ++} and {omega}{sup -} decuplet baryons are calculated for the configurations that are expected to have the lowest energy if the hyperfine interaction depends on both spin and flavor. The contributions from the uu,dd, and the ss components are given separately. It is shown that addition of qqqqq admixtures to the ground state baryons can improve the overall description of the magnetic moments of the baryon octet and decuplet in the quark model without SU(3) flavor symmetry breaking, beyond that of themore » different constituent masses of the strange and light-flavor quarks. The explicit flavor (and spin) wave functions for all the possible configurations of the qqqqq components with light and strange qq pairs are given for the baryon octet and decuplet. Admixtures of {approx}10% of the qqqqq configuration where the flavor-spin symmetry is [4]{sub FS}[22]{sub F}[22]{sub S}, which is likely to have the lowest energy, in particular reduces the deviation from the empirical values of the magnetic moments {sigma}{sup -} and the {xi}{sup 0} compared with the static qqq quark model.« less

Quark-level analogue of nuclear fusion with doubly heavy baryons

NASA Astrophysics Data System (ADS)

Karliner, Marek; Rosner, Jonathan L.

2017-11-01

The essence of nuclear fusion is that energy can be released by the rearrangement of nucleons between the initial- and final-state nuclei. The recent discovery of the first doubly charmed baryon , which contains two charm quarks (c) and one up quark (u) and has a mass of about 3,621 megaelectronvolts (MeV) (the mass of the proton is 938 MeV) also revealed a large binding energy of about 130 MeV between the two charm quarks. Here we report that this strong binding enables a quark-rearrangement, exothermic reaction in which two heavy baryons (Λc) undergo fusion to produce the doubly charmed baryon and a neutron n (), resulting in an energy release of 12 MeV. This reaction is a quark-level analogue of the deuterium-tritium nuclear fusion reaction (DT → 4He n). The much larger binding energy (approximately 280 MeV) between two bottom quarks (b) causes the analogous reaction with bottom quarks () to have a much larger energy release of about 138 MeV. We suggest some experimental setups in which the highly exothermic nature of the fusion of two heavy-quark baryons might manifest itself. At present, however, the very short lifetimes of the heavy bottom and charm quarks preclude any practical applications of such reactions.

{lambda}{sub b}{yields}p, {lambda} transition form factors from QCD light-cone sum rules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Yuming; Lue Caidian; Shen Yuelong

2009-10-01

Light-cone sum rules for the {lambda}{sub b}{yields}p, {lambda} transition form factors are derived from the correlation functions expanded by the twist of the distribution amplitudes of the {lambda}{sub b} baryon. In terms of the {lambda}{sub b} three-quark distribution amplitude models constrained by the QCD theory, we calculate the form factors at small momentum transfers and compare the results with those estimated in the conventional light-cone sum rules (LCSR) and perturbative QCD approaches. Our results indicate that the two different versions of sum rules can lead to the consistent numbers of form factors responsible for {lambda}{sub b}{yields}p transition. The {lambda}{sub b}{yields}{lambda}more » transition form factors from LCSR with the asymptotic {lambda} baryon distribution amplitudes are found to be almost 1 order larger than those obtained in the {lambda}{sub b}-baryon LCSR, implying that the preasymptotic corrections to the baryonic distribution amplitudes are of great importance. Moreover, the SU(3) symmetry breaking effects between the form factors f{sub 1}{sup {lambda}{sub b}}{sup {yields}}{sup p} and f{sub 1}{sup {lambda}{sub b}}{sup {yields}}{sup {lambda}} are computed as 28{sub -8}{sup +14}% in the framework of {lambda}{sub b}-baryon LCSR.« less

Cosmological perturbation theory for baryons and dark matter: One-loop corrections in the renormalized perturbation theory framework

NASA Astrophysics Data System (ADS)

Somogyi, Gábor; Smith, Robert E.

2010-01-01

We generalize the renormalized perturbation theory (RPT) formalism of Crocce and Scoccimarro [M. Crocce and R. Scoccimarro, Phys. Rev. DPRVDAQ1550-7998 73, 063519 (2006)10.1103/PhysRevD.73.063519] to deal with multiple fluids in the Universe and here we present the complete calculations up to the one-loop level in the RPT. We apply this approach to the problem of following the nonlinear evolution of baryon and cold dark matter (CDM) perturbations, evolving from the distinct sets of initial conditions, from the high redshift post-recombination Universe right through to the present day. In current theoretical and numerical models of structure formation, it is standard practice to treat baryons and CDM as an effective single matter fluid—the so-called dark matter only modeling. In this approximation, one uses a weighed sum of late-time baryon and CDM transfer functions to set initial mass fluctuations. In this paper we explore whether this approach can be employed for high precision modeling of structure formation. We show that, even if we only follow the linear evolution, there is a large-scale scale-dependent bias between baryons and CDM for the currently favored WMAP5 ΛCDM model. This time evolving bias is significant (>1%) until the present day, when it is driven towards unity through gravitational relaxation processes. Using the RPT formalism we test this approximation in the nonlinear regime. We show that the nonlinear CDM power spectrum in the two-component fluid differs from that obtained from an effective mean-mass one-component fluid by ˜3% on scales of order k˜0.05hMpc-1 at z=10, and by ˜0.5% at z=0. However, for the case of the nonlinear evolution of the baryons the situation is worse and we find that the power spectrum is suppressed, relative to the total matter, by ˜15% on scales k˜0.05hMpc-1 at z=10, and by ˜3%-5% at z=0. Importantly, besides the suppression of the spectrum, the baryonic acoustic oscillation (BAO) features are amplified for baryon and slightly damped for CDM spectra. If we compare the total matter power spectra in the two- and one-component fluid approaches, then we find excellent agreement, with deviations being <0.5% throughout the evolution. Consequences: high precision modeling of the large-scale distribution of baryons in the Universe cannot be achieved through an effective mean-mass one-component fluid approximation; detection significance of BAO will be amplified in probes that study baryonic matter, relative to probes that study the CDM or total mass only. The CDM distribution can be modeled accurately at late times and the total matter at all times. This is good news for probes that are sensitive to the total mass, such as gravitational weak lensing as existing modeling techniques are good enough. Lastly, we identify an analytic approximation that greatly simplifies the evaluation of the full PT expressions, and it is better than <1% over the full range of scales and times considered.

Skyrmion black hole hair: Conservation of baryon number by black holes and observable manifestations

NASA Astrophysics Data System (ADS)

Dvali, Gia; Gußmann, Alexander

2016-12-01

We show that the existence of black holes with classical skyrmion hair invalidates standard proofs that global charges, such as the baryon number, cannot be conserved by a black hole. By carefully analyzing the standard arguments based on a Gedankenexperiment in which a black hole is seemingly-unable to return the baryon number that it swallowed, we identify inconsistencies in this reasoning, which does not take into the account neither the existence of skyrmion black holes nor the baryon/skyrmion correspondence. We then perform a refined Gedankenexperiment by incorporating the new knowledge and show that no contradiction with conservation of baryon number takes place at any stage of black hole evolution. Our analysis also indicates no conflict between semi-classical black holes and the existence of baryonic gauge interaction arbitrarily-weaker than gravity. Next, we study classical cross sections of a minimally-coupled massless probe scalar field scattered by a skyrmion black hole. We investigate how the skyrmion hair manifests itself by comparing this cross section with the analogous cross section caused by a Schwarzschild black hole which has the same ADM mass as the skyrmion black hole. Here we find an order-one difference in the positions of the characteristic peaks in the cross sections. The peaks are shifted to smaller scattering angles when the skyrmion hair is present. This comes from the fact that the skyrmion hair changes the near horizon geometry of the black hole when compared to a Schwarzschild black hole with same ADM mass. We keep the study of this second aspect general so that the qualitative results which we obtain can also be applied to black holes with classical hair of different kind.

Study of excited charm-strange baryons with evidence for new baryons {xi}{sub c}(3055){sup +} and {xi}{sub c}(3123){sup +}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Bona, M.; Boutigny, D.

We present a study of excited charm-strange baryon states produced in e{sup +}e{sup -} annihilations at or near a center-of-mass energy of 10.58 GeV, in a data sample with an integrated luminosity of 384 fb{sup -1} recorded with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings at the Stanford Linear Accelerator Center. We study strong decays of charm-strange baryons to {lambda}{sub c}{sup +}K{sub S}{sup 0}, {lambda}{sub c}{sup +}K{sup -}, {lambda}{sub c}{sup +}K{sup -}{pi}{sup +}, {lambda}{sub c}{sup +}K{sub S}{sup 0}{pi}{sup -}, {lambda}{sub c}{sup +}K{sub S}{sup 0}{pi}{sup -}{pi}{sup +}, and {lambda}{sub c}{sup +}K{sup -}{pi}{sup +}{pi}{sup -}. This study confirmsmore » the existence of the states {xi}{sub c}(2980){sup +}, {xi}{sub c}(3077){sup +}, and {xi}{sub c}(3077){sup 0}, with a more accurate determination of the {xi}{sub c}(2980){sup +} mass and width. We also present evidence for two new states, {xi}{sub c}(3055){sup +} and {xi}{sub c}(3123){sup +}, decaying through the intermediate-resonant modes {sigma}{sub c}(2455){sup ++}K{sup -} and {sigma}{sub c}(2520){sup ++}K{sup -}, respectively. For each of these baryons, we measure the yield in each final state, determine the statistical significance, and calculate the product of the production cross section and branching fractions. We also measure the masses and widths of these excited charm-strange baryons.« less

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measuring H(z) and DA(z) at z = 0.57 with clustering wedges

NASA Astrophysics Data System (ADS)

Kazin, Eyal A.; Sánchez, Ariel G.; Cuesta, Antonio J.; Beutler, Florian; Chuang, Chia-Hsun; Eisenstein, Daniel J.; Manera, Marc; Padmanabhan, Nikhil; Percival, Will J.; Prada, Francisco; Ross, Ashley J.; Seo, Hee-Jong; Tinker, Jeremy; Tojeiro, Rita; Xu, Xiaoying; Brinkmann, J.; Joel, Brownstein; Nichol, Robert C.; Schlegel, David J.; Schneider, Donald P.; Thomas, Daniel

2013-10-01

We analyse the 2D correlation function of the Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey (BOSS) CMASS sample of massive galaxies of the ninth data release to measure cosmic expansion H and the angular diameter distance DA at a mean redshift of = 0.57. We apply, for the first time, a new correlation function technique called clustering wedges ξΔμ(s). Using a physically motivated model, the anisotropic baryonic acoustic feature in the galaxy sample is detected at a significance level of 4.7σ compared to a featureless model. The baryonic acoustic feature is used to obtain model-independent constraints cz/H/rs = 12.28 ± 0.82 (6.7 percent accuracy) and DA/rs = 9.05 ± 0.27 (3.0 per cent) with a correlation coefficient of -0.5, where rs is the sound horizon scale at the end of the baryonic drag era. We conduct thorough tests on the data and 600 simulated realizations, finding robustness of the results regardless of the details of the analysis method. Combining this with rs constraints from the cosmic microwave background, we obtain H(0.57) = 90.8 ± 6.2 km s-1 Mpc-1 and DA(0.57) = 1386 ± 45 Mpc. We use simulations to forecast results of the final BOSS CMASS data set. We apply the reconstruction technique on the simulations demonstrating that the sharpening of the anisotropic baryonic acoustic feature should improve the detection as well as tighten constraints of H and DA by ˜30 per cent on average.

Baryons and their Effects on Planes of Satellites Around Milky Way-Mass Galaxies

NASA Astrophysics Data System (ADS)

Ahmed, Sheehan H.

2017-01-01

Both the Milky Way and Andromeda have thin, coherently rotating planes of satellites. In this study I try to find similar satellite planes around four different Milky Way-mass simulations, each run both as dark matter-only and with baryons included. In all halos I am able to identify a planar configuration that significantly maximizes the number of satellites that are members of a plane. The member satellites that make up this maximum plane are consistently different between the dark matter-only and baryonic versions of the same run. In the baryonic runs, satellites are more likely to be destroyed through interactions with the disk, and substructure tends to infall later. Hence, studying satellite planes in dark matter-only simulations is misleading, because they will be composed of different satellite members than those that would exist if baryons were included. Additionally, baryonic runs tend to have less radially concentrated satellite distributions. Since all planes pass through the center of the galaxy, it is much harder to create a plane containing a large number of satellites from a random distribution if the satellites have a low radial concentration. Andromeda’s low radial satellite concentration is possibly a key reason behind why the plane in Andromeda is highly significant. Despite this, when co-rotation is considered, none of the satellite planes identified for the simulated galaxies are as statistically significant as the observed planes around the Milky Way and Andromeda. I will then show that co-rotation in our satellite planes can be attributed to how the satellites are accreted through filaments from the cosmic web. When two sets of opposing filaments contribute, coherent planes are more likely to form, when there are no well-defined filaments, there is a lack of coherent satellite rotation.

How does non-linear dynamics affect the baryon acoustic oscillation?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugiyama, Naonori S.; Spergel, David N., E-mail: nao.s.sugiyama@gmail.com, E-mail: dns@astro.princeton.edu

2014-02-01

We study the non-linear behavior of the baryon acoustic oscillation in the power spectrum and the correlation function by decomposing the dark matter perturbations into the short- and long-wavelength modes. The evolution of the dark matter fluctuations can be described as a global coordinate transformation caused by the long-wavelength displacement vector acting on short-wavelength matter perturbation undergoing non-linear growth. Using this feature, we investigate the well known cancellation of the high-k solutions in the standard perturbation theory. While the standard perturbation theory naturally satisfies the cancellation of the high-k solutions, some of the recently proposed improved perturbation theories do notmore » guarantee the cancellation. We show that this cancellation clarifies the success of the standard perturbation theory at the 2-loop order in describing the amplitude of the non-linear power spectrum even at high-k regions. We propose an extension of the standard 2-loop level perturbation theory model of the non-linear power spectrum that more accurately models the non-linear evolution of the baryon acoustic oscillation than the standard perturbation theory. The model consists of simple and intuitive parts: the non-linear evolution of the smoothed power spectrum without the baryon acoustic oscillations and the non-linear evolution of the baryon acoustic oscillations due to the large-scale velocity of dark matter and due to the gravitational attraction between dark matter particles. Our extended model predicts the smoothing parameter of the baryon acoustic oscillation peak at z = 0.35 as ∼ 7.7Mpc/h and describes the small non-linear shift in the peak position due to the galaxy random motions.« less

Baryon Asymmetry of the Universe (1/2)

ScienceCinema

None

2017-12-09

In two lectures, the following topics will be discussed: (1) Why baryon asymmetry is a problem at all (2) Review of the Sakharov's conditions (3) Why old models based on GUT did not work (4) Electroweak baryogenesis (5) Leptogenesis (6) Connections to the near-future experiments

Baryon Asymmetry of the Universe (2/2)

ScienceCinema

None

2017-12-09

In two lectures, the following topics will be discussed: (1) Why baryon asymmetry is a problem at all (2) Review of the Sakharov's conditions (3) Why old models based on GUT did not work (4) Electroweak baryogenesis (5) Leptogenesis (6) Connections to the near-future experiments

THE EIGHTFOLD WAY: A THEORY OF STRONG INTERACTION SYMMETRY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gell-Mann, M.

1961-03-15

A new model of the higher symmetry of elementary particles is introduced ln which the eight known baryons are treated as a supermultiplet, degenerate in the limit of unitary symmetry but split into isotopic spin multiplets by a symmetry-breaking term. The symmetry violation is sscribed phenomenologically to the mass differences. The baryons correspond to an eight-dimensional irreducible representation of the unitary group. The pion and K meson fit into a similar set of eight particles along with a predicted pseudoscalar meson X/sup o/ having I = 0. A ninth vector meson coupled to the baryon current can be accomodated natarallymore » in the scheme. It is predicted that the eight baryons should all have the same spin and parity and that pseudoscalar and vector mesons should form octets with possible additional singlets. The mathematics of the unitary group is described by considering three fictitious leptons, nu , e/sup -/ , and mu /sup -/, which may throw light on the structure of weak interactions. (D. L.C.)« less

Reconciling threshold and subthreshold expansions for pion-nucleon scattering

NASA Astrophysics Data System (ADS)

Siemens, D.; Ruiz de Elvira, J.; Epelbaum, E.; Hoferichter, M.; Krebs, H.; Kubis, B.; Meißner, U.-G.

2017-07-01

Heavy-baryon chiral perturbation theory (ChPT) at one loop fails in relating the pion-nucleon amplitude in the physical region and for subthreshold kinematics due to loop effects enhanced by large low-energy constants. Studying the chiral convergence of threshold and subthreshold parameters up to fourth order in the small-scale expansion, we address the question to what extent this tension can be mitigated by including the Δ (1232) as an explicit degree of freedom and/or using a covariant formulation of baryon ChPT. We find that the inclusion of the Δ indeed reduces the low-energy constants to more natural values and thereby improves consistency between threshold and subthreshold kinematics. In addition, even in the Δ-less theory the resummation of 1 /mN corrections in the covariant scheme improves the results markedly over the heavy-baryon formulation, in line with previous observations in the single-baryon sector of ChPT that so far have evaded a profound theoretical explanation.

Is the continuous matter creation cosmology an alternative to ΛCDM?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fabris, J.C.; Pacheco, J.A. de Freitas; Piattella, O.F., E-mail: fabris@pq.cnpq.br, E-mail: pacheco@oca.eu, E-mail: oliver.piattella@pq.cnpq.br

2014-06-01

The matter creation cosmology is revisited, including the evolution of baryons and dark matter particles. The creation process affects only dark matter and not baryons. The dynamics of the ΛCDM model can be reproduced only if two conditions are satisfied: 1) the entropy density production rate and the particle density variation rate are equal and 2) the (negative) pressure associated to the creation process is constant. However, the matter creation model predicts a present dark matter-to-baryon ratio much larger than that observed in massive X-ray clusters of galaxies, representing a potential difficulty for the model. In the linear regime, amore » fully relativistic treatment indicates that baryons are not affected by the creation process but this is not the case for dark matter. Both components evolve together at early phases but lately the dark matter density contrast decreases since the background tends to a constant value. This behaviour produces a negative growth factor, in disagreement with observations, being a further problem for this cosmology.« less

Measurement of the production cross section for charmed baryons in proton–nucleus interactions at 70 GeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryadovikov, V. N., E-mail: riadovikov@ihep.ru; Aleev, A. N.; Ardashev, E. N.

2016-03-15

The results of an analysis of data from the SERP-E-184 experiment devoted to studying mechanisms of the production of charmed particles in proton–nucleus interactions at 70 GeV and their decays are presented. The data in question were obtained upon irradiating the SVD-2 active target consisting of carbon, silicon, and lead plates with a beam of 70-GeV protons. A detailed simulation on the basis of the FRITIOF7.02 and GEANT3.21 code packages made it possible to optimize event-selection criteria and to calculate the detection efficiency for Λ{sub c}{sup +} baryons. After selecting a signal from the threebody decay of a Λ{sub c}{supmore » +} baryon, the inclusive cross section for its production at near-threshold energies, its lifetime, and the parameter of the A dependence of the cross section were found. The Λ{sub c}{sup +} -baryon yields are tabulated along with data from other experiments and theoretical predictions.« less

Charmed bottom baryon spectroscopy from lattice QCD

DOE PAGES

Brown, Zachary S.; Detmold, William; Meinel, Stefan; ...

2014-11-19

In this study, we calculate the masses of baryons containing one, two, or three heavy quarks using lattice QCD. We consider all possible combinations of charm and bottom quarks, and compute a total of 36 different states with J P = 1/2 + and J P = 3/2 +. We use domain-wall fermions for the up, down, and strange quarks, a relativistic heavy-quark action for the charm quarks, and nonrelativistic QCD for the bottom quarks. Our analysis includes results from two different lattice spacings and seven different pion masses. We perform extrapolations of the baryon masses to the continuum limitmore » and to the physical pion mass using SU(4|2) heavy-hadron chiral perturbation theory including 1/m Q and finite-volume effects. For the 14 singly heavy baryons that have already been observed, our results agree with the experimental values within the uncertainties. We compare our predictions for the hitherto unobserved states with other lattice calculations and quark-model studies.« less

Reconciling threshold and subthreshold expansions for pion–nucleon scattering

DOE PAGES

Siemens, D.; Ruiz de Elvira, J.; Epelbaum, E.; ...

2017-04-21

Heavy-baryon chiral perturbation theory (ChPT) at one loop fails in relating the pion–nucleon amplitude in the physical region and for subthreshold kinematics due to loop effects enhanced by large low-energy constants. Studying the chiral convergence of threshold and subthreshold parameters up to fourth order in the small-scale expansion, we address the question to what extent this tension can be mitigated by including the Δ(1232) as an explicit degree of freedom and/or using a covariant formulation of baryon ChPT. We find that the inclusion of the Δ indeed reduces the low-energy constants to more natural values and thereby improves consistency betweenmore » threshold and subthreshold kinematics. In addition, even in the Δ-less theory the resummation of 1/m N corrections in the covariant scheme improves the results markedly over the heavy-baryon formulation, in line with previous observations in the single-baryon sector of ChPT that so far have evaded a profound theoretical explanation.« less

The Eightfold Way: A Theory of Strong Interaction Symmetry

DOE R&D Accomplishments Database

Gell-Mann, M.

1961-03-15

A new model of the higher symmetry of elementary particles is introduced ln which the eight known baryons are treated as a supermultiplet, degenerate in the limit of unitary symmetry but split into isotopic spin multiplets by a symmetry-breaking term. The symmetry violation is ascribed phenomenologically to the mass differences. The baryons correspond to an eight-dimensional irreducible representation of the unitary group. The pion and K meson fit into a similar set of eight particles along with a predicted pseudoscalar meson X {sup o} having I = 0. A ninth vector meson coupled to the baryon current can be accommodated naturally in the scheme. It is predicted that the eight baryons should all have the same spin and parity and that pseudoscalar and vector mesons should form octets with possible additional singlets. The mathematics of the unitary group is described by considering three fictitious leptons, nu , e {sup -}, and mu {sup -}, which may throw light on the structure of weak interactions. (D. L.C.)

Observation of the {omega}{sub b}{sup -} baryon and measurement of the properties of the {xi}{sub b}{sup -} and {omega}{sub b}{sup -} baryons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, T.; Maki, T.; Mehtala, P.

We report the observation of the bottom, doubly-strange baryon {omega}{sub b}{sup -} through the decay chain {omega}{sub b}{sup -}{yields}J/{psi}{omega}{sup -}, where J/{psi}{yields}{mu}{sup +}{mu}{sup -}, {omega}{sup -}{yields}{lambda}K{sup -}, and {lambda}{yields}p{pi}{sup -}, using 4.2 fb{sup -1} of data from pp collisions at {radical}(s)=1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0x10{sup -8}, or 5.5 Gaussian standard deviations. The {omega}{sub b}{sup -} mass is measured to be 6054.4{+-}6.8(stat){+-}0.9(syst) MeV/c{sup 2}. The lifetime of the {omega}{sub b}{sup -} baryon is measured to be 1.13{sub -0.40}{sup +0.53}(stat){+-}0.02(syst) ps. In addition,more » for the {xi}{sub b}{sup -} baryon we measure a mass of 5790.9{+-}2.6(stat){+-}0.8(syst) MeV/c{sup 2} and a lifetime of 1.56{sub -0.25}{sup +0.27}(stat){+-}0.02(syst) ps. Under the assumption that the {xi}{sub b}{sup -} and {omega}{sub b}{sup -} are produced with similar kinematic distributions to the {lambda}{sub b}{sup 0} baryon, we find ({sigma}({xi}{sub b}{sup -})B({xi}{sub b}{sup -}{yields}J/{psi}{xi}{sup -})/{sigma}({lambda}{sub b}{sup 0})B({lambda}{sub b}{sup 0}{yields}J/{psi}{lambda}))=0.167{sub -0.025}{sup +0.037}(stat){+-}0.012(syst) and ({sigma}({omega}{sub b}{sup -})B({omega}{sub b}{sup -}{yields}J/{psi}{omega}{sup -})/{sigma}({lambda}{sub b}{sup 0})B({lambda}{sub b}{sup 0}{yields}J/{psi}{lambda}))=0.045{sub -0.012}{sup +0.017}(stat){+-} 0.004(syst) for baryons produced with transverse momentum in the range of 6-20 GeV/c.« less

FIREBall, CHaS, and the diffuse universe

NASA Astrophysics Data System (ADS)

Hamden, Erika Tobiason

The diffuse universe, consisting of baryons that have not yet collapsed into structures such as stars, galaxies, etc., has not been well studied. While the intergalactic and circumgalactic mediums (IGM & CGM) may contain 30-40% of the baryons in the universe, this low density gas is difficult to observe. Yet it is likely a key driver of the evolution of galaxies and star formation through cosmic time. The IGM provides a reservoir of gas that can be used for star formation, if it is able to accrete onto a galaxy. The CGM bridges the IGM and the galaxy itself, as a region of both inflows from the IGM and outflows from galactic star formation and feedback. The diffuse interstellar medium (ISM) gas and dust in the galaxy itself may also be affected by the CGM of the galaxy. Careful observations of the ISM of our own Galaxy may provide evidence of interaction with the CGM. These three regions of low density, the IGM, CGM, and ISM, are arbitrary divisions of a continuous flow of low density material into and out of galaxies. My thesis focuses on observations of this low density material using existing telescopes as well as on the development of technology and instruments that will increase the sensitivity of future missions. I used data from the Galaxy Evolution Explorer (GALEX) to create an all sky map of the diffuse Galactic far ultraviolet (FUV) background, probing the ISM of our own galaxy and comparing to other Galactic all sky maps. The FUV background is primarily due to dust scattered starlight from bright stars in the Galactic plane, and the changing intensity across the sky can be used to characterize dust scattering asymmetry and albedo. We measure a consistent low level non-scattered isotropic component to the diffuse FUV, which may be due in small part to an extragalactic component. There are also several regions of unusually high FUV intensity given other Galactic quantities. Such regions may be the location of interactions between Galactic super-bubbles and the CGM. Other ways of probing the CGM including direct detection via emission lines. I built a proto-type of the Circumgalactic Halpha Spectrograph (CHalphaS), a wide-field, low-cost, narrow-band integral field unit (IFU) that is designed to observe Halpha emission from the CGM of nearby, low-z galaxies. This proto-type has had two recent science runs, with preliminary data on several nearby galaxies. Additional probes of the CGM are emission lines in the rest ultra-violet. These include OVI, Lyalpha, CIV, SiIII, CIII, CII, FeII, and MgII. Such lines are accessible for low redshift galaxies in the space UV, historically a difficult wavelength range in which to work due in part to low efficiency of the available detectors. I have worked with NASA's Jet Propulsion Laboratory to develop advanced anti-reflection (AR) coatings for use on thinned, delta-doped charge coupled device (CCD) detectors. These detectors have achieved world record quantum efficiency (QE) at UV wavelengths (>50% between 130 nm and 300nm), with the potential for even greater QE with a more complex coating. One of these AR coated detectors will be used on the Faint Intergalactic Redshifted Emission Balloon (FIREBall-2), a balloon-born UV spectrograph designed to observe the CGM at 205 nm via redshifted Lyalpha (at z=0.7), CIV (at z=0.3), and OVI (at z=1.0). FIREBall-2 will launch in the fall of 2015.

Study of baryon production mechanism in e+e- annihilation into hadrons

NASA Astrophysics Data System (ADS)

Topaz Collaboration; Aoki, M.; Itoh, R.; Watanabe, Y.; Kaneyuki, K.; Ohshima, Y.; Ochi, A.; Tanimori, T.; Abe, K.; Abe, T.; Adachi, I.; Adachi, K.; Aoki, M.; Emi, K.; Enomoto, R.; Fujii, H.; Fujii, T.; Fujii, K.; Fujimoto, J.; Fujiwara, N.; Hayashii, H.; Hirano, H.; Howell, B.; Ikeda, H.; Inoue, Y.; Itami, S.; Iwasaki, H.; Iwasaki, M.; Kajikawa, R.; Kato, S.; Kawabata, S.; Kichimi, H.; Kobayashi, M.; Koltick, D.; Levine, I.; Mamada, H.; Miyabayashi, K.; Miyamoto, A.; Nagai, K.; Nakabayashi, K.; Nakamura, M.; Nakano, E.; Nitoh, O.; Noguchi, S.; Ochiai, F.; Ohishi, N.; Ohnishi, Y.; Okuno, H.; Okusawa, T.; Shibata, E.; Sugiyama, A.; Suzuki, S.; Takahashi, K.; Takahashi, T.; Teramoto, Y.; Tauchi, T.; Tomoto, M.; Tsukamoto, T.; Tsumura, T.; Uno, S.; Yamamoto, A.; Yamauchi, M.

1998-11-01

The mechanism of baryon-anti-baryon pair production in e+e- annihilation into hadrons has been studied using the TOPAZ detector at the TRISTAN e+e- collider at an average center-of-mass energy of 58 GeV. The distributions of various p¯p correlations were compared with two prominent models: the cluster-fragmentation model and the string-fragmentation model. We rejected the cluster-fragmentation model at the 90% C.L. Furthermore, in the context of the string-fragmentation model, we favor the ``popcorn'' model, rejecting the ``diquark'' model, where a diquark is considered to be a fundamental entity, at the 95% C.L.

Quantum Numbers of Recently Discovered Ωc0 Baryons from Lattice QCD

NASA Astrophysics Data System (ADS)

Padmanath, M.; Mathur, Nilmani

2017-07-01

We present the ground and excited state spectra of Ωc0 baryons with spin up to 7 /2 from lattice quantum chromodynamics with dynamical quark fields. Based on our lattice results, we predict the quantum numbers of five Ωc0 baryons, which have recently been observed by the LHCb Collaboration. Our results strongly indicate that the observed states Ωc(3000 )0 and Ωc(3050 )0 have spin-parity JP=1 /2-, the states Ωc(3066 )0 and Ωc(3090 )0 have JP=3 /2-, whereas Ωc(3119 )0 is possibly a 5 /2- state.

Neutrino CP violation and sign of baryon asymmetry in the minimal seesaw model

NASA Astrophysics Data System (ADS)

Shimizu, Yusuke; Takagi, Kenta; Tanimoto, Morimitsu

2018-03-01

We discuss the correlation between the CP violating Dirac phase of the lepton mixing matrix and the cosmological baryon asymmetry based on the leptogenesis in the minimal seesaw model with two right-handed Majorana neutrinos and the trimaximal mixing for neutrino flavors. The sign of the CP violating Dirac phase at low energy is fixed by the observed cosmological baryon asymmetry since there is only one phase parameter in the model. According to the recent T2K and NOνA data of the CP violation, the Dirac neutrino mass matrix of our model is fixed only for the normal hierarchy of neutrino masses.

Observation of an Exotic S=+1 Baryon in Exclusive Photoproduction from the Deuteron

NASA Astrophysics Data System (ADS)

Stepanyan, S.; Hicks, K.; Carman, D. S.; Pasyuk, E.; Schumacher, R. A.; Smith, E. S.; Tedeschi, D. J.; Todor, L.; Adams, G.; Ambrozewicz, P.; Anciant, E.; Anghinolfi, M.; Asavapibhop, B.; Audit, G.; Avakian, H.; Bagdasaryan, H.; Ball, J. P.; Barrow, S. P.; Battaglieri, M.; Beard, K.; Bektasoglu, M.; Bellis, M.; Berman, B. L.; Bianchi, N.; Biselli, A. S.; Boiarinov, S.; Bouchigny, S.; Bradford, R.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Butuceanu, C.; Calarco, J. R.; Carnahan, B.; Chen, S.; Ciciani, L.; Cole, P. L.; Coleman, A.; Cords, D.; Corvisiero, P.; Crabb, D.; Crannell, H.; Cummings, J. P.; de Sanctis, E.; Degtyarenko, P. V.; Denizli, H.; Dennis, L.; de Vita, R.; Dharmawardane, K. V.; Dhuga, K. S.; Djalali, C.; Dodge, G. E.; Doughty, D.; Dragovitsch, P.; Dugger, M.; Dytman, S.; Dzyubak, O. P.; Egiyan, H.; Egiyan, K. S.; Elouadrhiri, L.; Empl, A.; Eugenio, P.; Fatemi, R.; Feuerbach, R. J.; Ficenec, J.; Forest, T. A.; Funsten, H.; Garçon, M.; Gavalian, G.; Gilfoyle, G. P.; Giovanetti, K. L.; Gordon, C. I.; Gothe, R.; Griffioen, K.; Guidal, M.; Guillo, M.; Guo, L.; Gyurjyan, V.; Hadjidakis, C.; Hakobyan, R. S.; Hardie, J.; Heddle, D.; Heimberg, P.; Hersman, F. W.; Hicks, R. S.; Holtrop, M.; Hu, J.; Hyde-Wright, C. E.; Ito, M. M.; Jenkins, D.; Joo, K.; Juengst, H. G.; Kellie, J. D.; Khandaker, M.; Kim, K. Y.; Kim, K.; Kim, W.; Klein, A.; Klein, F. J.; Klimenko, A. V.; Klusman, M.; Kossov, M.; Kramer, L. H.; Kuang, Y.; Kubarovsky, V.; Kuhn, S. E.; Kuhn, J.; Lachniet, J.; Lawrence, D.; Li, J.; Lima, A.; Livingston, K.; Lukashin, K.; Manak, J. J.; McAleer, S.; McNabb, J. W.; Mecking, B. A.; Mehrabyan, S.; Melone, J. J.; Mestayer, M. D.; Meyer, C. A.; Mikhailov, K.; Minehart, R.; Mirazita, M.; Miskimen, R.; Mokeev, V.; Morand, L.; Morrow, S.; Muccifora, V.; Mueller, J.; Murphy, L. Y.; Mutchler, G. S.; Napolitano, J.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niczyporuk, B. B.; Niyazov, R. A.; Nozar, M.; O'Brien, J.; O'Rielly, G. V.; Opper, A. K.; Osipenko, M.; Park, K.; Peterson, G.; Philips, S. A.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Polli, E.; Pozdniakov, S.; Preedom, B. M.; Price, J. W.; Prok, Y.; Protopopescu, D.; Qin, L. M.; Raue, B. A.; Riccardi, G.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Ronchetti, F.; Rossi, P.; Rowntree, D.; Rubin, P.; Sabatié, F.; Salgado, C.; Santoro, J.; Sapunenko, V.; Serov, V. S.; Sharabian, Y. G.; Shaw, J.; Simionatto, S.; Skabelin, A. V.; Smith, L. C.; Sober, D. I.; Strakovsky, I. I.; Stavinsky, A.; Stoler, P.; Suleiman, R.; Taiuti, M.; Taylor, S.; Thoma, U.; Thompson, R.; Tur, C.; Ungaro, M.; Vineyard, M. F.; Vlassov, A. V.; Wang, K.; Weinstein, L. B.; Weller, H.; Weygand, D. P.; Whisnant, C. S.; Wolin, E.; Wood, M. H.; Yegneswaran, A.; Yun, J.

2003-12-01

In an exclusive measurement of the reaction γd→K+K-pn, a narrow peak that can be attributed to an exotic baryon with strangeness S=+1 is seen in the K+n invariant mass spectrum. The peak is at 1.542±0.005 GeV/c2 with a measured width of 0.021 GeV/c2 FWHM, which is largely determined by experimental mass resolution. The statistical significance of the peak is (5.2±0.6)σ. The mass and width of the observed peak are consistent with recent reports of a narrow S=+1 baryon by other experimental groups.

Anisotropy effects on baryogenesis in f(R) theories of gravity

NASA Astrophysics Data System (ADS)

Aghamohammadi, A.; Hossienkhani, H.; Saaidi, Kh.

2018-04-01

We study the f(R) theory of gravity in an anisotropic metric and its effect on the baryon number-to-entropy ratio. The mechanism of gravitational baryogenesis based on the CPT-violating gravitational interaction between derivative of the Ricci scalar curvature and the baryon-number current is investigated in the context of the f(R) gravity. The gravitational baryogenesis in the Bianchi type I (BI) Universe is examined. We survey the effect of anisotropy of the Universe on the baryon asymmetry from the point of view of the f(R) theories of gravity and its effect on nb/s for radiation dominant regime.

Deforming baryons into confining strings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartnoll, Sean A.; Portugues, Ruben

2004-09-15

We find explicit probe D3-brane solutions in the infrared of the Maldacena-Nunez background. The solutions describe deformed baryon vertices: q external quarks are separated in spacetime from the remaining N-q. As the separation is taken to infinity we recover known solutions describing infinite confining strings in N=1 gauge theory. We present results for the mass of finite confining strings as a function of length. We also find probe D2-brane solutions in a confining type IIA geometry, the reduction of a G{sub 2} holonomy M theory background. The relation between these deformed baryons and confining strings is not as straightforward.

Bound H dibaryon in flavor SU(3) limit of lattice QCD.

PubMed

Inoue, Takashi; Ishii, Noriyoshi; Aoki, Sinya; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji

2011-04-22

The flavor-singlet H dibaryon, which has strangeness -2 and baryon number 2, is studied by the approach recently developed for the baryon-baryon interactions in lattice QCD. The flavor-singlet central potential is derived from the spatial and imaginary-time dependence of the Nambu-Bethe-Salpeter wave function measured in N(f)=3 full QCD simulations with the lattice size of L≃2,3,4  fm. The potential is found to be insensitive to the volume, and it leads to a bound H dibaryon with the binding energy of 30-40 MeV for the pseudoscalar meson mass of 673-1015 MeV.

Quantum Numbers of Recently Discovered Ω_{c}^{0} Baryons from Lattice QCD.

PubMed

Padmanath, M; Mathur, Nilmani

2017-07-28

We present the ground and excited state spectra of Ω_{c}^{0} baryons with spin up to 7/2 from lattice quantum chromodynamics with dynamical quark fields. Based on our lattice results, we predict the quantum numbers of five Ω_{c}^{0} baryons, which have recently been observed by the LHCb Collaboration. Our results strongly indicate that the observed states Ω_{c}(3000)^{0} and Ω_{c}(3050)^{0} have spin-parity J^{P}=1/2^{-}, the states Ω_{c}(3066)^{0} and Ω_{c}(3090)^{0} have J^{P}=3/2^{-}, whereas Ω_{c}(3119)^{0} is possibly a 5/2^{-} state.

Systematic study of baryons in a three-body quark model

NASA Astrophysics Data System (ADS)

Aslanzadeh, M.; Rajabi, A. A.

2016-09-01

We investigated the structure of baryons within a three-body quark model based on hypercentral approach. We considered an SU(6)-invariant potential consisting of the well-known "Coulomb-plus-linear" potential plus some multipole interactions as V ( x) ∝ x - n with n > 2. Then, through an analytical solution, we obtained the energy eigenvalues and eigenfunctions of the three-body problem and evaluated some observables such as the mass spectrum of light baryons and both the electromagnetic elastic form factors, and the charge radii of nucleons. We compared our results with the experimental data and showed that the present model provides a good description of the observed resonances.

Decay widths of ground-state and excited {Xi}{sub b} baryons in a nonrelativistic quark model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Limphirat, Ayut; Thailand Center of Excellence in Physics; Department of Applied Physics, Faculty of Sciences and Liberal Arts, Rajamangala University of Technology Isan, Nakhon Ratchasima 30000

Decay processes of ground and excited bottom baryons are studied in the {sup 3}P{sub 0} nonrelativistic quark model with all model parameters fixed in the sector of light quarks. Using as an input the recent mass of {Xi}{sub b} and the theoretical masses of {Xi}{sub b}{sup *} and {Xi}{sub b}{sup '}, narrow decay widths are predicted for the ground-state bottom baryons {Xi}{sub b}{sup *} and {Xi}{sub b}{sup '}. The work predicts large decay widths, about 100 MeV for the {rho}-type orbital excitation states of {Xi}{sub b}.

Accurate initial conditions in mixed dark matter-baryon simulations

NASA Astrophysics Data System (ADS)

Valkenburg, Wessel; Villaescusa-Navarro, Francisco

2017-06-01

We quantify the error in the results of mixed baryon-dark-matter hydrodynamic simulations, stemming from outdated approximations for the generation of initial conditions. The error at redshift 0 in contemporary large simulations is of the order of few to 10 per cent in the power spectra of baryons and dark matter, and their combined total-matter power spectrum. After describing how to properly assign initial displacements and peculiar velocities to multiple species, we review several approximations: (1) using the total-matter power spectrum to compute displacements and peculiar velocities of both fluids, (2) scaling the linear redshift-zero power spectrum back to the initial power spectrum using the Newtonian growth factor ignoring homogeneous radiation, (3) using a mix of general-relativistic gauges so as to approximate Newtonian gravity, namely longitudinal-gauge velocities with synchronous-gauge densities and (4) ignoring the phase-difference in the Fourier modes for the offset baryon grid, relative to the dark-matter grid. Three of these approximations do not take into account that dark matter and baryons experience a scale-dependent growth after photon decoupling, which results in directions of velocity that are not the same as their direction of displacement. We compare the outcome of hydrodynamic simulations with these four approximations to our reference simulation, all setup with the same random seed and simulated using gadget-III.

Evolution of Structure in the Intergalactic Medium and the Nature of the LY-Alpha Forest

NASA Technical Reports Server (NTRS)

Bi, Hongguang; Davidsen, Arthur F.

1997-01-01

We have performed a detailed statistical study of the evolution of structure in a photoionized intergalactic medium (IGM) using analytical simulations to extend the calculation into the mildly nonlinear density regime found to prevail at z = 3. Our work is based on a simple fundamental conjecture: that the probability distribution function of the density of baryonic diffuse matter in the universe is described by a lognormal (LN) random field. The LN distribution has several attractive features and follows plausibly from the assumption of initial linear Gaussian density and velocity fluctuations at arbitrarily early times. Starting with a suitably normalized power spectrum of primordial fluctuations in a universe dominated by cold dark matter (CDM), we compute the behavior of the baryonic matter, which moves slowly toward minima in the dark matter potential on scales larger than the Jeans length. We have computed two models that succeed in matching observations. One is a nonstandard CDM model with OMEGA = 1, h = 0.5, and GAMMA = 0.3, and the other is a low-density flat model with a cosmological constant (LCDM), with OMEGA = 0.4, OMEGA(sub LAMBDA) = 0.6, and h = 0.65. In both models, the variance of the density distribution function grows with time, reaching unity at about z = 4, where the simulation yields spectra that closely resemble the Ly-alpha forest absorption seen in the spectra of high-z quasars. The calculations also successfully predict the observed properties of the Ly-alpha forest clouds and their evolution from z = 4 down to at least z = 2, assuming a constant intensity for the metagalactic UV background over this redshift range. However, in our model the forest is not due to discrete clouds, but rather to fluctuations in a continuous intergalactic medium. At z = 3; typical clouds with measured neutral hydrogen column densities N(sub H I) = 10(exp 13.3), 10(exp 13.5), and 10(exp 11.5) /sq cm correspond to fluctuations with mean total densities approximately 10, 1, and 0.1 times the universal mean baryon density. Perhaps surprisingly, fluctuations whose amplitudes are less than or equal to the mean density still appear as "clouds" because in our model more than 70% of the volume of the IGM at z = 3 is filled with gas at densities below the mean value.

Instability of gravitational baryogenesis with fermions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arbuzova, E.; Dolgov, A., E-mail: arbuzova@uni-dubna.ru, E-mail: dolgov@fe.infn.it

2017-06-01

The derivative coupling of baryonic current to the curvature scalar in gravitational baryogenesis scenarios leads to higher order equations for gravitational field. It is shown that these equations are strongly unstable and destroy standard cosmology. This is a generalization of our earlier results obtained for scalar baryons to realistic fermions.

Baryon production from cluster hadronisation

NASA Astrophysics Data System (ADS)

Gieseke, Stefan; Kirchgaeßer, Patrick; Plätzer, Simon

2018-02-01

We present an extension to the colour reconnection model in the Monte Carlo event generator Herwig to account for the production of baryons and compare it to a series of observables for soft physics. The new model is able to improve the description of charged-particle multiplicities and hadron flavour observables in pp collisions.

Progress in Solving the Elusive Ag Transport Mechanism in TRISO Coated Particles: What is new?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isabella Van Rooyen

2014-10-01

The TRISO particle for HTRs has been developed to an advanced state where the coating withstands internal gas pressures and retains fission products during irradiation and under postulated accidents. However, one exception is Ag that has been found to be released from high quality TRISO coated particles when irradiated and can also during high temperature accident heating tests. Although out- of- pile laboratory tests have never hither to been able to demonstrate a diffusion process of Ag in SiC, effective diffusion coefficients have been derived to successfully reproduce measured Ag-110m releases from irradiated HTR fuel elements, compacts and TRISO particlesmore » It was found that silver transport through SiC does not proceed via bulk volume diffusion. Presently grain boundary diffusion that may be irradiation enhanced either by neutron bombardment or by the presence of fission products such as Pd, are being investigated. Recent studies of irradiated AGR-1 TRISO fuel using scanning transmission electron microscopy (STEM), transmission kukuchi diffraction (TKD) patterns and high resolution transmission electron microscopy (HRTEM) have been used to further the understanding of Ag transport through TRISO particles. No silver was observed in SiC grains, but Ag was identified at triple-points and grain boundaries of the SiC layer in the TRISO particle. Cadmium was also found in some of the very same triple junctions, but this could be related to silver behavior as Ag-110m decays to Cd-110. Palladium was identified as the main constituent of micron-sized precipitates present at the SiC grain boundaries and in most SiC grain boundaries and the potential role of Pd in the transport of Ag will be discussed.« less

Feasibility Study of a 400 Hz, 4160 Volt 3-Phase Electrical Power Distribution System

DTIC Science & Technology

1977-02-25

accordance with HIL-E-917. 8. The primary insulation shall be adequate to withstand a high potential test of 60 Hz voltage windings to winding and to ground... withstand a short circuit current of 500 percent for 10 seconds without exceeding the voltage rating of any capacitors. They shall operate within...shaft. separation is required to withstand high voltages . The limited contact movement results in a very small contactor size be- cause it permits the use

Asymmetric dark matter, baryon asymmetry and lepton number violation

NASA Astrophysics Data System (ADS)

Frandsen, Mads T.; Hagedorn, Claudia; Huang, Wei-Chih; Molinaro, Emiliano; Päs, Heinrich

2018-07-01

We study the effect of lepton number violation (LNV) on baryon asymmetry, generated in the early Universe, in the presence of a dark sector with a global symmetry U(1)X, featuring asymmetric dark matter (ADM). We show that in general LNV, observable at the LHC or in neutrinoless double beta decay experiments, cannot wash out a baryon asymmetry generated at higher scales, unlike in scenarios without such dark sector. An observation of LNV at the TeV scale may thus support ADM scenarios. Considering several models with different types of dark matter (DM), we find that the DM mass is of the order of a few GeV or below in our scenario.

Charm Production in Interactions of Antiproton with Proton and Nuclei at \\bar{it{P}}it{ANDA} Energies

NASA Astrophysics Data System (ADS)

Shyam, R.; Tsushima, K.

2018-05-01

We study the production of charmed baryons in the antiproton-proton and antiproton-nucleus interactions within a fully covariant model that is based on an effective Lagrangian approach. The baryon production proceeds via the t-channel D^0 and D^{*0} meson-exchange diagrams. We have also explored the production of the charm-baryon hypernucleus ^{16}_{Λ_c^+}O in the antiproton-^{16}O collisions. For antiproton beam momenta of interest to the {\\bar{P}}ANDA experiment, the 0° differential cross sections for the formation of ^{16}_{Λ_c^+}O hypernuclear states with simple particle-hole configurations, have magnitudes in the range of a few μ b/sr.

The impact of baryonic matter on gravitational lensing by galaxy clusters

NASA Astrophysics Data System (ADS)

Lee, Brandyn E.; King, Lindsay; Applegate, Douglas; McCarthy, Ian

2017-01-01

Since the bulk of the matter comprising galaxy clusters exists in the form of dark matter, gravitational N-body simulations have historically been an effective way to investigate large scale structure formation and the astrophysics of galaxy clusters. However, upcoming telescopes such as the Large Synoptic Survey Telescope are expected to have lower systematic errors than older generations, reducing measurement uncertainties and requiring that astrophysicists better quantify the impact of baryonic matter on the cluster lensing signal. Here we outline the effects of baryonic processes on cluster density profiles and on weak lensing mass and concentration estimates. Our analysis is done using clusters grown in the suite of cosmological hydrodynamical simulations known as cosmo-OWLS.

Baryon magnetic moments: Symmetries and relations

NASA Astrophysics Data System (ADS)

Parreño, Assumpta; Savage, Martin J.; Tiburzi, Brian C.; Wilhelm, Jonas; Chang, Emmanuel; Detmold, William; Orginos, Kostas

2018-03-01

Magnetic moments of the octet baryons are computed using lattice QCD in background magnetic fields, including the first treatment of the magnetically coupled ∑0- ⋀ system. Although the computations are performed for relatively large values of the up and down quark masses, we gain new insight into the symmetries and relations between magnetic moments by working at a three-flavor mass-symmetric point. While the spinflavor symmetry in the large Nc limit of QCD is shared by the naïve constituent quark model, we find instances where quark model predictions are considerably favored over those emerging in the large Nc limit. We suggest further calculations that would shed light on the curious patterns of baryon magnetic moments.

Baryon number violation and novel canonical anti-commutation relations

NASA Astrophysics Data System (ADS)

Fujikawa, Kazuo; Tureanu, Anca

2018-02-01

The possible neutron-antineutron oscillation is described by an effective quadratic Lagrangian analogous to the BCS theory. It is shown that the conventional equal-time anti-commutation relations of the neutron variable n (t , x →) are modified by the baryon number violating terms. This is established by the Bjorken-Johnson-Low prescription and also by the canonical quantization combined with equations of motion. This novel canonical behavior can give rise to an important physical effect, which is illustrated by analyzing the Lagrangian that violates the baryon number but gives rise to the degenerate effective Majorana fermions and thus no neutron-antineutron oscillation. Technically, this model is neatly treated using a relativistic analogue of the Bogoliubov transformation.

On the nature of the baryon asymmetry

NASA Technical Reports Server (NTRS)

Stecker, F. W.

1984-01-01

Whether the baryon asymmetry in the universe is a locally varying or universally fixed number is examined with focus on the existence of a possible matter antimatter domain structure in the universe arising from a GUT with spontaneous CP symmetry breaking. Theoretical considerations and observational data and astrophysical tests relating to this fundamental question are reviewed.

Implications of heavy quark-diquark symmetry for excited doubly heavy baryons and tetraquarks

NASA Astrophysics Data System (ADS)

Mehen, Thomas

2017-11-01

We give heavy quark-diquark symmetry predictions for doubly heavy baryons and tetraquarks in light of the recent discovery of the Ξcc ++ by LHCb. For five excited doubly charm baryons that are predicted to lie below the ΛcD threshold, we give predictions for their electromagnetic and strong decays using a previously developed chiral Lagrangian with heavy quark-diquark symmetry. Based on the mass of the Ξcc ++, the existence of a doubly heavy bottom I =0 tetraquark that is stable to strong and electromagnetic decays has been predicted. If the mass of this state is below 10405 MeV, as predicted in some models, we argue using heavy quark-diquark symmetry that the JP=1+ I =1 doubly bottom tetraquark state will lie just below the open bottom threshold and likely be a narrow state as well. In this scenario, we compute strong decay width for this state using a new Lagrangian for doubly heavy tetraquarks which is related to the singly heavy baryon Lagrangian by heavy quark-diquark symmetry.

A meson-baryon molecular interpretation for some Ωc excited states

NASA Astrophysics Data System (ADS)

Montaña, Glòria; Feijoo, Albert; Ramos, Àngels

2018-04-01

We explore the possibility that some of the five narrow Ωc resonances recently observed at LHCb could correspond to pentaquark states, structured as meson-baryon bound states or molecules. The interaction of the low-lying pseudoscalar mesons with the ground-state baryons in the charm +1 , strangeness -2 and isospin 0 sector is built from t-channel vector meson exchange, using effective Lagrangians. The resulting s-wave coupled-channel unitarized amplitudes show the presence of two structures with similar masses and widths to those of the observed Ωc(3050)0 and Ωc(3090)0. The identification of these resonances with the meson-baryon bound states found in this work would also imply assigning the values 1/2- for their spin-parity. An experimental determination of the spin-parity of the Ωc(3090)0 would contribute to a better understanding of its structure, as the quark-based models predict its spin-parity to be either 3/2- or 5/2-. Predictions for the analogue bottom Ωb- resonances are also given.

Correlation Analysis between Spin, Velocity Shear, and Vorticity of Baryonic and Dark Matter Halos

NASA Astrophysics Data System (ADS)

Liu, Li-li

2017-04-01

Based on the cosmological hydrodynamic simulations, we investigate the correlations between the spin, velocity shear and vorticity in dark matter halos, as well as the relationship between the baryonic matter and the dark matter. We find that (1) the difference between the vorticity of baryonic matter and that of dark matter is evident on the scales of < 0.2 h-1 Mpc; (2) the vorticity of baryonic matter exhibits a stronger correlation with the tensor of velocity shear than the vorticity of dark matter does; and (3) the spinning direction of small-mass dark matter halos tends to be parallel to the direction of their host filaments, while the spinning direction of massive dark matter halos tends to be perpendicular to the direction of their host filaments, and the intensity of this kind correlation depends on the size of simulation box, and the simulation accuracy. These factors may cause the relationship between the the spins of dark matter halos and those of galaxies to be complicated, and affect the correlation between the galaxy spins and the nearby large-scale structures.

Twin Higgs Asymmetric Dark Matter.

PubMed

García García, Isabel; Lasenby, Robert; March-Russell, John

2015-09-18

We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors.

Ratchet baryogenesis and an analogy with the forced pendulum

NASA Astrophysics Data System (ADS)

Bamba, Kazuharu; Barrie, Neil D.; Sugamoto, Akio; Takeuchi, Tatsu; Yamashita, Kimiko

2018-06-01

A new scenario of baryogenesis via the ratchet mechanism is proposed based on an analogy with the forced pendulum. The oscillation of the inflaton field during the reheating epoch after inflation plays the role of the driving force, while the phase 𝜃 of a scalar baryon field (a complex scalar field with baryon number) plays the role of the angle of the pendulum. When the inflaton is coupled to the scalar baryon, the behavior of the phase 𝜃 can be analogous to that of the angle of the forced pendulum. If the oscillation of the driving force is adjusted to the pendulum’s motion, a directed rotation of the pendulum is obtained with a nonvanishing value of 𝜃˙, which models successful baryogenesis since 𝜃˙ is proportional to the baryon number density. Similar ratchet models which lead to directed motion have been used in the study of molecular motors in biology. There, the driving force is supplied by chemical reactions, while in our scenario this role is played by the inflaton during the reheating epoch.

Limits to the primordial helium abundance in the baryon-inhomogeneous big bang

NASA Technical Reports Server (NTRS)

Mathews, G. J.; Schramm, D. N.; Meyer, B. S.

1993-01-01

The parameter space for baryon inhomogeneous big bang models is explored with the goal of determining the minimum helium abundance obtainable in such models while still satisfying the other light-element constraints. We find that the constraint of (D + He-3)/H less than 10 exp -4 restricts the primordial helium mass fraction from baryon-inhomogeneous big bang models to be greater than 0.231 even for a scenario which optimizes the effects of the inhomogeneities and destroys the excess lithium production. Thus, this modification to the standard big bang as well as the standard homogeneous big bang model itself would be falsifiable by observation if the primordial He-4 abundance were observed to be less than 0.231. Furthermore, a present upper limit to the observed helium mass fraction of Y(obs)(p) less than 0.24 implies that the maximum baryon-to-photon ratio allowable in the inhomogeneous models corresponds to eta less than 2.3 x 10 exp -9 (omega(b) h-squared less than 0.088) even if all conditions are optimized.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.; de Teramond, Guy F.; Dosch, Hans Gunter

An effective supersymmetric QCD light-front Hamiltonian for hadrons composed of light quarks, which includes a spin–spin interaction between the hadronic constituents, is constructed by embedding superconformal quantum mechanics into AdS space. A specific breaking of conformal symmetry inside the graded algebra determines a unique effective quark-confining potential for light hadrons, as well as remarkable connections between the meson and baryon spectra. The results are consistent with the empirical features of the light-quark hadron spectra, including a universal mass scale for the slopes of the meson and baryon Regge trajectories and a zero-mass pion in the limit of massless quarks. Ourmore » analysis is consistently applied to the excitation spectra of the π , ρ , K , K* and Φ meson families as well as to the N , Δ, Λ, Σ, Σ* , Ξ and Ξ* in the baryon sector. Here, we also predict the existence of tetraquarks which are degenerate in mass with baryons with the same angular momentum. The mass of light hadrons is expressed in a universal and frame-independent decomposition in the semiclassical approximation described here.« less

Universal effective hadron dynamics from superconformal algebra

DOE PAGES

Brodsky, Stanley J.; de Teramond, Guy F.; Dosch, Hans Gunter; ...

2016-05-25

An effective supersymmetric QCD light-front Hamiltonian for hadrons composed of light quarks, which includes a spin–spin interaction between the hadronic constituents, is constructed by embedding superconformal quantum mechanics into AdS space. A specific breaking of conformal symmetry inside the graded algebra determines a unique effective quark-confining potential for light hadrons, as well as remarkable connections between the meson and baryon spectra. The results are consistent with the empirical features of the light-quark hadron spectra, including a universal mass scale for the slopes of the meson and baryon Regge trajectories and a zero-mass pion in the limit of massless quarks. Ourmore » analysis is consistently applied to the excitation spectra of the π , ρ , K , K* and Φ meson families as well as to the N , Δ, Λ, Σ, Σ* , Ξ and Ξ* in the baryon sector. Here, we also predict the existence of tetraquarks which are degenerate in mass with baryons with the same angular momentum. The mass of light hadrons is expressed in a universal and frame-independent decomposition in the semiclassical approximation described here.« less

Transverse Densities of Octet Baryons from Chiral Effective Field Theory

DOE PAGES

Alarcón, Jose Manuel; Hiller Blin, Astrid N.; Weiss, Christian

2017-03-24

Transverse densities describe the distribution of charge and current at fixed light-front time and provide a frame-independent spatial representation of hadrons as relativistic systems. In this paper, we calculate the transverse densities of the octet baryons at peripheral distances b=O(M π -1) in an approach that combines chiral effective field theory (χχEFT) and dispersion analysis. The densities are represented as dispersive integrals of the imaginary parts of the baryon electromagnetic form factors in the timelike region (spectral functions). The spectral functions on the two-pion cut at t>4Mmore » $$2\\atop{π}$$ are computed using relativistic χEFT with octet and decuplet baryons in the extended on-mass-shell renormalization scheme. The calculations are extended into the ρ-meson mass region using a dispersive method that incorporates the timelike pion form-factor data. The approach allows us to construct densities at distances b>1 fm with controlled uncertainties. Finally, our results provide insight into the peripheral structure of nucleons and hyperons and can be compared with empirical densities and lattice-QCD calculations.« less

On the Matter Probed by Quasar Absorption Spectra

NASA Astrophysics Data System (ADS)

Peroux, Celine

2010-10-01

The intergalactic medium (IGM) constitutes a reservoir of baryons from which galaxies form and is, in turn, affected by the processes of galaxy formation. These latter processes are responsible for the reionisation of most of the hydrogen content of the intergalactic medium and later on, for the reionisation of helium with a contribution from quasars. Galactic winds due to massive stars and supernovae pollute the IGM with metals. The mechanical energy released by the collisional excitation due to galaxy and structure formation heats the medium into the Warm-Hot Intergalactic Medium (WHIM). Most of the baryons are probably in this hotter phase, since only a small fraction has been observed in galaxies and the ionised medium so far. In turn, these modifications of the IGM state impact the star formation history by providing a mechanism for global cold gas accretion. Therefore the interactions between galaxies and the intergalactic medium play a major role in the cosmological evolution of structures and the history of baryons, which cannot be solely traced by the starlight from galaxies (representing only 10% of the baryons).

KSC-04pd1716

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, modules and equipment are being covered in plastic in preparation for the expected impact of Hurricane Frances on Saturday. KSC workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

A VLT/MUSE galaxy survey towards QSO Q1410: looking for a WHIM traced by BLAs in inter-cluster filaments

NASA Astrophysics Data System (ADS)

Pessa, Ismael; Tejos, Nicolas; Barrientos, L. Felipe; Werk, Jessica; Bielby, Richard; Padilla, Nelson; Morris, Simon L.; Prochaska, J. Xavier; Lopez, Sebastian; Hummels, Cameron

2018-07-01

Cosmological simulations predict that a significant fraction of the low-z baryon budget resides in large-scale filaments in the form of a diffuse plasma at temperatures T ˜ 105 - 107 K. However, direct observation of this so-called warm-hot intergalactic medium (WHIM) has been elusive. In the Λcold dark matter paradigm, galaxy clusters correspond to the nodes of the cosmic web at the intersection of several large-scale filamentary threads. In previous work, we used HST/COS data to conduct the first survey of broad H I Lyα absorbers (BLAs) potentially produced by WHIM in inter-cluster filaments. We targeted a single QSO, namely Q1410, whose sightline intersects seven independent inter-cluster axes at impact parameters <3 Mpc (comoving), and found a tentative excess of a factor of ˜4 with respect to the field. Here, we further investigate the origin of these BLAs by performing a blind galaxy survey within the Q1410 field using VLT/MUSE. We identified 77 sources and obtained the redshifts for 52 of them. Out of the total sample of seven BLAs in inter-cluster axes, we found three without any galaxy counterpart to stringent luminosity limits (˜4 × 108 L⊙ ˜0.01 L*), providing further evidence that these BLAs may represent genuine WHIM detections. We combined this sample with other suitable BLAs from the literature and inferred the corresponding baryon mean density for these filaments in the range Ω ^fil_bar= 0.02-0.04. Our rough estimates are consistent with the predictions from numerical simulations but still subject to large systematic uncertainties, mostly from the adopted geometry, ionization corrections, and density profile.

Cross-correlating Planck tSZ with RCSLenS weak lensing: implications for cosmology and AGN feedback

NASA Astrophysics Data System (ADS)

Hojjati, Alireza; Tröster, Tilman; Harnois-Déraps, Joachim; McCarthy, Ian G.; van Waerbeke, Ludovic; Choi, Ami; Erben, Thomas; Heymans, Catherine; Hildebrandt, Hendrik; Hinshaw, Gary; Ma, Yin-Zhe; Miller, Lance; Viola, Massimo; Tanimura, Hideki

2017-10-01

We present measurements of the spatial mapping between (hot) baryons and the total matter in the Universe, via the cross-correlation between the thermal Sunyaev-Zeldovich (tSZ) map from Planck and the weak gravitational lensing maps from the Red Cluster Sequence Lensing Survey (RCSLenS). The cross-correlations are performed on the map level where all the sources (including diffuse intergalactic gas) contribute to the signal. We consider two configuration-space correlation function estimators, ξy-κ and ξ ^ {y-γ t}, and a Fourier-space estimator, C_{ℓ}^{y-κ}, in our analysis. We detect a significant correlation out to 3° of angular separation on the sky. Based on statistical noise only, we can report 13σ and 17σ detections of the cross-correlation using the configuration-space y-κ and y-γt estimators, respectively. Including a heuristic estimate of the sampling variance yields a detection significance of 7σ and 8σ, respectively. A similar level of detection is obtained from the Fourier-space estimator, C_{ℓ}^{y-κ}. As each estimator probes different dynamical ranges, their combination improves the significance of the detection. We compare our measurements with predictions from the cosmo-OverWhelmingly Large Simulations suite of cosmological hydrodynamical simulations, where different galactic feedback models are implemented. We find that a model with considerable active galactic nuclei (AGN) feedback that removes large quantities of hot gas from galaxy groups and Wilkinson Microwave Anisotropy Probe 7-yr best-fitting cosmological parameters provides the best match to the measurements. All baryonic models in the context of a Planck cosmology overpredict the observed signal. Similar cosmological conclusions are drawn when we employ a halo model with the observed 'universal' pressure profile.

Single-particle potential of the Λ hyperon in nuclear matter with chiral effective field theory NLO interactions including effects of Y N N three-baryon interactions

NASA Astrophysics Data System (ADS)

Kohno, M.

2018-03-01

Adopting hyperon-nucleon and hyperon-nucleon-nucleon interactions parametrized in chiral effective field theory, single-particle potentials of the Λ and Σ hyperons are evaluated in symmetric nuclear matter and in pure neutron matter within the framework of lowest-order Bruckner theory. The chiral NLO interaction bears strong Λ N -Σ N coupling. Although the Λ potential is repulsive if the coupling is switched off, the Λ N -Σ N correlation brings about the attraction consistent with empirical data. The Σ potential is repulsive, which is also consistent with empirical information. The interesting result is that the Λ potential becomes shallower beyond normal density. This provides the possibility of solving the hyperon puzzle without introducing ad hoc assumptions. The effects of the Λ N N -Λ N N and Λ N N -Σ N N three-baryon forces are considered. These three-baryon forces are first reduced to normal-ordered effective two-baryon interactions in nuclear matter and then incorporated in the G -matrix equation. The repulsion from the Λ N N -Λ N N interaction is of the order of 5 MeV at normal density and becomes larger with increasing density. The effects of the Λ N N -Σ N N coupling compensate the repulsion at normal density. The net effect of the three-baryon interactions on the Λ single-particle potential is repulsive at higher densities.

Testing of the coalescence mechanism in high energy heavy ion collisions using two-particle correlations with identified particle trigger

NASA Astrophysics Data System (ADS)

Choudhury, Subikash; Sarkar, Debojit; Chattopadhyay, Subhasis

2016-05-01

In central Au-Au collisions at top RHIC energy, two-particle correlation measurements with identified hadron trigger have shown attenuation of near-side proton triggered jetlike yield at intermediate transverse momentum (p T ),2

The production of π±, K±, p and p¯ in p-Pb collisions at sNN = 5.02 TeV

NASA Astrophysics Data System (ADS)

Tabassam, U.; Ali, Y.; Suleymanov, M.; Bhatti, A. S.; Ajaz, M.

2018-06-01

In this study, we are reporting comprehensive results on π±, K±, p and p¯ production in the transverse momentum range of 0 < pT < 4 GeV/c at midrapidity of 0 < y < 0.5 GeV/c, in p-Pb collisions at sNN = 5.02 TeV. HIJING 1.0 and UrQMD 3.4 event generators are used to perform simulations and the results are compared with the ALICE and RHIC data. It is observed from the comparison that the yields for the baryons are more complex compared to the mesons and the complexity in baryons is due to the striping dynamics (spectators, leading particles of projectiles) of inner nucleus protons and neutrons. Though all the mesons could be produced during the interaction, they have maximum longitudinal momentum pL; baryons and mesons could be produced as a result of decay of massive baryon-resonances. Yields for the π± mesons are greater than the yield for the K± mesons. These are the well-known results from the RHIC data, which stated that the Cronin Effect is mainly due to π± mesons that can be produced as a result of multi-particle inner nucleus cascade. There exists the regions where yields for the K± mesons and baryons are same that may be due to the appearance of parton nature. The code used in simulation includes the parton dynamics earlier than it is included in the experiment.

Modeling the Impact of Baryons on Subhalo Populations with Machine Learning

NASA Astrophysics Data System (ADS)

Nadler, Ethan O.; Mao, Yao-Yuan; Wechsler, Risa H.; Garrison-Kimmel, Shea; Wetzel, Andrew

2018-06-01

We identify subhalos in dark matter–only (DMO) zoom-in simulations that are likely to be disrupted due to baryonic effects by using a random forest classifier trained on two hydrodynamic simulations of Milky Way (MW)–mass host halos from the Latte suite of the Feedback in Realistic Environments (FIRE) project. We train our classifier using five properties of each disrupted and surviving subhalo: pericentric distance and scale factor at first pericentric passage after accretion and scale factor, virial mass, and maximum circular velocity at accretion. Our five-property classifier identifies disrupted subhalos in the FIRE simulations with an 85% out-of-bag classification score. We predict surviving subhalo populations in DMO simulations of the FIRE host halos, finding excellent agreement with the hydrodynamic results; in particular, our classifier outperforms DMO zoom-in simulations that include the gravitational potential of the central galactic disk in each hydrodynamic simulation, indicating that it captures both the dynamical effects of a central disk and additional baryonic physics. We also predict surviving subhalo populations for a suite of DMO zoom-in simulations of MW-mass host halos, finding that baryons impact each system consistently and that the predicted amount of subhalo disruption is larger than the host-to-host scatter among the subhalo populations. Although the small size and specific baryonic physics prescription of our training set limits the generality of our results, our work suggests that machine-learning classification algorithms trained on hydrodynamic zoom-in simulations can efficiently predict realistic subhalo populations.

Challenges in QCD matter physics -The scientific programme of the Compressed Baryonic Matter experiment at FAIR

NASA Astrophysics Data System (ADS)

Ablyazimov, T.; Abuhoza, A.; Adak, R. P.; Adamczyk, M.; Agarwal, K.; Aggarwal, M. M.; Ahammed, Z.; Ahmad, F.; Ahmad, N.; Ahmad, S.; Akindinov, A.; Akishin, P.; Akishina, E.; Akishina, T.; Akishina, V.; Akram, A.; Al-Turany, M.; Alekseev, I.; Alexandrov, E.; Alexandrov, I.; Amar-Youcef, S.; Anđelić, M.; Andreeva, O.; Andrei, C.; Andronic, A.; Anisimov, Yu.; Appelshäuser, H.; Argintaru, D.; Atkin, E.; Avdeev, S.; Averbeck, R.; Azmi, M. D.; Baban, V.; Bach, M.; Badura, E.; Bähr, S.; Balog, T.; Balzer, M.; Bao, E.; Baranova, N.; Barczyk, T.; Bartoş, D.; Bashir, S.; Baszczyk, M.; Batenkov, O.; Baublis, V.; Baznat, M.; Becker, J.; Becker, K.-H.; Belogurov, S.; Belyakov, D.; Bendarouach, J.; Berceanu, I.; Bercuci, A.; Berdnikov, A.; Berdnikov, Y.; Berendes, R.; Berezin, G.; Bergmann, C.; Bertini, D.; Bertini, O.; Beşliu, C.; Bezshyyko, O.; Bhaduri, P. P.; Bhasin, A.; Bhati, A. K.; Bhattacharjee, B.; Bhattacharyya, A.; Bhattacharyya, T. K.; Biswas, S.; Blank, T.; Blau, D.; Blinov, V.; Blume, C.; Bocharov, Yu.; Book, J.; Breitner, T.; Brüning, U.; Brzychczyk, J.; Bubak, A.; Büsching, H.; Bus, T.; Butuzov, V.; Bychkov, A.; Byszuk, A.; Cai, Xu; Cãlin, M.; Cao, Ping; Caragheorgheopol, G.; Carević, I.; Cătănescu, V.; Chakrabarti, A.; Chattopadhyay, S.; Chaus, A.; Chen, Hongfang; Chen, LuYao; Cheng, Jianping; Chepurnov, V.; Cherif, H.; Chernogorov, A.; Ciobanu, M. I.; Claus, G.; Constantin, F.; Csanád, M.; D'Ascenzo, N.; Das, Supriya; Das, Susovan; de Cuveland, J.; Debnath, B.; Dementiev, D.; Deng, Wendi; Deng, Zhi; Deppe, H.; Deppner, I.; Derenovskaya, O.; Deveaux, C. A.; Deveaux, M.; Dey, K.; Dey, M.; Dillenseger, P.; Dobyrn, V.; Doering, D.; Dong, Sheng; Dorokhov, A.; Dreschmann, M.; Drozd, A.; Dubey, A. K.; Dubnichka, S.; Dubnichkova, Z.; Dürr, M.; Dutka, L.; Dželalija, M.; Elsha, V. V.; Emschermann, D.; Engel, H.; Eremin, V.; Eşanu, T.; Eschke, J.; Eschweiler, D.; Fan, Huanhuan; Fan, Xingming; Farooq, M.; Fateev, O.; Feng, Shengqin; Figuli, S. P. D.; Filozova, I.; Finogeev, D.; Fischer, P.; Flemming, H.; Förtsch, J.; Frankenfeld, U.; Friese, V.; Friske, E.; Fröhlich, I.; Frühauf, J.; Gajda, J.; Galatyuk, T.; Gangopadhyay, G.; García Chávez, C.; Gebelein, J.; Ghosh, P.; Ghosh, S. K.; Gläßel, S.; Goffe, M.; Golinka-Bezshyyko, L.; Golovatyuk, V.; Golovnya, S.; Golovtsov, V.; Golubeva, M.; Golubkov, D.; Gómez Ramírez, A.; Gorbunov, S.; Gorokhov, S.; Gottschalk, D.; Gryboś, P.; Grzeszczuk, A.; Guber, F.; Gudima, K.; Gumiński, M.; Gupta, A.; Gusakov, Yu.; Han, Dong; Hartmann, H.; He, Shue; Hehner, J.; Heine, N.; Herghelegiu, A.; Herrmann, N.; Heß, B.; Heuser, J. M.; Himmi, A.; Höhne, C.; Holzmann, R.; Hu, Dongdong; Huang, Guangming; Huang, Xinjie; Hutter, D.; Ierusalimov, A.; Ilgenfritz, E.-M.; Irfan, M.; Ivanischev, D.; Ivanov, M.; Ivanov, P.; Ivanov, Valery; Ivanov, Victor; Ivanov, Vladimir; Ivashkin, A.; Jaaskelainen, K.; Jahan, H.; Jain, V.; Jakovlev, V.; Janson, T.; Jiang, Di; Jipa, A.; Kadenko, I.; Kähler, P.; Kämpfer, B.; Kalinin, V.; Kallunkathariyil, J.; Kampert, K.-H.; Kaptur, E.; Karabowicz, R.; Karavichev, O.; Karavicheva, T.; Karmanov, D.; Karnaukhov, V.; Karpechev, E.; Kasiński, K.; Kasprowicz, G.; Kaur, M.; Kazantsev, A.; Kebschull, U.; Kekelidze, G.; Khan, M. M.; Khan, S. A.; Khanzadeev, A.; Khasanov, F.; Khvorostukhin, A.; Kirakosyan, V.; Kirejczyk, M.; Kiryakov, A.; Kiš, M.; Kisel, I.; Kisel, P.; Kiselev, S.; Kiss, T.; Klaus, P.; Kłeczek, R.; Klein-Bösing, Ch.; Kleipa, V.; Klochkov, V.; Kmon, P.; Koch, K.; Kochenda, L.; Koczoń, P.; Koenig, W.; Kohn, M.; Kolb, B. W.; Kolosova, A.; Komkov, B.; Korolev, M.; Korolko, I.; Kotte, R.; Kovalchuk, A.; Kowalski, S.; Koziel, M.; Kozlov, G.; Kozlov, V.; Kramarenko, V.; Kravtsov, P.; Krebs, E.; Kreidl, C.; Kres, I.; Kresan, D.; Kretschmar, G.; Krieger, M.; Kryanev, A. V.; Kryshen, E.; Kuc, M.; Kucewicz, W.; Kucher, V.; Kudin, L.; Kugler, A.; Kumar, Ajit; Kumar, Ashwini; Kumar, L.; Kunkel, J.; Kurepin, A.; Kurepin, N.; Kurilkin, A.; Kurilkin, P.; Kushpil, V.; Kuznetsov, S.; Kyva, V.; Ladygin, V.; Lara, C.; Larionov, P.; Laso García, A.; Lavrik, E.; Lazanu, I.; Lebedev, A.; Lebedev, S.; Lebedeva, E.; Lehnert, J.; Lehrbach, J.; Leifels, Y.; Lemke, F.; Li, Cheng; Li, Qiyan; Li, Xin; Li, Yuanjing; Lindenstruth, V.; Linnik, B.; Liu, Feng; Lobanov, I.; Lobanova, E.; Löchner, S.; Loizeau, P.-A.; Lone, S. A.; Lucio Martínez, J. A.; Luo, Xiaofeng; Lymanets, A.; Lyu, Pengfei; Maevskaya, A.; Mahajan, S.; Mahapatra, D. P.; Mahmoud, T.; Maj, P.; Majka, Z.; Malakhov, A.; Malankin, E.; Malkevich, D.; Malyatina, O.; Malygina, H.; Mandal, M. M.; Mandal, S.; Manko, V.; Manz, S.; Marin Garcia, A. M.; Markert, J.; Masciocchi, S.; Matulewicz, T.; Meder, L.; Merkin, M.; Mialkovski, V.; Michel, J.; Miftakhov, N.; Mik, L.; Mikhailov, K.; Mikhaylov, V.; Milanović, B.; Militsija, V.; Miskowiec, D.; Momot, I.; Morhardt, T.; Morozov, S.; Müller, W. F. J.; Müntz, C.; Mukherjee, S.; Muñoz Castillo, C. E.; Murin, Yu.; Najman, R.; Nandi, C.; Nandy, E.; Naumann, L.; Nayak, T.; Nedosekin, A.; Negi, V. S.; Niebur, W.; Nikulin, V.; Normanov, D.; Oancea, A.; Oh, Kunsu; Onishchuk, Yu.; Ososkov, G.; Otfinowski, P.; Ovcharenko, E.; Pal, S.; Panasenko, I.; Panda, N. R.; Parzhitskiy, S.; Patel, V.; Pauly, C.; Penschuck, M.; Peshekhonov, D.; Peshekhonov, V.; Petráček, V.; Petri, M.; Petriş, M.; Petrovici, A.; Petrovici, M.; Petrovskiy, A.; Petukhov, O.; Pfeifer, D.; Piasecki, K.; Pieper, J.; Pietraszko, J.; Płaneta, R.; Plotnikov, V.; Plujko, V.; Pluta, J.; Pop, A.; Pospisil, V.; Poźniak, K.; Prakash, A.; Prasad, S. K.; Prokudin, M.; Pshenichnov, I.; Pugach, M.; Pugatch, V.; Querchfeld, S.; Rabtsun, S.; Radulescu, L.; Raha, S.; Rami, F.; Raniwala, R.; Raniwala, S.; Raportirenko, A.; Rautenberg, J.; Rauza, J.; Ray, R.; Razin, S.; Reichelt, P.; Reinecke, S.; Reinefeld, A.; Reshetin, A.; Ristea, C.; Ristea, O.; Rodriguez Rodriguez, A.; Roether, F.; Romaniuk, R.; Rost, A.; Rostchin, E.; Rostovtseva, I.; Roy, Amitava; Roy, Ankhi; Rożynek, J.; Ryabov, Yu.; Sadovsky, A.; Sahoo, R.; Sahu, P. K.; Sahu, S. K.; Saini, J.; Samanta, S.; Sambyal, S. S.; Samsonov, V.; Sánchez Rosado, J.; Sander, O.; Sarangi, S.; Satława, T.; Sau, S.; Saveliev, V.; Schatral, S.; Schiaua, C.; Schintke, F.; Schmidt, C. J.; Schmidt, H. R.; Schmidt, K.; Scholten, J.; Schweda, K.; Seck, F.; Seddiki, S.; Selyuzhenkov, I.; Semennikov, A.; Senger, A.; Senger, P.; Shabanov, A.; Shabunov, A.; Shao, Ming; Sheremetiev, A. D.; Shi, Shusu; Shumeiko, N.; Shumikhin, V.; Sibiryak, I.; Sikora, B.; Simakov, A.; Simon, C.; Simons, C.; Singaraju, R. N.; Singh, A. K.; Singh, B. K.; Singh, C. P.; Singhal, V.; Singla, M.; Sitzmann, P.; Siwek-Wilczyńska, K.; Škoda, L.; Skwira-Chalot, I.; Som, I.; Song, Guofeng; Song, Jihye; Sosin, Z.; Soyk, D.; Staszel, P.; Strikhanov, M.; Strohauer, S.; Stroth, J.; Sturm, C.; Sultanov, R.; Sun, Yongjie; Svirida, D.; Svoboda, O.; Szabó, A.; Szczygieł, R.; Talukdar, R.; Tang, Zebo; Tanha, M.; Tarasiuk, J.; Tarassenkova, O.; Târzilă, M.-G.; Teklishyn, M.; Tischler, T.; Tlustý, P.; Tölyhi, T.; Toia, A.; Topil'skaya, N.; Träger, M.; Tripathy, S.; Tsakov, I.; Tsyupa, Yu.; Turowiecki, A.; Tuturas, N. G.; Uhlig, F.; Usenko, E.; Valin, I.; Varga, D.; Vassiliev, I.; Vasylyev, O.; Verbitskaya, E.; Verhoeven, W.; Veshikov, A.; Visinka, R.; Viyogi, Y. P.; Volkov, S.; Volochniuk, A.; Vorobiev, A.; Voronin, Aleksey; Voronin, Alexander; Vovchenko, V.; Vznuzdaev, M.; Wang, Dong; Wang, Xi-Wei; Wang, Yaping; Wang, Yi; Weber, M.; Wendisch, C.; Wessels, J. P.; Wiebusch, M.; Wiechula, J.; Wielanek, D.; Wieloch, A.; Wilms, A.; Winckler, N.; Winter, M.; Wiśniewski, K.; Wolf, Gy.; Won, Sanguk; Wu, Ke-Jun; Wüstenfeld, J.; Xiang, Changzhou; Xu, Nu; Yang, Junfeng; Yang, Rongxing; Yin, Zhongbao; Yoo, In-Kwon; Yuldashev, B.; Yushmanov, I.; Zabołotny, W.; Zaitsev, Yu.; Zamiatin, N. I.; Zanevsky, Yu.; Zhalov, M.; Zhang, Yifei; Zhang, Yu; Zhao, Lei; Zheng, Jiajun; Zheng, Sheng; Zhou, Daicui; Zhou, Jing; Zhu, Xianglei; Zinchenko, A.; Zipper, W.; Żoładź, M.; Zrelov, P.; Zryuev, V.; Zumbruch, P.; Zyzak, M.

2017-03-01

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (√{s_{NN}}= 2.7-4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials ( μ_B > 500 MeV), effects of chiral symmetry, and the equation of state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2024, in the context of the worldwide efforts to explore high-density QCD matter.

Kinematic Sunyaev-Zel'dovich Effect with Projected Fields: A Novel Probe of the Baryon Distribution with Planck, WMAP, and WISE Data.

PubMed

Hill, J Colin; Ferraro, Simone; Battaglia, Nick; Liu, Jia; Spergel, David N

2016-07-29

The kinematic Sunyaev-Zel'dovich (KSZ) effect-the Doppler boosting of cosmic microwave background (CMB) photons due to Compton scattering off free electrons with nonzero bulk velocity-probes the abundance and the distribution of baryons in the Universe. All KSZ measurements to date have explicitly required spectroscopic redshifts. Here, we implement a novel estimator for the KSZ-large-scale structure cross-correlation based on projected fields: it does not require redshift estimates for individual objects, allowing KSZ measurements from large-scale imaging surveys. We apply this estimator to cleaned CMB temperature maps constructed from Planck and WMAP data and a galaxy sample from the Wide-field Infrared Survey Explorer (WISE). We measure the KSZ effect at 3.8σ-4.5σ significance, depending on the use of additional WISE galaxy bias constraints. We verify that our measurements are robust to possible dust emission from the WISE galaxies. Assuming the standard Λ cold dark matter cosmology, we directly constrain (f_{b}/0.158)(f_{free}/1.0)=1.48±0.19 (statistical error only) at redshift z≈0.4, where f_{b} is the fraction of matter in baryonic form and f_{free} is the free electron fraction. This is the tightest KSZ-derived constraint reported to date on these parameters. Astronomers have long known that baryons do not trace dark matter on ∼ kiloparsec scales and there has been strong evidence that galaxies are baryon poor. The consistency between the f_{b} value found here and the values inferred from analyses of the primordial CMB and big bang nucleosynthesis verifies that baryons approximately trace the dark matter distribution down to ∼ megaparsec scales. While our projected-field estimator is already competitive with other KSZ approaches when applied to current data sets (because we are able to use the full-sky WISE photometric survey), it will yield enormous signal-to-noise ratios when applied to upcoming high-resolution, multifrequency CMB surveys.

Kinematic Sunyaev-Zel'dovich Effect with Projected Fields: A Novel Probe of the Baryon Distribution with Planck, WMAP, and WISE Data

NASA Astrophysics Data System (ADS)

Hill, J. Colin; Ferraro, Simone; Battaglia, Nick; Liu, Jia; Spergel, David N.

2016-07-01

The kinematic Sunyaev-Zel'dovich (KSZ) effect—the Doppler boosting of cosmic microwave background (CMB) photons due to Compton scattering off free electrons with nonzero bulk velocity—probes the abundance and the distribution of baryons in the Universe. All KSZ measurements to date have explicitly required spectroscopic redshifts. Here, we implement a novel estimator for the KSZ—large-scale structure cross-correlation based on projected fields: it does not require redshift estimates for individual objects, allowing KSZ measurements from large-scale imaging surveys. We apply this estimator to cleaned CMB temperature maps constructed from Planck and WMAP data and a galaxy sample from the Wide-field Infrared Survey Explorer (WISE). We measure the KSZ effect at 3.8 σ - 4.5 σ significance, depending on the use of additional WISE galaxy bias constraints. We verify that our measurements are robust to possible dust emission from the WISE galaxies. Assuming the standard Λ cold dark matter cosmology, we directly constrain (fb/0.158 ) (ffree/1.0 ) =1.48 ±0.19 (statistical error only) at redshift z ≈0.4 , where fb is the fraction of matter in baryonic form and ffree is the free electron fraction. This is the tightest KSZ-derived constraint reported to date on these parameters. Astronomers have long known that baryons do not trace dark matter on ˜ kiloparsec scales and there has been strong evidence that galaxies are baryon poor. The consistency between the fb value found here and the values inferred from analyses of the primordial CMB and big bang nucleosynthesis verifies that baryons approximately trace the dark matter distribution down to ˜ megaparsec scales. While our projected-field estimator is already competitive with other KSZ approaches when applied to current data sets (because we are able to use the full-sky WISE photometric survey), it will yield enormous signal-to-noise ratios when applied to upcoming high-resolution, multifrequency CMB surveys.

Complex Langevin simulation of chiral symmetry restoration at finite baryonic density

NASA Astrophysics Data System (ADS)

Ilgenfritz, Ernst-Michael

1986-12-01

A recently proposed effective SU(3) spin model with chiral order parameter is studied by means of the complex Langevin equation. A first-order chiral symmetry restoring and deconfining transition is observed at sufficiently low temperature at finite baryonic density. Permanent address: Sektion Physik, Karl-Marx Universität, DDR-7010 Leipzig, German Democratic Republic.

Baryonic dark matter

NASA Technical Reports Server (NTRS)

Silk, Joseph

1991-01-01

Both canonical primordial nucleosynthesis constraints and large-scale structure measurements, as well as observations of the fundamental cosmological parameters, appear to be consistent with the hypothesis that the universe predominantly consists of baryonic dark matter (BDM). The arguments for BDM to consist of compact objects that are either stellar relics or substellar objects are reviewed. Several techniques for searching for halo BDM are described.

∑s-∑s as a di-baryonic molecule

NASA Astrophysics Data System (ADS)

Rathaud, D. P.; Rai, Ajay Kumar

2018-05-01

We study the ∑s-∑s, as a possible di-baryonic molecule in the potential model framework. We approximated the binding mechanism mainly as One Boson Exchange (QBE) plus screen type Yukawa potential. We predict the ∑s-∑s bound state molecule with I(Jp)=0(0+) and 0(1+) possible quantum numbers.

Observation of the Heavy Baryons Sigma b and Sigma b*.

PubMed

Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; DaRonco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dörr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Tesarek, R J; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vazquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

2007-11-16

We report an observation of new bottom baryons produced in pp collisions at the Tevatron. Using 1.1 fb(-1) of data collected by the CDF II detector, we observe four Lambda b 0 pi+/- resonances in the fully reconstructed decay mode Lambda b 0-->Lambda c + pi-, where Lambda c+-->pK* pi+. We interpret these states as the Sigma b(*)+/- baryons and measure the following masses: m Sigma b+=5807.8 -2.2 +2.0(stat.)+/-1.7(syst.) MeV/c2, m Sigma b- =5815.2+/-1.0(stat.)+/-1.7(syst.) MeV/c2, and m(Sigma b*)-m(Sigma b)=21.2-1.9 +2.0(stat.)-0.3+0.4(syst.) MeV/c2.

Production of multiply heavy flavoured baryons from Quark Gluon Plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Becattini, F.; INFN Sezione di Firenze, Via G. Sansone 1, I-50019, Sesto F.no

We show that in heavy ion collisions at LHC there could be a measurable production of baryons containing two or three heavy quarks from statistical coalescence. This production mechanism is peculiar of Quark Gluon Plasma and the predicted rates, in heavy ion collisions at LHC energy, exceed those from a purely hadronic scenario, particularly for {xi}bc and {omega}ccc. Thus, besides the interest in the discovery of these new states, enhanced ratios of these baryons over singly heavy flavoured hadrons, like B or D, in heavy ion collisions with respect to pp at the same energy, would be a clear indicationmore » of kinetical equilibration of heavy quarks in the Quark Gluon Plasma.« less

Baryon magnetic moments: Symmetries and relations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parreno, Assumpta; Savage, Martin; Tiburzi, Brian

Magnetic moments of the octet baryons are computed using lattice QCD in background magnetic fields, including the first treatment of the magnetically coupled Σ0- Λ system. Although the computations are performed for relatively large values of the up and down quark masses, we gain new insight into the symmetries and relations between magnetic moments by working at a three-flavor mass-symmetric point. While the spinflavor symmetry in the large Nc limit of QCD is shared by the naïve constituent quark model, we find instances where quark model predictions are considerably favored over those emerging in the large Nc limit. We suggestmore » further calculations that would shed light on the curious patterns of baryon magnetic moments.« less

Heavy baryons in the large N c limit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Albertus, C.; Ruiz Arriola, Enrique; Fernando, Ishara P.

It is shown that in the large N c limit heavy baryon masses can be estimated quantitatively in a 1/N c expansion using the Hartree approximation. The results are compared with available lattice calculations for different values of the ratio between the square root of the string tension and the heavy quark mass tension independent of N c. Using a potential adjusted to agree with the one obtained in lattice QCD, a variational analysis of the ground state spin averaged baryon mass is performed using Gaussian Hartree wave functions. Relativistic corrections through the quark kinetic energy are included. Lastly, themore » results provide good estimates for the first sub-leading in 1/N c corrections.« less

Heavy baryons in the large N c limit

DOE PAGES

Albertus, C.; Ruiz Arriola, Enrique; Fernando, Ishara P.; ...

2015-09-16

It is shown that in the large N c limit heavy baryon masses can be estimated quantitatively in a 1/N c expansion using the Hartree approximation. The results are compared with available lattice calculations for different values of the ratio between the square root of the string tension and the heavy quark mass tension independent of N c. Using a potential adjusted to agree with the one obtained in lattice QCD, a variational analysis of the ground state spin averaged baryon mass is performed using Gaussian Hartree wave functions. Relativistic corrections through the quark kinetic energy are included. Lastly, themore » results provide good estimates for the first sub-leading in 1/N c corrections.« less

The Mass Distribution in Disk Galaxies

NASA Astrophysics Data System (ADS)

Courteau, Stéphane; Dutton, Aaron A.

We present the relative fraction of baryons and dark matter at various radii in galaxies. For spiral galaxies, this fraction measured in a galaxy's inner parts is typically baryon-dominated (maximal) and dark-matter dominated (sub-maximal) in the outskirts. The transition from maximal to sub-maximal baryons occurs within the inner parts of low-mass disk galaxies (with V tot <= 200 km s-1) and in the outer disk for more massive systems. The mean mass fractions for late- and early-type galaxies vary significantly at the same fiducial radius and circular velocity, suggesting a range of galaxy formation mechanisms. A more detailed discussion, and resolution of the so-called ``maximal disk problem'', is presented in Courteau & Dutton, ApJL, 801, 20.

Best Phd thesis Prize: Statistical analysis of ALFALFA galaxies: insights in galaxy

NASA Astrophysics Data System (ADS)

Papastergis, E.

2013-09-01

We use the rich dataset of local universe galaxies detected by the ALFALFA 21cm survey to study the statistical properties of gas-bearing galaxies. In particular, we measure the number density of galaxies as a function of their baryonic mass ("baryonic mass function") and rotational velocity ("velocity width function"), and we characterize their clustering properties ("two-point correlation function"). These statistical distributions are determined by both the properties of dark matter on small scales, as well as by the complex baryonic processes through which galaxies form over cosmic time. We interpret the ALFALFA measurements with the aid of publicly available cosmological N-body simulations and we present some key results related to galaxy formation and small-scale cosmology.

Baryon Spectroscopy Through Partial-Wave Analysis and Meson Photoproduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manley, D. Mark

2016-09-08

The principal goal of this project is the experimental and phenomenological study of baryon spectroscopy. The PI's group consists of himself and three graduate students. This final report summarizes research activities by the PI's group during the period 03/01/2015 to 08/14/2016. During this period, the PI co-authored 11 published journal papers and one proceedings article and presented three invited talks. The PI's general interest is the investigation of the baryon resonance spectrum up to masses of ~ 2 GeV. More detail is given on two research projects: Neutral Kaon Photoproduction and Partial-Wave Analyses of γp → η p, γn →more » η n, and γp → K⁺ Λ.« less

Asymmetric twin Dark Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farina, Marco

2015-11-09

We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of themore » cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.« less

Asymmetric twin Dark Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farina, Marco, E-mail: mf627@cornell.edu

2015-11-01

We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of themore » cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.« less

Large-scale structure from cosmic-string loops in a baryon-dominated universe

NASA Technical Reports Server (NTRS)

Melott, Adrian L.; Scherrer, Robert J.

1988-01-01

The results are presented of a numerical simulation of the formation of large-scale structure in a universe with Omega(0) = 0.2 and h = 0.5 dominated by baryons in which cosmic strings provide the initial density perturbations. The numerical model yields a power spectrum. Nonlinear evolution confirms that the model can account for 700 km/s bulk flows and a strong cluster-cluster correlation, but does rather poorly on smaller scales. There is no visual 'filamentary' structure, and the two-point correlation has too steep a logarithmic slope. The value of G mu = 4 x 10 to the -6th is significantly lower than previous estimates for the value of G mu in baryon-dominated cosmic string models.

Towards Lattice QCD Baryon Forces at the Physical Point: First Results

NASA Astrophysics Data System (ADS)

Doi, Takumi; Aoki, Sinya; Gongyo, Shinya; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Iritani, Takumi; Ishii, Noriyoshi; Miyamoto, Takaya; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji

Lattice QCD calculations of baryon forces are performed for the first time with (almost) physical quark masses. Nf = 2 + 1 dynamical clover fermion gauge configurations are generated at the lattice spacing of a ≃ 0.085 fm on a (96a)4 ≃ (8.2 fm)4 lattice with quark masses corresponding to (mπ,mK) ≃ (146,525) MeV. Baryon forces are calculated using the time-dependent HAL QCD method. In this report, we study ΞΞ and NN systems both in 1S0 and 3S1-3D1 channels, and the results for the central and tensor forces as well as phase shifts in the ΞΞ (1S0) channel are presented.

Big bang nucleosynthesis and the quark-hadron transition

NASA Technical Reports Server (NTRS)

Kurki-Suonio, Hannu; Matzner, Richard A.; Olive, Keith A.; Schramm, David N.

1990-01-01

An examination and brief review is made of the effects of quark-hadron transition induced fluctuations on Big Bang nucleosynthesis. It is shown that cosmologically critical densities in baryons are difficult to reconcile with observation, but the traditional baryon density constraints from homogeneous calculations might be loosened by as much as 50 percent, to 0.3 of critical density, and the limit on the number of neutrino flavors remains about N(sub nu) is less than or approximately 4. To achieve baryon densities of greater than or approximately 0.3 of critical density would require initial density contrasts R is much greater the 10(exp e), whereas the simplest models for the transition seem to restrict R to less than of approximately 10(exp 2).

Big Bang nucleosynthesis and the Quark-Hadron transition

NASA Technical Reports Server (NTRS)

Kurki-Suonio, Hannu; Matzner, Richard A.; Olive, Keith A.; Schramm, David N.

1989-01-01

An examination and brief review is made of the effects of quark-hadron transistion induced fluctuations on Big Bang nucleosynthesis. It is shown that cosmologically critical densities in baryons are difficult to reconcile with observation, but the traditional baryon density constraints from homogeneous calculations might be loosened by as much as 50 percent, to 0.3 of critical density, and the limit on the number of neutrino flavors remains about N(sub nu) is less than or approximately 4. To achieve baryon densities of greater than or approximately 0.3 of critical density would require initial density contrasts R is much greater the 10(exp 3), whereas the simplest models for the transition seem to restrict R to less than of approximately 10(exp 2).

OMEGA{sup -}, XI*{sup -}, SIGMA*{sup -}, and DELTA{sup -} decuplet baryon magnetic moments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slaughter, Milton Dean

The properties of the ground-state U spin =(3/2) baryon decuplet magnetic moments DELTA{sup -}, XI*{sup -}, SIGMA*{sup -}, and OMEGA{sup -} and their ground-state spin-(1/2) cousins p, n, LAMBDA, SIGMA{sup +}, SIGMA{sup 0}, SIGMA{sup -}, XI{sup +}, and XI{sup -} have been studied for many years with a modicum of success. The magnetic moments of many are yet to be determined. Of the decuplet baryons, only the magnetic moment of the OMEGA{sup -} has been accurately determined. We calculate the magnetic moments of the physical decuplet U spin =(3/2) quartet members without ascribing any specific form to their quark structuremore » or intraquark interactions.« less

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

KSC-04pd1714

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers cover with plastic the Multi-Purpose Logistics Module Donatello in preparation for the expected impact of Hurricane Frances on Saturday. Other modules and equipment are being covered as well. Workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1712

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers cover with plastic the U.S. Node 2 in preparation for the expected impact of Hurricane Frances on Saturday. Other modules and equipment are being covered as well. Workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1713

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers cover with plastic the Multi-Purpose Logistics Module Raffaello in preparation for the expected impact of Hurricane Frances on Saturday. Other modules and equipment are being covered as well. Workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1715

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, modules wrapped in plastic line one wall. The modules and equipment are being covered in preparation for the expected impact of Hurricane Frances on Saturday. KSC workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

LH2 fuel tank design for SSTO

NASA Technical Reports Server (NTRS)

Wright, Geoff

1994-01-01

This report will discuss the design of a liquid hydrogen fuel tank constructed from composite materials. The focus of this report is to recommend a design for a fuel tank which will be able to withstand all static and dynamic forces during manned flight. Areas of study for the design include material selection, material structural analysis, heat transfer, thermal expansion, and liquid hydrogen diffusion. A structural analysis FORTRAN program was developed for analyzing the buckling and yield characteristics of the tank. A thermal analysis Excel spreadsheet was created to determine a specific material thickness which will minimize heat transfer through the wall of the tank. The total mass of the tank was determined by the combination of both structural and thermal analyses. The report concludes with the recommendation of a layered material tank construction. The designed system will include exterior insulation, combination of metal and organize composite matrices and honeycomb.

Synthesis of advanced aluminide intermetallic coatings by low-energy Al-ion radiation

NASA Astrophysics Data System (ADS)

Shen, Mingli; Gu, Yan; Zhao, Panpan; Zhu, Shenglong; Wang, Fuhui

2016-05-01

Metals that work at high temperatures (for instance, superalloys in gas-turbines) depend on thermally grown oxide (TGO, commonly alumina) to withstand corrosion attack. Nickel Aluminide (NiAl) as one superior alumina TGO former plays an important role in protective coatings for turbine blades in gas-turbine engines used for aircraft propulsion and power generation. Lowering TGO growth rate is essentially favored for offering sustainable protection, especially in thermal barrier coatings (TBC). However, it can only be achieved currently by a strategy of adding the third element (Pt or reactive elements) into NiAl during traditional diffusion- or deposition-based synthesis of the coating. Here we present a highly flexible Al-ion radiation-based synthesis of advanced NiAl coatings, achieving low TGO growth rate without relying on the third element addition. Our results expand the strategy for lowering TGO growth rate and demonstrate potentials for ion radiation in advancing materials synthesis.

Molecular coordination of Staphylococcus aureus cell division

PubMed Central

Cotterell, Bryony E; Walther, Christa G; Fenn, Samuel J; Grein, Fabian; Wollman, Adam JM; Leake, Mark C; Olivier, Nicolas; Cadby, Ashley; Mesnage, Stéphane; Jones, Simon

2018-01-01

The bacterial cell wall is essential for viability, but despite its ability to withstand internal turgor must remain dynamic to permit growth and division. Peptidoglycan is the major cell wall structural polymer, whose synthesis requires multiple interacting components. The human pathogen Staphylococcus aureus is a prolate spheroid that divides in three orthogonal planes. Here, we have integrated cellular morphology during division with molecular level resolution imaging of peptidoglycan synthesis and the components responsible. Synthesis occurs across the developing septal surface in a diffuse pattern, a necessity of the observed septal geometry, that is matched by variegated division component distribution. Synthesis continues after septal annulus completion, where the core division component FtsZ remains. The novel molecular level information requires re-evaluation of the growth and division processes leading to a new conceptual model, whereby the cell cycle is expedited by a set of functionally connected but not regularly distributed components. PMID:29465397

Synthesis of advanced aluminide intermetallic coatings by low-energy Al-ion radiation

PubMed Central

Shen, Mingli; Gu, Yan; Zhao, Panpan; Zhu, Shenglong; Wang, Fuhui

2016-01-01

Metals that work at high temperatures (for instance, superalloys in gas-turbines) depend on thermally grown oxide (TGO, commonly alumina) to withstand corrosion attack. Nickel Aluminide (NiAl) as one superior alumina TGO former plays an important role in protective coatings for turbine blades in gas-turbine engines used for aircraft propulsion and power generation. Lowering TGO growth rate is essentially favored for offering sustainable protection, especially in thermal barrier coatings (TBC). However, it can only be achieved currently by a strategy of adding the third element (Pt or reactive elements) into NiAl during traditional diffusion- or deposition-based synthesis of the coating. Here we present a highly flexible Al-ion radiation-based synthesis of advanced NiAl coatings, achieving low TGO growth rate without relying on the third element addition. Our results expand the strategy for lowering TGO growth rate and demonstrate potentials for ion radiation in advancing materials synthesis. PMID:27194417

Diffusion, Thermal Properties and Chemical Compatibilities of Select MAX Phases with Materials For Advanced Nuclear Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barsoum, Michel; Bentzel, Grady; Tallman, Darin J.

2016-04-04

The demands of Gen IV nuclear power plants for long service life under neutron irradiation at high temperature are severe. Advanced materials that would withstand high temperatures (up to 1000+ ºC) to high doses in a neutron field would be ideal for reactor internal structures and would add to the long service life and reliability of the reactors. The objective of this work is to investigate the chemical compatibility of select MAX with potential materials that are important for nuclear energy, as well as to measure the thermal transport properties as a function of neutron irradiation. The chemical counterparts chosenmore » for this work are: pyrolytic carbon, SiC, U, Pd, FLiBe, Pb-Bi and Na, the latter 3 in the molten state. The thermal conductivities and heat capacities of non-irradiated MAX phases will be measured.« less

Synthesis of advanced aluminide intermetallic coatings by low-energy Al-ion radiation.

PubMed

Shen, Mingli; Gu, Yan; Zhao, Panpan; Zhu, Shenglong; Wang, Fuhui

2016-05-19

Metals that work at high temperatures (for instance, superalloys in gas-turbines) depend on thermally grown oxide (TGO, commonly alumina) to withstand corrosion attack. Nickel Aluminide (NiAl) as one superior alumina TGO former plays an important role in protective coatings for turbine blades in gas-turbine engines used for aircraft propulsion and power generation. Lowering TGO growth rate is essentially favored for offering sustainable protection, especially in thermal barrier coatings (TBC). However, it can only be achieved currently by a strategy of adding the third element (Pt or reactive elements) into NiAl during traditional diffusion- or deposition-based synthesis of the coating. Here we present a highly flexible Al-ion radiation-based synthesis of advanced NiAl coatings, achieving low TGO growth rate without relying on the third element addition. Our results expand the strategy for lowering TGO growth rate and demonstrate potentials for ion radiation in advancing materials synthesis.

The Evolution of the Tully-Fisher Relation between z ˜ 2.3 and z ˜ 0.9 with KMOS3D

NASA Astrophysics Data System (ADS)

Übler, H.; Förster Schreiber, N. M.; Genzel, R.; Wisnioski, E.; Wuyts, S.; Lang, P.; Naab, T.; Burkert, A.; van Dokkum, P. G.; Tacconi, L. J.; Wilman, D. J.; Fossati, M.; Mendel, J. T.; Beifiori, A.; Belli, S.; Bender, R.; Brammer, G. B.; Chan, J.; Davies, R.; Fabricius, M.; Galametz, A.; Lutz, D.; Momcheva, I. G.; Nelson, E. J.; Saglia, R. P.; Seitz, S.; Tadaki, K.

2017-06-01

We investigate the stellar mass and baryonic mass Tully-Fisher relations (TFRs) of massive star-forming disk galaxies at redshift z˜ 2.3 and z˜ 0.9 as part of the {{KMOS}}3{{D}} integral field spectroscopy survey. Our spatially resolved data allow reliable modeling of individual galaxies, including the effect of pressure support on the inferred gravitational potential. At fixed circular velocity, we find higher baryonic masses and similar stellar masses at z˜ 2.3 as compared to z˜ 0.9. Together with the decreasing gas-to-stellar mass ratios with decreasing redshift, this implies that the contribution of dark matter to the dynamical mass on the galaxy scale increases toward lower redshift. A comparison to local relations reveals a negative evolution of the stellar and baryonic TFR zero points from z = 0 to z˜ 0.9, no evolution of the stellar TFR zero point from z˜ 0.9 to z˜ 2.3, and a positive evolution of the baryonic TFR zero point from z˜ 0.9 to z˜ 2.3. We discuss a toy model of disk galaxy evolution to explain the observed nonmonotonic TFR evolution, taking into account the empirically motivated redshift dependencies of galactic gas fractions and the relative amount of baryons to dark matter on galaxy and halo scales. Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere under ESO programs 092.A-0091, 093.A-0079, 094.A-0217, 095.A-0047, and 096.A-0025.

Modeling the Impact of Baryons on Subhalo Populations with Machine Learning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nadler, Ethan O.; Mao, Yao -Yuan; Wechsler, Risa H.

Here, we identify subhalos in dark matter–only (DMO) zoom-in simulations that are likely to be disrupted due to baryonic effects by using a random forest classifier trained on two hydrodynamic simulations of Milky Way (MW)–mass host halos from the Latte suite of the Feedback in Realistic Environments (FIRE) project. We train our classifier using five properties of each disrupted and surviving subhalo: pericentric distance and scale factor at first pericentric passage after accretion and scale factor, virial mass, and maximum circular velocity at accretion. Our five-property classifier identifies disrupted subhalos in the FIRE simulations with an 85% out-of-bag classification score.more » We predict surviving subhalo populations in DMO simulations of the FIRE host halos, finding excellent agreement with the hydrodynamic results; in particular, our classifier outperforms DMO zoom-in simulations that include the gravitational potential of the central galactic disk in each hydrodynamic simulation, indicating that it captures both the dynamical effects of a central disk and additional baryonic physics. We also predict surviving subhalo populations for a suite of DMO zoom-in simulations of MW-mass host halos, finding that baryons impact each system consistently and that the predicted amount of subhalo disruption is larger than the host-to-host scatter among the subhalo populations. Although the small size and specific baryonic physics prescription of our training set limits the generality of our results, our work suggests that machine-learning classification algorithms trained on hydrodynamic zoom-in simulations can efficiently predict realistic subhalo populations.« less

Modeling the Impact of Baryons on Subhalo Populations with Machine Learning

DOE PAGES

Nadler, Ethan O.; Mao, Yao -Yuan; Wechsler, Risa H.; ...

2018-06-01

Here, we identify subhalos in dark matter–only (DMO) zoom-in simulations that are likely to be disrupted due to baryonic effects by using a random forest classifier trained on two hydrodynamic simulations of Milky Way (MW)–mass host halos from the Latte suite of the Feedback in Realistic Environments (FIRE) project. We train our classifier using five properties of each disrupted and surviving subhalo: pericentric distance and scale factor at first pericentric passage after accretion and scale factor, virial mass, and maximum circular velocity at accretion. Our five-property classifier identifies disrupted subhalos in the FIRE simulations with an 85% out-of-bag classification score.more » We predict surviving subhalo populations in DMO simulations of the FIRE host halos, finding excellent agreement with the hydrodynamic results; in particular, our classifier outperforms DMO zoom-in simulations that include the gravitational potential of the central galactic disk in each hydrodynamic simulation, indicating that it captures both the dynamical effects of a central disk and additional baryonic physics. We also predict surviving subhalo populations for a suite of DMO zoom-in simulations of MW-mass host halos, finding that baryons impact each system consistently and that the predicted amount of subhalo disruption is larger than the host-to-host scatter among the subhalo populations. Although the small size and specific baryonic physics prescription of our training set limits the generality of our results, our work suggests that machine-learning classification algorithms trained on hydrodynamic zoom-in simulations can efficiently predict realistic subhalo populations.« less

The BAHAMAS project: the CMB-large-scale structure tension and the roles of massive neutrinos and galaxy formation

NASA Astrophysics Data System (ADS)

McCarthy, Ian G.; Bird, Simeon; Schaye, Joop; Harnois-Deraps, Joachim; Font, Andreea S.; van Waerbeke, Ludovic

2018-05-01

Recent studies have presented evidence for tension between the constraints on Ωm and σ8 from the cosmic microwave background (CMB) and measurements of large-scale structure (LSS). This tension can potentially be resolved by appealing to extensions of the standard model of cosmology and/or untreated systematic errors in the modelling of LSS, of which baryonic physics has been frequently suggested. We revisit this tension using, for the first time, carefully calibrated cosmological hydrodynamical simulations, which thus capture the backreaction of the baryons on the total matter distribution. We have extended the BAryons and HAloes of MAssive Sysmtes simulations to include a treatment of massive neutrinos, which currently represents the best-motivated extension to the standard model. We make synthetic thermal Sunyaev-Zel'dovich effect, weak galaxy lensing, and CMB lensing maps and compare to observed auto- and cross-power spectra from a wide range of recent observational surveys. We conclude that: (i) in general, there is tension between the primary CMB and LSS when adopting the standard model with minimal neutrino mass; (ii) after calibrating feedback processes to match the gas fractions of clusters, the remaining uncertainties in the baryonic physics modelling are insufficient to reconcile this tension; and (iii) if one accounts for internal tensions in the Planck CMB data set (by allowing the lensing amplitude, ALens, to vary), invoking a non-minimal neutrino mass, typically of 0.2-0.4 eV, can resolve the tension. This solution is fully consistent with separate constraints from the primary CMB and baryon acoustic oscillations.

Charmed baryon weak decays with SU(3) flavor symmetry

NASA Astrophysics Data System (ADS)

Geng, C. Q.; Hsiao, Y. K.; Liu, Chia-Wei; Tsai, Tien-Hsueh

2017-11-01

We study the semileptonic and non-leptonic charmed baryon decays with SU(3) flavor symmetry, where the charmed baryons can be B c = (Ξ c 0 , Ξ c + , Λ c + ), B c ' = ( Σ c (++,+,0) , Ξ c ' (+,0) , Ω c 0 ), B cc = (Ξ cc + + , Ξ cc + , Ω c + ) or B cc = Ω ccc + + . With B n (') denoted as the baryon octet (decuplet), we find that the B c → B n ' ℓ + ν ℓ decays are forbidden, while the Ω c 0 → Ω- ℓ + ν ℓ , Ω cc + → Ω c 0 ℓ + ν ℓ , and Ω ccc + + → Ω cc + ℓ + ν ℓ decays are the only existing Cabibbo- allowed modes for B c ' → B n ' ℓ + ν ℓ , B cc → B c ' ℓ + ν ℓ , and B ccc → B cc (') ℓ + ν ℓ , respectively. We predict the rarely studied B c → B n (') M decays, such as B({Ξ}_c^0\\to {Λ}^0{\\overline{K}}^0,{Ξ}_c+\\to {Ξ}^0{π}+)=(8.3± 0.9, 8.0± 4.1)× {10}^{-3} and B({Λ}_c+\\to {Δ}^{++}{π}-,{Ξ}_c^0\\to {Ω}-{K}+)=(5.5± 1.3, 4.8± 0.5)× {10}^{-3} . For the observation, the doubly and triply charmed baryon decays of {Ω}_{cc}+\\to {Ξ}_c+{\\overline{K}}^0,{Ξ}_{cc}^{++}\\to ({Ξ}_c+{π}+,{Σ}_c^{++}{\\overline{K}}^0), and {Ω}_{ccc}^{++}\\to ({Ξ}_{cc}^{++}{\\overline{K}}^0,{Ω}_{cc}+{π}+,{Ξ}_c+{D}+) are the favored Cabibbo-allowed decays, which are accessible to the BESIII and LHCb experiments.

Tuning the Shell Number of Multishelled Metal Oxide Hollow Fibers for Optimized Lithium-Ion Storage.

PubMed

Sun, Jin; Lv, Chunxiao; Lv, Fan; Chen, Shuai; Li, Daohao; Guo, Ziqi; Han, Wei; Yang, Dongjiang; Guo, Shaojun

2017-06-27

Searching the long-life transition-metal oxide (TMO)-based materials for future lithium-ion batteries (LIBs) is still a great challenge because of the mechanical strain resulting from volume change of TMO anodes during the lithiation/delithiation process. To well address this challenging issue, we demonstrate a controlled method for making the multishelled TMO hollow microfibers with tunable shell numbers to achieve the optimal void for efficient lithium-ion storage. Such a particularly designed void can lead to a short diffusion distance for fast diffusion of Li + ions and also withstand a large volume variation upon cycling, both of which are the key for high-performance LIBs. Triple-shelled TMO hollow microfibers are a quite stable anode material for LIBs with high reversible capacities (NiO: 698.1 mA h g -1 at 1 A g -1 ; Co 3 O 4 : 940.2 mA h g -1 at 1 A g -1 ; Fe 2 O 3 : 997.8 mA h g -1 at 1 A g -1 ), excellent rate capability, and stability. The present work opens a way for rational design of the void of multiple shells in achieving the stable lithium-ion storage through the biomass conversion strategy.

Effect of Mesostructured Layer upon Crystalline Properties and Device Performance on Perovskite Solar Cells.

PubMed

Listorti, Andrea; Juarez-Perez, Emilio J; Frontera, Carlos; Roiati, Vittoria; Garcia-Andrade, Laura; Colella, Silvia; Rizzo, Aurora; Ortiz, Pablo; Mora-Sero, Ivan

2015-05-07

One of the most fascinating characteristics of perovskite solar cells (PSCs) is the retrieved obtainment of outstanding photovoltaic (PV) performances withstanding important device configuration variations. Here we have analyzed CH3NH3PbI3-xClx in planar or in mesostructured (MS) configurations, employing both titania and alumina scaffolds, fully infiltrated with perovskite material or presenting an overstanding layer. The use of the MS scaffold induces to the perovskite different structural properties, in terms of grain size, preferential orientation, and unit cell volume, in comparison to the ones of the material grown with no constraints, as we have found out by X-ray diffraction analyses. We have studied the effect of the PSC configuration on photoinduced absorption and time-resolved photoluminescence, complementary techniques that allow studying charge photogeneration and recombination. We have estimated electron diffusion length in the considered configurations observing a decrease when the material is confined in the MS scaffold with respect to a planar architecture. However, the presence of perovskite overlayer allows an overall recovering of long diffusion lengths explaining the record PV performances obtained with a device configuration bearing both the mesostructure and a perovskite overlayer. Our results suggest that performance in devices with perovskite overlayer is mainly ruled by the overlayer, whereas the mesoporous layer influences the contact properties.

Insights to N(udd) baryon spectra

NASA Astrophysics Data System (ADS)

Rai, Ajay Kumar; Shah, Zalak; Gandhi, Keval

2018-05-01

The nucleons are the basic elements of the light baryons. In this paper, we choose neutron (N) with a combination of one up(u) and two down(d) quarks. The ground state of N is determined with quantum number JP = 1/2+. Also, the first radial and orbital excited states are calculated. The results are compared with experimental masses as well as other theoretical predictions.

Balance of dark and luminous mass in rotating galaxies.

PubMed

McGaugh, Stacy S

2005-10-21

A fine balance between dark and baryonic mass is observed in spiral galaxies. As the contribution of the baryons to the total rotation velocity increases, the contribution of the dark matter decreases by a compensating amount. This poses a fine-tuning problem for galaxy formation models, and may point to new physics for dark matter particles or even a modification of gravity.

The Fixed Target Experiment for Studies of Baryonic Matter at the Nuclotron (BM@N)

NASA Astrophysics Data System (ADS)

Kapishin, M. N.

2017-12-01

BM@N (Baryonic Matter at Nuclotron) is the first experiment to be realized at the NICA-Nuclotron accelerator complex. The aim of the BM@N experiment is to study relativistic heavy ion beam interactions with fixed targets. The BM@N setup, results of Monte Carlo simulations, and the BM@N experimental program are presented.

Gamma ray cosmology: The extra galactic gamma spectrum and methods to detect the underlying source

NASA Technical Reports Server (NTRS)

Cline, David B.

1990-01-01

The possible sources of extragalactic gamma rays and methods to distinguish the different sources are discussed. The sources considered are early universe decays and annihilation of Particles, active galactic nuclei (AGN) sources, and baryon-antibaryon annihilation in a baryon symmetric cosmology. The energy spectrum and possible angular fluctuations due to these sources are described.

Gamma-Ray background spectrum and annihilation rate in the baryon-symmetric big-bang cosmology

NASA Technical Reports Server (NTRS)

Puget, J. L.

1973-01-01

An attempt was made to extract experimental data on baryon symmetry by observing annihilation products. Specifically, gamma rays and neutrons with long mean free paths were analyzed. Data cover absorption cross sections and radiation background of the 0.511 MeV gamma rays from positron annihilations and the 70 MeV gamma rays from neutral pion decay.

Quark model and strange baryon production in heavy ion collisions

NASA Astrophysics Data System (ADS)

Bialas, A.

1998-12-01

It is pointed out that the recent data on strange baryon and antibaryon production in Pb-Pb collisions at 159 GeV/c agree well with the hypothesis of an intermediate state of quasi-free and randomly distributed constituent quarks and antiquarks. Also the S-S data are consistent with this hypothesis. The p-Pb data follow a different pattern.

Magnetic properties of four dimensional fermions

NASA Astrophysics Data System (ADS)

Bergman, Oren; Lifschytz, Gilad; Lippert, Matthew

2013-12-01

We investigate the Sakai-Sugimoto model at nonzero baryon chemical potential in a background magnetic field in the chiral symmetric phase. We find that a new form of baryonic matter shows up, and we investigate its properties. We find a generated axial current, a reduction in the amount of charge participating in dissipative interactions and a metamagnetic like phase transition at low temperature.

ON THE PERSISTENCE OF TWO SMALL-SCALE PROBLEMS IN ΛCDM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pawlowski, Marcel S.; Famaey, Benoit; Merritt, David

2015-12-10

We investigate the degree to which the inclusion of baryonic physics can overcome two long-standing problems of the standard cosmological model on galaxy scales: (1) the problem of satellite planes around Local Group galaxies, and (2) the “too big to fail” problem. By comparing dissipational and dissipationless simulations, we find no indication that the addition of baryonic physics results in more flattened satellite distributions around Milky-Way-like systems. Recent claims to the contrary are shown to derive in part from a non-standard metric for the degree of flattening, which ignores the satellites’ radial positions. If the full 3D positions of themore » satellite galaxies are considered, none of the simulations we analyze reproduce the observed flattening nor the observed degree of kinematic coherence of the Milky Way satellite system. Our results are consistent with the expectation that baryonic physics should have little or no influence on the structure of satellite systems on scales of hundreds of kiloparsecs. Claims that the “too big to fail” problem can be resolved by the addition of baryonic physics are also shown to be problematic.« less

Tracing the Baryon Cycle within Nearby Galaxies with a next-generation VLA

NASA Astrophysics Data System (ADS)

Kepley, Amanda A.; Leroy, Adam; Murphy, Eric J.; ngVLA Baryon Cycle Science Working Group

2017-01-01

The evolution of galaxies over cosmic time is shaped by the cycling of baryons through these systems, namely the inflow of atomic gas, the formation of molecular structures, the birth of stars, and the expulsion of gas due to associated feedback processes. The best way to study this cycle in detail are observations of nearby galaxies. These systems provide a complete picture of baryon cycling over a wide range of astrophysical conditions. In the next decade, higher resolution/sensitivity observations of such galaxies will fundamentally improve our knowledge of galaxy formation and evolution, allowing us to better interpret higher redshift observations of sources that were rapidly evolving at epochs soon after the Big Bang. In particular, the centimeter-to-millimeter part of the spectrum provides critical diagnostics for each of the key baryon cycling processes and access to almost all phases of gas in galaxies: cool and cold gas (via emission and absorption lines), ionized gas (via free-free continuum and recombination lines), cosmic rays and hot gas (via synchrotron emission and the Sunyaev-Zeldovich effect). This poster highlights a number of key science problems in this area whose solutions require a next-generation radio-mm interferometer such as the next-generation VLA.

A low-dimensional analogue of holographic baryons

NASA Astrophysics Data System (ADS)

Bolognesi, Stefano; Sutcliffe, Paul

2014-04-01

Baryons in holographic QCD correspond to topological solitons in the bulk. The most prominent example is the Sakai-Sugimoto model, where the bulk soliton in the five-dimensional spacetime of AdS-type can be approximated by the flat space self-dual Yang-Mills instanton with a small size. Recently, the validity of this approximation has been verified by comparison with the numerical field theory solution. However, multi-solitons and solitons with finite density are currently beyond numerical field theory computations. Various approximations have been applied to investigate these important issues and have led to proposals for finite density configurations that include dyonic salt and baryonic popcorn. Here we introduce and investigate a low-dimensional analogue of the Sakai-Sugimoto model, in which the bulk soliton can be approximated by a flat space sigma model instanton. The bulk theory is a baby Skyrme model in a three-dimensional spacetime with negative curvature. The advantage of the lower-dimensional theory is that numerical simulations of multi-solitons and finite density solutions can be performed and compared with flat space instanton approximations. In particular, analogues of dyonic salt and baryonic popcorn configurations are found and analysed.

Return of grand unified theory baryogenesis: Source of helical hypermagnetic fields for the baryon asymmetry of the universe

NASA Astrophysics Data System (ADS)

Kamada, Kohei

2018-05-01

It has been considered that baryogenesis models without a generation of B -L asymmetry such as the GUT baryogenesis do not work since the asymmetry is washed out by the electroweak sphalerons. Here, we point out that helical hypermagnetic fields can be generated through the chiral magnetic effect with a chiral asymmetry generated in such baryogenesis models. The helical hypermagnetic fields then produce baryon asymmetry mainly at the electroweak symmetry breaking, which remains until today. Therefore, the baryogenesis models without B -L asymmetry can still be the origin of the present baryon asymmetry. In particular, if it can produce chiral asymmetry mainly carried by right-handed electrons of order of 10-3 in terms of the chemical potential to temperature ratio, the resultant present-day baryon asymmetry can be consistent with our Universe, although simple realizations of the GUT baryogenesis are hard to satisfy the condition. We also argue the way to overcome the difficulty in the GUT baryogenesis. The intergalactic magnetic fields with B0˜10-16 - 17 G and λ0˜10-2 - 3 pc are the smoking gun of the baryogenesis scenario as discussed before.

Baryon Distribution in Galaxy Clusters as a Result of Sedimentation of Helium Nuclei.

PubMed

Qin; Wu

2000-01-20

Heavy particles in galaxy clusters tend to be more centrally concentrated than light ones according to the Boltzmann distribution. An estimate of the drift velocity suggests that it is possible that the helium nuclei may have entirely or partially sedimented into the cluster core within the Hubble time. We demonstrate this scenario using the Navarro-Frenk-White profile as the dark matter distribution of clusters and assuming that the intracluster gas is isothermal and in hydrostatic equilibrium. We find that a greater fraction of baryonic matter is distributed at small radii than at large radii, which challenges the prevailing claim that the baryon fraction increases monotonically with cluster radius. It shows that the conventional mass estimate using X-ray measurements of intracluster gas along with a constant mean molecular weight may have underestimated the total cluster mass by approximately 20%, which in turn leads to an overestimate of the total baryon fraction by the same percentage. Additionally, it is pointed out that the sedimentation of helium nuclei toward cluster cores may at least partially account for the sharp peaks in the central X-ray emissions observed in some clusters.

Primordial nucleosynthesis

PubMed Central

Schramm, David N.

1998-01-01

With the advent of the new extragalactic deuterium observations, Big Bang nucleosynthesis (BBN) is on the verge of undergoing a transformation. In the past, the emphasis has been on demonstrating the concordance of the BBN model with the abundances of the light isotopes extrapolated back to their primordial values by using stellar and galactic evolution theories. As a direct measure of primordial deuterium is converged upon, the nature of the field will shift to using the much more precise primordial D/H to constrain the more flexible stellar and galactic evolution models (although the question of potential systematic error in 4He abundance determinations remains open). The remarkable success of the theory to date in establishing the concordance has led to the very robust conclusion of BBN regarding the baryon density. This robustness remains even through major model variations such as an assumed first-order quark-hadron phase transition. The BBN constraints on the cosmological baryon density are reviewed and demonstrate that the bulk of the baryons are dark and also that the bulk of the matter in the universe is nonbaryonic. Comparison of baryonic density arguments from Lyman-α clouds, x-ray gas in clusters, and the microwave anisotropy are made. PMID:9419322

Primordial nucleosynthesis.

PubMed

Schramm, D N

1998-01-06

With the advent of the new extragalactic deuterium observations, Big Bang nucleosynthesis (BBN) is on the verge of undergoing a transformation. In the past, the emphasis has been on demonstrating the concordance of the BBN model with the abundances of the light isotopes extrapolated back to their primordial values by using stellar and galactic evolution theories. As a direct measure of primordial deuterium is converged upon, the nature of the field will shift to using the much more precise primordial D/H to constrain the more flexible stellar and galactic evolution models (although the question of potential systematic error in 4He abundance determinations remains open). The remarkable success of the theory to date in establishing the concordance has led to the very robust conclusion of BBN regarding the baryon density. This robustness remains even through major model variations such as an assumed first-order quark-hadron phase transition. The BBN constraints on the cosmological baryon density are reviewed and demonstrate that the bulk of the baryons are dark and also that the bulk of the matter in the universe is nonbaryonic. Comparison of baryonic density arguments from Lyman-alpha clouds, x-ray gas in clusters, and the microwave anisotropy are made.

Staggered heavy baryon chiral perturbation theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bailey, Jon A.

2008-03-01

Although taste violations significantly affect the results of staggered calculations of pseudoscalar and heavy-light mesonic quantities, those entering staggered calculations of baryonic quantities have not been quantified. Here I develop staggered chiral perturbation theory in the light-quark baryon sector by mapping the Symanzik action into heavy baryon chiral perturbation theory. For 2+1 dynamical quark flavors, the masses of flavor-symmetric nucleons are calculated to third order in partially quenched and fully dynamical staggered chiral perturbation theory. To this order the expansion includes the leading chiral logarithms, which come from loops with virtual decuplet-like states, as well as terms of O(m{sub {pi}}{supmore » 3}), which come from loops with virtual octet-like states. Taste violations enter through the meson propagators in loops and tree-level terms of O(a{sup 2}). The pattern of taste symmetry breaking and the resulting degeneracies and mixings are discussed in detail. The resulting chiral forms are appropriate to lattice results obtained with operators already in use and could be used to study the restoration of taste symmetry in the continuum limit. I assume that the fourth root of the fermion determinant can be incorporated in staggered chiral perturbation theory using the replica method.« less

van der Waals Interactions in Hadron Resonance Gas: From Nuclear Matter to Lattice QCD.

PubMed

Vovchenko, Volodymyr; Gorenstein, Mark I; Stoecker, Horst

2017-05-05

An extension of the ideal hadron resonance gas (HRG) model is constructed which includes the attractive and repulsive van der Waals (VDW) interactions between baryons. This VDW-HRG model yields the nuclear liquid-gas transition at low temperatures and high baryon densities. The VDW parameters a and b are fixed by the ground state properties of nuclear matter, and the temperature dependence of various thermodynamic observables at zero chemical potential are calculated within the VDW-HRG model. Compared to the ideal HRG model, the inclusion of VDW interactions between baryons leads to a qualitatively different behavior of second and higher moments of fluctuations of conserved charges, in particular in the so-called crossover region T∼140-190  MeV. For many observables this behavior resembles closely the results obtained from lattice QCD simulations. This hadronic model also predicts nontrivial behavior of net-baryon fluctuations in the region of phase diagram probed by heavy-ion collision experiments. These results imply that VDW interactions play a crucial role in the thermodynamics of hadron gas. Thus, the commonly performed comparisons of the ideal HRG model with the lattice and heavy-ion data may lead to misconceptions and misleading conclusions.

29 CFR 1926.403 - General requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ready and safe operation and maintenance of such equipment. (i) Working clearances. Except as required... sufficient durability to withstand the environment involved. (h) Identification of disconnecting means and... sufficient durability to withstand the environment involved. (i) 600 Volts, nominal, or less. This paragraph...

Vorticity and Λ polarization in baryon rich matter

NASA Astrophysics Data System (ADS)

Baznat, Mircea; Gudima, Konstantin; Prokhorov, George; Sorin, Alexander; Teryaev, Oleg; Zakharov, Valentin

2018-02-01

The polarization of Λ hyperons due to axial chiral vortical effect is discussed. The effect is proportional to (strange) chemical potential and is pronounced at lower energies in baryon-rich matter. The polarization of ¯ has the same sihn and larger magnitude. The emergence of vortical structures is observed in kinetic QGSM models. The hydrodynamical helicity separation receives the contribution of longitudinal velocity and vorticity implying the quadrupole structure of the latter. The transition from the quark vortical effects to baryons in confined phase may be achieved by exploring the axial charge. At the hadronic level the polarization corresponds to the cores of quantized vortices in pionic superfluid. The chiral vortical effects may be also studied in the frmework of Wigner function establishing the relation to the thermodynamical approach to polarization.

Constraints on the interaction between dark matter and Baryons from cooling flow clusters.

PubMed

Qin, B; Wu, X P

2001-08-06

Other nongravitational heating processes are needed to resolve the disagreement between the absence of cool gas components in the centers of galaxy clusters revealed recently by Chandra and XMM observations and the expectations of conventional radiative cooling models. We propose that the interaction between dark matter and baryonic matter may act as an alternative for the reheating of intracluster medium (ICM) in the inner regions of clusters, in which kinetic energy of dark matter is transported to ICM to balance radiative cooling. Using the Chandra and XMM data, we set a useful constraint on the dark-matter-baryon cross section: sigma(xp)/m(x) approximately 1x10(-25) cm(2) GeV-1, where m(x) is the mass of dark matter particles.

Properties of ΣQ*, ΞQ* and ΩQ* heavy baryons in cold nuclear matter

NASA Astrophysics Data System (ADS)

Azizi, K.; Er, N.

2018-02-01

The in-medium properties of the heavy spin-3/2 ΣQ*, ΞQ* and ΩQ* baryons with Q being b or c quark are investigated. The shifts in some spectroscopic parameters of these particles due to the saturated cold nuclear matter are calculated. The variations of those parameters with respect to the changes in the density of the cold nuclear medium are studied, as well. It is observed that the parameters of ΣQ* baryons are considerably affected by the nuclear matter compared to the ΞQ* and ΩQ* particles that roughly do not see the medium. The results obtained may be used in analyses of the data to be provided by the in-medium experiments like PANDA.

Molecular Ωb states

NASA Astrophysics Data System (ADS)

Liang, Wei-Hong; Dias, J. M.; Debastiani, V. R.; Oset, E.

2018-05-01

Motivated by the recent finding of five Ωc states by the LHCb collaboration, and the successful reproduction of three of them in a recent approach searching for molecular states of meson-baryon with the quantum numbers of Ωc, we extend these ideas and make predictions for the interaction of meson-baryon in the beauty sector, searching for poles in the scattering matrix that correspond to physical states. We find several Ωb states: two states with masses 6405 MeV and 6465 MeV for JP =1/2-; two more states with masses 6427 MeV and 6665 MeV for 3/2 -; and three states between 6500 and 6820 MeV, degenerate with JP =1/2 - , 3/2 -, stemming from the interaction of vector-baryon in the beauty sector.

Relativistic direct Urca processes in cooling neutron stars

NASA Astrophysics Data System (ADS)

Leinson, L. B.; Pérez, A.

2001-10-01

We derive a relativistic expression for neutrino energy losses caused by the direct Urca processes in degenerate baryon matter of neutron stars. We use two different ways to calculate the emissivity caused by the reactions to our interest. First we perform a standard calculation by Fermi's ``golden'' rule. The second calculation, resulting in the same expression, is performed with the aid of polarization functions of the medium. Our result for neutrino energy losses strongly differs from previous nonrelativistic results. We also discuss nonconservation of the baryon vector current in reactions through weak charged currents in the medium, when the asymmetry between protons and neutrons is considered. The above effects, not discussed in the literature before, substantially modify the polarization functions responsible for the induced weak charged currents in baryon matter.

Warped unification, proton stability, and dark matter.

PubMed

Agashe, Kaustubh; Servant, Géraldine

2004-12-03

We show that solving the problem of baryon-number violation in nonsupersymmetric grand unified theories (GUT's) in warped higher-dimensional spacetime can lead to a stable Kaluza-Klein particle. This exotic particle has gauge quantum numbers of a right-handed neutrino, but carries fractional baryon number and is related to the top quark within the higher-dimensional GUT. A combination of baryon number and SU(3) color ensures its stability. Its relic density can easily be of the right value for masses in the 10 GeV-few TeV range. An exciting aspect of these models is that the entire parameter space will be tested at near future dark matter direct detection experiments. Other exotic GUT partners of the top quark are also light and can be produced at high energy colliders with distinctive signatures.

Asymmetric dark matter and baryogenesis from pseudoscalar inflation

NASA Astrophysics Data System (ADS)

Cado, Yann; Sabancilar, Eray

2017-04-01

We show that both the baryon asymmetry of the Universe and the dark matter abundance can be explained within a single framework that makes use of maximally helical hypermagnetic fields produced during pseudoscalar inflation and the chiral anomaly in the Standard Model. We consider a minimal asymmetric dark matter model free from anomalies and constraints. We find that the observed baryon and the dark matter abundances are achieved for a wide range of inflationary parameters, and the dark matter mass ranges between 7-15 GeV . The novelty of our mechanism stems from the fact that the same source of CP violation occurring during inflation explains both baryonic and dark matter in the Universe with two inflationary parameters, hence addressing all the initial condition problems in an economical way.

Simulations of Cold Electroweak Baryogenesis: quench from portal coupling to new singlet field

NASA Astrophysics Data System (ADS)

Mou, Zong-Gang; Saffin, Paul M.; Tranberg, Anders

2018-01-01

We compute the baryon asymmetry generated from Cold Electroweak Baryogenesis, when a dynamical Beyond-the-Standard-Model scalar singlet field triggers the spinodal transition. Using a simple potential for this additional field, we match the speed of the quench to earlier simulations with a "by-hand" mass flip. We find that for the parameter subspace most similar to a by-hand transition, the final baryon asymmetry shows a similar dependence on quench time and is of the same magnitude. For more general parameter choices the Higgs-singlet dynamics can be very complicated, resulting in an enhancement of the final baryon asymmetry. Our results validate and generalise results of simulations in the literature and open up the Cold Electroweak Baryogenesis scenario to further model building.

Structure of the Roper resonance from lattice QCD constraints

NASA Astrophysics Data System (ADS)

Wu, Jia-jun; Leinweber, Derek B.; Liu, Zhan-wei; Thomas, Anthony W.

2018-05-01

Two different effective field theory descriptions of the pion-nucleon scattering data are constructed to describe the region of the Roper resonance. In one, the resonance is the result of strong rescattering between coupled meson-baryon channels, while in the other the resonance has a large bare-baryon (or quark-model-like) component. The predictions of these two scenarios are compared with the latest lattice QCD simulation results in this channel. We find that the second scenario is not consistent with lattice QCD results, whereas the first agrees with those constraints. In that preferred scenario, the mass of the quark-model-like state is approximately 2 GeV, with the infinite-volume Roper resonance best described as a resonance generated dynamically through strongly coupled meson-baryon channels.

Asymmetric dark matter and baryogenesis from pseudoscalar inflation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cado, Yann; Sabancilar, Eray, E-mail: yann.cado@epfl.ch, E-mail: eray.sabancilar@epfl.ch

2017-04-01

We show that both the baryon asymmetry of the Universe and the dark matter abundance can be explained within a single framework that makes use of maximally helical hypermagnetic fields produced during pseudoscalar inflation and the chiral anomaly in the Standard Model. We consider a minimal asymmetric dark matter model free from anomalies and constraints. We find that the observed baryon and the dark matter abundances are achieved for a wide range of inflationary parameters, and the dark matter mass ranges between 7–15 GeV . The novelty of our mechanism stems from the fact that the same source of CPmore » violation occurring during inflation explains both baryonic and dark matter in the Universe with two inflationary parameters, hence addressing all the initial condition problems in an economical way.« less

Superconformal Baryon-Meson Symmetry and Light-Front Holographic QCD

DOE PAGES

Dosch, Hans Guenter; de Teramond, Guy F.; Brodsky, Stanley J.

2015-04-10

We construct an effective QCD light-front Hamiltonian for both mesons and baryons in the chiral limit based on the generalized supercharges of a superconformal graded algebra. The superconformal construction is shown to be equivalent to a semi-classical approximation to light-front QCD and its embedding in AdS space. The specific breaking of conformal invariance inside the graded algebra uniquely determines the effective confinement potential. The generalized supercharges connect the baryon and meson spectra to each other in a remarkable manner. In particular, the π/b 1 Regge trajectory is identified as the superpartner of the nucleon trajectory. However, the lowest-lying state onmore » this trajectory, the π-meson is massless in the chiral limit and has no supersymmetric partner.« less

29 CFR 1926.1436 - Derricks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and guying must be designed to withstand maximum horizontal and vertical forces encountered when... be designed to withstand maximum horizontal and vertical forces encountered when operating within...”). (D) Applicable terms in section 7-0.2 (“Definitions”). (ii) Load tests for new hoists. The employer...

29 CFR 1926.1436 - Derricks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and guying must be designed to withstand maximum horizontal and vertical forces encountered when... be designed to withstand maximum horizontal and vertical forces encountered when operating within...”). (D) Applicable terms in section 7-0.2 (“Definitions”). (ii) Load tests for new hoists. The employer...

29 CFR 1926.1436 - Derricks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and guying must be designed to withstand maximum horizontal and vertical forces encountered when... be designed to withstand maximum horizontal and vertical forces encountered when operating within...”). (D) Applicable terms in section 7-0.2 (“Definitions”). (ii) Load tests for new hoists. The employer...

29 CFR 1926.1436 - Derricks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and guying must be designed to withstand maximum horizontal and vertical forces encountered when... be designed to withstand maximum horizontal and vertical forces encountered when operating within...”). (D) Applicable terms in section 7-0.2 (“Definitions”). (ii) Load tests for new hoists. The employer...

Observation of excited Ωc charmed baryons in e+e- collisions

NASA Astrophysics Data System (ADS)

Yelton, J.; Adachi, I.; Aihara, H.; Al Said, S.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Ayad, R.; Aziz, T.; Babu, V.; Bakich, A. M.; Bansal, V.; Barberio, E.; Behera, P.; Berger, M.; Bhardwaj, V.; Bhuyan, B.; Biswal, J.; Bobrov, A.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chang, P.; Chen, A.; Cheon, B. G.; Chilikin, K.; Cho, K.; Choi, S.-K.; Choi, Y.; Choudhury, S.; Cinabro, D.; Czank, T.; Dash, N.; Di Carlo, S.; Doležal, Z.; Dutta, D.; Eidelman, S.; Fast, J. E.; Ferber, T.; Fulsom, B. G.; Garg, R.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gelb, M.; Giri, A.; Goldenzweig, P.; Golob, B.; Greenwald, D.; Guido, E.; Haba, J.; Hayasaka, K.; Hayashii, H.; Hedges, M. T.; Hou, W.-S.; Inami, K.; Inguglia, G.; Ishikawa, A.; Itoh, R.; Iwasaki, M.; Iwasaki, Y.; Jacobs, W. W.; Jeon, H. B.; Jin, Y.; Julius, T.; Kang, K. H.; Karyan, G.; Kato, Y.; Kawasaki, T.; Kichimi, H.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, S. H.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Kotchetkov, D.; Križan, P.; Kroeger, R.; Krokovny, P.; Kuhr, T.; Kulasiri, R.; Kumita, T.; Kuzmin, A.; Kwon, Y.-J.; Lange, J. S.; Lee, I. S.; Lee, S. C.; Li, C. H.; Li, L. K.; Li, Y.; Li Gioi, L.; Liventsev, D.; Lubej, M.; Luo, T.; Masuda, M.; Matvienko, D.; Merola, M.; Miyata, H.; Mizuk, R.; Mohanty, G. B.; Moon, H. K.; Mori, T.; Mussa, R.; Nakano, E.; Nakao, M.; Nanut, T.; Nath, K. J.; Nayak, M.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Ogawa, S.; Okuno, S.; Ono, H.; Pakhlov, P.; Pakhlova, G.; Pal, B.; Park, H.; Paul, S.; Pavelkin, I.; Pedlar, T. K.; Pestotnik, R.; Piilonen, L. E.; Popov, V.; Ritter, M.; Russo, G.; Sakai, Y.; Sandilya, S.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Seino, Y.; Sevior, M. E.; Shebalin, V.; Shen, C. P.; Shibata, T.-A.; Shimizu, N.; Shiu, J.-G.; Shwartz, B.; Simon, F.; Singh, J. B.; Solovieva, E.; Starič, M.; Strube, J. F.; Sumihama, M.; Sumiyoshi, T.; Suzuki, K.; Takizawa, M.; Tamponi, U.; Tanida, K.; Tenchini, F.; Uchida, M.; Uglov, T.; Unno, Y.; Uno, S.; Usov, Y.; Varner, G.; Varvell, K. E.; Vinokurova, A.; Vorobyev, V.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Wang, X. L.; Watanabe, Y.; Watanuki, S.; Widmann, E.; Won, E.; Ye, H.; Yusa, Y.; Zakharov, S.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.; Belle Collaboration

2018-03-01

Using the entire Belle data sample of 980 fb-1 of e+e- collisions, we present the results of a study of excited Ωc charmed baryons in the decay mode Ξc+K-. We show confirmation of four of the five narrow states reported by the LHCb Collaboration: the Ωc(3000 ), Ωc(3050 ), Ωc(3066 ), and Ωc(3090 ).

Extraction of the photon beam asymmetry Sigma in pi 0 photoproduction off the proton using the CBELSA/TAPS experiment

NASA Astrophysics Data System (ADS)

Sparks, Nathan Andrew

The CBELSA/TAPS experiment at the electron accelerator ELSA, in Bonn, Germany, was used in order to study the photoproduction of neutral pions off the proton with a linearly polarized photon beam; Neutral pions were reconstructed through their dominant decay mode into two photons. The photons were detected in a barrel/forward electromagnetic calorimeter system which covered 99% of the 4pi solid angle. The Crystal Barrel CsI(Tl) calorimeter detected photons at polar angles from 30° to 168°, while TAPS, a BaF2 spectrometer, covered forward polar angles from 5.8° to 30° and served as a fast trigger; Both calorimeters had complete azimuthal angular coverage. Coherent bremsstrahlung of electrons in a diamond radiator was used to produce a linearly polarized beam of photons with a coherent peak at 1305 or 1610 MeV. The analysis of these two datasets allowed for the measurement of the photon beam asymmetry in the beam photon energy range of 920 to 1680 MeV. For the first time, these results cover the very forward polar angles of the neutral pion. The measurements are compared to the SAID, MAID, and BnGa models and to previous measurements. These new measurements of the photon beam asymmetry contribute to the ongoing experimentally-driven exploration of the N and Delta resonances. The study of strange baryons provides a link between the strong interaction physics of the excited nucleons and the heavy flavor baryons. The upcoming GlueX experiment at Jefferson Lab is expected to provide an opportunity to examine strange baryons in much greater detail than ever before. GEANT-based Monte Carlo simulations of Cascade baryons at the GlueX experiment were conducted in order to better understand the capabilities of this experiment. A proposal, "An initial study of mesons and baryons containing strange quarks with GlueX", was submitted to the 40th Jefferson Lab Program Advisory Committee (PAC), in part, supported by these Cascade baryon simulations. 200 days of additional beam time were approved, with the proposal receiving an A scientific rating.

14 CFR 23.365 - Pressurized cabin loads.

Code of Federal Regulations, 2011 CFR

2011-01-01

... landing. (d) The airplane structure must be strong enough to withstand the pressure differential loads... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23... structure must be strong enough to withstand the flight loads combined with pressure differential loads from...

KSC-04pd1717

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, a worker wraps equipment in plastic in preparation for the expected impact of Hurricane Frances on Saturday. The various modules in the SSPF, such as the Japanese Experiment Module, U.S. Node 2 and Multi-Purpose Logistics Modules, are being covered as well. KSC workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

Can the standard model CP violation near the W bags explain the cosmological baryonic asymmetry?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burnier, Yannis; Shuryak, Edward

2011-10-01

In the scenario of cold electroweak baryogenesis, oscillations of the Higgs field lead to metastable domains of unbroken phase where the Higgs field nearly vanishes. Those domains have also been identified with the W-t-t bags, a nontopological solitons made of large number ({approx}1000) of gauge quanta and heavy (top and antitop) quarks. As real-time numerical studies had shown, sphalerons (topological transition events violating the baryon number) occur only inside those bags. In this work we estimate the amount of CP violation in this scenario coming from the standard model, via the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix, resulting in top-minus-antitop differencemore » of the population in the bags. Since these tops/antitops are recycled by sphalerons, this population difference leads directly to the baryonic asymmetry of the Universe. We look at the effect appearing in the 4th order in weak W diagrams describing interference of different quark flavor contributions. We found that there are multiple cancellations of diagrams and clearly sign-definite effect appears only in the 6th-order expansion over flavor-dependent phases. We then estimate contributions to these diagrams in which weak interaction occurs (i) inside, (ii) near and (iii) far from the W-t-t b-bags, optimizing the contributions in each of them. We conclude that the second (near) scenario is the dominant one, producing CP violation of the order of 10{sup -10}, in our crude estimates. Together with the baryon violation rate of about 10{sup -2}, previously demonstrated for this scenario, it puts the resulting asymmetry close to what is needed to explain the observed baryonic asymmetry in the Universe. Our answer also has a definite sign, which apparently seems to be the correct one.« less

The Thomas–Fermi quark model: Non-relativistic aspects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Quan, E-mail: quan_liu@baylor.edu; Wilcox, Walter, E-mail: walter_wilcox@baylor.edu

The first numerical investigation of non-relativistic aspects of the Thomas–Fermi (TF) statistical multi-quark model is given. We begin with a review of the traditional TF model without an explicit spin interaction and find that the spin splittings are too small in this approach. An explicit spin interaction is then introduced which entails the definition of a generalized spin “flavor”. We investigate baryonic states in this approach which can be described with two inequivalent wave functions; such states can however apply to multiple degenerate flavors. We find that the model requires a spatial separation of quark flavors, even if completely degenerate.more » Although the TF model is designed to investigate the possibility of many-quark states, we find surprisingly that it may be used to fit the low energy spectrum of almost all ground state octet and decuplet baryons. The charge radii of such states are determined and compared with lattice calculations and other models. The low energy fit obtained allows us to extrapolate to the six-quark doubly strange H-dibaryon state, flavor symmetric strange states of higher quark content and possible six quark nucleon–nucleon resonances. The emphasis here is on the systematics revealed in this approach. We view our model as a versatile and convenient tool for quickly assessing the characteristics of new, possibly bound, particle states of higher quark number content. -- Highlights: • First application of the statistical Thomas–Fermi quark model to baryonic systems. • Novel aspects: spin as generalized flavor; spatial separation of quark flavor phases. • The model is statistical, but the low energy baryonic spectrum is successfully fit. • Numerical applications include the H-dibaryon, strange states and nucleon resonances. • The statistical point of view does not encourage the idea of bound many-quark baryons.« less

Gas dynamics in tidal dwarf galaxies: Disc formation at z = 0

NASA Astrophysics Data System (ADS)

Lelli, Federico; Duc, Pierre-Alain; Brinks, Elias; Bournaud, Frédéric; McGaugh, Stacy S.; Lisenfeld, Ute; Weilbacher, Peter M.; Boquien, Médéric; Revaz, Yves; Braine, Jonathan; Koribalski, Bärbel S.; Belles, Pierre-Emmanuel

2015-12-01

Tidal dwarf galaxies (TDGs) are recycled objects that form within the collisional debris of interacting and merging galaxies. They are expected to be devoid of non-baryonic dark matter, since they can only form from dissipative material ejected from the discs of the progenitor galaxies. We investigate the gas dynamics in a sample of six bona fide TDGs around three interacting and post-interacting systems: NGC 4694, NGC 5291, and NGC 7252 ("Atoms for Peace"). For NGC 4694 and NGC 5291, we analyse existing H I data from the Very Large Array (VLA), while for NGC 7252 we present new H I observations from the Jansky VLA, together with long-slit and integral-field optical spectroscopy. For all six TDGs, the H I emission can be described by rotating disc models. These H I discs, however, have undergone less than a full rotation since the time of the interaction/merger event, raising the question of whether they are in dynamical equilibrium. Assuming that these discs are in equilibrium, the inferred dynamical masses are consistent with the observed baryonic masses, implying that TDGs are devoid of dark matter. This puts constraints on putative "dark discs" (either baryonic or non-baryonic) in the progenitor galaxies. Moreover, TDGs seem to systematically deviate from the baryonic Tully-Fisher relation. These results provide a challenging test for alternative theories like MOND. Based on observations made with ESO telescopes at Paranal Observatory under programmes 65.O-0563, 67.B-0049, and 083.B-0647.Appendices are available in electronic form at http://www.aanda.orgThe reduced data cubes are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/584/A113

Exploring a Potential Bias in Dark Matter Investigations Using Strongly Lensed Quasars

NASA Astrophysics Data System (ADS)

Hsueh, Jen-Wei; Fassnacht, Christopher; Vegetti, Simona; Springola, Cristiana; Oldham, Lindsay; Despali, Giulia; Auger, Matthew; Xu, Dandan; Metcalf, Benton; McKean, John; Koopmans, Leon; Lagattuta, David

2018-01-01

Simulations based on ΛCDM cosmology predict thousands of substructures under galactic scale have not been detected in the local universe. One hypothesis proposes that most of these substructures are dark for various astrophysical reasons. Gravitational lensing provides a powerful alternative way to probe dark substructures in distant galaxies by detecting their gravitational perturbations and therefore provides insights into the nature of dark matter. Lensed quasars with certain image configurations are especially promising for probing substructure abundance in lens galaxy halos. When the observed flux ratios of the lensed quasar images deviate from the smooth mass model predictions, these “flux-ratio anomalies” are considered to be the evidence of gravitational perturbations. While the standard analysis of flux-ratio anomalies assumes that substructures are the only cause of anomalies, we found that in two edge-on disk lenses, B1555+375 and B0712+472, their flux anomalies can be explained by including disk components into their mass models. Our results bring up a concern with a potential bias in the previous analyses of flux-ratio anomalies. To further investigate the baryonic effects in flux-ratio anomalies, we create mock quasar lenses by selecting disk and elliptical galaxies in the Illustris simulation. Our analysis shows that baryon-induced flux anomalies can be found in all morphological types of lens galaxies. The baryonic effects increase the probability of finding lenses with strong anomalies by 8% in ellipticals and 10~20% in disk lenses, showing that the baryonic effects are unneglectable in the analysis. As future large-scale surveys are expected to bring numerous lensed quasar samples, further investigations on baryonic effects should be done in order to achieve precise constraints on dark matter in the future.

The impact of baryons on the direct detection of dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelso, Chris; Savage, Christopher; Freese, Katherine

2016-08-01

The spatial and velocity distributions of dark matter particles in the Milky Way Halo affect the signals expected to be observed in searches for dark matter. Results from direct detection experiments are often analyzed assuming a simple isothermal distribution of dark matter, the Standard Halo Model (SHM). Yet there has been skepticism regarding the validity of this simple model due to the complicated gravitational collapse and merger history of actual galaxies. In this paper we compare the SHM to the results of cosmological hydrodynamical simulations of galaxy formation to investigate whether or not the SHM is a good representation ofmore » the true WIMP distribution in the analysis of direct detection data. We examine two Milky Way-like galaxies from the MaGICC cosmological simulations (a) with dark matter only and (b) with baryonic physics included. The inclusion of baryons drives the shape of the DM halo to become more spherical and makes the velocity distribution of dark matter particles less anisotropic especially at large heliocentric velocities, thereby making the SHM a better fit. We also note that we do not find a significant disk-like rotating dark matter component in either of the two galaxy halos with baryons that we examine, suggesting that dark disks are not a generic prediction of cosmological hydrodynamical simulations. We conclude that in the Solar neighborhood, the SHM is in fact a good approximation to the true dark matter distribution in these cosmological simulations (with baryons) which are reasonable representations of the Milky Way, and hence can also be used for the purpose of dark matter direct detection calculations.« less

Baryons Matter: Why Luminous Satellite Galaxies have Reduced Central Masses

NASA Astrophysics Data System (ADS)

Zolotov, Adi; Brooks, Alyson M.; Willman, Beth; Governato, Fabio; Pontzen, Andrew; Christensen, Charlotte; Dekel, Avishai; Quinn, Tom; Shen, Sijing; Wadsley, James

2012-12-01

Using high-resolution cosmological hydrodynamical simulations of Milky Way-massed disk galaxies, we demonstrate that supernovae feedback and tidal stripping lower the central masses of bright (-15 < MV < -8) satellite galaxies. These simulations resolve high-density regions, comparable to giant molecular clouds, where stars form. This resolution allows us to adopt a prescription for H2 formation and destruction that ties star formation to the presence of shielded, molecular gas. Before infall, supernova feedback from the clumpy, bursty star formation captured by this physically motivated model leads to reduced dark matter (DM) densities and shallower inner density profiles in the massive satellite progenitors (M vir >= 109 M ⊙, M * >= 107 M ⊙) compared with DM-only simulations. The progenitors of the lower mass satellites are unable to maintain bursty star formation histories, due to both heating at reionization and gas loss from initial star-forming events, preserving the steep inner density profile predicted by DM-only simulations. After infall, gas stripping from satellites reduces the total central masses of satellites simulated with DM+baryons relative to DM-only satellites. Additionally, enhanced tidal stripping after infall due to the baryonic disk acts to further reduce the central DM densities of the luminous satellites. Satellites that enter with cored DM halos are particularly vulnerable to the tidal effects of the disk, exacerbating the discrepancy in the central masses predicted by baryon+DM and DM-only simulations. We show that DM-only simulations, which neglect the highly non-adiabatic evolution of baryons described in this work, produce denser satellites with larger central velocities. We provide a simple correction to the central DM mass predicted for satellites by DM-only simulations. We conclude that DM-only simulations should be used with great caution when interpreting kinematic observations of the Milky Way's dwarf satellites.

The impact of baryons on massive galaxy clusters: halo structure and cluster mass estimates

NASA Astrophysics Data System (ADS)

Henson, Monique A.; Barnes, David J.; Kay, Scott T.; McCarthy, Ian G.; Schaye, Joop

2017-03-01

We use the BAHAMAS (BAryons and HAloes of MAssive Systems) and MACSIS (MAssive ClusterS and Intercluster Structures) hydrodynamic simulations to quantify the impact of baryons on the mass distribution and dynamics of massive galaxy clusters, as well as the bias in X-ray and weak lensing mass estimates. These simulations use the subgrid physics models calibrated in the BAHAMAS project, which include feedback from both supernovae and active galactic nuclei. They form a cluster population covering almost two orders of magnitude in mass, with more than 3500 clusters with masses greater than 1014 M⊙ at z = 0. We start by characterizing the clusters in terms of their spin, shape and density profile, before considering the bias in both weak lensing and hydrostatic mass estimates. Whilst including baryonic effects leads to more spherical, centrally concentrated clusters, the median weak lensing mass bias is unaffected by the presence of baryons. In both the dark matter only and hydrodynamic simulations, the weak lensing measurements underestimate cluster masses by ≈10 per cent for clusters with M200 ≤ 1015 M⊙ and this bias tends to zero at higher masses. We also consider the hydrostatic bias when using both the true density and temperature profiles, and those derived from X-ray spectroscopy. When using spectroscopic temperatures and densities, the hydrostatic bias decreases as a function of mass, leading to a bias of ≈40 per cent for clusters with M500 ≥ 1015 M⊙. This is due to the presence of cooler gas in the cluster outskirts. Using mass weighted temperatures and the true density profile reduces this bias to 5-15 per cent.

Observations of the missing baryons in the warm-hot intergalactic medium.

PubMed

Nicastro, F; Kaastra, J; Krongold, Y; Borgani, S; Branchini, E; Cen, R; Dadina, M; Danforth, C W; Elvis, M; Fiore, F; Gupta, A; Mathur, S; Mayya, D; Paerels, F; Piro, L; Rosa-Gonzalez, D; Schaye, J; Shull, J M; Torres-Zafra, J; Wijers, N; Zappacosta, L

2018-06-01

It has been known for decades that the observed number of baryons in the local Universe falls about 30-40 per cent short 1,2 of the total number of baryons predicted 3 by Big Bang nucleosynthesis, as inferred 4,5 from density fluctuations of the cosmic microwave background and seen during the first 2-3 billion years of the Universe in the so-called 'Lyman α forest' 6,7 (a dense series of intervening H I Lyman α absorption lines in the optical spectra of background quasars). A theoretical solution to this paradox locates the missing baryons in the hot and tenuous filamentary gas between galaxies, known as the warm-hot intergalactic medium. However, it is difficult to detect them there because the largest by far constituent of this gas-hydrogen-is mostly ionized and therefore almost invisible in far-ultraviolet spectra with typical signal-to-noise ratios 8,9 . Indeed, despite large observational efforts, only a few marginal claims of detection have been made so far 2,10 . Here we report observations of two absorbers of highly ionized oxygen (O VII) in the high-signal-to-noise-ratio X-ray spectrum of a quasar at a redshift higher than 0.4. These absorbers show no variability over a two-year timescale and have no associated cold absorption, making the assumption that they originate from the quasar's intrinsic outflow or the host galaxy's interstellar medium implausible. The O VII systems lie in regions characterized by large (four times larger than average 11 ) galaxy overdensities and their number (down to the sensitivity threshold of our data) agrees well with numerical simulation predictions for the long-sought warm-hot intergalactic medium. We conclude that the missing baryons have been found.

Evolution of Mass and Velocity Field in the Cosmic Web: Comparison between Baryonic and Dark Matter

NASA Astrophysics Data System (ADS)

Zhu, Weishan; Feng, Long-Long

2017-03-01

We investigate the evolution of the cosmic web since z = 5 in grid-based cosmological hydrodynamical simulations, focusing on the mass and velocity fields of both baryonic and cold dark matter. The tidal tensor of density is used as the main method for web identification, with λ th = 0.2-1.2. The evolution trends in baryonic and dark matter are similar, although moderate differences are observed. Sheets appear early, and their large-scale pattern may have been set up by z = 3. In terms of mass, filaments supersede sheets as the primary collapsing structures from z ˜ 2-3. Tenuous filaments assembled with each other to form prominent ones at z < 2. In accordance with the construction of the frame of the sheets, the cosmic divergence velocity, v div, was already well-developed above 2-3 Mpc by z = 3. Afterwards, the curl velocity, v curl, grew dramatically along with the rising of filaments, becoming comparable to v div, for <2-3 Mpc at z = 0. The scaling of v curl can be described by the hierarchical turbulence model. The alignment between the vorticity and the eigenvectors of the shear tensor in the baryonic matter field resembles that in the dark matter field, and is even moderately stronger between {\\boldsymbol{ω }} and {{\\boldsymbol{e}}}1, and ω and {{\\boldsymbol{e}}}3. Compared with dark matter, there is slightly less baryonic matter found residing in filaments and clusters, and its vorticity developed more significantly below 2-3 Mpc. These differences may be underestimated because of the limited resolution and lack of star formation in our simulation. The impact of the change of dominant structures in overdense regions at z ˜ 2-3 on galaxy formation and evolution is shortly discussed.

High-energy Neutrino Flares from X-Ray Bright and Dark Tidal Disruption Events

DOE Office of Scientific and Technical Information (OSTI.GOV)

Senno, Nicholas; Murase, Kohta; Mészáros, Peter

X-ray and γ-ray observations by the Swift satellite revealed that a fraction of tidal disruption events (TDEs) have relativistic jets. Jetted TDEs have been considered to be potential sources of very-high-energy cosmic-rays and neutrinos. In this work, using semi-analytical methods, we calculate neutrino spectra of X-ray bright TDEs with powerful jets and dark TDEs with possible choked jets, respectively. We estimate their neutrino fluxes and find that non-detection would give us an upper limit on the baryon loading of the jet luminosity contained in cosmic-rays ξ {sub cr} ≲ 20–50 for Sw J1644+57. We show that X-ray bright TDEs makemore » a sub-dominant (≲5%–10%) contribution to IceCube’s diffuse neutrino flux, and study possible contributions of X-ray dark TDEs given that particles are accelerated in choked jets or disk winds. We discuss future prospects for multi-messenger searches of the brightest TDEs.« less

Implications of Stellar Feedback for Dynamical Modeling of the Milky Way and Dwarf Galaxies

NASA Astrophysics Data System (ADS)

Wetzel, Andrew

2018-04-01

I will present recent results on dynamical modeling of stellar populations from the FIRE cosmological zoom-in baryonic simulations of Milky Way-like and dwarf galaxies. First, I will discuss the dynamical formation of the Milky Way, including the origin of thin+thick stellar disk morphology. I also will discuss the curious origin of metal-rich stars on halo-like orbits near the Sun, as recently measured by Gaia, with new insights from FIRE simulations on stellar radial migration/heating. Next, I will discuss role of stellar feedback in generating non-equilibrium fluctuations of the gravitational potential in low-mass 'dwarf' galaxies, which can explain the origin of cores in their dark-matter density profiles. In particular, we predict significant observable effects on stellar dynamics, including radial migration, size fluctuations, and population gradients, which can provide observational tests of feedback-driven core formation. Finally, this scenario can explain the formation of newly discovered 'ultra-diffuse' galaxies.

Reply to 'Comment on 'Heavy element production in inhomogeneous big bang nucleosynthesis''

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuura, Shunji; Fujimoto, Shin-ichirou; Hashimoto, Masa-aki

2007-03-15

This is a reply to Rauscher [Phys. Rev. D 75, 068301 (2007)]. We studied heavy element production in the high baryon density region in the early universe [Phys. Rev. D 72, 123505 (2005)]. However, it is claimed by Rauscher [Phys. Rev. D 75, 068301 (2007)] that a small scale but high baryon density region contradicts observations for the light element abundance or, in order not to contradict the observations, the high density region must be so small that it cannot affect the present heavy element abundance. In this paper, we study big bang nucleosynthesis in the high baryon density regionmore » and show that in certain parameter spaces it is possible to produce enough of the heavy element without contradiction to cosmic microwave background and light element observations.« less

Compressed baryonic matter at FAIR: JINR participation

NASA Astrophysics Data System (ADS)

Kurilkin, P.; Ladygin, V.; Malakhov, A.; Senger, P.

2015-11-01

The scientific mission of the Compressed Baryonic Matter(CBM) experiment is the study of the nuclear matter properties at the high baryon densities in heavy ion collisions at the Facility of Antiproton and Ion Research (FAIR) in Darmstadt. We present the results on JINR participation in the CBM experiment. JINR teams are responsible on the design, the coordination of superconducting(SC) magnet manufacture, its testing and installation in CBM cave. Together with Silicon Tracker System it will provide the momentum resolution better 1% for different configuration of CBM setup. The characteristics and technical aspects of the magnet are discussed. JINR plays also a significant role in the manufacture of two straw tracker station for the muon detection system. JINR team takes part in the development of new method for simulation, processing and analysis experimental data for different basic detectors of CBM.

Probing sub-GeV dark matter-baryon scattering with cosmological observables

NASA Astrophysics Data System (ADS)

Xu, Weishuang Linda; Dvorkin, Cora; Chael, Andrew

2018-05-01

We derive new limits on the elastic scattering cross section between baryons and dark matter using cosmic microwave background data from the Planck satellite and measurements of the Lyman-alpha forest flux power spectrum from the Sloan Digital Sky Survey. Our analysis addresses generic cross sections of the form σ ∝vn , where v is the dark matter-baryon relative velocity, allowing for constraints on the cross section independent of specific particle physics models. We include high-ℓ polarization data from Planck in our analysis, improving over previous constraints. We apply a more careful treatment of dark matter thermal evolution than previously done, allowing us to extend our constraints down to dark matter masses of ˜MeV . We show in this work that cosmological probes are complementary to current direct detection and astrophysical searches.

Universal formula for baryon spectra in heavy-ion collisions and its implications

NASA Astrophysics Data System (ADS)

Hwa, Rudolph C.; Zhu, Lilin

2018-05-01

In an unconventional presentation of the data on the transverse momentum spectra of baryons produced in heavy-ion collisions, regularities are found that make possible the discovery of a universal formula valid for p ,Λ ,Ξ , and Ω . The formula describes the baryon distributions over wide ranges of pT(0.5 ≲ pT≲5 GeV/c ) for 0.06 ≲√{sN N}≲3 TeV, except for very peripheral collisions. Some aspects of their empirical properties are derived in the recombination model, resulting in a revelation of some features of the light and strange quark distributions before hadronization. Interpretation of the inverse slopes of their exponential behavior leads to an implication that cannot accommodate the conventional description of fluid flow. This is mainly a study of phenomenology without detailed model input.

SYSTEMATIZATION OF MASS LEVELS OF PARTICLES AND RESONANCES ON HEURISTIC BASIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takabayasi, T.

1963-12-16

Once more a scheme of simple mass rules and formulas for particles and resonant levels is investigated and organized, based on some general hypotheses. The essential ingredients in the scheme are, on one hand, the equalinterval rule governing the isosinglet meson series, associated with particularly simple mass ratio between the 2/sup ++/ level f and 0/sup ++/ level ABC, and on the other a new basic mass formula that unifies some of the meson and baryon levels. The whole baryon levels are arranged in a table analogous to the periodic table, and then correspondences between different series and equivalence betweenmore » spin and hypercharge, when properly applied, just fix the whole baryon mass spectrum in good agreement with observations. Connections with the scheme of mass formulas formerly given are also shown. (auth)« less

Cosmological structure formation

NASA Technical Reports Server (NTRS)

Schramm, David N.

1991-01-01

A summary of the current forefront problem of physical cosmology, the formation of structures (galaxies, clusters, great walls, etc.) in the universe is presented. Solutions require two key ingredients: (1) matter; and (2) seeds. Regarding the matter, it now seems clear that both baryonic and non-baryonic matter are required. Whether the non-baryonic matter is hot or cold depends on the choice of seeds. Regarding the seeds, both density fluctuations and topological defects are discussed. The combination of isotropy of the microwave background and the recent observations indicating more power on large scales have severly constrained, if not eliminated, Gaussian fluctuations with equal power on all scales, regardless of the eventual resolution of both the matter and seed questions. It is important to note that all current structure formation ideas require new physics beyond SU(3) x SU(2) x U(1).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doring, Michael; Landay, Justin; Mai, Maxim

Results for light baryon spectroscopy by different collaborations and the state of the art in the subfield is reviewed. Highlights contain common efforts of different phenomenology groups and the impact of recent high-precision data from ELSA, JLab, MAMI, and other facilities. Questions will be addressed, on one side, of how to proceed to reach conclusive answers in baryon spectroscopy, and, on the other side, how phenomenology can be connected to theory in a meaningful way.

Unexpected manifestation of quark condensation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zinovjev, G. M., E-mail: Gennady.Zinovjev@cern.ch; Molodtsov, S. V.

A comparative analysis of some quark ensembles governed by a four-fermion interaction is performed. Arguments in support of the statement that the presence of a gas-liquid phase transition is a feature peculiar to them are adduced. The instability of small quark droplets is discussed and is attributed to the formation of a chiral soliton. The stability of baryon matter is due to a mixed phase of the vacuum and baryon matter.

Phase transitions in neutron star equation of state induced by the delta resonances matter

NASA Astrophysics Data System (ADS)

T, Oliveira J. C.; Rodrigues, H.; Duarte, S. B.

2016-04-01

In the present work we determine the equation of state and the population of baryons and leptons, and also we discuss the implication of changes in the baryon-meson coupling constants to the formation of delta matter in the stellar medium. And also in this work the phase transition is explored with respect to the domain of the delta-mesons coupling constants.

Production cross-sections of prompt ⋀c+ in pPb collisions at √SNN = 5 TeV with the LHCb detector

NASA Astrophysics Data System (ADS)

Sun, Jiayin

2018-02-01

The study of the nuclear modification factor and the forward/backward asymmetry in pPb collisions at = 5 TeV is extended to the baryon, providing the first measurement of charmed baryon production in pA collisions. The result is compared to the analogous measurement on charmed mesons, providing an insight on the production mechanism of charmed hadrons.

Baryon non-invariant couplings in Higgs effective field theory

NASA Astrophysics Data System (ADS)

Merlo, Luca; Saa, Sara; Sacristán-Barbero, Mario

2017-03-01

The basis of leading operators which are not invariant under baryon number is constructed within the Higgs effective field theory. This list contains 12 dimension six operators, which preserve the combination B-L, to be compared to only 6 operators for the standard model effective field theory. The discussion of the independent flavour contractions is presented in detail for a generic number of fermion families adopting the Hilbert series technique.

A Fast Algorithm for Lattice Hyperonic Potentials

NASA Astrophysics Data System (ADS)

Nemura, Hidekatsu; Aoki, Sinya; Doi, Takumi; Gongyo, Shinya; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Iritani, Takumi; Ishii, Noriyoshi; Miyamoto, Takaya; Murano, Keiko; Sasaki, Kenji

We describe an efficient algorithm to compute a large number of baryon-baryon interactions from NN to ΞΞ by means of HAL QCD method, which lays the groundwork for the nearly physical point lattice QCD calculation with volume (96a)4 ≈ (8.2 fm)4. Preliminary results of ΛN potential calculated with quark masses corresponding to (mπ, mK) ≈ (146,525) MeV are presented.

QSO absorption spectroscopy and baryonic dark matter

NASA Astrophysics Data System (ADS)

Cirković, Milan M.

2005-04-01

The present book should serve a double purpose: first, as an introduction into the host of tightly related topics in astrophysics and cosmology all dealing with the history and evolution of the baryonic matter in the universe. Secondly, it gives argument for still somewhat controversial view that large baryonic reservoirs are present (at least in the low-redshift regime) in form of huge gaseous galactic haloes surrounding normal luminous galaxies, and manifesting through the Lyman-α absorption lines in spectra of background sources. If accepted, this view would profoundly impact our understanding of the galactic structure and evolution, and will deeply influence our views of the future evolution of galactic systems. After an introduction into cosmological jargon and symbols used throughout, and other important introductory material given in Chapter 1, the bulk of the argumentation is given in Chapter 2, which exposes phenomenology of Lyα absorption systems and various theories advanced to account for their physical origin. Chapter 3 deals with models of absorbing gas in the extended haloes of normal galaxies, and Chapter 4 gives a global discussion of main candidates for the reservoirs of the still elusive baryonic dark matter. A set of closely related technical issues which are used at several places in the main narrative are given in the appendices.

Discriminating Majorana neutrino textures in light of the baryon asymmetry

NASA Astrophysics Data System (ADS)

Borah, Manikanta; Borah, Debasish; Das, Mrinal Kumar

2015-06-01

We study all possible texture zeros in the Majorana neutrino mass matrix which are allowed from neutrino oscillation as well as cosmology data when the charged lepton mass matrix is assumed to take the diagonal form. In the case of one-zero texture, we write down the Majorana phases which are assumed to be equal and the lightest neutrino mass as a function of the Dirac C P phase. In the case of two-zero texture, we numerically evaluate all the three C P phases and lightest neutrino mass by solving four real constraint equations. We then constrain texture zero mass matrices from the requirement of producing correct baryon asymmetry through the mechanism of leptogenesis by assuming the Dirac neutrino mass matrix to be diagonal. Adopting a type I seesaw framework, we consider the C P -violating out of equilibrium decay of the lightest right-handed neutrino as the source of lepton asymmetry. Apart from discriminating between the texture zero mass matrices and light neutrino mass hierarchy, we also constrain the Dirac and Majorana C P phases so that the observed baryon asymmetry can be produced. In two-zero texture, we further constrain the diagonal form of the Dirac neutrino mass matrix from the requirement of producing correct baryon asymmetry.

EXPLAINING THE OBSERVED VELOCITY DISPERSION OF DWARF GALAXIES BY BARYONIC MASS LOSS DURING THE FIRST COLLAPSE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gritschneder, Matthias; Lin, Douglas N. C., E-mail: gritschneder@ucolick.org

2013-03-01

In the widely adopted {Lambda} cold dark matter ({Lambda}CDM) scenario for galaxy formation, dwarf galaxies are the building blocks of larger galaxies. Since they formed at relatively early epochs when the background density was relatively high, they are expected to retain their integrity as satellite galaxies when they merge to form larger entities. Although many dwarf spheroidal galaxies are found in the galactic halo around the Milky Way, their phase-space density (or velocity dispersion) appears to be significantly smaller than that expected for satellite dwarf galaxies in the {Lambda}CDM scenario. In order to account for this discrepancy, we consider themore » possibility that they may have lost a significant fraction of their baryonic matter content during the first infall at the Hubble expansion turnaround. Such mass loss arises naturally due to the feedback by relatively massive stars that formed in their centers briefly before the maximum contraction. Through a series of N-body simulations, we show that the timely loss of a significant fraction of the dSphs initial baryonic matter content can have profound effects on their asymptotic half-mass radius, velocity dispersion, phase-space density, and the mass fraction between residual baryonic and dark matter.« less

Baryonic Content in the Warm-Hot IGM at Low Redshift

NASA Technical Reports Server (NTRS)

Sonneborn, George; Shull, M.; Danforth, C.; Moos, W.

2007-01-01

Baryons are 4.5% of the universe's mass/energy density; only 10% of these are in stars, galaxies, and clusters. At low-redshift 90% of baryons are in the IGM, 30% in Ly-alpha forest, but most are in hot gas (10(exp 5-7) K) produced by shocks during structure formation. O VI 1032-38 A are the best tracers of this gas. The distribution of O VI absorbers observed by FUSE rises as N(sup -2+/-0.2, down to 10(exp 13)/sq cm. Integrated to logN=13, 7% of baryons reside in the O VI-bearing IGM at 10% solar metallicity, T approx. 10(exp 5.5) K. At redshift z<0.1 metals have been transported less than 800/h kpc from L* galaxies and 200/h kpc from 0.1 L* galaxies. The steepness of dN/dz means that low-N absorbers contribute an equal mass of hot IGM as higher N gas. The total mass of O VI-bearing gas in the IGM depends on determining the turnover in dN/dz at low N(O VI). Future observations by FUSE are needed to reach lower N and to reduce the uncertainty in the dN/dz power law.

Symmetry energy effects on the mixed hadron-quark phase at high baryon density

NASA Astrophysics Data System (ADS)

di Toro, M.; Liu, B.; Greco, V.; Baran, V.; Colonna, M.; Plumari, S.

2011-01-01

The phase transition of hadronic to quark matter at high baryon and isospin density is analyzed. Relativistic mean-field models are used to describe hadronic matter, and the MIT bag model is adopted for quark matter. The boundaries of the mixed phase and the related critical points for symmetric and asymmetric matter are obtained. Due to the different symmetry term in the two phases, isospin effects appear to be rather significant. With increasing isospin asymmetry the binodal transition line of the (T,ρB) diagram is lowered to a region accessible through heavy-ion collisions in the energy range of the new planned facilities (e.g., the FAIR/NICA projects). Some observable effects are suggested, in particular an isospin distillation mechanism with a more isospin asymmetric quark phase, to be seen in charged meson yield ratios, and an onset of quark number scaling of the meson-baryon elliptic flows. The presented isospin effects on the mixed phase appear to be robust with respect to even large variations of the poorly known symmetry term at high baryon density in the hadron phase. The dependence of the results on a suitable treatment of isospin contributions in effective QCD Lagrangian approaches, at the level of explicit isovector parts and/or quark condensates, is discussed.

Baryonic impact on the dark matter orbital properties of Milky Way-sized haloes

NASA Astrophysics Data System (ADS)

Zhu, Qirong; Hernquist, Lars; Marinacci, Federico; Springel, Volker; Li, Yuexing

2017-04-01

We study the orbital properties of dark matter haloes by combining a spectral method and cosmological simulations of Milky Way-sized Galaxies. We compare the dynamics and orbits of individual dark matter particles from both hydrodynamic and N-body simulations, and find that the fraction of box, tube and resonant orbits of the dark matter halo decreases significantly due to the effects of baryons. In particular, the central region of the dark matter halo in the hydrodynamic simulation is dominated by regular, short-axis tube orbits, in contrast to the chaotic, box and thin orbits dominant in the N-body run. This leads to a more spherical dark matter halo in the hydrodynamic run compared to a prolate one as commonly seen in the N-body simulations. Furthermore, by using a kernel-based density estimator, we compare the coarse-grained phase-space densities of dark matter haloes in both simulations and find that it is lower by ˜0.5 dex in the hydrodynamic run due to changes in the angular momentum distribution, which indicates that the baryonic process that affects the dark matter is irreversible. Our results imply that baryons play an important role in determining the shape, kinematics and phase-space density of dark matter haloes in galaxies.

30 CFR 75.1905-1 - Diesel fuel piping systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... storage facility. (h) The diesel fuel piping system must not be located in a borehole with electric power... Diesel fuel piping systems. (a) Diesel fuel piping systems from the surface must be designed and operated...) Capable of withstanding working pressures and stresses; (2) Capable of withstanding four times the static...

77 FR 29857 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-21

... of cabin pressurization and the inability of the fuselage to withstand fail-safe loads. DATES: This... cabin pressurization and the inability of the fuselage to withstand fail-safe loads. (f) Compliance You... reference of certain publications listed in the AD as of June 25, 2012. ADDRESSES: For service information...

30 CFR 57.4430 - Surface storage facilities.

Code of Federal Regulations, 2013 CFR

2013-07-01

... liquids shall be— (1) Capable of withstanding working pressures and stresses and compatible with the type.... These pressure relief requirements do not apply to tanks used for storage of Class IIIB liquids that are... withstanding working pressures and stresses; (2) Compatible with the type of liquid stored; and (3) Maintained...

30 CFR 57.4430 - Surface storage facilities.

Code of Federal Regulations, 2011 CFR

2011-07-01

... liquids shall be— (1) Capable of withstanding working pressures and stresses and compatible with the type.... These pressure relief requirements do not apply to tanks used for storage of Class IIIB liquids that are... withstanding working pressures and stresses; (2) Compatible with the type of liquid stored; and (3) Maintained...

Hurricane Proof This!

ERIC Educational Resources Information Center

Sterling, Donna R.

2010-01-01

While learning about the types of weather events that occur in the local area, students in grades 4-6 were asked to consider how structures can be built to withstand extreme weather conditions. Teams of students designed, constructed, and tested buildings to withstand hurricanes and designed the tests they would use to evaluate their structures.…

29 CFR 1926.97 - Electrical protective equipment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... glove. (2) Electrical requirements. (i) Equipment shall be capable of withstanding the ac proof-test voltage specified in Table E-1 or the dc proof-test voltage specified in Table E-2. (A) The proof test shall reliably indicate that the equipment can withstand the voltage involved. (B) The test voltage...

Commissioning and initial experimental program of the BGO-OD experiment at ELSA

NASA Astrophysics Data System (ADS)

Alef, S.; Bauer, P.; Bayadilov, D.; Beck, R.; Becker, M.; Bella, A.; Bielefeldt, P.; Böse, S.; Braghieri, A.; Brinkmann, K.; Cole, P.; Di Salvo, R.; Dutz, H.; Elsner, D.; Fantini, A.; Freyermuth, O.; Friedrich, S.; Frommberger, F.; Ganenko, V.; Geffers, D.; Gervino, G.; Ghio, F.; Görtz, S.; Gridnev, A.; Gutz, E.; Hammann, D.; Hannappel, J.; Hillert, W.; Ignatov, A.; Jahn, R.; Joosten, R.; Jude, T. C.; Klein, F.; Knaust, J.; Kohl, K.; Koop, K.; Krusche, B.; Lapik, A.; Levi Sandri, P.; Lopatin, I. V.; Mandaglio, G.; Messi, F.; Messi, R.; Metag, V.; Moricciani, D.; Mushkarenkov, A.; Nanova, M.; Nedorezov, V.; Novinskiy, D.; Pedroni, P.; Reitz, B.; Romaniuk, M.; Rostomyan, T.; Rudnev, N.; Schaerf, C.; Scheluchin, G.; Schmieden, H.; Stugelev, A.; Sumachev, V.; Tarakanov, V.; Vegna, V.; Walther, D.; Watts, D.; Zaunick, H.; Zimmermann, T.

2016-11-01

BGO-OD is a new meson photoproduction experiment at the ELSA facility of Bonn University. It aims at the investigation of non strange and strange baryon excitations, and is especially designed to be able to detect weekly bound meson-baryon type structures. The setup for the BGO-OD experiment is presented, the characteristics of the photon beam and the detector performances are shown and the initial experimental program is discussed.

BRYNTRN: A baryon transport computer code, computation procedures and data base

NASA Technical Reports Server (NTRS)

Wilson, John W.; Townsend, Lawrence W.; Chun, Sang Y.; Buck, Warren W.; Khan, Ferdous; Cucinotta, Frank

1988-01-01

The development is described of an interaction data base and a numerical solution to the transport of baryons through the arbitrary shield material based on a straight ahead approximation of the Boltzmann equation. The code is most accurate for continuous energy boundary values but gives reasonable results for discrete spectra at the boundary with even a relatively coarse energy grid (30 points) and large spatial increments (1 cm in H2O).

Baryon currents in QCD with compact dimensions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lucini, B.; Patella, A.; Istituto Nazionale Fisica Nucleare Sezione di Pisa, Largo Pontecorvo 3, 56126 Pisa

2007-06-15

On a compact space with nontrivial cycles, for sufficiently small values of the radii of the compact dimensions, SU(N) gauge theories coupled with fermions in the fundamental representation spontaneously break charge conjugation, time reversal, and parity. We show at one loop in perturbation theory that a physical signature for this phenomenon is a nonzero baryonic current wrapping around the compact directions. The persistence of this current beyond the perturbative regime is checked by lattice simulations.

On the Generation of the Hubble Sequence Through an Internal Secular Dynamical Process

DTIC Science & Technology

2004-01-01

is apparently brought about by the fact that spiral galaxies still have varying reserves of baryonic dark matter to form stars, therefore as the...central baryonic dark matter supply, thus the ellipticals in more advanced stage of evolution (which also generally have larger L) will experi- ence...This view is particularly favored by the currently popular hierarchical clustering/cold dark matter (CDM) paradigm of structure formation and evolution

People’s Republic of China Scientific Abstracts, Number 194.

DTIC Science & Technology

1978-07-21

personal names, title and series) are available through Bell & Howell, Old Mansfield Road, Wooster, Ohio, 44691. Correspondence pertaining to matters ...meson and a charmed baryon , based on ana- lysis of decay products, was reported in this journal in early 1976. At the end of 1976 the track of a... baryons and mesons. The structural basis of these particles is the quarks (stratons) of which there are k, plus k antiparticles. Mesons con- siste

Electromagnetic dipole moments of charged baryons with bent crystals at the LHC

NASA Astrophysics Data System (ADS)

Bagli, E.; Bandiera, L.; Cavoto, G.; Guidi, V.; Henry, L.; Marangotto, D.; Martinez Vidal, F.; Mazzolari, A.; Merli, A.; Neri, N.; Ruiz Vidal, J.

2017-12-01

We propose a unique program of measurements of electric and magnetic dipole moments of charm, beauty and strange charged baryons at the LHC, based on the phenomenon of spin precession of channeled particles in bent crystals. Studies of crystal channeling and spin precession of positively- and negatively-charged particles are presented, along with feasibility studies and expected sensitivities for the proposed experiment using a layout based on the LHCb detector.

The effect of interstellar absorption on measurements of the baryon acoustic peak in the Lyman α forest

DOE PAGES

Vadai, Yishay; Poznanski, Dovi; Baron, Dalya; ...

2017-08-14

In recent years, the autocorrelation of the hydrogen Lyman α forest has been used to observe the baryon acoustic peak at redshift 2 < z < 3.5 using tens of thousands of QSO spectra from the BOSS survey. However, the interstellar medium of the Milky Way introduces absorption lines into the spectrum of any extragalactic source. These lines, while weak and undetectable in a single BOSS spectrum, could potentially bias the cosmological signal. In order to examine this, we generate absorption line maps by stacking over a million spectra of galaxies and QSOs. Here, we find that the systematics introducedmore » are too small to affect the current accuracy of the baryon acoustic peak, but might be relevant to future surveys such as the Dark Energy Spectroscopic Instrument (DESI). We outline a method to account for this with future data sets.« less

Strong and radiative decays of the doubly charmed baryons

NASA Astrophysics Data System (ADS)

Xiao, Li-Ye; Wang, Kai-Lei; Lü, Qi-Fang; Zhong, Xian-Hui; Zhu, Shi-Lin

2017-11-01

We have systematically studied the strong and radiative decays of the low-lying 1 P -wave doubly charmed baryons. Some interesting observations are: (i) The states Ξcc * and Ωcc * with JP=3 /2+ have a fairly large decay rate into the Ξc cγ and Ωc cγ channels with a width ˜15 and ˜7 keV , respectively. (ii) The lowest lying excited doubly charmed baryons are dominated by the 1 P ρ mode excitations, which should be quite narrow states. They decay into the ground state with JP=1 /2+ through the radiative transitions with a significant ratio. (iii) The total decay widths of the first orbital excitations of λ mode (1 Pλ states with JP=1 /2-, 3 /2-, 5 /2-) are about Γ ˜100 MeV , and the ratio between the radiative and hadronic decay widths is about O (10-3).

Conserved charge fluctuations at vanishing and non-vanishing chemical potential

NASA Astrophysics Data System (ADS)

Karsch, Frithjof

2017-11-01

Up to 6th order cumulants of fluctuations of net baryon-number, net electric charge and net strangeness as well as correlations among these conserved charge fluctuations are now being calculated in lattice QCD. These cumulants provide a wealth of information on the properties of strong-interaction matter in the transition region from the low temperature hadronic phase to the quark-gluon plasma phase. They can be used to quantify deviations from hadron resonance gas (HRG) model calculations which frequently are used to determine thermal conditions realized in heavy ion collision experiments. Already some second order cumulants like the correlations between net baryon-number and net strangeness or net electric charge differ significantly at temperatures above 155 MeV in QCD and HRG model calculations. We show that these differences increase at non-zero baryon chemical potential constraining the applicability range of HRG model calculations to even smaller values of the temperature.

Quark Matter May Not Be Strange.

PubMed

Holdom, Bob; Ren, Jing; Zhang, Chen

2018-06-01

If quark matter is energetically favored over nuclear matter at zero temperature and pressure, then it has long been expected to take the form of strange quark matter (SQM), with comparable amounts of u, d, and s quarks. The possibility of quark matter with only u and d quarks (udQM) is usually dismissed because of the observed stability of ordinary nuclei. However, we find that udQM generally has lower bulk energy per baryon than normal nuclei and SQM. This emerges in a phenomenological model that describes the spectra of the lightest pseudoscalar and scalar meson nonets. Taking into account the finite size effects, udQM can be the ground state of baryonic matter only for baryon number A>A_{min} with A_{min}≳300. This ensures the stability of ordinary nuclei and points to a new form of stable matter just beyond the periodic table.

Asymmetric Higgsino dark matter.

PubMed

Blum, Kfir; Efrati, Aielet; Grossman, Yuval; Nir, Yosef; Riotto, Antonio

2012-08-03

In the supersymmetric framework, prior to the electroweak phase transition, the existence of a baryon asymmetry implies the existence of a Higgsino asymmetry. We investigate whether the Higgsino could be a viable asymmetric dark matter candidate. We find that this is indeed possible. Thus, supersymmetry can provide the observed dark matter abundance and, furthermore, relate it with the baryon asymmetry, in which case the puzzle of why the baryonic and dark matter mass densities are similar would be explained. To accomplish this task, two conditions are required. First, the gauginos, squarks, and sleptons must all be very heavy, such that the only electroweak-scale superpartners are the Higgsinos. With this spectrum, supersymmetry does not solve the fine-tuning problem. Second, the temperature of the electroweak phase transition must be low, in the (1-10) GeV range. This condition requires an extension of the minimal supersymmetric standard model.

Hexaquark states as possible candidates for di-baryonic molecular states with Yukawa potential in a semi-relativistic scheme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, Smruti J., E-mail: fizix.smriti@gmail.com; Vinodkumar, P. C.

2016-05-06

We study the mass spectra of hexaquark states as di-hadronic molecules with Yukawa potential in a semi-relativistic scheme. We have solved numerically the relevant equation using mathematica notebook of Range-Kutta method including effective Yukawa like potential between two baryons to model the two-body interaction and have calculated their masses and binding energy. We have been able to assign the J{sup P} values for many of the exotic states according to their compositions. We have predicted some of the di-baryonic exotic states for which experimental as well as theoretical data are not available and we look forward to see the experimentalmore » support in favour of our predictions. So in the absence of such results our predictions can be used as guidelines for future experimental and theoretical analysis of exotic states.« less

Baryon masses and σ terms in SU(3) BChPT × 1/Nc

NASA Astrophysics Data System (ADS)

Fernando, I. P.; Alarcón, J. M.; Goity, J. L.

2018-06-01

Baryon masses and nucleon σ terms are studied with the effective theory that combines the chiral and 1 /Nc expansions for three flavors. In particular the connection between the deviation of the Gell-Mann-Okubo relation and the σ term associated with the scalar density u bar u + d bar d - 2 s bar s is emphasized. The latter is at lowest order related to a mass combination whose low value has given rise to a σ term puzzle. It is shown that while the nucleon σ terms have a well behaved low energy expansion, that mass combination is affected by large higher order corrections non-analytic in quark masses. Adding to the analysis lattice QCD baryon masses, it is found that σπN = 69 (10) MeV and σs has natural magnitude within its relatively large uncertainty.

Baryon masses and σ terms in SU(3) BChPT×1/N c

DOE PAGES

Fernando, Ishara P.; Alarcon-Soriano, Jose-Manuel; Goity, Jose Luis

2018-04-27

Baryon masses and nucleonmore » $$\\sigma$$ terms are studied with the effective theory that combines the chiral and $$1/N_c$$ expansions for three flavors. In particular the connection between the deviation of the Gell-Mann-Okubo relation and the $$\\sigma$$ term associated with the scalar density $$\\bar u u+\\bar d d-2\\bar s s$$ is emphasized. The latter is at lowest order related to a mass combination whose low value has given rise to a $$\\sigma$$ term puzzle. It is shown that while the nucleon $$\\sigma$$ terms have a well behaved low energy expansion, that mass combination is affected by large higher order corrections non-analytic in quark masses. Lastly, adding to the analysis lattice QCD baryon masses, it is found that $$\\sigma_{\\pi N}=69(10)$$~MeV and $$\\sigma_s$$ has natural magnitude within its relative large uncertainty.« less

Molecular Ωc states generated from coupled meson-baryon channels

NASA Astrophysics Data System (ADS)

Debastiani, V. R.; Dias, J. M.; Liang, W. H.; Oset, E.

2018-05-01

We have investigated Ωc states that are dynamically generated from the meson-baryon interaction. We use an extension of the local hidden gauge to obtain the interaction from the exchange of vector mesons. We show that the dominant terms come from the exchange of light vectors, where the heavy quarks are spectators. This has as a consequence that heavy quark symmetry is preserved for the dominant terms in the (1 /mQ ) counting, and also that the interaction in this case can be obtained from the SU(3) chiral Lagrangians. We show that for a standard value for the cutoff regulating the loop, we obtain two states with JP=1/2 - and two more with JP=3/2 -, three of them in remarkable agreement with three experimental states in mass and width. We also make predictions at higher energies for states of vector-baryon nature.

Isospin splittings in the light-baryon octet from lattice QCD and QED.

PubMed

Borsanyi, Sz; Dürr, S; Fodor, Z; Frison, J; Hoelbling, C; Katz, S D; Krieg, S; Kurth, Th; Lellouch, L; Lippert, Th; Portelli, A; Ramos, A; Sastre, A; Szabo, K

2013-12-20

While electromagnetic and up-down quark mass difference effects on octet baryon masses are very small, they have important consequences. The stability of the hydrogen atom against beta decay is a prominent example. Here, we include these effects by adding them to valence quarks in a lattice QCD calculation based on Nf=2+1 simulations with five lattice spacings down to 0.054 fm, lattice sizes up to 6 fm, and average up-down quark masses all the way down to their physical value. This allows us to gain control over all systematic errors, except for the one associated with neglecting electromagnetism in the sea. We compute the octet baryon isomultiplet mass splittings, as well as the individual contributions from electromagnetism and the up-down quark mass difference. Our results for the total splittings are in good agreement with experiment.

Baryon chiral perturbation theory extended beyond the low-energy region.

PubMed

Epelbaum, E; Gegelia, J; Meißner, Ulf-G; Yao, De-Liang

We consider an extension of the one-nucleon sector of baryon chiral perturbation theory beyond the low-energy region. The applicability of this approach for higher energies is restricted to small scattering angles, i.e. the kinematical region, where the quark structure of hadrons cannot be resolved. The main idea is to re-arrange the low-energy effective Lagrangian according to a new power counting and to exploit the freedom of the choice of the renormalization condition for loop diagrams. We generalize the extended on-mass-shell scheme for the one-nucleon sector of baryon chiral perturbation theory by choosing a sliding scale, that is, we expand the physical amplitudes around kinematical points beyond the threshold. This requires the introduction of complex-valued renormalized coupling constants, which can be either extracted from experimental data, or calculated using the renormalization group evolution of coupling constants fixed in threshold region.

Baryogenesis in nonminimally coupled f (R ) theories

NASA Astrophysics Data System (ADS)

Ramos, M. P. L. P.; Páramos, J.

2017-11-01

We generalize the mechanism for gravitational baryogensis in the context of f (R ) theories of gravity, including a nonminimal coupling between curvature and matter. In these models, the baryon asymmetry is generated through an effective coupling between the Ricci scalar curvature and the net baryon current that dynamically breaks Charge conjugation, parity and time reversal (C P T ) invariance. We study the combinations of characteristic mass scales and exponents for both nontrivial functions present in the modified action functional and establish the allowed region for these parameters: we find that very small deviations from general relativity are consistent with the observed baryon asymmetry and lead to temperatures compatible with the subsequent formation of the primordial abundances of light elements. In particular, we show the viability of a power-law nonminimal coupling function f2(R )˜Rn with 0

K S 0 - K L 0 asymmetries and CP violation in charmed baryon decays into neutral kaons

NASA Astrophysics Data System (ADS)

Wang, Di; Guo, Peng-Fei; Long, Wen-Hui; Yu, Fu-Sheng

2018-03-01

We study the K S 0 - K L 0 asymmetries and CP violations in charm-baryon decays with neutral kaons in the final state. The K S 0 - K L 0 asymmetry can be used to search for two-body doubly Cabibbo-suppressed amplitudes of charm-baryon decays, with the one in Λ c + → pK S, L 0 as a promising observable. Besides, it is studied for a new CP-violation effect in these processes, induced by the interference between the Cabibbo-favored and doubly Cabibbo-suppressed amplitudes with the neutral kaon mixing. Once the new CP-violation effect is determined by experiments, the direct CP asymmetry in neutral kaon modes can then be extracted and used to search for new physics. The numerical results based on SU(3) symmetry will be tested by the experiments in the future.

Tying dark matter to baryons with self-interactions.

PubMed

Kaplinghat, Manoj; Keeley, Ryan E; Linden, Tim; Yu, Hai-Bo

2014-07-11

Self-interacting dark matter (SIDM) models have been proposed to solve the small-scale issues with the collisionless cold dark matter paradigm. We derive equilibrium solutions in these SIDM models for the dark matter halo density profile including the gravitational potential of both baryons and dark matter. Self-interactions drive dark matter to be isothermal and this ties the core sizes and shapes of dark matter halos to the spatial distribution of the stars, a radical departure from previous expectations and from cold dark matter predictions. Compared to predictions of SIDM-only simulations, the core sizes are smaller and the core densities are higher, with the largest effects in baryon-dominated galaxies. As an example, we find a core size around 0.3 kpc for dark matter in the Milky Way, more than an order of magnitude smaller than the core size from SIDM-only simulations, which has important implications for indirect searches of SIDM candidates.

The effect of interstellar absorption on measurements of the baryon acoustic peak in the Lyman α forest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vadai, Yishay; Poznanski, Dovi; Baron, Dalya

In recent years, the autocorrelation of the hydrogen Lyman α forest has been used to observe the baryon acoustic peak at redshift 2 < z < 3.5 using tens of thousands of QSO spectra from the BOSS survey. However, the interstellar medium of the Milky Way introduces absorption lines into the spectrum of any extragalactic source. These lines, while weak and undetectable in a single BOSS spectrum, could potentially bias the cosmological signal. In order to examine this, we generate absorption line maps by stacking over a million spectra of galaxies and QSOs. Here, we find that the systematics introducedmore » are too small to affect the current accuracy of the baryon acoustic peak, but might be relevant to future surveys such as the Dark Energy Spectroscopic Instrument (DESI). We outline a method to account for this with future data sets.« less

Big bang nucleosynthesis - The standard model and alternatives

NASA Technical Reports Server (NTRS)

Schramm, David N.

1991-01-01

The standard homogeneous-isotropic calculation of the big bang cosmological model is reviewed, and alternate models are discussed. The standard model is shown to agree with the light element abundances for He-4, H-2, He-3, and Li-7 that are available. Improved observational data from recent LEP collider and SLC results are discussed. The data agree with the standard model in terms of the number of neutrinos, and provide improved information regarding neutron lifetimes. Alternate models are reviewed which describe different scenarios for decaying matter or quark-hadron induced inhomogeneities. The baryonic density relative to the critical density in the alternate models is similar to that of the standard model when they are made to fit the abundances. This reinforces the conclusion that the baryonic density relative to critical density is about 0.06, and also reinforces the need for both nonbaryonic dark matter and dark baryonic matter.

X(1835), X(2120), and X(2370) in flux tube models

NASA Astrophysics Data System (ADS)

Deng, Chengrong; Ping, Jialun; Yang, Youchang; Wang, Fan

2012-07-01

Nonstrange hexaquark state q3q¯3 spectrum is systematically studied by using the Gaussian expansion method in flux tube models with a six-body confinement potential. All the model parameters are fixed by baryon properties, so the calculation of hexaquark state q3q¯3 is parameter-free. It is found that some ground states of q3q¯3 are stable against disintegrating into a baryon and an anti-baryon. The main components of X(1835) and X(2370), which are observed in the radiative decay of J/ψ by BES collaboration, can be described as compact hexaquark states N8N¯8 and Δ8Δ¯8 with quantum numbers IGJPC=0+0-+, respectively. These bound states should be color confinement resonances with three-dimensional configurations similar to a rugby ball, however, X(2120) can not be accommodated in this model approach.

Particle physics in the very early universe

NASA Technical Reports Server (NTRS)

Schramm, D. N.

1981-01-01

Events in the very early big bang universe in which elementary particle physics effects may have been dominant are discussed, with attention to the generation of a net baryon number by way of grand unification theory, and emphasis on the possible role of massive neutrinos in increasing current understanding of various cosmological properties and of the constraints placed on neutrino properties by cosmology. It is noted that when grand unification theories are used to describe very early universe interactions, an initially baryon-symmetrical universe can evolve a net baryon excess of 10 to the -9th to 10 to the -11th per photon, given reasonable parameters. If neutrinos have mass, the bulk of the mass of the universe may be in the form of leptons, implying that the form of matter most familiar to physical science may not be the dominant form of matter in the universe.

Baryon masses and σ terms in SU(3) BChPT×1/N c

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernando, Ishara P.; Alarcon-Soriano, Jose-Manuel; Goity, Jose Luis

Baryon masses and nucleonmore » $$\\sigma$$ terms are studied with the effective theory that combines the chiral and $$1/N_c$$ expansions for three flavors. In particular the connection between the deviation of the Gell-Mann-Okubo relation and the $$\\sigma$$ term associated with the scalar density $$\\bar u u+\\bar d d-2\\bar s s$$ is emphasized. The latter is at lowest order related to a mass combination whose low value has given rise to a $$\\sigma$$ term puzzle. It is shown that while the nucleon $$\\sigma$$ terms have a well behaved low energy expansion, that mass combination is affected by large higher order corrections non-analytic in quark masses. Lastly, adding to the analysis lattice QCD baryon masses, it is found that $$\\sigma_{\\pi N}=69(10)$$~MeV and $$\\sigma_s$$ has natural magnitude within its relative large uncertainty.« less