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Sample records for nonluminous matter

  1. Improved Bounds on Non-Luminous Matter in Solar Orbit

    NASA Technical Reports Server (NTRS)

    Anderson, J.; Lau, E.; Krisher, T.; Dicus, D.; Rosenbaum, D.; Teplitz, V.

    1994-01-01

    We improve, using a larger set of observations including Voyager 2 Neptune flyby data, previous bounds on the amount of dark matter (DM) trapped in a spherically symmetric distribution about the sun. We bound DM by noting that such a distribution would increase the effective mass of the sun as seen by the outer planets and by finding the uncertainty in that effective mass for Uranus and Neptune in fits to the JPL Developmental Ephermeris residuals, including optical data and those two planets' Voyager 2 flybys. We extend our previous procedure by fitting more parameters of the developmental ephemerides. Additionally, we present here the values for Pioneer 10 and 11 and Voyager 1 and 2 Jupiter ranging normal points (and incorporate these data as well).

  2. Improved Bounds on Nonluminous Matter in Solar Orbit

    NASA Technical Reports Server (NTRS)

    Anderson, John D.; Lau, Eunice L.; Krisher, Timothy P.; Dicus, Duane A.; Rosenbaum, Doris C.; Teplitz, Vigdor L.

    1995-01-01

    We improve, using a larger set of observations including Voyager 2 Neptune flyby data, previous bounds on the amount of dark matter (DM) trapped in a spherically symmetric distribution about the Sun. We bound DM by noting that such a distribution would increase the effective mass of the Sun as seen by the outer planets and by finding the uncertainty in that effective mass for Uranus and Neptune in fits to the JPL developmental ephemeris residuals, including optical data and those two planets' Voyager 2 flybys. We extend our previous procedure by fitting more parameters of the developmental ephamerides. In addition, we present here the values for Pioneer 10, Pioneer 11, Voyager 1, and Voyager 2 Jupiter-ranging normal points (and incorporate these data as well). Our principal result is to limit DM in spherically symmetric distributions in orbit about the Sun interior to Neptune's orbit to less than Earth mass and interior to Uranus's orbit to about 1/6 of Earth's mass.

  3. Improved Bounds on Nonluminous Matter in Solar Orbit

    NASA Technical Reports Server (NTRS)

    Anderson, John D.; Lau, Eunice L.; Krisher, Timothy P.; Dicus, Duane A.; Rosenbaum, Doris C.; Teplitz, Vigdor L.

    1995-01-01

    We improve, using a larger set of observations including Voyager 2 Neptune flyby data, previous bounds on the amount of dark matter (DM) trapped in a spherically symmetric distribution about the Sun. We bound DM by noting that such a distribution would increase the effective mass of the Sun as seen by the outer planets and by finding the uncertainty in that effective mass for Uranus and Neptune in fits to the JPL developmental ephemeris residuals, including optical data and those two planets' Voyager 2 flybys. We extend our previous procedure by fitting more parameters of the developmental ephamerides. In addition, we present here the values for Pioneer 10, Pioneer 11, Voyager 1, and Voyager 2 Jupiter-ranging normal points (and incorporate these data as well). Our principal result is to limit DM in spherically symmetric distributions in orbit about the Sun interior to Neptune's orbit to less than Earth mass and interior to Uranus's orbit to about 1/6 of Earth's mass.

  4. Identification of a functional luciferase gene in the non-luminous diurnal firefly, Lucidina biplagiata.

    PubMed

    Oba, Y; Furuhashi, M; Inouye, S

    2010-12-01

    We isolated a luciferase gene (LbLuc) from the non-luminous diurnal firefly, Lucidina biplagiata, with high similarity to that from the nocturnal firefly, Photinus pyralis. The recombinant LbLuc showed luminescence activity comparable to that of the luciferases from P. pyralis and Luciola cruciata. To understand the non-luminosity of L. biplagiata, we determined the amount of luciferase in the adult specimen using the luciferin-luciferase reaction and found that the content of luciferase in L. biplagiata was estimated to be only 0.1% of that in L. cruciata. As previously reported, the content of luciferin in L. biplagiata was less than 0.1% of that in L. cruciata. Thus, the non-luminosity of L. biplagiata might be explained by low levels of both luciferase and luciferin.

  5. Nonluminous diffusion flame of diluted acetylene in oxygen-enriched air

    SciTech Connect

    Sugiyama, G.

    1994-12-31

    A soot-reducing mechanism of fuel dilution and oxygen enrichment in laminar diffusion flames is suggested. Analysis using the Burke-Schumann theory for the shape of over ventilated diffusion flames has shown that there is a critical ratio of stoichiometric coefficients of the fuel and the oxidizer under which the gas flows from the fuel side to the oxidizer side throughout the flame. When this condition is satisfied, the soot growth region vanishes. A similar result is also found in a numerical simulation for diffusion flames that do not satisfy the Burke-Schumann assumption of uniform flow field. KIVA code is used for that purpose. The theoretically predicted direction of gas-flow across the flame sheet is verified in an experiment in a coaxial-flow diffusion flame. Soot cloud and velocity fields are visualized through a laser sheet method in the experiment. The fuel is a mixture of acetylene and nitrogen. The oxidizer is a mixture of oxygen and nitrogen. The compositions of the reactants are controlled so that the adiabatic flame temperature is kept constant to avoid the effect of temperature change. Experimental results show substantial reduction of scattered light intensity by fuel dilution and oxygen enrichment. When a sufficient amount of nitrogen is added to the fuel, nonluminous blue flames are obtained. At higher oxygen concentrations, blue flames are obtained at higher flame temperature region. When oxygen concentration in the oxidizer is 70 vol.%, blue flames are obtained up to 2,250 K. The critical condition of the reactants for nonluminous flames agrees with the theoretical prediction when the oxidizer is ordinary air. In oxygen-enriched conditions, the fuel must be diluted more, than theoretically predicted.

  6. Coronaridine congeners inhibit human α3β4 nicotinic acetylcholine receptors by interacting with luminal and non-luminal sites.

    PubMed

    Arias, Hugo R; Targowska-Duda, Katarzyna M; Feuerbach, Dominik; Jozwiak, Krzysztof

    2015-08-01

    To characterize the interaction of coronaridine congeners with human (h) α3β4 nicotinic acetylcholine receptors (AChRs), structural and functional approaches were used. The Ca(2+) influx results established that coronaridine congeners noncompetitively inhibit hα3β4 AChRs with the following potency (IC50's in μM) sequence: (-)-ibogamine (0.62±0.23)∼(+)-catharanthine (0.68±0.10)>(-)-ibogaine (0.95±0.10)>(±)-18-methoxycoronaridine [(±)-18-MC] (1.47±0.21)>(-)-voacangine (2.28±0.33)>(±)-18-methylaminocoronaridine (2.62±0.57 μM)∼(±)-18-hydroxycoronaridine (2.81±0.54)>(-)-noribogaine (6.82±0.78). A good linear correlation (r(2)=0.771) between the calculated IC50 values and their polar surface area was found, suggesting that this is an important structural feature for its activity. The radioligand competition results indicate that (±)-18-MC and (-)-ibogaine partially inhibit [(3)H]imipramine binding by an allosteric mechanism. Molecular docking, molecular dynamics, and in silico mutation results suggest that protonated (-)-18-MC binds to luminal [i.e., β4-Phe255 (phenylalanine/valine ring; position 13'), and α3-Leu250 and β4-Leu251 (leucine ring; position 9')], non-luminal, and intersubunit sites. The pharmacophore model suggests that nitrogens from the ibogamine core as well as methylamino, hydroxyl, and methoxyl moieties at position 18 form hydrogen bonds. Collectively our data indicate that coronaridine congeners inhibit hα3β4 AChRs by blocking the ion channel's lumen and probably by additional negative allosteric mechanisms by interacting with a series of non-luminal sites.

  7. Dark matter candidates

    NASA Technical Reports Server (NTRS)

    Turner, Michael S.

    1989-01-01

    The types of particles which may provide the nonluminous mass required by big-bang cosmological models are listed and briefly characterized. The observational evidence for the existence of dark matter (outweighing the luminous component by at least a factor of 10) is reviewed; the theoretical arguments favoring mainly nonbaryonic dark matter are summarized; and particular attention is given to weakly interacting massive particles (WIMPs) remaining as relics from the early universe. The WIMPs are classified as thermal relics (heavy stable neutrinos and lighter neutralinos), asymmetric relics (including baryons), nonthermal relics (superheavy magnetic monopoles, axions, and soliton stars), and truly exotic relics (relativistic debris or vacuum energy). Explanations for the current apparent baryon/exotica ratio of about 0.1 in different theoretical scenarios are considered, and the problems of experimental and/or observational dark-matter detection are examined.

  8. Dark matter candidates

    NASA Technical Reports Server (NTRS)

    Turner, Michael S.

    1989-01-01

    The types of particles which may provide the nonluminous mass required by big-bang cosmological models are listed and briefly characterized. The observational evidence for the existence of dark matter (outweighing the luminous component by at least a factor of 10) is reviewed; the theoretical arguments favoring mainly nonbaryonic dark matter are summarized; and particular attention is given to weakly interacting massive particles (WIMPs) remaining as relics from the early universe. The WIMPs are classified as thermal relics (heavy stable neutrinos and lighter neutralinos), asymmetric relics (including baryons), nonthermal relics (superheavy magnetic monopoles, axions, and soliton stars), and truly exotic relics (relativistic debris or vacuum energy). Explanations for the current apparent baryon/exotica ratio of about 0.1 in different theoretical scenarios are considered, and the problems of experimental and/or observational dark-matter detection are examined.

  9. Dark matter and triality symmetry of leptons and quarks

    NASA Astrophysics Data System (ADS)

    Furui, Sadataka

    2012-11-01

    The radiation in the universe has a mass equivalent of approximately 2% of the luminous matter. Presence of a large amount of non-luminous matter is a problem. In order to solve this puzzle, I use quaternion basis for the leptons, and make an octonion from a combination of two quaternions. With a principle that the electro-magnetic interaction selects one triality and photon couples with a gluon of one triality sector, color-flavor locking becomes natural, and the problem of dark matter may be solved.

  10. Dark matter and triality symmetry of leptons and quarks

    SciTech Connect

    Furui, Sadataka

    2012-11-12

    The radiation in the universe has a mass equivalent of approximately 2% of the luminous matter. Presence of a large amount of non-luminous matter is a problem. In order to solve this puzzle, I use quaternion basis for the leptons, and make an octonion from a combination of two quaternions. With a principle that the electro-magnetic interaction selects one triality and photon couples with a gluon of one triality sector, color-flavor locking becomes natural, and the problem of dark matter may be solved.

  11. Multi-Dimensional Effective Field Theory Analysis for Direct Detection of Dark Matter

    NASA Astrophysics Data System (ADS)

    Rogers, Hannah; SuperCDMS Collaboration

    2016-03-01

    Experiments like the Cryogenic Dark Matter Search (CDMS) attempt to find dark matter (non-luminous matter that makes up approximately 80% of the matter in the universe) through direct detection of interactions between dark matter and a target material. The Effective Field Theory (EFT) approach increases the number of considered interactions between dark matter and the normal, target matter from two (spin independent and spin dependent interactions) to eleven operators with four possible interference terms. These additional operators allow for a more complete analysis of complimentary direct dark matter searches; however, the higher dimensional likelihoods necessary to span an increase in operators requires a clever computational tool such as MultiNest. I present here analyses of published and projected data from CDMS (Si and Ge targets) and LUX (liquid Xe target) assuming operator parameter spaces ranging from 3 - 5 dimensions and folding in information on energy-dependent backgrounds when possible.

  12. Dark Matter in the Universe

    NASA Astrophysics Data System (ADS)

    Freese, Katherine

    2017-06-01

    “What is the Universe made of?” This question is the longest outstanding problem in all of modern physics, and it is one of the most important research topics in cosmology and particle physics today. The ordinary atoms that make up the known universe, from our bodies and the air we breathe to the planets and stars, constitute only 5% of all matter and energy in the cosmos. The remaining 95% is made up of a recipe of 25% dark matter and 70% dark energy, both nonluminous components whose nature remains a mystery. I’ll begin by discussing the evidence that dark matter is the predominant mass in galaxies, and then turn to the hunt to understand its nature. Leading candidates are fundamental particles including WIMPs (weakly interacting massive particles), axions, and sterile neutrinos. There are three approaches in the experimental searches for WIMPs: at the Large Hadron Collider at CERN in Geneva; in underground laboratory experiments; and with astrophysical searches for dark matter annihilation products. If WIMPs do constitute the dark matter, they would have been the power source for the first stars to form in the Universe; these Dark Stars may be detectable with the upcoming James Webb Space Telescope. At the end of the talk I'll turn to dark energy and its effect on the future of the Universe.

  13. Search for pseudoscalar cold dark matter

    SciTech Connect

    van Bibber, K.; Stoeffl, W.; LLNL Collaborators

    1992-05-29

    AH dynamical evidence points to the conclusion that the predominant form of matter in the universe is in a non-luminous form. Furthermore, large scale deviations from uniform Hubble flow, and the recent COBE reports of inhomogeneities in the cosmic microwave background strongly suggest that we live in an exactly closed universe. If this is true, then ordinary baryonic matter could only be a minority component (10% at most) of the missing mass, and that what constitutes the majority of the dark matter must involve new physics. The axion is one of very few well motivated candidates which may comprise the dark matter. Additionally it is a `cold` dark-matter candidate which is preferred by the COBE data. We propose to construct and operate an experiment to search for axions which may constitute the dark matter of our own galaxy. As proposed by Sikivie, dark-matter axions may be detected by their stimulated conversion into monochromatic microwave photons in a tunable high-Q cavity inside a strong magnetic field. Our ability to mount an experiment quickly and take data within one year is due to a confluence of three factors. The first is the availability of a compact high field superconducting magnet and a local industrial partner, Wang NMR, who can make a very thermally efficient and economical cryostat for it. The second is an ongoing joint venture with the Institute for Nuclear Research of the Russian Academy of Sciences to do R&D on metalized precision-formed ceramic microwave cavities for the axion search, and INR has commited to providing all the microwave cavity arrays for this experiment, should this proposal be approved. The third is a commitment of very substantial startup capital monies from MIT for all of the state-of-the-art ultra-low noise microwave electronics, to one of our outstanding young collaborators who is joining their faculty.

  14. Low-Mass Dark Matter Search Results and Radiogenic Backgrounds for the Cryogenic Dark Matter Search

    NASA Astrophysics Data System (ADS)

    Pepin, Mark David

    An ever-increasing amount of evidence suggests that approximately one quarter of the energy in the universe is composed of some non-luminous, and hitherto unknown, "dark matter". Physicists from numerous sub-fields have been working on and trying to solve the dark matter problem for decades. The common solution is the existence of some new type of elementary particle with particular focus on weakly interacting massive particles (WIMPs). One avenue of dark matter research is to create an extremely sensitive particle detector with the goal of directly observing the interaction of WIMPs with standard matter. The Cryogenic Dark Matter Search (CDMS) project operated at the Soudan Underground Laboratory from 2003-2015, under the CDMS II and SuperCDMS Soudan experiments, with this goal of directly detecting dark matter. The next installation, SuperCDMS SNOLAB, is planned for near-future operation. The reason the dark-matter particle has not yet been observed in traditional particle physics experiments is that it must have very small cross sections, thus making such interactions extremely rare. In order to identify these rare events in the presence of a background of known particles and interactions, direct detection experiments employ various types and amounts of shielding to prevent known backgrounds from reaching the instrumented detector(s). CDMS utilized various gamma and neutron shielding to such an effect that the shielding, and other experimental components, themselves were sources of background. These radiogenic backgrounds must be understood to have confidence in any WIMP-search result. For this dissertation, radiogenic background studies and estimates were performed for various analyses covering CDMS II, SuperCDMS Soudan, and SuperCDMS SNOLAB. Lower-mass dark matter has become more prominent in the past few years. The CDMS detectors can be operated in an alternative, higher-biased, mode to decrease their energy thresholds and correspondingly increase their

  15. Low-Mass Dark Matter Search Results and Radiogenic Backgrounds for the Cryogenic Dark Matter Search

    SciTech Connect

    Pepin, Mark David

    2016-12-01

    An ever-increasing amount of evidence suggests that approximately one quarter of the energy in the universe is composed of some non-luminous, and hitherto unknown, “dark matter”. Physicists from numerous sub-fields have been working on and trying to solve the dark matter problem for decades. The common solution is the existence of some new type of elementary particle with particular focus on weakly interacting massive particles (WIMPs). One avenue of dark matter research is to create an extremely sensitive particle detector with the goal of directly observing the interaction of WIMPs with standard matter. The Cryogenic Dark Matter Search (CDMS) project operated at the Soudan Underground Laboratory from 2003–2015, under the CDMS II and SuperCDMS Soudan experiments, with this goal of directly detecting dark matter. The next installation, SuperCDMS SNOLAB, is planned for near-future operation. The reason the dark-matter particle has not yet been observed in traditional particle physics experiments is that it must have very small cross sections, thus making such interactions extremely rare. In order to identify these rare events in the presence of a background of known particles and interactions, direct detection experiments employ various types and amounts of shielding to prevent known backgrounds from reaching the instrumented detector(s). CDMS utilized various gamma and neutron shielding to such an effect that the shielding, and other experimental components, themselves were sources of background. These radiogenic backgrounds must be understood to have confidence in any WIMP-search result. For this dissertation, radiogenic background studies and estimates were performed for various analyses covering CDMS II, SuperCDMS Soudan, and SuperCDMS SNOLAB. Lower-mass dark matter t c2 inent in the past few years. The CDMS detectors can be operated in an alternative, higher-biased, mode v to decrease their energy thresholds and correspondingly increase their sensitivity

  16. Searching for dark matter with single phase liquid argon

    NASA Astrophysics Data System (ADS)

    Caldwell, Thomas S., Jr.

    The first hint that we fail to understand the nature of a large fraction of the gravitating matter in the universe came from Fritz Zwicky's measurements of the velocity distribution of the Coma cluster in 1933. Using the Virial theorem, Zwicky found that galaxies in the cluster were orbiting far too fast to remain gravitationally bound when their mass was estimated by the brightness of the visible matter. This led to the postulation that some form of non-luminous dark matter is present in galaxies comprising a large fraction of the galactic mass. The nature of this dark matter remains yet unknown over 80 years after Zwicky's measurements despite the efforts of many experiments. Dark matter is widely believed to be a beyond the Standard Model particle which brings the dark matter problem into the realm of particle physics. Supersymmetry is one widely explored extension of the Standard model, from which particles meeting the constraints on dark matter properties can naturally arise. These particles are generically termed weakly interacting massive particles (WIMPs), and are a currently favored dark matter candidate. A variety of experimental efforts are underway aimed towards direct detection of dark matter through observation of rare scattering of WIMPs in terrestrial detectors. Single phase liquid argon detectors are an appealing WIMP detection technique due to the scintillation properties of liquid argon and the scalability of the single phase approach. The MiniCLEAN dark matter detector is a single phase liquid argon scintillation scintillation detector with a 500 kg active mass. The modular design offers 4pi coverage with 92 optical cassettes, each containing TPB coated acrylic and a cryogenic photomultiplier tube. The MiniCLEAN detector has recently completed construction at SNOLAB. The detector is currently being commissioned, and will soon begin operation with the liquid argon target. Utilizing advanced pulse-shape discrimination techniques, MiniCLEAN will

  17. Direct Dark Matter Search with the XENON100 Experiment

    NASA Astrophysics Data System (ADS)

    Mei, Yuan

    Dark matter, a non-luminous, non-baryonic matter, is thought to constitute 23 % of the matter-energy components in the universe today. Except for its gravitational effects, the existence of dark matter has never been confirmed by any other means and its nature remains unknown. If a hypothetical Weakly Interacting Massive Particle (WIMP) were in thermal equilibrium in the early universe, it could have a relic abundance close to that of dark matter today, which provides a promising particle candidate of dark matter. Minimal Super-Symmetric extensions to the standard model predicts a stable particle with mass in the range 10 GeV/c2 to 1000 GeV/c2, and spin-independent cross-section with ordinary matter nucleon sigmax < 1 x 10--43 cm2. The XENON100 experiment deploys a Dual Phase Liquid Xenon Time Projection Chamber (LXeTPC) of 62 kg liquid xenon as its sensitive volume, to detect scintillation (S1) and ionization (S2) signals from WIMP dark matter particles directly scattering off xenon nuclei. The detector is located underground at Laboratori Nazionali del Gran Sasso (LNGS) in central Italy. 1.4 km of rock (3.7 km water equivalent) reduces the cosmic muon background by a factor of 106. The event-by-event 3D positioning capability of TPC allows volume fiducialization. With the self-shielding power of liquid xenon, as well as a 99 kg liquid xenon active veto, the electromagnetic radiation background is greatly suppressed. By utilizing the difference of (S2/S1) between electronic recoil and nuclear recoil, the expected WIMP signature, a small nuclear recoil energy deposition, could be discriminated from electronic recoil background with high efficiency. XENON100 achieved the lowest background rate (< 2.2 x 10--2 events/kg/day/keV) in the dark matter search region (< 40 keV) among all direct dark matter detectors. With 11.2 days of data, XENON100 already sets the world's best spin-independent WIMP-nucleon cross-section limit of 2.7 x 10--44 cm2 at WIMP mass 50 GeV/c 2

  18. A gamma-ray constraint on the nature of dark matter

    NASA Technical Reports Server (NTRS)

    Silk, Joseph; Bloemen, Hans

    1987-01-01

    If even a small component of the Galactic spheroid consists of the weakly interacting majorana fermions that are cold-dark-matter candidate particles for the Galactic halo, there should be a substantial flux of annihilation gamma rays from a source of about 1-deg extent at the Galactic center. COS B observations already constrain the halo cold-dark-matter (CDM) content entrained in the inner spheroid to be less than about 10 percent. A somewhat weaker constraint applies to the CDM believed to be present in the Galactic disk, but still only about 15 percent can be in such particles. Monochromatic line photons of energy 3-10 GeV are also predicted, and future experiments may be capable of improving these limits. Since both theoretical models of galaxy formation in a CDM-dominated universe and mass models for the rotation curve in the inner Galaxy suggest that a substantial fraction of the spheroid component should be nonluminous and incorporate entrained halo CDM, the hypothesis that the halo CDM consists predominantly of weakly interacting fermions such as photinos or heavy majorana mass neutrinos or higgsinos may already be subject to observational test.

  19. A gamma-ray constraint on the nature of dark matter

    NASA Technical Reports Server (NTRS)

    Silk, Joseph; Bloemen, Hans

    1987-01-01

    If even a small component of the Galactic spheroid consists of the weakly interacting majorana fermions that are cold-dark-matter candidate particles for the Galactic halo, there should be a substantial flux of annihilation gamma rays from a source of about 1-deg extent at the Galactic center. COS B observations already constrain the halo cold-dark-matter (CDM) content entrained in the inner spheroid to be less than about 10 percent. A somewhat weaker constraint applies to the CDM believed to be present in the Galactic disk, but still only about 15 percent can be in such particles. Monochromatic line photons of energy 3-10 GeV are also predicted, and future experiments may be capable of improving these limits. Since both theoretical models of galaxy formation in a CDM-dominated universe and mass models for the rotation curve in the inner Galaxy suggest that a substantial fraction of the spheroid component should be nonluminous and incorporate entrained halo CDM, the hypothesis that the halo CDM consists predominantly of weakly interacting fermions such as photinos or heavy majorana mass neutrinos or higgsinos may already be subject to observational test.

  20. When matter matters

    SciTech Connect

    Easson, Damien A.; Sawicki, Ignacy; Vikman, Alexander E-mail: ignacy.sawicki@uni-heidelberg.de

    2013-07-01

    We study a recently proposed scenario for the early universe:Subluminal Galilean Genesis. We prove that without any other matter present in the spatially flat Friedmann universe, the perturbations of the Galileon scalar field propagate with a speed at most equal to the speed of light. This proof applies to all cosmological solutions — to the whole phase space. However, in a more realistic situation, when one includes any matter which is not directly coupled to the Galileon, there always exists a region of phase space where these perturbations propagate superluminally, indeed with arbitrarily high speed. We illustrate our analytic proof with numerical computations. We discuss the implications of this result for the possible UV completion of the model.

  1. Comparing dark matter models, modified Newtonian dynamics and modified gravity in accounting for galaxy rotation curves

    NASA Astrophysics Data System (ADS)

    Li, Xin; Tang, Li; Lin, Hai-Nan

    2017-05-01

    We compare six models (including the baryonic model, two dark matter models, two modified Newtonian dynamics models and one modified gravity model) in accounting for galaxy rotation curves. For the dark matter models, we assume NFW profile and core-modified profile for the dark halo, respectively. For the modified Newtonian dynamics models, we discuss Milgrom’s MOND theory with two different interpolation functions, the standard and the simple interpolation functions. For the modified gravity, we focus on Moffat’s MSTG theory. We fit these models to the observed rotation curves of 9 high-surface brightness and 9 low-surface brightness galaxies. We apply the Bayesian Information Criterion and the Akaike Information Criterion to test the goodness-of-fit of each model. It is found that none of the six models can fit all the galaxy rotation curves well. Two galaxies can be best fitted by the baryonic model without involving nonluminous dark matter. MOND can fit the largest number of galaxies, and only one galaxy can be best fitted by the MSTG model. Core-modified model fits about half the LSB galaxies well, but no HSB galaxies, while the NFW model fits only a small fraction of HSB galaxies but no LSB galaxies. This may imply that the oversimplified NFW and core-modified profiles cannot model the postulated dark matter haloes well. Supported by Fundamental Research Funds for the Central Universities (106112016CDJCR301206), National Natural Science Fund of China (11305181, 11547305 and 11603005), and Open Project Program of State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, China (Y5KF181CJ1)

  2. The Cryogenic Dark Matter Search (CDMS-II) Experiment: First Results from the Soudan Mine

    SciTech Connect

    Chang, Clarence Leeder

    2004-09-01

    There is an abundance of evidence that the majority of the mass of the universe is in the form of non-baryonic non-luminous matter that was non-relativistic at the time when matter began to dominate the energy density. Weakly Interacting Massive Particles, or WIMPs, are attractive cold dark matter candidates because they would have a relic abundance today of ~0.1 which is consistent with precision cosmological measurements. WIMPs are also well motivated theoretically. Many minimal supersymmetric extensions of the Standard Model have WIMPs in the form of the lightest supersymmetric partner, typically taken to be the neutralino. The CDMS II experiment searches for WIMPs via their elastic scattering off of nuclei. The experiment uses Ge and Si ZIP detectors, operated at <50 mK, which simultaneously measure the ionization and athermal phonons produced by the scattering of an external particle. The dominant background for the experiment comes from electromagnetic interactions taking place very close to the detector surface. Analysis of the phonon signal from these interactions makes it possible to discriminate them from interactions caused by WIMPs. This thesis presents the details of an important aspect of the phonon pulse shape analysis known as the ''Lookup Table Correction''. The Lookup Table Correction is a position dependent calibration of the ZIP phonon response which improves the rejection of events scattering near the detector surface. The CDMS collaboration has recently commissioned its experimental installation at the Soudan Mine. This thesis presents an analysis of the data from the first WIMP search at the Soudan Mine. The results of this analysis set the world's lowest exclusion limit making the CDMS II experiment at Soudan the most sensitive WIMP search to this date.

  3. Dark Matters

    ScienceCinema

    Joseph Silk

    2016-07-12

    One of the greatest mysteries in the cosmos is that it is mostly dark.  Astronomers and particle physicists today are seeking to unravel the nature of this mysterious, but pervasive dark matter which has profoundly influenced the formation of structure in the universe.  I will describe the complex interplay between galaxy formation and dark matter detectability and review recent attempts to measure particle dark matter by direct and indirect means.

  4. Dark Matter

    SciTech Connect

    Bashir, A.; Cotti, U.; De Leon, C. L.; Raya, A; Villasenor, L.

    2008-07-02

    One of the biggest scientific mysteries of our time resides in the identification of the particles that constitute a large fraction of the mass of our Universe, generically known as dark matter. We review the observations and the experimental data that imply the existence of dark matter. We briefly discuss the properties of the two best dark-matter candidate particles and the experimental techniques presently used to try to discover them. Finally, we mention a proposed project that has recently emerged within the Mexican community to look for dark matter.

  5. Describing Matter

    ERIC Educational Resources Information Center

    Adams, Krista; Feagin, Shannon

    2017-01-01

    This article presents a lesson that was designed to explore the scientific descriptions of matter through both the intensive and extensive properties that students successfully added to their vocabulary. Students' examples demonstrated that there were places where their reasoning about matter faltered as related to how the material is the same…

  6. Literacy Matters.

    ERIC Educational Resources Information Center

    Macedo, Donaldo

    2003-01-01

    Suggests that in an era of excessive high-stakes testing and a blind embrace of "technicism," literacy not only matters, but may represent one of the last hopes to "salvage our already feeble democracy." Concludes that literacy matters if, and only if, it is viewed as a democratic right and as a human right. (SG)

  7. Invisible matter.

    NASA Astrophysics Data System (ADS)

    Dolgov, A. D.

    These lectures have been given to particle physicists, mostly experimentalists and very briefly and at a pedestrian level review the problems of dark matter. The content of the lectures is the following: 1. Introduction. 2. Cosmological background. 3. Luminous matter. 4. Primordial nucleosynthesis and the total amount of baryons. 5. Gravitating invisible matter. 6. Baryonic crisis. 7. Inflationary omega. 8. Intermediate summary. 9. Possible forms of dark matter. 10. Structure formation: basic assumptions. 11. Structure formations: basics of the theory. 12. Evolution of perturbations with different forms of dark matter. 13. Conclusion. The presentation and conclusion reflect personal view of the author that a considerable amount of invisible energy in the universe is in the form of vacuum energy (cosmological constant) and possibly in the form of a classical field which adjusts vacuum energy to the value permitted and requested by astronomical data.

  8. SABRE: A search for dark matter and a test of the DAMA/LIBRA annual-modulation result using thallium-doped sodium-iodide scintillation detectors

    NASA Astrophysics Data System (ADS)

    Shields, Emily Kathryn

    Ample evidence has been gathered demonstrating that the majority of the mass in the universe is composed of non-luminous, non-baryonic matter. Though the evidence for dark matter is unassailable, its nature and properties remain unknown. A broad effort has been undertaken by the physics community to detect dark-matter particles through direct-detection techniques. For over a decade, the DAMA/LIBRA experiment has observed a highly significant (9.3sigma) modulation in the scintillation event rate in their highly pure NaI(Tl) detectors, which they use as the basis of a claim for the discovery of dark-matter particles. However, the dark-matter interpretation of the DAMA/LIBRA modulation remains unverified. While there have been some recent hints of dark matter in the form of a light Weakly-Interacting Massive Particle (WIMP) from the CoGeNT and CDMS-Si experiments, when assuming a WIMP dark-matter model, several other experiments, including the LUX and XENON noble-liquid experiments, the KIMS CsI(Tl) experiment, and several bubble chamber experiments, conflict with DAMA/LIBRA. However, these experiments use different dark-matter targets and cannot be compared with DAMA/LIBRA in a model-independent way. The uncertainty surrounding the dark-matter model, astrophysical model, and nuclear-physics effects makes it necessary for a new NaI(Tl) experiment to directly test the DAMA/LIBRA result. The Sodium-iodide with Active Background REjection (SABRE) experiment seeks to provide a much-needed model-independent test of the DAMA/LIBRA modulation by developing highly pure crystal detectors with very low radioactivity and deploying them in an active veto detector that can reject key backgrounds in a dark-matter measurement. This work focuses on the efforts put forward by the SABRE collaboration in developing low-background, low-threshold crystal detectors, designing and fabricating a liquid-scintillator veto detector, and simulating the predicted background spectrum for a dark-matter

  9. Cultures Matter

    ERIC Educational Resources Information Center

    Foster, Charles R.

    2007-01-01

    In this article, the author shares his belief that, in the interactions between teachers and learners, it is not just culture that matters, but the encounter of the cultures that shape who they are, what they believe, and how they practice those beliefs in their relationships with each other and the world around them. When teachers teach they…

  10. Guidance Matters

    ERIC Educational Resources Information Center

    Gartrell, Dan

    2006-01-01

    Conflicts happen all the time in early childhood classrooms--and just about everywhere else in life. Conflict management includes the ability to: (1) prevent conflicts from becoming too serious to resolve easily and (2) resolve conflicts peaceably no matter how serious they get. When a third person assists others in resolving a conflict, this is…

  11. Changes Matter!

    ERIC Educational Resources Information Center

    Lott, Kimberly; Jensen, Anitra

    2012-01-01

    Being able to distinguish between physical and chemical changes of matter is a foundational chemistry concept that at first seems like a simple elementary concept to teach, but students often have misconceptions that hinder their understanding. These misconceptions are seen among elementary students, but these ideas are perpetuated throughout…

  12. Changes Matter!

    ERIC Educational Resources Information Center

    Lott, Kimberly; Jensen, Anitra

    2012-01-01

    Being able to distinguish between physical and chemical changes of matter is a foundational chemistry concept that at first seems like a simple elementary concept to teach, but students often have misconceptions that hinder their understanding. These misconceptions are seen among elementary students, but these ideas are perpetuated throughout…

  13. Interstellar Matters

    NASA Astrophysics Data System (ADS)

    Verschuur, Gerrit L.

    In this provocative new book, radio astronomer and author Gerrit L. Verschuur describes the phenomena of scientific curiosity and discovery by following the exciting story of interstellar matter. The discovery of "stuff between the stars" was the result of decades of work by hundreds of astronomers, and the evolving recognition of its existence has profoundly changed the way we view the Universe. Verschuur begins with E.E. Barnard, who puzzled for a quarter century over the interpretation of photographs of dark patches between the stars. Verschuur then traces the tortuous path to acceptance of the existence of interstellar matter. He shares with us the thrill of discovery that motivates astronomers, the use of metaphors and modeling by scientist, and other tricks of the astronomical trade. Finally, we learn about the modern study of interstellar matter: the discovery of complex organic molecules between the stars and how they may have seeded the early earth with the precursors for life, new insights into star formation, the structure of the Milky Way and the elusive interstellar magnetic field. More than a history, Interstellar Matters is a detective story that evokes the excitement and serendipity of science against the background of a century of shared effort by the world community of astronomers. From the reviews: "I can't imagine anyone interested in astronomy who won't enjoy this book - it's chocked full of science, personalities and insights. We are products of the stuff between the stars - Verschuur tells the fascinating story of how its existence was discovered. Interstellar Matters is his best book, I think. It's certainly one of the best astronomy popularizations I've read." Leif J. Robinson, Sky and Teleskope#1

  14. Dark matter

    PubMed Central

    Peebles, P. James E.

    2015-01-01

    The evidence for the dark matter (DM) of the hot big bang cosmology is about as good as it gets in natural science. The exploration of its nature is now led by direct and indirect detection experiments, to be complemented by advances in the full range of cosmological tests, including judicious consideration of the rich phenomenology of galaxies. The results may confirm ideas about DM already under discussion. If we are lucky, we also will be surprised once again. PMID:24794526

  15. Dark matter.

    PubMed

    Peebles, P James E

    2015-10-06

    The evidence for the dark matter (DM) of the hot big bang cosmology is about as good as it gets in natural science. The exploration of its nature is now led by direct and indirect detection experiments, to be complemented by advances in the full range of cosmological tests, including judicious consideration of the rich phenomenology of galaxies. The results may confirm ideas about DM already under discussion. If we are lucky, we also will be surprised once again.

  16. Dynamic Matter

    NASA Astrophysics Data System (ADS)

    Hohner, Jack

    2003-05-01

    First postulate: Following the Big Bang, quarks, born from zero point mass, did not acquire a constant size. They are growing. Atomic distances remain relative to increasing quark diameter resulting in molecular density remaining constant. Current rate of quark growth results in an increase of Earth radius of approximately 2.8 cm/year. The perpetual growth is sustained by the conversion of space to matter. The equality of space to matter is algebraically derived from Newton's law of gravity. There results an inward flow of space at each quark. This creates a vector field of space flowing inward at the Earth. Next postulate: Einstein space curvature is actually inward flow of space. Although this appears as an ether theory, it does not conflict with relativity. The combined vector fields of all stars in the universe create a scalar field equal to C. Inward velocity of space at the surface of the Earth is calculated at 1.46 cm/sec. This is derived from space curvature formula from relativity. This value accelerates toward the nucleus of each atom until it terminates at C at the diameter of a quark. These two predictions of the velocity C demonstrate why it is the universal constant. This work predicts the gravitational constant from a derivation based on C. Several unifying aspects emerge including; equivalence principle, 5 dimensions, time, strong nuclear force, decreasing rotational velocity of Earth, dark matter, red shift and quantum mechanics. This theory is an extension of Einstein and Newton.

  17. Active matter

    NASA Astrophysics Data System (ADS)

    Ramaswamy, Sriram

    2017-05-01

    The study of systems with sustained energy uptake and dissipation at the scale of the constituent particles is an area of central interest in nonequilibrium statistical physics. Identifying such systems as a distinct category—Active matter—unifies our understanding of autonomous collective movement in the living world and in some surprising inanimate imitations. In this article I present the active matter framework, briefly recall some early work, review our recent results on single-particle and collective behaviour, including experiments on active granular monolayers, and discuss new directions for the future.

  18. Marginal Matter

    NASA Astrophysics Data System (ADS)

    van Hecke, Martin

    2013-03-01

    All around us, things are falling apart. The foam on our cappuccinos appears solid, but gentle stirring irreversibly changes its shape. Skin, a biological fiber network, is firm when you pinch it, but soft under light touch. Sand mimics a solid when we walk on the beach but a liquid when we pour it out of our shoes. Crucially, a marginal point separates the rigid or jammed state from the mechanical vacuum (freely flowing) state - at their marginal points, soft materials are neither solid nor liquid. Here I will show how the marginal point gives birth to a third sector of soft matter physics: intrinsically nonlinear mechanics. I will illustrate this with shock waves in weakly compressed granular media, the nonlinear rheology of foams, and the nonlinear mechanics of weakly connected elastic networks.

  19. Age matters.

    PubMed

    McCutcheon, James Edgar; Marinelli, Michela

    2009-03-01

    The age of an experimental animal can be a critical variable, yet age matters are often overlooked within neuroscience. Many studies make use of young animals, without considering possible differences between immature and mature subjects. This is especially problematic when attempting to model traits or diseases that do not emerge until adulthood. In this commentary we discuss the reasons for this apparent bias in age of experimental animals, and illustrate the problem with a systematic review of published articles on long-term potentiation. Additionally, we review the developmental stages of a rat and discuss the difficulty of using the weight of an animal as a predictor of its age. Finally, we provide original data from our laboratory and review published data to emphasize that development is an ongoing process that does not end with puberty. Developmental changes can be quantitative in nature, involving gradual changes, rapid switches, or inverted U-shaped curves. Changes can also be qualitative. Thus, phenomena that appear to be unitary may be governed by different mechanisms at different ages. We conclude that selection of the age of the animals may be critically important in the design and interpretation of neurobiological studies.

  20. XENON100 Dark Matter Search: Scintillation Response of Liquid Xenon to Electronic Recoils

    NASA Astrophysics Data System (ADS)

    Lim, Kyungeun Elizabeth

    Dark matter is one of the missing pieces necessary to complete the puzzle of the universe. Numerous astrophysical observations at all scales suggest that 23 % of the universe is made of nonluminous, cold, collisionless, nonbaryonic, yet undiscovered dark matter. Weakly Interacting Massive Particles (WIMPs) are the most well-motivated dark matter candidates and significant efforts have been made to search for WIMPs. The XENON100 dark matter experiment is currently the most sensitive experiment in the global race for the first direct detection of WIMP dark matter. XENON100 is a dual-phase (liquid-gas) time projection chamber containing a total of 161 kg of liquid xenon (LXe) with a 62kg WIMP target mass. It has been built with radiopure materials to achieve an ultra-low electromagnetic background and operated at the Laboratori Nazionali del Gran Sasso in Italy. WIMPs are expected to scatter off xenon nuclei in the target volume. Simultaneous measurement of ionization and scintillation produced by nuclear recoils allows for the detection of WIMPs in XENON100. Data from the XENON100 experiment have resulted in the most stringent limits on the spin-independent elastic WIMP-nucleon scattering cross sections for most of the significant WIMP masses. As the experimental precision increases, a better understanding of the scintillation and ionization response of LXe to low energy (< 10 keV) particles is crucial for the interpretation of data from LXe based WIMP searches. A setup has been built and operated at Columbia University to measure the scintillation response of LXe to both electronic and nuclear recoils down to energies of a few keV, in particular for the XENON100 experiment. In this thesis, I present the research carried out in the context of the XENON100 dark matter search experiment. For the theoretical foundation of the XENON100 experiment, the first two chapters are dedicated to the motivation for and detection medium choice of the XENON100 experiment

  1. A Search for Low-Mass Dark Matter with the Cryogenic Dark Matter Search and the Development of Highly Multiplexed Phonon-Mediated Particle Detectors

    NASA Astrophysics Data System (ADS)

    Moore, David Craig

    2012-06-01

    A wide variety of astrophysical observations indicate that approximately 85% of the matter in the universe is nonbaryonic and nonluminous. Understanding the nature of this "dark matter" is one of the most important outstanding questions in cosmology. Weakly Interacting Massive Particles (WIMPs) are a leading candidate for dark matter since they would be thermally produced in the early universe in the correct abundance to account for the observed relic density of dark matter. If WIMPs account for the dark matter, then rare interactions from relic WIMPs should be observable in terrestrial detectors. Recently, unexplained excess events in the DAMA/LIBRA, CoGeNT, and CRESST-II experiments have been interpreted as evidence of scattering from WIMPs with masses ˜10 GeV and spin-independent scattering cross sections of 10--41--10 --40 cm2. The Cryogenic Dark Matter Search (CDMS II) attempts to identify WIMP interactions using an array of cryogenic germanium and silicon particle detectors located at the Soudan Underground Laboratory in northern Minnesota. In this dissertation, data taken by CDMS II are reanalyzed using a 2 keV recoil energy threshold to increase the sensitivity to WIMPs with masses ˜10 GeV. These data disfavor an explanation for the DAMA/LIBRA, CoGeNT, and CRESST-II results in terms of spin-independent elastic scattering of WIMPs with masses ≲ 12 GeV, under standard assumptions. At the time of publication, they provided the strongest constraints on spin-independent elastic scattering from 5--9 GeV, ruling out previously unexplored parameter space. To detect WIMPs or exclude the remaining parameter space favored by the most popular models will ultimately require detectors with target masses ≳ 1 ton, requiring an increase in mass by more than two orders of magnitude over CDMS II. For cryogenic detectors such as CDMS, scaling to such large target masses will require individual detector elements to be fabricated more quickly and cheaply, while maintaining

  2. A search for low-mass dark matter with the cryogenic dark matter search and the development of highly multiplexed phonon-mediated particle detectors

    SciTech Connect

    Moore, David Craig

    2012-01-01

    A wide variety of astrophysical observations indicate that approximately 85% of the matter in the universe is nonbaryonic and nonluminous. Understanding the nature of this "dark matter" is one of the most important outstanding questions in cosmology. Weakly Interacting Massive Particles (WIMPs) are a leading candidate for dark matter since they would be thermally produced in the early universe in the correct abundance to account for the observed relic density of dark matter. If WIMPs account for the dark matter, then rare interactions from relic WIMPs should be observable in terrestrial detectors. Recently, unexplained excess events in the DAMA/LIBRA, CoGeNT, and CRESST-II experiments have been interpreted as evidence of scattering from WIMPs with masses ~10 GeV and spin-independent scattering cross sections of 10-41-10-40 cm2. The Cryogenic Dark Matter Search (CDMS II) attempts to identify WIMP interactions using an array of cryogenic germanium and silicon particle detectors located at the Soudan Underground Laboratory in northern Minnesota. In this dissertation, data taken by CDMS II are reanalyzed using a 2 keV recoil energy threshold to increase the sensitivity to WIMPs with masses ~10 GeV. These data disfavor an explanation for the DAMA/LIBRA, CoGeNT, and CRESST-II results in terms of spin-independent elastic scattering of WIMPs with masses ≲12 GeV, under standard assumptions. At the time of publication, they provided the strongest constraints on spin-independent elastic scattering from 5-9 GeV, ruling out previously unexplored parameter space. To detect WIMPs or exclude the remaining parameter space favored by the most popular models will ultimately require detectors with target masses ≳1 ton, requiring an increase in mass by more than two orders of magnitude over CDMS II. For cryogenic detectors such as CDMS, scaling to such large target masses will require individual detector elements to be fabricated more quickly and cheaply, while

  3. Conducting Compositions of Matter

    NASA Technical Reports Server (NTRS)

    Viswanathan, Tito (Inventor)

    1999-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.

  4. Conducting Compositions of Matter

    NASA Technical Reports Server (NTRS)

    Viswanathan, Tito (Inventor)

    2001-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.

  5. Conducting compositions of matter

    NASA Technical Reports Server (NTRS)

    Viswanathan, Tito (Inventor)

    2000-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.

  6. Hollow nuclear matter

    NASA Astrophysics Data System (ADS)

    Yong, Gao-Chan

    2016-01-01

    It is generally considered that an atomic nucleus is always compact. Based on the isospin-dependent Boltzmann nuclear transport model, here I show that large block nuclear matter or excited nuclear matter may both be hollow. The size of the inner bubble in these matter is affected by the charge number of nuclear matter. The existence of hollow nuclear matter may have many implications in nuclear or atomic physics or astrophysics as well as some practical applications.

  7. States of Matter

    NASA Image and Video Library

    NASA scientists and engineers utilize the basic principles of the states of matter on a daily basis. The states and properties of matter are very important to the design and construction of NASA sp...

  8. Asymmetric dark matter

    SciTech Connect

    Kumar, Jason

    2014-06-24

    We review the theoretical framework underlying models of asymmetric dark matter, describe astrophysical constraints which arise from observations of neutron stars, and discuss the prospects for detecting asymmetric dark matter.

  9. Particulate Matter (PM) Pollution

    MedlinePlus

    ... Environmental Protection Agency Search Search Particulate Matter (PM) Pollution Contact Us Share Most PM particles form in ... and cause serious health effects. Particulate Matter (PM) Pollution PM Basics What is PM, and how does ...

  10. Nonthermal Supermassive Dark Matter

    NASA Technical Reports Server (NTRS)

    Chung, Daniel J. H.; Kolb, Edward W.; Riotto, Antonio

    1999-01-01

    We discuss several cosmological production mechanisms for nonthermal supermassive dark matter and argue that dark matter may he elementary particles of mass much greater than the weak scale. Searches for dark matter should ma be limited to weakly interacting particles with mass of the order of the weak scale, but should extend into the supermassive range as well.

  11. Nonthermal Supermassive Dark Matter

    NASA Technical Reports Server (NTRS)

    Chung, Daniel J. H.; Kolb, Edward W.; Riotto, Antonio

    1999-01-01

    We discuss several cosmological production mechanisms for nonthermal supermassive dark matter and argue that dark matter may he elementary particles of mass much greater than the weak scale. Searches for dark matter should ma be limited to weakly interacting particles with mass of the order of the weak scale, but should extend into the supermassive range as well.

  12. Impeded Dark Matter

    SciTech Connect

    Kopp, Joachim; Liu, Jia; Slatyer, Tracy; Wang, Xiao-Ping; Xue, Wei

    2016-12-12

    Here, we consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario \\Impeded Dark Matter". We also demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may even be kinematically forbidden, making this scenario almost insensitive to constraints from the cosmic microwave background and from observations of dwarf galaxies. Accordingly, it may be possible for Impeded Dark Matter to yield observable signals in clusters or the Galactic center, with no corresponding signal in dwarfs. Furthermore, for positive mass splitting, we show that the annihilation cross-section is suppressed by the small mass splitting, which helps light dark matter to survive increasingly stringent constraints from indirect searches. As specific realizations for Impeded Dark Matter, we introduce a model of vector dark matter from a hidden SU(2) sector, and a composite dark matter scenario based on a QCD-like dark sector.

  13. Birth to Three Matters

    ERIC Educational Resources Information Center

    Abbott, Lesley; Langston, Ann

    2004-01-01

    "Birth to Three Matters" is essential for all those involved in developing policy and providing care and education for children between birth and three. It carefully examines the structure and content of the recently published Birth to Three Matters materials and explores a range of "matters" that impact on the development of quality in early…

  14. Impeded Dark Matter

    DOE PAGES

    Kopp, Joachim; Liu, Jia; Slatyer, Tracy; ...

    2016-12-12

    Here, we consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario \\Impeded Dark Matter". We also demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may evenmore » be kinematically forbidden, making this scenario almost insensitive to constraints from the cosmic microwave background and from observations of dwarf galaxies. Accordingly, it may be possible for Impeded Dark Matter to yield observable signals in clusters or the Galactic center, with no corresponding signal in dwarfs. Furthermore, for positive mass splitting, we show that the annihilation cross-section is suppressed by the small mass splitting, which helps light dark matter to survive increasingly stringent constraints from indirect searches. As specific realizations for Impeded Dark Matter, we introduce a model of vector dark matter from a hidden SU(2) sector, and a composite dark matter scenario based on a QCD-like dark sector.« less

  15. Impeded Dark Matter

    NASA Astrophysics Data System (ADS)

    Kopp, Joachim; Liu, Jia; Slatyer, Tracy R.; Wang, Xiao-Ping; Xue, Wei

    2016-12-01

    We consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario "Impeded Dark Matter". We demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may even be kinematically forbidden, making this scenario almost insensitive to constraints from the cosmic microwave background and from observations of dwarf galaxies. Accordingly, it may be possible for Impeded Dark Matter to yield observable signals in clusters or the Galactic center, with no corresponding signal in dwarfs. For positive mass splitting, we show that the annihilation cross-section is suppressed by the small mass splitting, which helps light dark matter to survive increasingly stringent constraints from indirect searches. As specific realizations for Impeded Dark Matter, we introduce a model of vector dark matter from a hidden SU(2) sector, and a composite dark matter scenario based on a QCD-like dark sector.

  16. Secretly asymmetric dark matter

    NASA Astrophysics Data System (ADS)

    Agrawal, Prateek; Kilic, Can; Swaminathan, Sivaramakrishnan; Trendafilova, Cynthia

    2017-01-01

    We study a mechanism where the dark matter number density today arises from asymmetries generated in the dark sector in the early Universe, even though the total dark matter number remains zero throughout the history of the Universe. The dark matter population today can be completely symmetric, with annihilation rates above those expected from thermal weakly interacting massive particles. We give a simple example of this mechanism using a benchmark model of flavored dark matter. We discuss the experimental signatures of this setup, which arise mainly from the sector that annihilates the symmetric component of dark matter.

  17. The physics of strange matter

    SciTech Connect

    Olinto, A.V. |

    1991-12-01

    Strange matter may be the ground state of matter. We review the phenomenology and astrophysical implications of strange matter, and discuss the possible ways for testing the strange matter hypothesis.

  18. Big Questions: Dark Matter

    ScienceCinema

    Lincoln, Don

    2016-07-12

    Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

  19. Big Questions: Dark Matter

    SciTech Connect

    Lincoln, Don

    2013-12-05

    Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

  20. How dark matter came to matter

    NASA Astrophysics Data System (ADS)

    de Swart, J. G.; Bertone, G.; van Dongen, J.

    2017-03-01

    The history of the dark matter problem can be traced back to at least the 1930s, but it was not until the early 1970s that the issue of 'missing matter' was widely recognized as problematic. In the latter period, previously separate issues involving missing mass were brought together in a single anomaly. We argue that reference to a straightforward accumulation of evidence alone is inadequate to comprehend this episode. Rather, the rise of cosmological research, the accompanying renewed interest in the theory of relativity and changes in the manpower division of astronomy in the 1960s are key to understanding how dark matter came to matter. At the same time, this story may also enlighten us on the methodological dimensions of past practices of physics and cosmology.

  1. Teachers Matter. Yes. Schools Matter. Yes. Districts Matter--Really?

    ERIC Educational Resources Information Center

    Chenoweth, Karin

    2015-01-01

    School districts shape the conditions in which schools operate and as such can support or undermine school success and thus student success. All of which is to say that school districts matter. This article looks at the success of two districts whose low-income and minority students beat the odds in academic achievement. Lessons from these…

  2. Teachers Matter. Yes. Schools Matter. Yes. Districts Matter--Really?

    ERIC Educational Resources Information Center

    Chenoweth, Karin

    2015-01-01

    School districts shape the conditions in which schools operate and as such can support or undermine school success and thus student success. All of which is to say that school districts matter. This article looks at the success of two districts whose low-income and minority students beat the odds in academic achievement. Lessons from these…

  3. Neutrinos and dark matter

    SciTech Connect

    Ibarra, Alejandro

    2015-07-15

    Neutrinos could be key particles to unravel the nature of the dark matter of the Universe. On the one hand, sterile neutrinos in minimal extensions of the Standard Model are excellent dark matter candidates, producing potentially observable signals in the form of a line in the X-ray sky. On the other hand, the annihilation or the decay of dark matter particles produces, in many plausible dark matter scenarios, a neutrino flux that could be detected at neutrino telescopes, thus providing non-gravitational evidence for dark matter. More conservatively, the non-observation of a significant excess in the neutrino fluxes with respect to the expected astrophysical backgrounds can be used to constrain dark matter properties, such as the self-annihilation cross section, the scattering cross section with nucleons and the lifetime.

  4. Codecaying Dark Matter.

    PubMed

    Dror, Jeff Asaf; Kuflik, Eric; Ng, Wee Hao

    2016-11-18

    We propose a new mechanism for thermal dark matter freeze-out, called codecaying dark matter. Multicomponent dark sectors with degenerate particles and out-of-equilibrium decays can codecay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles rather than from Boltzmann suppression. The relic abundance is set by the dark matter annihilation cross section, which is predicted to be boosted, and the decay rate of the dark sector particles. The mechanism is viable in a broad range of dark matter parameter space, with a robust prediction of an enhanced indirect detection signal. Finally, we present a simple model that realizes codecaying dark matter.

  5. Ghost dark matter

    SciTech Connect

    Furukawa, Tomonori; Yokoyama, Shuichiro; Ichiki, Kiyotomo; Sugiyama, Naoshi; Mukohyama, Shinji E-mail: shu@a.phys.nagoya-u.ac.jp E-mail: naoshi@a.phys.nagoya-u.ac.jp

    2010-05-01

    We revisit ghost dark matter, the possibility that ghost condensation may serve as an alternative to dark matter. In particular, we investigate the Friedmann-Robertson-Walker (FRW) background evolution and the large-scale structure (LSS) in the ΛGDM universe, i.e. a late-time universe dominated by a cosmological constant and ghost dark matter. The FRW background of the ΛGDM universe is indistinguishable from that of the standard ΛCDM universe if M∼>1eV, where M is the scale of spontaneous Lorentz breaking. From the LSS we find a stronger bound: M∼>10eV. For smaller M, ghost dark matter would have non-negligible sound speed after the matter-radiation equality, and thus the matter power spectrum would significantly differ from observation. These bounds are compatible with the phenomenological upper bound M∼<100GeV known in the literature.

  6. Complex Dark Matter

    ScienceCinema

    Lincoln, Don

    2016-07-12

    After a century of study, scientists have come to the realization that the ordinary matter made of atoms is a minority in the universe. In order to explain observations, it appears that there exists a new and undiscovered kind of matter, called dark matter, that is five times more prevalent than ordinary matter. The evidence for this new matter’s existence is very strong, but scientists know only a little about its nature. In today’s video, Fermilab’s Dr. Don Lincoln talks about an exciting and unconventional idea, specifically that dark matter might have a very complex set of structures and interactions. While this idea is entirely speculative, it is an interesting hypothesis and one that scientists are investigating.

  7. Clumpy cold dark matter

    NASA Technical Reports Server (NTRS)

    Silk, Joseph; Stebbins, Albert

    1993-01-01

    A study is conducted of cold dark matter (CDM) models in which clumpiness will inhere, using cosmic strings and textures suited to galaxy formation. CDM clumps of 10 million solar mass/cu pc density are generated at about z(eq) redshift, with a sizable fraction surviving. Observable implications encompass dark matter cores in globular clusters and in galactic nuclei. Results from terrestrial dark matter detection experiments may be affected by clumpiness in the Galactic halo.

  8. Clumpy cold dark matter

    NASA Technical Reports Server (NTRS)

    Silk, Joseph; Stebbins, Albert

    1993-01-01

    A study is conducted of cold dark matter (CDM) models in which clumpiness will inhere, using cosmic strings and textures suited to galaxy formation. CDM clumps of 10 million solar mass/cu pc density are generated at about z(eq) redshift, with a sizable fraction surviving. Observable implications encompass dark matter cores in globular clusters and in galactic nuclei. Results from terrestrial dark matter detection experiments may be affected by clumpiness in the Galactic halo.

  9. Dark Matter 2013

    NASA Astrophysics Data System (ADS)

    Schumann, Marc

    2014-10-01

    This article reviews the status of the exciting and fastly evolving field of dark matter research as of summer 2013, when it was discussed at the International Cosmic Ray Conference (ICRC) 2013 in Rio de Janeiro. It focuses on the three main avenues to detect weakly interacting massive particle (WIMP) dark matter: direct detection, indirect detection, and collider searches. The article is based on the dark matter rapporteur talk summarizing the presentations given at the conference, filling some gaps for completeness.

  10. Galactic Dark Matter

    NASA Astrophysics Data System (ADS)

    Burch, Benjamin P.

    The precise phase-space distribution and properties of Galactic dark matter necessary for its direct and indirect detection are currently unknown. Since the distributions of normal and dark matter in the Milky Way are coupled to each other as they both move in the same gravitational potential, constraints on the distribution and properties of dark matter can be derived by studying the distribution of visible matter in the Galaxy and making some general assumptions regarding the phase-space distribution of the dark matter. In this study, the visible components of the Galaxy have been comprehensively reviewed to create an axisymmetric model of the Galaxy that is consistent with the available observations, and the dark matter phase-space distribution is assumed to follow a lowered-isothermal form. Poisson's equations are then solved self-consistently to construct models of the spatial and velocity distribution of Galactic dark matter. The total gravitational potential from normal and dark matter are calculated and compared to the current observations of the rotation curve and to the radial velocity distributions of blue horizontal-branch and blue straggler stars. It is found that this analysis allows for a wide range of parameters for the dark matter. The implications for direct and indirect detection of dark matter are discussed in detail. In the appendices, two additional projects are presented. In Appendix A, the recent observations of the positron fraction and the total electron spectrum in cosmic rays are addressed by considering a nested leaky-box model for the propagation of cosmic rays in the Galaxy. This is found to obviate the need for exotic processes such as the annihilation or decay of dark matter to explain the recent observations. In Appendix B, we discuss a novel dark matter detector involving triggered cavitation in acoustic fields. The theory behind the detector is presented in detail, and we discuss the work than has been done to create a prototype

  11. The nuclear matter problem

    SciTech Connect

    Carlson, J. A.; Cowell, S.; Morales, J.; Ravenhall, D. G.; Pandharipande, V. R.

    2002-01-01

    We review the present statiis of the many-body theory of nuclear and pure neutron matter based on realistic models of nuclear forces, The current models of two- and three-nucleon interactions are discussed along with recent results obtained with the Brueckner and variatioual methods. New initiatives in the variational method and quantuni Monte Carlo nicthods to study pure neutron matter are described, and finally, the analytic behavior of the energy of piire neutron matter at low densities is cliscussed.

  12. Cosmology with Mimetic Matter

    SciTech Connect

    Chamseddine, Ali H.; Mukhanov, Viatcheslav; Vikman, Alexander E-mail: viatcheslav.Mukhanov@lmu.de

    2014-06-01

    We consider minimal extensions of the recently proposed Mimetic Dark Matter and show that by introducing a potential for the mimetic non-dynamical scalar field we can mimic nearly any gravitational properties of the normal matter. In particular, the mimetic matter can provide us with inflaton, quintessence and even can lead to a bouncing nonsingular universe. We also investigate the behaviour of cosmological perturbations due to a mimetic matter. We demonstrate that simple mimetic inflation can produce red-tilted scalar perturbations which are largely enhanced over gravity waves.

  13. The Dark Matter Problem

    NASA Astrophysics Data System (ADS)

    Sanders, Robert H.

    2014-02-01

    1. Introduction; 2. Early history of the dark matter hypothesis; 3. The stability of disk galaxies: the dark halo solutions; 4. Direct evidence: extended rotation curves of spiral galaxies; 5. The maximum disk: light traces mass; 6. Cosmology and the birth of astroparticle physics; 7. Clusters revisited: missing mass found; 8. CDM confronts galaxy rotation curves; 9. The new cosmology: dark matter is not enough; 10. An alternative to dark matter: Modified Newtonian Dynamics; 11. Seeing dark matter: the theory and practice of detection; 12. Reflections: a personal point of view; Appendix; References; Index.

  14. Dark matter and cosmology

    SciTech Connect

    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.

  15. Dark matter and cosmology

    SciTech Connect

    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.

  16. Matter in transition

    SciTech Connect

    Anderson, Lara B.; Gray, James; Raghuram, Nikhil; Taylor, Washington

    2016-04-13

    In this study, we explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, where a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU(N) require Weierstrass models that cannot be realized from the standard SU(N) Tate form. We also briefly describe some other situations, with groups such as Sp(3), SO(12), and SU(3), where analogous matter transitions can occur between different representations. For SU(3), in particular, we find a matter transition between adjoint matter and matter in the symmetric representation, giving an explicit Weierstrass model for the F-theory description of the symmetric representation that complements another recent analogous construction.

  17. Condensate dark matter stars

    SciTech Connect

    Li, X.Y.; Harko, T.; Cheng, K.S. E-mail: harko@hkucc.hku.hk

    2012-06-01

    We investigate the structure and stability properties of compact astrophysical objects that may be formed from the Bose-Einstein condensation of dark matter. Once the critical temperature of a boson gas is less than the critical temperature, a Bose-Einstein Condensation process can always take place during the cosmic history of the universe. Therefore we model the dark matter inside the star as a Bose-Einstein condensate. In the condensate dark matter star model, the dark matter equation of state can be described by a polytropic equation of state, with polytropic index equal to one. We derive the basic general relativistic equations describing the equilibrium structure of the condensate dark matter star with spherically symmetric static geometry. The structure equations of the condensate dark matter stars are studied numerically. The critical mass and radius of the dark matter star are given by M{sub crit} ≈ 2(l{sub a}/1fm){sup 1/2}(m{sub χ}/1 GeV){sup −3/2}M{sub s}un and R{sub crit} ≈ 1.1 × 10{sup 6}(l{sub a}/1 fm){sup 1/2}(m{sub χ}/1 GeV){sup −3/2} cm respectively, where l{sub a} and m{sub χ} are the scattering length and the mass of dark matter particle, respectively.

  18. Language (Policy) Matters!

    ERIC Educational Resources Information Center

    Kozleski, E. B.; Mulligan, E.; Hernandez-Saca, D.

    2011-01-01

    Public education has a vital role in ensuring that this and subsequent generations are successful in a global, multilingual economy. In this What Matters brief, we examine how teachers, students, parents, and communities in our nation's schools can create rich opportunities for students to learn. Language (Policy) Matters! includes information and…

  19. Warm dark matter

    SciTech Connect

    Horiuchi, Shunsaku

    2016-06-21

    The cold dark matter paradigm has been extremely successful in explaining the large-scale structure of the Universe. However, it continues to face issues when confronted by observations on sub-Galactic scales. A major caveat, now being addressed, has been the incomplete treatment of baryon physics. We first summarize the small-scale issues surrounding cold dark matter and discuss the solutions explored by modern state-of-the-art numerical simulations including treatment of baryonic physics. We identify the too big to fail in field galaxies as among the best targets to study modifications to dark matter, and discuss the particular connection with sterile neutrino warm dark matter. We also discuss how the recently detected anomalous 3.55 keV X-ray lines, when interpreted as sterile neutrino dark matter decay, provide a very good description of small-scale observations of the Local Group.

  20. Complex Dark Matter

    SciTech Connect

    Lincoln, Don

    2015-04-16

    After a century of study, scientists have come to the realization that the ordinary matter made of atoms is a minority in the universe. In order to explain observations, it appears that there exists a new and undiscovered kind of matter, called dark matter, that is five times more prevalent than ordinary matter. The evidence for this new matter’s existence is very strong, but scientists know only a little about its nature. In today’s video, Fermilab’s Dr. Don Lincoln talks about an exciting and unconventional idea, specifically that dark matter might have a very complex set of structures and interactions. While this idea is entirely speculative, it is an interesting hypothesis and one that scientists are investigating.

  1. Dark matter universe.

    PubMed

    Bahcall, Neta A

    2015-10-06

    Most of the mass in the universe is in the form of dark matter--a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations--from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is "cold" (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology--a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)--fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle.

  2. Dark matter universe

    NASA Astrophysics Data System (ADS)

    Bahcall, Neta A.

    2015-10-01

    Most of the mass in the universe is in the form of dark matter-a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations-from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is "cold" (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology-a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)-fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle.

  3. Exothermic dark matter

    SciTech Connect

    Graham, Peter W.; Saraswat, Prashant; Harnik, Roni; Rajendran, Surjeet

    2010-09-15

    We propose a novel mechanism for dark matter to explain the observed annual modulation signal at DAMA/LIBRA which avoids existing constraints from every other dark matter direct detection experiment including CRESST, CDMS, and XENON10. The dark matter consists of at least two light states with mass {approx}few GeV and splittings {approx}5 keV. It is natural for the heavier states to be cosmologically long-lived and to make up an O(1) fraction of the dark matter. Direct detection rates are dominated by the exothermic reactions in which an excited dark matter state downscatters off of a nucleus, becoming a lower energy state. In contrast to (endothermic) inelastic dark matter, the most sensitive experiments for exothermic dark matter are those with light nuclei and low threshold energies. Interestingly, this model can also naturally account for the observed low-energy events at CoGeNT. The only significant constraint on the model arises from the DAMA/LIBRA unmodulated spectrum but it can be tested in the near future by a low-threshold analysis of CDMS-Si and possibly other experiments including CRESST, COUPP, and XENON100.

  4. Dark matter universe

    PubMed Central

    Bahcall, Neta A.

    2015-01-01

    Most of the mass in the universe is in the form of dark matter—a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations—from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is “cold” (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology—a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)—fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle. PMID:26417091

  5. Dark matter in voids

    NASA Astrophysics Data System (ADS)

    Fong, Richard; Doroshkevich, Andrei G.; Turchaninov, Victor I.

    1995-07-01

    The theory of the formation of large-scale structure in the universe through the action of gravitational instability imply the existence of substantial amounts of baryonic dark matter, of the order of 50% of the total baryon content in the universe, in the ``voids'' or under-dense regions seen in the large-scale distribution of galaxies. We discuss also the large-scale structure of dark matter expected in voids and the present and future possibilities for the observation of this baryonic dark matter in ``voids.''

  6. Condensed Matter Physics: Does Quantum Mechanics Matter?

    NASA Astrophysics Data System (ADS)

    Fisher, Michael E.

    Herman Feshbach, the organizer of this Symposium in honor of Niels Bohr, asked me, in his original invitation, for a review of the present state of condensed matter physics, with emphasis on major unsolved problems and comments on any overlap with Bohr's ideas regarding the fundamentals of quantum mechanics. That is surely a difficult assignment and, indeed, goes well beyond what is attempted here; nevertheless, I will take the liberty of raising one issue of a philosophical or metaphysical flavor.

  7. The Study of Matter.

    ERIC Educational Resources Information Center

    Campbell, Peter

    2000-01-01

    Reviews the booklet "The Study of Matter" produced by the Institute of Physics as part of their Shaping the Future series. This booklet is designed for teachers of chemistry, physics, design and technology, and biology. (Author/CCM)

  8. Inflatable Dark Matter

    NASA Astrophysics Data System (ADS)

    Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D.

    2016-01-01

    We describe a general scenario, dubbed "inflatable dark matter," in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early Universe. The overproduction of dark matter that is predicted within many, otherwise, well-motivated models of new physics can be elegantly remedied within this context. Thermal relics that would, otherwise, be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the nonthermal abundance of grand unified theory or Planck scale axions can be brought to acceptable levels without invoking anthropic tuning of initial conditions. A period of late-time inflation could have occurred over a wide range of scales from ˜MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the standard model.

  9. Mind Over Matter: Methamphetamine

    MedlinePlus

    ... Teaching Guide and Series / Methamphetamine Mind Over Matter: Methamphetamine (Meth) Print Order Free Publication in: English Spanish ... paranoia, aggressiveness, and hallucinations. The Brain's Response to Methamphetamine Hi, my name's Sara Bellum. Welcome to my ...

  10. Xenophobic dark matter

    NASA Astrophysics Data System (ADS)

    Feng, Jonathan L.; Kumar, Jason; Sanford, David

    2013-07-01

    We consider models of xenophobic dark matter, in which isospin-violating dark matter-nucleon interactions significantly degrade the response of xenon direct detection experiments. For models of near-maximal xenophobia, with neutron-to-proton coupling ratio fn/fp≈-0.64, and dark matter mass near 8 GeV, the regions of interest for CoGeNT and CDMS-Si and the region of interest identified by Collar and Fields in CDMS-Ge data can be brought into agreement. This model may be tested in future direct, indirect, and collider searches. Interestingly, because the natural isotope abundance of xenon implies that xenophobia has its limits, we find that this xenophobic model may be probed in the near future by xenon experiments. Near-future data from the LHC and Fermi-LAT may also provide interesting alternative probes of xenophobic dark matter.

  11. Inflatable Dark Matter.

    PubMed

    Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D

    2016-01-22

    We describe a general scenario, dubbed "inflatable dark matter," in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early Universe. The overproduction of dark matter that is predicted within many, otherwise, well-motivated models of new physics can be elegantly remedied within this context. Thermal relics that would, otherwise, be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the nonthermal abundance of grand unified theory or Planck scale axions can be brought to acceptable levels without invoking anthropic tuning of initial conditions. A period of late-time inflation could have occurred over a wide range of scales from ∼MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the standard model.

  12. Tunguska dark matter ball

    NASA Astrophysics Data System (ADS)

    Froggatt, C. D.; Nielsen, H. B.

    2015-04-01

    It is suggested that the Tunguska event in June 1908 was due to a cm-large ball of a condensate of bound states of 6 top and 6 antitop quarks containing highly compressed ordinary matter. Such balls are supposed to make up the dark matter as we earlier proposed. The expected rate of impact of this kind of dark matter ball with the earth seems to crudely match a time scale of 200 years between the impacts. The main explosion of the Tunguska event is explained in our picture as material coming out from deep within the earth, where it has been heated and compressed by the ball penetrating to a depth of several thousand km. Thus the effect has some similarity with volcanic activity as suggested by Kundt. We discuss the possible identification of kimberlite pipes with earlier Tunguska-like events. A discussion of how the dark matter balls may have formed in the early universe is also given.

  13. Mind Over Matter: Cocaine

    MedlinePlus

    ... Teaching Guide and Series / Cocaine Mind Over Matter: Cocaine Print Order Free Publication in: English Spanish Download ... crack, can be smoked. The Brain's Response to Cocaine Hi, my name’s Sara Bellum. Welcome to my ...

  14. Resonant Dark Matter

    SciTech Connect

    Bai, Yang; Fox, Patrick J.; /Fermilab

    2009-09-01

    It is usually assumed that dark matter direct detection is sensitive to a large fraction of the dark matter (DM) velocity distribution. We propose an alternative form of dark matter-nucleus scattering which only probes a narrow range of DM velocities due to the existence of a resonance, a DM-nucleus bound state, in the scattering - resonant dark matter (rDM). The scattering cross section becomes highly element dependent, has increased modulation and as a result can explain the DAMA/LIBRA results whilst not being in conflict with other direct detection experiments. We describe a simple model that realizes the dynamics of rDM, where the DM is the neutral component of a fermionic weak triplet whose charged partners differ in mass by approximately 10 MeV.

  15. Elastically Decoupling Dark Matter.

    PubMed

    Kuflik, Eric; Perelstein, Maxim; Lorier, Nicolas Rey-Le; Tsai, Yu-Dai

    2016-06-03

    We present a novel dark matter candidate, an elastically decoupling relic, which is a cold thermal relic whose present abundance is determined by the cross section of its elastic scattering on standard model particles. The dark matter candidate is predicted to have a mass ranging from a few to a few hundred MeV, and an elastic scattering cross section with electrons, photons and/or neutrinos in the 10^{-3}-1  fb range.

  16. Dark Matter Hunters

    NASA Astrophysics Data System (ADS)

    Peter, Annika

    2017-06-01

    We know just enough about dark matter to design beautiful and plausible particle models for it, but not enough to sharpen searches in this vast theoretical parameter space. In this talk, I will highlight new ideas from the community to cover this large parameter space, and how new laboratory measurements and techniques are helping the community probe previously inaccessible types of dark matter microphysics. I will discuss open questions and possible future directions.

  17. The Local Dark Matter

    SciTech Connect

    Helfer, H.L.

    2005-10-21

    The observations of the extended rotation curves of some galaxies provide important constraints upon the nature of the local dark matter present in the halos of these galaxies. Using these constraints, one can show that the halo dark matter cannot be some population of conventional astronomical objects and (most probably) cannot be a population of exotic non-interacting particles. We suggest that the halos can be regarded as large spatial fluctuations in a classic scalar field.

  18. Matter in transition

    DOE PAGES

    Anderson, Lara B.; Gray, James; Raghuram, Nikhil; ...

    2016-04-13

    In this study, we explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, wheremore » a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU(N) require Weierstrass models that cannot be realized from the standard SU(N) Tate form. We also briefly describe some other situations, with groups such as Sp(3), SO(12), and SU(3), where analogous matter transitions can occur between different representations. For SU(3), in particular, we find a matter transition between adjoint matter and matter in the symmetric representation, giving an explicit Weierstrass model for the F-theory description of the symmetric representation that complements another recent analogous construction.« less

  19. Dense cold matter

    SciTech Connect

    Stavinskiy, A. V.

    2015-07-15

    The possibility of studying matter at densities on the order of or higher than the neutron-star density in laboratory experiments is considered. For this, it is proposed to employ a rare kinematical trigger in collisions of relativistic ions. The expected properties of matter under such unusual conditions and a program for investigations into it are discussed, and a design of experimental setup for such investigations is proposed.

  20. Dark Matter Astrophysics

    NASA Astrophysics Data System (ADS)

    D'Amico, Guido; Kamionkowski, Marc; Sigurdson, Kris

    This chapter is intended to provide a brief pedagogical review of dark matter for the newcomer to the subject. We begin with a discussion of the astrophysical evidence for dark matter. The standard weakly interacting massive particle (WIMP) scenario—the motivation, particle models, and detection techniques—is then reviewed. We provide a brief sampling of some recent variations to the standard WIMP scenario, as well as some alternatives (axions and sterile neutrinos). Exercises are provided for the reader.

  1. Dark matter: theoretical perspectives.

    PubMed Central

    Turner, M S

    1993-01-01

    I both review and make the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that (i) there are no dark-matter candidates within the "standard model" of particle physics, (ii) there are several compelling candidates within attractive extensions of the standard model of particle physics, and (iii) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for "new physics." The compelling candidates are a very light axion (10(-6)-10(-4) eV), a light neutrino (20-90 eV), and a heavy neutralino (10 GeV-2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. I briefly mention more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos. PMID:11607395

  2. Dark matter: Theoretical perspectives

    SciTech Connect

    Turner, M.S. . Enrico Fermi Inst. Fermi National Accelerator Lab., Batavia, IL )

    1993-01-01

    I both review and make the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that: (1) there are no dark matter candidates within the standard model of particle physics; (2) there are several compelling candidates within attractive extensions of the standard model of particle physics; and (3) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for new physics.'' The compelling candidates are: a very light axion ( 10[sup [minus]6] eV--10[sup [minus]4] eV); a light neutrino (20 eV--90 eV); and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. I briefly mention more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos.

  3. Dark matter: Theoretical perspectives

    SciTech Connect

    Turner, M.S. |

    1993-01-01

    I both review and make the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that: (1) there are no dark matter candidates within the standard model of particle physics; (2) there are several compelling candidates within attractive extensions of the standard model of particle physics; and (3) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for ``new physics.`` The compelling candidates are: a very light axion ( 10{sup {minus}6} eV--10{sup {minus}4} eV); a light neutrino (20 eV--90 eV); and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. I briefly mention more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos.

  4. Pseudoscalar portal dark matter

    NASA Astrophysics Data System (ADS)

    Berlin, Asher; Gori, Stefania; Lin, Tongyan; Wang, Lian-Tao

    2015-07-01

    A fermion dark matter candidate with a relic abundance set by annihilation through a pseudoscalar can evade constraints from direct detection experiments. We present simplified models that realize this fact by coupling a fermion dark sector to a two-Higgs doublet model. These models are generalizations of mixed bino-Higgsino dark matter in the minimal supersymmetric standard model, with more freedom in the couplings and scalar spectra. Annihilation near a pseudoscalar resonance allows a significant amount of parameter space for thermal relic dark matter compared to singlet-doublet dark matter, in which the fermions couple only to the standard model (SM) Higgs doublet. In a general two-Higgs doublet model, there is also freedom for the pseudoscalar to be relatively light and it is possible to obtain thermal relic dark matter candidates even below 100 GeV. In particular, we find ample room to obtain dark matter with mass around 50 GeV and fitting the Galactic center excess in gamma-rays. This region of parameter space can be probed by LHC searches for heavy pseudoscalars or electroweakinos, and possibly by other new collider signals.

  5. Dark matter: Theoretical perspectives

    SciTech Connect

    Turner, M.S. Fermi National Accelerator Lab., Batavia, IL )

    1993-06-01

    The author both reviews and makes the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that (i) there are no dark-matter candidates within the [open quotes]standard model[close quotes] of particle physics, (ii) there are several compelling candidates within attractive extensions of the standard model of particle physics, and (iii) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for [open quotes]new physics.[close quotes] The compelling candidates are a very light axion (10[sup [minus]6]--10[sup [minus]4] eV), a light neutrino (20--90 eV), and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. The author briefly mentions more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos. 119 refs.

  6. Searches for Exotic Matter

    NASA Astrophysics Data System (ADS)

    Morgan, David Lee

    This research encompasses two quite distinct searches for exotic matter. The first half concerns exotic matter on the scale of elementary particles. In this chapter, I consider the production of gluinos, the supersymmetric partner of the gluon, in models where the gluino is very light. Cross sections are calculated for electroproduction and hadroproduction of gluinos and the results indicate that existing accelerators are capable of probing the region of gluino masses between 1.0 and 2.0GeV with lifetimes between 10-10 and 10-6 seconds. Such experiments could find a light gluino if it exists, or to close this unexplored mass-lifetime window. The second half concerns the search for exotic forms of matter on the macroscopic scale, namely the search for stable strange quark matter. If stable strange matter exists, then all neutron stars may in fact be strange stars. I examine a recent proposal that strange star oscillations may result in a detectable millimeter-wave radio signal. The effects of rotation on this signal are calculated with the motivation of providing a more distinctive signature for the detection of strange matter stars.

  7. The XENON100 Dark Matter Experiment: Design, Construction, Calibration and 2010 Search Results with Improved Measurement of the Scintillation Response of Liquid Xenon to Low-Energy Nuclear Recoils

    NASA Astrophysics Data System (ADS)

    Plante, Guillaume

    An impressive array of astrophysical observations suggest that 83% of the matter in the universe is in a form of non-luminous, cold, collisionless, non-baryonic dark matter. Several extensions of the Standard Model of particle physics aimed at solving the hierarchy problem predict stable weakly interacting massive particles (WIMPs) that could naturally have the right cosmological relic abundance today to compose most of the dark matter if their interactions with normal matter are on the order of a weak scale cross section. These candidates also have the added benefit that their properties and interaction rates can be computed in a well defined particle physics model. A considerable experimental effort is currently under way to uncover the nature of dark matter. One method of detecting WIMP dark matter is to look for its interactions in terrestrial detectors where it is expected to scatter off nuclei. In 2007, the XENON10 experiment took the lead over the most sensitive direct detection dark matter search in operation, the CDMS II experiment, by probing spin-independent WIMP-nucleon interaction cross sections down to sigmachi N ˜ 5 x 10-44 cm 2 at 30 GeV/c2. Liquefied noble gas detectors are now among the technologies at the forefront of direct detection experiments. Liquid xenon (LXe), in particular, is a well suited target for WIMP direct detection. It is easily scalable to larger target masses, allows discrimination between nuclear recoils and electronic recoils, and has an excellent stopping power to shield against external backgrounds. A particle losing energy in LXe creates both ionization electrons and scintillation light. In a dual-phase LXe time projection chamber (TPC) the ionization electrons are drifted and extracted into the gas phase where they are accelerated to amplify the charge signal into a proportional scintillation signal. These two signals allow the three-dimensional localization of events with millimeter precision and the ability to

  8. Asymmetric condensed dark matter

    SciTech Connect

    Aguirre, Anthony; Diez-Tejedor, Alberto E-mail: alberto.diez@fisica.ugto.mx

    2016-04-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.

  9. Vectorlike sneutrino dark matter

    NASA Astrophysics Data System (ADS)

    Tang, Yi-Lei; Zhu, Shou-hua

    2016-05-01

    In this paper, we discuss the minimal supersymmetric standard model (MSSM) extended with one vectorlike lepton doublet L -L ¯ and one right-handed neutrino N . The neutral vecotorlike sneutrino can be a candidate of dark matter. To avoid the interaction with the nucleons by exchanging a Z boson, the mass splitting between the real part and the imaginary part of the sneutrino field is needed. Compared with the MSSM sneutrino dark matter, the mass splitting between the vectorlike sneutrino field can be more naturally acquired without large A terms and constraints on the neutralino masses. We have also calculated the relic density and the elastic scattering cross sections with the nucleons in the cases that the dark matter particles coannihilate with or without the MSSM slepton doublets. The elastic scattering cross sections with the nucleons are well below the LUX bounds. In the case that the dark matter coannihilates with all the MSSM slepton doublets, the mass of the dark matter can be as light as 370 GeV.

  10. Entropy, matter, and cosmology

    PubMed Central

    Prigogine, I.; Géhéniau, J.

    1986-01-01

    The role of irreversible processes corresponding to creation of matter in general relativity is investigated. The use of Landau-Lifshitz pseudotensors together with conformal (Minkowski) coordinates suggests that this creation took place in the early universe at the stage of the variation of the conformal factor. The entropy production in this creation process is calculated. It is shown that these dissipative processes lead to the possibility of cosmological models that start from empty conditions and gradually build up matter and entropy. Gravitational entropy takes a simple meaning as associated to the entropy that is necessary to produce matter. This leads to an extension of the third law of thermodynamics, as now the zero point of entropy becomes the space-time structure out of which matter is generated. The theory can be put into a convenient form using a supplementary “C” field in Einstein's field equations. The role of the C field is to express the coupling between gravitation and matter leading to irreversible entropy production. PMID:16593747

  11. Asymmetric condensed dark matter

    NASA Astrophysics Data System (ADS)

    Aguirre, Anthony; Diez-Tejedor, Alberto

    2016-04-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.

  12. Imperfect Dark Matter

    SciTech Connect

    Mirzagholi, Leila; Vikman, Alexander E-mail: alexander.vikman@lmu.de

    2015-06-01

    We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models.

  13. Estrone degradation: does organic matter (quality), matter?

    PubMed

    Tan, David T; Temme, Hanna R; Arnold, William A; Novak, Paige J

    2015-01-06

    Understanding the parameters that drive E1 degradation is necessary to improve existing wastewater treatment systems and evaluate potential treatment options. Organic matter quality could be an important parameter. Microbial communities grown from activated sludge seeds using different dissolved organic matter sources were tested for E1 degradation rates. Synthetic wastewater was aged, filter-sterilized, and used as a carbon and energy source to determine if recalcitrant organic carbon enhances E1 degradation. Higher E1 degradation was observed by biomass grown on 8 d old synthetic wastewater compared to biomass grown on fresh synthetic wastewater (P = 0.033) despite much lower concentrations of bacteria. Minimal or no E1 degradation was observed in biomass grown on 2 d old synthetic wastewater. Organic carbon analyses suggest that products of cell lysis or microbial products released under starvation stress stimulate E1 degradation. Additional water sources were also tested: lake water, river water, and effluents from a municipal wastewater treatement plant and a treatment wetland. E1 degradation was only observed in biomass grown in treatment effluent. Nitrogen, dissolved organic carbon, and trace element concentrations were not causative factors for E1 degradation. In both experiments, spectrophotometric analyses reveal degradation of E1 is associated with microbially derived organic carbon but not general recalcitrance.

  14. Axion dark matter searches

    DOE PAGES

    Stern, Ian P.

    2014-01-01

    We report nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a μeV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 μeV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axionsmore » at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.« less

  15. Axion dark matter searches

    SciTech Connect

    Stern, Ian P.

    2014-01-01

    We report nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a μeV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 μeV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  16. Asymmetric twin Dark Matter

    SciTech Connect

    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 the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.

  17. Dark matter searches

    NASA Astrophysics Data System (ADS)

    Bettini, Alessandro

    These lectures begin with a brief survey of the astrophysical and cosmological evidence for dark matter. We then consider the three principal theoretically motivated types of dark matter, sterile neutrinos, axions and SUSY WIMPs. In chapter 4 we discuss the motivations for the so-called neutrino minimal standard model, nuMSM, an extension of the SM with three sterile neutrinos with masses similar to the charged fermions. In chapter 5 we briefly recall the strong CP problem of the SM and the solution proposed by Peccei and Quinn leading to the prediction of axions and of their characteristics. We then discuss the experimental status and perspectives. In chapter 6 we assume that the reader to be acquainted with the theoretical motivations for SUSY and move directly to the direct search for dark matter and the description of the principal detector techniques: scintillators, noble fluids and bolometers. We conclude with an outlook on the future perspectives.

  18. Does Dark Matter Exist?

    NASA Astrophysics Data System (ADS)

    Sellwood, J. A.; Kosowsky, A.

    The success of the ΛCDM model on large scales does not extend down to galaxy scales. We list a dozen problems of the dark matter hypothesis, some of which arise in specific models for the formation of structure in the universe, while others are generic and require fine tuning in any dark matter theory. Modifications to the theory, such as adding properties to the DM particles beyond gravitational interactions, or simply a better understanding of the physics of galaxy formation, may resolve some problems, but a number of conspiracies and correlations are unlikely to yield to this approach. The alternative is that mass discrepancies result from of a non-Newtonian law of gravity, a hypothesis which avoids many of the more intractable problems of dark matter. A modified law of gravity is not without formidable difficulties of its own, but it is no longer obvious that they are any more daunting than those facing DM.

  19. Inflation and shadow matter

    NASA Technical Reports Server (NTRS)

    Krauss, L. M.; Guth, A. H.; Spergel, D. N.; Field, G. B.; Press, W. H.

    1986-01-01

    The possible production of shadow matter during the period of cosmic inflation is considered. The superstring theory of Gross et al. (1985), which results in a gauge group E8 x E8, could, at low energies, result in the existence of two sectors: an observed sector associated with all familiar particles and interactions, and a hidden one whose particles couple only through gravitational interactions with ordinary matter. It is demonstrated here that if, in the early universe, an inflationary phase is associated with the breaking of one of the symmetries in the E8 x E8 theory, this strongly constrains the physics of both sectors if shadow matter is to be the missing mass in the universe.

  20. Asymmetric twin Dark Matter

    SciTech Connect

    Farina, Marco

    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 the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.

  1. Inflation and shadow matter

    NASA Technical Reports Server (NTRS)

    Krauss, L. M.; Guth, A. H.; Spergel, D. N.; Field, G. B.; Press, W. H.

    1986-01-01

    The possible production of shadow matter during the period of cosmic inflation is considered. The superstring theory of Gross et al. (1985), which results in a gauge group E8 x E8, could, at low energies, result in the existence of two sectors: an observed sector associated with all familiar particles and interactions, and a hidden one whose particles couple only through gravitational interactions with ordinary matter. It is demonstrated here that if, in the early universe, an inflationary phase is associated with the breaking of one of the symmetries in the E8 x E8 theory, this strongly constrains the physics of both sectors if shadow matter is to be the missing mass in the universe.

  2. Radiative light dark matter

    NASA Astrophysics Data System (ADS)

    Dedes, A.; Karamitros, D.; Pilaftsis, A.

    2017-06-01

    We present a Peccei-Quinn (PQ)-symmetric two-Higgs doublet model that naturally predicts a fermionic singlet dark matter in the mass range 10 keV-1 GeV. The origin of the smallness of the mass of this light singlet fermion arises predominantly at the one-loop level, upon soft or spontaneous breakdown of the PQ symmetry via a complex scalar field in a fashion similar to the so-called Dine-Fischler-Sredniki-Zhitnitsky axion model. The mass generation of this fermionic radiative light dark matter (RLDM) requires the existence of two heavy vectorlike SU(2) isodoublets, which are not charged under the PQ symmetry. We show how the RLDM can be produced via the freeze-in mechanism, thus accounting for the missing matter in the Universe. Finally, we briefly discuss possible theoretical and phenomenological implications of the RLDM model for the strong C P problem and the CERN Large Hadron Collider (LHC).

  3. Axion dark matter searches

    SciTech Connect

    Stern, Ian P.; Collaboration: ADMX Collaboration; ADMX-HF Collaboration

    2014-06-24

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a μeV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 μeV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  4. Signatures of dark matter

    NASA Astrophysics Data System (ADS)

    Baltz, Edward Anthony

    It is well known that most of the mass in the universe remains unobserved save for its gravitational effect on luminous matter. The nature of this ``dark matter'' remains a mystery. From measurements of the primordial deuterium abundance, the theory of big bang nucleosynthesis predicts that there are not enough baryons to account for the amount of dark matter observed, thus the missing mass must take an exotic form. Several promising candidates have been proposed. In this work I will describe my research along two main lines of inquiry into the dark matter puzzle. The first possibility is that the dark matter is exotic massive particles, such as those predicted by supersymmetric extensions to the standard model of particle physics. Such particles are generically called WIMPs, for weakly interacting massive particles. Focusing on the so-called neutralino in supersymmetric models, I discuss the possible signatures of such particles, including their direct detection via nuclear recoil experiments and their indirect detection via annihilations in the halos of galaxies, producing high energy antiprotons, positrons and gamma rays. I also discuss signatures of the possible slow decays of such particles. The second possibility is that there is a population of black holes formed in the early universe. Any dark objects in galactic halos, black holes included, are called MACHOs, for massive compact halo objects. Such objects can be detected by their gravitational microlensing effects. Several possibilities for sources of baryonic dark matter are also interesting for gravitational microlensing. These include brown dwarf stars and old, cool white dwarf stars. I discuss the theory of gravitational microlensing, focusing on the technique of pixel microlensing. I make predictions for several planned microlensing experiments with ground based and space based telescopes. Furthermore, I discuss binary lenses in the context of pixel microlensing. Finally, I develop a new technique for

  5. Interacting warm dark matter

    SciTech Connect

    Cruz, Norman; Palma, Guillermo; Zambrano, David; Avelino, Arturo E-mail: guillermo.palma@usach.cl E-mail: avelino@fisica.ugto.mx

    2013-05-01

    We explore a cosmological model composed by a dark matter fluid interacting with a dark energy fluid. The interaction term has the non-linear λρ{sub m}{sup α}ρ{sub e}{sup β} form, where ρ{sub m} and ρ{sub e} are the energy densities of the dark matter and dark energy, respectively. The parameters α and β are in principle not constrained to take any particular values, and were estimated from observations. We perform an analytical study of the evolution equations, finding the fixed points and their stability properties in order to characterize suitable physical regions in the phase space of the dark matter and dark energy densities. The constants (λ,α,β) as well as w{sub m} and w{sub e} of the EoS of dark matter and dark energy respectively, were estimated using the cosmological observations of the type Ia supernovae and the Hubble expansion rate H(z) data sets. We find that the best estimated values for the free parameters of the model correspond to a warm dark matter interacting with a phantom dark energy component, with a well goodness-of-fit to data. However, using the Bayesian Information Criterion (BIC) we find that this model is overcame by a warm dark matter – phantom dark energy model without interaction, as well as by the ΛCDM model. We find also a large dispersion on the best estimated values of the (λ,α,β) parameters, so even if we are not able to set strong constraints on their values, given the goodness-of-fit to data of the model, we find that a large variety of theirs values are well compatible with the observational data used.

  6. Dark matter detection

    NASA Astrophysics Data System (ADS)

    Baudis, Laura

    2016-08-01

    More than 80 years after its first postulation in modern form, the existence and distribution of dark matter in our Universe is well established. Dark matter is the gravitational glue that holds together galaxies, galaxy clusters and structures on the largest cosmological scales, and an essential component to explain the observed fluctuations in the cosmic microwave background. Yet its existence is inferred indirectly, through its gravitational influence on luminous matter, and its nature is not known. A viable hypothesis is that dark matter is made of new, elementary particles, with allowed masses and interaction strengths spanning a wide range. Two well-motivated classes of candidates are axions and weakly interacting massive particles (WIMPs), and experimental efforts have now reached sensitivities that allow them to test this hypothesis. Axions, produced non-thermally in the early Universe, can be detected by exploiting their predicted couplings to photons and electrons. WIMPs can be detected directly by looking for their collisions with atomic nuclei ultra-low background detectors, or indirectly, through the observation of their annihilation products such as neutrinos, gamma rays, positrons and antiprotons over the astrophysical background. A complementary method is the production of dark matter particles at colliders such as the Large Hadron Collider, where they could be observed indirectly via missing transverse energy, or via associated particle production. I will review the main experimental efforts to search for dark matter particles, and the existing constraints on the interaction cross sections. I will also discuss future experiments, their complementarity and their ability to measure the properties of these particles.

  7. 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.

  8. Teaching of subject matter.

    PubMed

    Mayer, Richard E

    2004-01-01

    Psychology of subject matter refers to the scientific study of learning and instruction within school subjects. The growing research literature on teaching and learning of school subjects represents one of educational psychology's most productive accomplishments of the past two decades. The purpose of this chapter is to examine representative advances in the psychology of subject matter, including how people learn to read words, comprehend printed passages, write compositions, solve arithmetic word problems, and understand how scientific systems work. The introduction provides a historical overview of how to promote transfer and is followed by reviews of representative research in learning and teaching of reading fluency, reading comprehension, writing, mathematics, and science.

  9. Education Matters, November 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Teacher Assessment (Mary Sanchez); (2) Our Economics…

  10. Education Matters, March 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) The Desperate Need for an Education Stimulus:…

  11. Education Matters, June 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Coaching Teachers Boosts Student Reading:…

  12. Education Matters, October 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) The Big Shift: Changing Demographics in the…

  13. Education Matters, September 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Lights, Camera, Action! Should Video Cameras…

  14. Education Matters, September 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Are They Ready? National Study Reveals Civics…

  15. Dichromatic dark matter

    SciTech Connect

    Bai, Yang; Su, Meng; Zhao, Yue

    2013-02-01

    Both the robust INTEGRAL 511 keV gamma-ray line and the recent tentative hint of the 135 GeV gamma-ray line from Fermi-LAT have similar signal morphologies, and may be produced from the same dark matter annihilation. Motivated by this observation, we construct a dark matter model to explain both signals and to accommodate the two required annihilation cross sections that are different by more than six orders of magnitude. In our model, to generate the low-energy positrons for INTEGRAL, dark matter particles annihilate into a complex scalar that couples to photon via a charge-radius operator. The complex scalar contains an excited state decaying into the ground state plus an off-shell photon to generate a pair of positron and electron. Two charged particles with non-degenerate masses are necessary for generating this charge-radius operator. One charged particle is predicted to be long-lived and have a mass around 3.8 TeV to explain the dark matter thermal relic abundance from its late decay. The other charged particle is predicted to have a mass below 1 TeV given the ratio of the two signal cross sections. The 14 TeV LHC will concretely test the main parameter space of this lighter charged particle.

  16. Education Matters, April 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Doing the Right Thing: Educator Ethics in an…

  17. Education Matters, October 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2008-01-01

    Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Fixing D.C.'s Schools: How a 38-Year-Old Rookie…

  18. Education Matters, September 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2008-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Superteacher (What if "Improving Teacher…

  19. Education Matters, November 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Education Stimulus Watch: Buckets of Money May Yield…

  20. Education Matters, June 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Who Deserves Tenure? Is It Time to Move beyond…

  1. Education Matters, February 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Making a Game of Math: AAE Affiliate Motivates…

  2. Education Matters, December 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.; Prause, Kelley, Ed.

    2008-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Historical Change (Barbara R. Davidson); (2)…

  3. Chromatin as active matter

    NASA Astrophysics Data System (ADS)

    Agrawal, Ankit; Ganai, Nirmalendu; Sengupta, Surajit; Menon, Gautam I.

    2017-01-01

    Active matter models describe a number of biophysical phenomena at the cell and tissue scale. Such models explore the macroscopic consequences of driving specific soft condensed matter systems of biological relevance out of equilibrium through ‘active’ processes. Here, we describe how active matter models can be used to study the large-scale properties of chromosomes contained within the nuclei of human cells in interphase. We show that polymer models for chromosomes that incorporate inhomogeneous activity reproduce many general, yet little understood, features of large-scale nuclear architecture. These include: (i) the spatial separation of gene-rich, low-density euchromatin, predominantly found towards the centre of the nucleus, vis a vis. gene-poor, denser heterochromatin, typically enriched in proximity to the nuclear periphery, (ii) the differential positioning of individual gene-rich and gene-poor chromosomes, (iii) the formation of chromosome territories, as well as (iv), the weak size-dependence of the positions of individual chromosome centres-of-mass relative to the nuclear centre that is seen in some cell types. Such structuring is induced purely by the combination of activity and confinement and is absent in thermal equilibrium. We systematically explore active matter models for chromosomes, discussing how our model can be generalized to study variations in chromosome positioning across different cell types. The approach and model we outline here represent a preliminary attempt towards a quantitative, first-principles description of the large-scale architecture of the cell nucleus.

  4. Education Matters, November 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Teacher Assessment (Mary Sanchez); (2) Our Economics…

  5. Education Matters, September 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) You Speak Out: 2010 AAE Member Survey; (2) Five Ways to…

  6. Energy Matters - Spring 2002

    SciTech Connect

    2002-03-01

    Quarterly newsletter from DOE's Industrial Technologies Program to promote the use of energy-efficient industrial systems. The focus of the Spring 2002 Issue of Energy Matters focuses on premium energy efficiency systems, with articles on new gas technologies, steam efficiency, the Augusta Newsprint Showcase, and more.

  7. Nature's engines: active matter

    NASA Astrophysics Data System (ADS)

    Yeomans, Julia M.

    2017-03-01

    Active materials, bacteria, molecular motors, and self-propelled colloids, continuously transform chemical energy from the environment to mechanical work. Dense active matter, from layers of cells to flocks of birds, self-assembles into intricate patterns. Nature's engines are complex and efficient, and we would like to exploit her ideas to fabricate nano-machines.

  8. Education Matters, January 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2008-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Agents of Change: Why So Many Teachers Are…

  9. Education Matters, November 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2008-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Peeking Behind the Blue Ribbon (Vicki E.…

  10. Education Matters, April 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Doing the Right Thing: Educator Ethics in an…

  11. Education Matters, September 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) National Standards Gain Steam: Governors'…

  12. Education Matters, November 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2008-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Peeking Behind the Blue Ribbon (Vicki E.…

  13. Education Matters, January 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2008-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Agents of Change: Why So Many Teachers Are…

  14. Education Matters, February 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Whatever It Takes? (Maybe Not): 4 Reasons…

  15. Education Matters, August 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Creating New Paths, Attracting New Teachers: Why…

  16. Education Matters, October 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2008-01-01

    Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Fixing D.C.'s Schools: How a 38-Year-Old Rookie…

  17. Education Matters, September 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) You Speak Out: 2010 AAE Member Survey; (2) Five Ways to…

  18. Education Matters, March 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Supreme Court Hears Union Coercion Case; What…

  19. Condensed Matter Physics

    NASA Astrophysics Data System (ADS)

    Marder, Michael P.

    2000-01-01

    A modern, unified treatment of condensed matter physics This new work presents for the first time in decades a sweeping review of the whole field of condensed matter physics. It consolidates new and classic topics from disparate sources, teaching "not only about the effective masses of electrons in semiconductor crystals and band theory, but also about quasicrystals, dynamics of phase separation, why rubber is more floppy than steel, electron interference in nanometer-sized channels, and the quantum Hall effect." Six major areas are covered---atomic structure, electronic structure, mechanical properties, electron transport, optical properties, and magnetism. But rather than defining the field in terms of particular materials, the author focuses on the way condensed matter physicists approach physical problems, combining phenomenology and microscopic arguments with information from experiments. For graduate students and professionals, researchers and engineers, applied mathematicians and materials scientists, Condensed Matter Physics provides: * An exciting collection of new topics from the past two decades. * A thorough treatment of classic topics, including band theory, transport theory, and semiconductor physics. * Over 300 figures, incorporating many images from experiments. * Frequent comparison of theory and experiment, both when they agree and when problems are still unsolved. * More than 50 tables of data and a detailed index. * Ample end-of-chapter problems, including computational exercises. * Over 1000 references, both recent and historically significant.

  20. Hot nuclear matter

    SciTech Connect

    Chapman, S.

    1992-11-01

    The goal in this thesis is thus twofold: The first is to investigate the feasibility of using heavy ion collisions to create conditions in the laboratory which are ripe for the formation of a quark-gluon plasma. The second is to develop a technique for studying some of the many non-perturbative features of this novel phase of matter.

  1. Elliott on Mind Matters.

    ERIC Educational Resources Information Center

    Maattanen, Pentti

    2000-01-01

    Argues that David Elliott's conception of the human mind presented in his book "Music Matters" is not coherent. Outlines three alternatives to Elliott's theory of mind. Suggests that the principles associated with the pragmatism of Charles Sanders Pierce would complement Elliott's ideas in his book. (CMK)

  2. Education Matters, March 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Supreme Court Hears Union Coercion Case; What…

  3. Particulate matter fugitive dusts

    SciTech Connect

    Not Available

    1988-01-01

    Topics covered in this conference include: Review of EPA's cost/benefit analysis for additional regulation of surface coal mines; Particulate monitoring on the Kilauea East Rift, Hawaii, and The MEDUSA sampling system: case histories in the measurement of particulate matter with wide spectrum analysis.

  4. Dark Matter Searches

    NASA Astrophysics Data System (ADS)

    Baudis, Laura

    2006-01-01

    More than 90% of matter in the Universe could be composed of heavy particles, which were non-relativistic, or 'cold', when they froze-out from the primordial soup. I will review current searches for these hypothetical particles, both via interactions with nuclei in deep underground detectors, and via the observation of their annihilation products in the Sun, galactic halo and galactic center.

  5. Dark Matter Searches

    NASA Astrophysics Data System (ADS)

    Baudis, Laura

    More than 90% of matter in the Universe could be composed of heavy particles, which were non-relativistic, or 'cold', when they froze-out from the primordial soup. I will review current searches for these hypothetical particles, both via interactions with nuclei in deep underground detectors, and via the observation of their annihilation products in the Sun, galactic halo and galactic center.

  6. Exceptional composite dark matter

    NASA Astrophysics Data System (ADS)

    Ballesteros, Guillermo; Carmona, Adrián; Chala, Mikael

    2017-07-01

    We study the dark matter phenomenology of non-minimal composite Higgs models with SO(7) broken to the exceptional group G_2. In addition to the Higgs, three pseudo-Nambu-Goldstone bosons arise, one of which is electrically neutral. A parity symmetry is enough to ensure this resonance is stable. In fact, if the breaking of the Goldstone symmetry is driven by the fermion sector, this Z_2 symmetry is automatically unbroken in the electroweak phase. In this case, the relic density, as well as the expected indirect, direct and collider signals are then uniquely determined by the value of the compositeness scale, f. Current experimental bounds allow one to account for a large fraction of the dark matter of the Universe if the dark matter particle is part of an electroweak triplet. The totality of the relic abundance can be accommodated if instead this particle is a composite singlet. In both cases, the scale f and the dark matter mass are of the order of a few TeV.

  7. Education Matters, December 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Notes from the Front Lines: Study Reveals…

  8. Education Matters, January 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Invading Privacy: Card Check is on the Way! (Hans…

  9. Education Matters, May 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Balancing Act: Achieving a Harmony between…

  10. Education Matters, November 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Education Stimulus Watch: Buckets of Money May Yield…

  11. Education Matters, September 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2008-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Superteacher (What if "Improving Teacher…

  12. Education Matters, May 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Balancing Act: Achieving a Harmony between…

  13. Education Matters, March 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) The Teacher Factor: Great Teachers Are the Key to Real…

  14. Education Matters, February 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Arrested Development: Time for Professional Development…

  15. Resources: Money Matters.

    ERIC Educational Resources Information Center

    Woodard, Dudley B., Jr.; Love, Patrick; Komives, Susan R.

    2000-01-01

    Fiscal concerns continue to challenge institutions of higher learning and will affect the financing of student services initiatives. By being aware of current fiscal trends, critiquing thinking about financial matters, and attempting to find new sources of revenue for the future, student affairs practitioners will be able to anticipate and address…

  16. Education Matters, March 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) The Teacher Factor: Great Teachers Are the Key to Real…

  17. Education Matters, April 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Teaching as Leadership: 6 Traits of Highly…

  18. Education Matters, July 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) How to Avoid Burnout (Kate Johanns); and (2)…

  19. Education Matters, October 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Some Math Programs are Out of Tune (Niki…

  20. Education Matters, May 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Leading Students to New Heights: Dr. Bill…

  1. Education Matters, October 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Does Demography Dictate Destiny? The Radical…

  2. Education Matters, December 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.; Prause, Kelley, Ed.

    2008-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Historical Change (Barbara R. Davidson); (2)…

  3. Education Matters, April 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Johnny Can Write...If We Challenge Him (Bill…

  4. Education Matters, September 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) National Standards Gain Steam: Governors'…

  5. Money Does Matter.

    ERIC Educational Resources Information Center

    Bracey, Gerald W.

    1996-01-01

    Schools have been criticized perennially for their profligate waste of taxpayer money. Currently, there are two separate myths about schools and money: the United States spends more than any other country; and money doesn't matter. U.S. schools have many nonteaching school employees because they provide services that other nations do not. (MLH)

  6. Education Matters, February 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Arrested Development: Time for Professional Development…

  7. Education Matters, September 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Are They Ready? National Study Reveals Civics…

  8. Why Poetry Matters

    ERIC Educational Resources Information Center

    Parini, Jay

    2008-01-01

    Poetry does not matter to most people. They go about their business as usual, rarely consulting Shakespeare, Wordsworth, or Frost. One has to wonder if poetry has any place in the 21st century, when music videos and satellite television offer daunting competition for poems, which demand a good deal of attention and considerable analytic skills, as…

  9. Education Matters, June 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Coaching Teachers Boosts Student Reading:…

  10. Education Matters, March 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) The War on Progress: Why the National…

  11. Education Matters, June 2008

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2008-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) A Few Good Men: The Success of the Male…

  12. Education Matters, March 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) The Desperate Need for an Education Stimulus:…

  13. Education Matters, April 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Teaching as Leadership: 6 Traits of Highly…

  14. Why Philosophy Matters

    ERIC Educational Resources Information Center

    Mason, Richard

    2005-01-01

    The motives of philosophers tend to be personal. Philosophy has mattered politically as part of continuing political debates. Its effects on politics, religion and the development of the sciences have been evident. Philosophy has been supposed to have special educational value, from its contents or from the benefits of its methods and arguments.…

  15. Education Matters, May 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Leading Students to New Heights: Dr. Bill…

  16. Education Matters, April 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Johnny Can Write...If We Challenge Him (Bill…

  17. Accountability for What Matters

    ERIC Educational Resources Information Center

    Rothman, Robert

    2016-01-01

    For more than a decade, states have evaluated school performance largely through a single measure--test scores--and rated schools on whether they improved students' performance in reading or math. The idea was to focus schools' attention on the outcomes that mattered most and to focus states' attention on the schools that needed the most help in…

  18. Education Matters, February 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Making a Game of Math: AAE Affiliate Motivates…

  19. Education Matters, June 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) You Told Us What You Think of No Child Left…

  20. Education Matters, June 2011

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2011-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Who Deserves Tenure? Is It Time to Move beyond…

  1. Cancer Epidemiology Matters Blog

    Cancer.gov

    The Cancer Epidemiology Matters blog helps foster a dialogue between the National Cancer Institute's (NCI) Epidemiology and Genomics Research Program (EGRP), extramural researchers, and other individuals, such as clinicians, community partners, and advocates, who are interested in cancer epidemiology and genomics.

  2. Education Matters, August 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) How to Improve Reading First (G. Reid Lyon); (2) Drop…

  3. Education Matters, October 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Lessons from the Frontlines of the Charter…

  4. Accountability for What Matters

    ERIC Educational Resources Information Center

    Rothman, Robert

    2016-01-01

    For more than a decade, states have evaluated school performance largely through a single measure--test scores--and rated schools on whether they improved students' performance in reading or math. The idea was to focus schools' attention on the outcomes that mattered most and to focus states' attention on the schools that needed the most help in…

  5. Education Matters, March 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) The War on Progress: Why the National…

  6. Education Matters, June 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) You Told Us What You Think of No Child Left…

  7. Education Matters, October 2009

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2009-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Does Demography Dictate Destiny? The Radical…

  8. Education Matters, August 2007

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2007-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) How to Improve Reading First (G. Reid Lyon); (2) Drop…

  9. Education Matters, May 2010

    ERIC Educational Resources Information Center

    Beckner, Gary, Ed.

    2010-01-01

    "Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Who Me? Yes, You Can Use Technology to Individualize…

  10. No Laughing Matter. Commentary

    ERIC Educational Resources Information Center

    Simmons, Steven

    2011-01-01

    Steve Kolowich's article, "No Laughing Matter" (2010), highlights the disconnect between information found on university and college websites and information relevant to students. Using a carton by Randall Munroe, Kolowich points out that website designers and college marketing officials really do not understand what is important to prospective…

  11. Energy Matters - Fall 2002

    SciTech Connect

    2002-09-01

    Quarterly newsletter from DOE's Industrial Technologies Program to promote the use of energy-efficient industrial systems. This issue focus of this edition of the Energy Matters Newsletter is on energy and environmental issues. Read more about compressed air's role in productivity, making good motor decisions, and more.

  12. Particle Dark Matter

    NASA Astrophysics Data System (ADS)

    Bertone, Gianfranco

    2013-11-01

    Part I. DM in Cosmology: 1. Particle dark matter G. Bertone and J. Silk; 2. Simulations of CDM haloes B. Moore and J. Diemand; 3. MW substructures J. Bullock, M. Kaplinghat and L. Strigari; 4. Gravitational lensing and dark matter Y. Mellier; 5. Dark matter at the centers of galaxies D. Merritt; 6. Modified gravity as an alternative to DM J. Bekenstein; Part II. Candidates: 7. DM production mechanisms G. Gelmini and P. Gondolo; 8. Supersymmetric DM candidates J. Ellis and K. Olive; 9. DM at the EW scale: non-SUSY candidates G. Servant; 10. Non-WIMP candidates J. L. Feng; 11. Axions P. Sikivie; 12. Sterile neutrinos M. Shaposhnikov; Part III. Colliders Searches: 13. SUSY searches at the LHC T. Plehn and G. Polesello; 14. SUSY DM at colliders M. Battaglia and M. E. Peskin; 15. Extra dimensions at the LHC K. Kong, K. Matchev and G. Servant; 16. SUSY tools F. Boudjema, J. Edsjö and P. Gondolo; Part IV. Direct Detection: 17. Direct detection of WIMPs D. G. Cerdeño and A. Green; 18. Annual modulation with NaI(Tl) R. Bernabei and P. Belli; 19. Particle DM and DAMA N. Fornengo; 20. Cryogenic detectors G. Gerbier and J. Gascon; 21. Liquid noble gases E. Aprile and L. Baudis; 22. Directional detectors N. Spooner; 23. Axion searches S. Asztalos; Part V. Indirect Detection and Astrophysical Constraints: 24. Gamma-rays L. Bergström and G. Bertone; 25. Neutrinos F. Halzen and D. Hooper; 26. Antimatter P. Salati, F. Donato and N. Fornengo; 27. Multi-wavelength S. Profumo and P. Ullio; 28. Dark matter and BBN K. Jedamzik and M. Pospelov; 29. Dark matter and stars G. Bertone; Appendix; References; Index.

  13. White matter of the brain

    MedlinePlus

    White matter is found in the deeper tissues of the brain (subcortical). It contains nerve fibers (axons), which are ... or covering called myelin. Myelin gives the white matter its color. It also protects the nerve fibers ...

  14. The Search for Dark Matter

    ScienceCinema

    Orrell, John

    2016-07-12

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  15. The Search for Dark Matter

    SciTech Connect

    Orrell, John

    2013-11-20

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  16. Direct search for dark matter

    SciTech Connect

    Yoo, Jonghee; /Fermilab

    2009-12-01

    Dark matter is hypothetical matter which does not interact with electromagnetic radiation. The existence of dark matter is only inferred from gravitational effects of astrophysical observations to explain the missing mass component of the Universe. Weakly Interacting Massive Particles are currently the most popular candidate to explain the missing mass component. I review the current status of experimental searches of dark matter through direct detection using terrestrial detectors.

  17. Normal matter storage of antiprotons

    SciTech Connect

    Campbell, L.J.

    1987-01-01

    Various simple issues connected with the possible storage of anti p in relative proximity to normal matter are discussed. Although equilibrium storage looks to be impossible, condensed matter systems are sufficiently rich and controllable that nonequilibrium storage is well worth pursuing. Experiments to elucidate the anti p interactions with normal matter are suggested. 32 refs.

  18. Engaged Learning: Why Feelings Matter

    ERIC Educational Resources Information Center

    Fried, Jane

    2013-01-01

    People remember information that is important to them--because it is fundamental to their well-being, or because it matters to them in some other significant way. This is all one really needs to know about unlocking student learning. People learn and remember information that matters to them. So what matters to students? That is a complicated…

  19. Engaged Learning: Why Feelings Matter

    ERIC Educational Resources Information Center

    Fried, Jane

    2013-01-01

    People remember information that is important to them--because it is fundamental to their well-being, or because it matters to them in some other significant way. This is all one really needs to know about unlocking student learning. People learn and remember information that matters to them. So what matters to students? That is a complicated…

  20. Is old organic matter simple organic matter?

    NASA Astrophysics Data System (ADS)

    Nunan, Naoise; Lerch, Thomas; Pouteau, Valérie; Mora, Philippe; Changey, Fréderique; Kätterer, Thomas; Herrmann, Anke

    2016-04-01

    Bare fallow soils that have been deprived of fresh carbon inputs for prolonged periods contain mostly old, stable organic carbon. In order to shed light on the nature of this carbon, the functional diversity profiles (MicroResp™, Biolog™ and enzyme activity spectra) of the microbial communities of long-term barefallow soils were analysed and compared with those of the microbial communities from their cultivated counterparts. The study was based on the idea that microbial communities adapt to their environment and that therefore the catabolic and enzymatic profiles would reflect the type of substrates available to the microbial communities. The catabolic profiles suggested that the microbial communities in the long-term bare-fallow soil were exposed to a less diverse range of substrates and that these substrates tended to be of simpler molecular forms. Both the catabolic and enzyme activity profiles suggested that the microbial communities from the long-term bare-fallow soils were less adapted to using polymers. These results do not fit with the traditional view of old, stable carbon being composed of complex, recalcitrant polymers. An energetics analysis of the substrate use of the microbial communities for the different soils suggested that the microbial communities from the long-term bare-fallow soils were better adapted to using readily oxidizable,although energetically less rewarding, substrates. Microbial communities appear to adapt to the deprivation of fresh organic matter by using substrates that require little investment.

  1. Rigid particulate matter sensor

    SciTech Connect

    Hall, Matthew

    2011-02-22

    A sensor to detect particulate matter. The sensor includes a first rigid tube, a second rigid tube, a detection surface electrode, and a bias surface electrode. The second rigid tube is mounted substantially parallel to the first rigid tube. The detection surface electrode is disposed on an outer surface of the first rigid tube. The detection surface electrode is disposed to face the second rigid tube. The bias surface electrode is disposed on an outer surface of the second rigid tube. The bias surface electrode is disposed to face the detection surface electrode on the first rigid tube. An air gap exists between the detection surface electrode and the bias surface electrode to allow particulate matter within an exhaust stream to flow between the detection and bias surface electrodes.

  2. The tachyon does matter

    NASA Astrophysics Data System (ADS)

    Buchel, A.; Walcher, J.

    2003-07-01

    We review the concept of S-branes introduced by Gutperle and Strominger [1]. Using the effective spacetime description of the rolling tachyon worldsheets discussed by Sen, we analyze the possibility that the gravitational backreaction of tachyon matter is important in the time-dependent process. We show that this is indeed the case in the example of the S0-brane in 4-dimensional Einstein-Maxwell theory. This talk is based on [21].

  3. Matter in general relativity

    NASA Technical Reports Server (NTRS)

    Ray, J. R.

    1982-01-01

    Two theories of matter in general relativity, the fluid theory and the kinetic theory, were studied. Results include: (1) a discussion of various methods of completing the fluid equations; (2) a method of constructing charged general relativistic solutions in kinetic theory; and (3) a proof and discussion of the incompatibility of perfect fluid solutions in anisotropic cosmologies. Interpretations of NASA gravitational experiments using the above mentioned results were started. Two papers were prepared for publications based on this work.

  4. Matter in general relativity

    NASA Technical Reports Server (NTRS)

    Ray, J. R.

    1982-01-01

    Two theories of matter in general relativity, the fluid theory and the kinetic theory, were studied. Results include: (1) a discussion of various methods of completing the fluid equations; (2) a method of constructing charged general relativistic solutions in kinetic theory; and (3) a proof and discussion of the incompatibility of perfect fluid solutions in anisotropic cosmologies. Interpretations of NASA gravitational experiments using the above mentioned results were started. Two papers were prepared for publications based on this work.

  5. Inflatable Dark Matter

    SciTech Connect

    Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D.

    2016-01-22

    We describe a general scenario, dubbed “Inflatable Dark Matter”, in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early universe. The overproduction of dark matter that is predicted within many otherwise well-motivated models of new physics can be elegantly remedied within this context, without the need to tune underlying parameters or to appeal to anthropic considerations. Thermal relics that would otherwise be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the non-thermal abundance of GUT or Planck scale axions can be brought to acceptable levels, without invoking anthropic tuning of initial conditions. Additionally, a period of late-time inflation could have occurred over a wide range of scales from ~ MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the Standard Model.

  6. Inflatable Dark Matter

    DOE PAGES

    Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D.

    2016-01-22

    We describe a general scenario, dubbed “Inflatable Dark Matter”, in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early universe. The overproduction of dark matter that is predicted within many otherwise well-motivated models of new physics can be elegantly remedied within this context, without the need to tune underlying parameters or to appeal to anthropic considerations. Thermal relics that would otherwise be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the non-thermal abundance of GUTmore » or Planck scale axions can be brought to acceptable levels, without invoking anthropic tuning of initial conditions. Additionally, a period of late-time inflation could have occurred over a wide range of scales from ~ MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the Standard Model.« less

  7. Cosmology with matter diffusion

    SciTech Connect

    Calogero, Simone; Velten, Hermano E-mail: velten@cce.ufes.br

    2013-11-01

    We construct a viable cosmological model based on velocity diffusion of matter particles. In order to ensure the conservation of the total energy-momentum tensor in the presence of diffusion, we include a cosmological scalar field φ which we identify with the dark energy component of the universe. The model is characterized by only one new degree of freedom, the diffusion parameter σ. The standard ΛCDM model can be recovered by setting σ = 0. If diffusion takes place (σ > 0) the dynamics of the matter and of the dark energy fields are coupled. We argue that the existence of a diffusion mechanism in the universe may serve as a theoretical motivation for interacting models. We constrain the background dynamics of the diffusion model with Supernovae, H(z) and BAO data. We also perform a perturbative analysis of this model in order to understand structure formation in the universe. We calculate the impact of diffusion both on the CMB spectrum, with particular attention to the integrated Sachs-Wolfe signal, and on the matter power spectrum P(k). The latter analysis places strong constraints on the magnitude of the diffusion mechanism but does not rule out the model.

  8. Dark matter and cosmological nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Schramm, D. N.

    1986-01-01

    Existing dark matter problems, i.e., dynamics, galaxy formation and inflation, are considered, along with a model which proposes dark baryons as the bulk of missing matter in a fractal universe. It is shown that no combination of dark, nonbaryonic matter can either provide a cosmological density parameter value near unity or, as in the case of high energy neutrinos, allow formation of condensed matter at epochs when quasars already existed. The possibility that correlations among galactic clusters are scale-free is discussed. Such a distribution of matter would yield a fractal of 1.2, close to a one-dimensional universe. Biasing, cosmic superstrings, and percolated explosions and hot dark matter are theoretical approaches that would satisfy the D = 1.2 fractal model of the large-scale structure of the universe and which would also allow sufficient dark matter in halos to close the universe.

  9. Dark matter and cosmological nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Schramm, D. N.

    1986-01-01

    Existing dark matter problems, i.e., dynamics, galaxy formation and inflation, are considered, along with a model which proposes dark baryons as the bulk of missing matter in a fractal universe. It is shown that no combination of dark, nonbaryonic matter can either provide a cosmological density parameter value near unity or, as in the case of high energy neutrinos, allow formation of condensed matter at epochs when quasars already existed. The possibility that correlations among galactic clusters are scale-free is discussed. Such a distribution of matter would yield a fractal of 1.2, close to a one-dimensional universe. Biasing, cosmic superstrings, and percolated explosions and hot dark matter are theoretical approaches that would satisfy the D = 1.2 fractal model of the large-scale structure of the universe and which would also allow sufficient dark matter in halos to close the universe.

  10. Antiprotons are another matter

    SciTech Connect

    Hynes, M.V.

    1987-01-01

    Theories of gravity abound, whereas experiments in gravity are few in number. An important experiment in gravity that has not been performed is the measurement of the gravitational acceleration of antimatter. Although there have been attempts to infer these properties from those of normal matter, none of these theoretical arguments are compelling. Modern theories of gravity that attempt to unify gravity with the other forces of nature predict that in principle antimatter can fall differently than normal matter in the Earth's field. Some of these supergravity theories predict that antimatter will fall faster, and that normal matter will fall with a small Baryon-number dependance in the earth's field. All of these predictions violate the Weak Equivalence Principle, a cornerstone of General Relativity, but are consistent with CPT conservation. In our approved experiment at LEAR (PS-200) we will test the Weak Equivalence Principle for antimatter by measuring the gravitational acceleration of the antiproton. Through a series of deceleration stages, antiprotons from LEAR will be lowered in energy to approx.4 Kelvin at which energy the gravitational effect will be measureable. The measurement will employ the time-of-flight technique wherein the antiprotons are released vertically in a drift tube. The spectrum of time-of-flight measurements can be used to extract the gravitational acceleration experienced by the particles. The system will be calibrated using H/sup -/ ions which simulates the electromagnetic behavior of the antiproton, yet is a baryon to approx.0.1%. To extract the gravitational acceleration of the antiproton relative to the H/sup -/ ion with a statistical precision of 1% will require the release of approx.10/sup 6/ to 10/sup 7/ particles.

  11. Modeling white matter microstructure

    PubMed Central

    Duval, Tanguy; Stikov, Nikola; Cohen-Adad, Julien

    2016-01-01

    Summary Quantitative magnetic resonance imaging can be combined with advanced biophysical models to measure microstructural features of white matter. Non-invasive microstructural imaging has the potential to revolutionize neuroscience, and acquiring these measures in clinically feasible times would greatly improve patient monitoring and clinical studies of drug efficacy. However, a good understanding of microstructural imaging techniques is essential to set realistic expectations and to prevent over-interpretation of results. This review explains the methodology behind microstructural modeling and imaging, and gives an overview of the breakthroughs and challenges associated with it. PMID:28072382

  12. Analysis for Extraneous Matter

    NASA Astrophysics Data System (ADS)

    Dogan, Hulya; Subramanyam, Bhadriraju; Pedersen, John R.

    Analysis for extraneous matter is an important element both in the selection of raw materials for food manufacturing and for monitoring the quality of processed foods. The presence of extraneous material in a food product is unappealing and can pose a serious health hazard to the consumer. It also represents lack of good manufacturing practices and sanitary conditions in production, storage, or distribution. The presence of extraneous materials in the product ingredients may render the final product adulterated and not suitable for human food.

  13. Cool Quark Matter.

    PubMed

    Kurkela, Aleksi; Vuorinen, Aleksi

    2016-07-22

    We generalize the state-of-the-art perturbative equation of state of cold quark matter to nonzero temperatures, needed in the description of neutron star mergers and core collapse processes. The new result is accurate to O(g^{5}) in the gauge coupling, and is based on a novel framework for dealing with the infrared sensitive soft field modes of the theory. The zero Matsubara mode sector is treated via a dimensionally reduced effective theory, while the soft nonzero modes are resummed using the hard thermal loop approximation. This combination of known effective descriptions offers unprecedented access to small but nonzero temperatures, both in and out of beta equilibrium.

  14. Dark Matter Velocity Spectroscopy.

    PubMed

    Speckhard, Eric G; Ng, Kenny C Y; Beacom, John F; Laha, Ranjan

    2016-01-22

    Dark matter decays or annihilations that produce linelike spectra may be smoking-gun signals. However, even such distinctive signatures can be mimicked by astrophysical or instrumental causes. We show that velocity spectroscopy-the measurement of energy shifts induced by relative motion of source and observer-can separate these three causes with minimal theoretical uncertainties. The principal obstacle has been energy resolution, but upcoming experiments will have the precision needed. As an example, we show that the imminent Astro-H mission can use Milky Way observations to separate possible causes of the 3.5-keV line. We discuss other applications.

  15. (Mainly) axion dark matter

    NASA Astrophysics Data System (ADS)

    Baer, Howard

    2016-06-01

    The strong CP problem of QCD is at heart a problem of naturalness: why is the FF ˜ term highly suppressed in the QCD Lagrangian when it seems necessary to explain why there are three and not four light pions? The most elegant solution posits a spontaneously broken Peccei-Quinn (PQ) symmetry which requires the existence of the axion field a. The axion field settles to the minimum of its potential thus removing the offensive term but giving rise to the physical axion whose coherent oscillations can make up the cold dark matter. Only now are experiments such as ADMX beginning to explore QCD axion parameter space. Since a bonafide scalar particle- the Higgs boson- has been discovered, one might expect its mass to reside at the axion scale fa ˜ 1011 GeV. The Higgs mass is elegantly stabilized by supersymmetry: in this case the axion is accompanied by its axino and saxion superpartners. Requiring naturalness also in the electroweak sector implies higgsino-like WIMPs so then we expect mixed axion-WIMP dark matter. Ultimately we would expect detection of both an axion and a WIMP while signals for light higgsinos may show up at LHC and must show up at ILC.

  16. Levitating dark matter

    NASA Astrophysics Data System (ADS)

    Kaloper, Nemanja; Padilla, Antonio

    2009-10-01

    A sizable fraction of the total energy density of the universe may be in heavy particles with a net dark U(1)' charge comparable to its mass. When the charges have the same sign the cancellation between their gravitational and gauge forces may lead to a mismatch between different measures of masses in the universe. Measuring galactic masses by orbits of normal matter, such as galaxy rotation curves or lensing, will give the total mass, while the flows of dark matter agglomerates may yield smaller values if the gauge repulsion is not accounted for. If distant galaxies which house light beacons like SNe Ia contain such dark particles, the observations of their cosmic recession may mistake the weaker forces for an extra `antigravity', and infer an effective dark energy equation of state smaller than the real one. In some cases, including that of a cosmological constant, these effects can mimic w < -1. They can also lead to a local variation of galaxy-galaxy forces, yielding a larger `Hubble Flow' in those regions of space that could be taken for a dynamical dark energy, or superhorizon effects.

  17. Dark matter candidates

    SciTech Connect

    Turner, M.S.

    1989-01-01

    One of the simplest, yet most profound, questions we can ask about the Universe is, how much stuff is in it, and further what is that stuff composed of. Needless to say, the answer to this question has very important implications for the evolution of the Universe, determining both the ultimate fate and the course of structure formation. Remarkably, at this late date in the history of the Universe we still do not have a definitive answer to this simplest of questions---although we have some very intriguing clues. It is known with certainty that most of the material in the Universe is dark, and we have the strong suspicion that the dominant component of material in the Cosmos is not baryons, but rather is exotic relic elementary particles left over from the earliest, very hot epoch of the Universe. If true, the Dark Matter question is a most fundamental one facing both particle physics and cosmology. The leading particle dark matter candidates are: the axion, the neutralino, and a light neutrino species. All three candidates are accessible to experimental tests, and experiments are now in progress. In addition, there are several dark horse, long shot, candidates, including the superheavy magnetic monopole and soliton stars. 13 refs.

  18. Programmable matter by folding

    PubMed Central

    Hawkes, E.; An, B.; Benbernou, N. M.; Tanaka, H.; Kim, S.; Demaine, E. D.; Rus, D.; Wood, R. J.

    2010-01-01

    Programmable matter is a material whose properties can be programmed to achieve specific shapes or stiffnesses upon command. This concept requires constituent elements to interact and rearrange intelligently in order to meet the goal. This paper considers achieving programmable sheets that can form themselves in different shapes autonomously by folding. Past approaches to creating transforming machines have been limited by the small feature sizes, the large number of components, and the associated complexity of communication among the units. We seek to mitigate these difficulties through the unique concept of self-folding origami with universal crease patterns. This approach exploits a single sheet composed of interconnected triangular sections. The sheet is able to fold into a set of predetermined shapes using embedded actuation. To implement this self-folding origami concept, we have developed a scalable end-to-end planning and fabrication process. Given a set of desired objects, the system computes an optimized design for a single sheet and multiple controllers to achieve each of the desired objects. The material, called programmable matter by folding, is an example of a system capable of achieving multiple shapes for multiple functions. PMID:20616049

  19. Radiative accidental matter

    NASA Astrophysics Data System (ADS)

    Sierra, D. Aristizabal; Simoes, C.; Wegman, D.

    2016-07-01

    Accidental matter models are scenarios where the beyond-the-standard model physics preserves all the standard model accidental and approximate symmetries up to a cutoff scale related with lepton number violation. We study such scenarios assuming that the new physics plays an active role in neutrino mass generation, and show that this unavoidably leads to radiatively induced neutrino masses. We systematically classify all possible models and determine their viability by studying electroweak precision data, big bang nucleosynthesis and electroweak perturbativity, finding that the latter places the most stringent constraints on the mass spectra. These results allow the identification of minimal radiative accidental matter models for which perturbativity is lost at high scales. We calculate radiative charged-lepton flavor violating processes in these setups, and show that μ → eγ has a rate well within MEG sensitivity provided the lepton-number violating scale is at or below 5×105 GeV, a value (naturally) assured by the radiative suppression mechanism. Sizeable τ → μγ branching fractions within SuperKEKB sensitivity are possible for lower lepton-number breaking scales. We thus point out that these scenarios can be tested not only in direct searches but also in lepton flavor-violating experiments.

  20. Phase transitions in nuclear matter

    SciTech Connect

    Glendenning, N.K.

    1984-11-01

    The rather general circumstances under which a phase transition in hadronic matter at finite temperature to an abnormal phase in which baryon effective masses become small and in which copious baryon-antibaryon pairs appear is emphasized. A preview is also given of a soliton model of dense matter, in which at a density of about seven times nuclear density, matter ceases to be a color insulator and becomes increasingly color conducting. 22 references.

  1. Quark matter or new particles?

    NASA Technical Reports Server (NTRS)

    Michel, F. Curtis

    1988-01-01

    It has been argued that compression of nuclear matter to somewhat higher densities may lead to the formation of stable quark matter. A plausible alternative, which leads to radically new astrophysical scenarios, is that the stability of quark matter simply represents the stability of new particles compounded of quarks. A specific example is the SU(3)-symmetric version of the alpha particle, composed of spin-zero pairs of each of the baryon octet (an 'octet' particle).

  2. Direct detection of Dark Matter

    NASA Astrophysics Data System (ADS)

    Belli, P.

    2016-07-01

    An overview of the latest results of Dark Matter direct detection will be summarized, with particular care to the DAMA/LIBRA-phase1 results and the evidence with high confidence level obtained by exploiting the model independent Dark Matter annual modulation signature for the presence of Dark Matter particles in the galactic halo. Results from other experiments using different procedures, different techniques and different target-materials will be shortly discussed. Results, implications and experimental perspectives will be addressed.

  3. Arctic River organic matter transport

    NASA Astrophysics Data System (ADS)

    Raymond, Peter; Gustafsson, Orjan; Vonk, Jorien; Spencer, Robert; McClelland, Jim

    2016-04-01

    Arctic Rivers have unique hydrology and biogeochemistry. They also have a large impact on the Arctic Ocean due to the large amount of riverine inflow and small ocean volume. With respect to organic matter, their influence is magnified by the large stores of soil carbon and distinct soil hydrology. Here we present a recap of what is known of Arctic River organic matter transport. We will present a summary of what is known of the ages and sources of Arctic River dissolved and particulate organic matter. We will also discuss the current status of what is known about changes in riverine organic matter export due to global change.

  4. Chiral symmetry in quarkyonic matter

    SciTech Connect

    Kojo, T.

    2012-05-15

    The 1/N{sub c} expansion classifies nuclear matter, deconfined quark matter, and Quarkyonic matter in low temperature region. We investigate the realization of chiral symmetry in Quarkyonic matter by taking into account condensations of chiral particle-hole pairs. It is argued that chiral symmetry and parity are locally violated by the formation of chiral spirals, <{psi}-bar exp (2i{mu}{sub q} z{gamma}{sup 0} {gamma}{sup z}){psi}> . An extension to multiple chiral spirals is also briefly discussed.

  5. Dark Matter, Waves, and Identification

    NASA Astrophysics Data System (ADS)

    Wagner, Orvin

    2011-10-01

    In 1994 I wrote article for Physics Essays (Waves in Dark Matter) showing how the solar system is organized and stabilized by dark matter standing waves from the dark matter oscillating sun. Wave velocity is apparently inversely proportional to the square root of the dark matter density. At the sun's surface the wave velocity is near 1.25 m/s. More recently I have found local dark matter waves that appear to travel near 25 m/s near April 1 and appear to organize plants. They travel between plants and artificial transmitters and receivers, and penetrate my local hill. From my measurements the local dark matter density is a function of the time of year. The data indicate that dark matter interacts much more than just with gravity as others have surmised. I present experimental proofs and a local dark matter density equation in terms of the measured velocity. The waves and the earth's location may be very important for nature's organization. The observed behavior appears to go a long way towards dark matter identification. These waves also may explain the rings of the gaseous planets in terms of oscillating layers. See the ring article on the web site Darkmatterwaves.com.

  6. Solving the Dark Matter Problem

    ScienceCinema

    Baltz, Ted

    2016-07-12

    Cosmological observations have firmly established that the majority of matter in the universe is of an unknown type, called 'dark matter'. A compelling hypothesis is that the dark matter consists of weakly interacting massive particles (WIMPs) in the mass range around 100 GeV. If the WIMP hypothesis is correct, such particles could be created and studied at accelerators. Furthermore they could be directly detected as the primary component of our galaxy. Solving the dark matter problem requires that the connection be made between the two. We describe some theoretical and experimental avenues that might lead to this connection.

  7. Nucleons, Nuclear Matter and Quark Matter: A unified NJL approach

    SciTech Connect

    S. Lawley; W. Bentz; A.W. Thomas

    2006-02-10

    We use an effective quark model to describe both hadronic matter and deconfined quark matter. By calculating the equations of state and the corresponding neutron star properties, we show that the internal properties of the nucleon have important implications for the properties of these systems.

  8. Our Lopsided Universe: The Matter with Anti-Matter

    SciTech Connect

    Sekula, Steve

    2004-06-29

    Half of our universe appears to be missing, and scientists at SLAC and all over the world are trying to understand why. Don't miss this talk in which Steve Sekula will explain the core issues surrounding matter and anti-matter.

  9. Resident Assistant Mattering: Do Placement and Community Size Matter?

    ERIC Educational Resources Information Center

    Stoner, James C.; Zhang, Yi

    2017-01-01

    A sense of mattering among college students has been found to have positive outcomes, including lower levels of anxiety and depression as well as increased self-esteem, wellness, happiness, and job satisfaction. However, the feeling of mattering among Resident Assistants (RAs) has received little attention in literature. This quantitative study…

  10. Parents Matter: Supporting the Birth to Three Matters Framework

    ERIC Educational Resources Information Center

    Abbott, Lesley; Langston, Ann

    2006-01-01

    This book explores the important role of parents and the extended family in the lives of babies and young children. It complements and extends the DfES Birth to Three Matters framework, which supports practitioners in working with children aged birth to three, and builds on the information provided in the companion book "Birth to Three Matters:…

  11. PREFACE: Quark Matter 2008

    NASA Astrophysics Data System (ADS)

    Jan-e~Alam; Subhasis~Chattopadhyay; Tapan~Nayak

    2008-10-01

    Quark Matter 2008—the 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions was held in Jaipur, the Pink City of India, from 4-10 February, 2008. Organizing Quark Matter 2008 in India itself indicates the international recognition of the Indian contribution to the field of heavy-ion physics, which was initiated and nurtured by Bikash Sinha, Chair of the conference. The conference was inaugurated by the Honourable Chief Minister of Rajasthan, Smt. Vasundhara Raje followed by the key note address by Professor Carlo Rubbia. The scientific programme started with the theoretical overview, `SPS to RHIC and onwards to LHC' by Larry McLerran followed by several theoretical and experimental overview talks on the ongoing experiments at SPS and RHIC. The future experiments at the LHC, FAIR and J-PARC, along with the theoretical predictions, were discussed in great depth. Lattice QCD predictions on the nature of the phase transition and critical point were vigorously debated during several plenary and parallel session presentations. The conference was enriched by the presence of an unprecedented number of participants; about 600 participants representing 31 countries across the globe. This issue contains papers based on plenary talks and oral presentations presented at the conference. Besides invited and contributed talks, there were also a large number of poster presentations. Members of the International Advisory Committee played a pivotal role in the selection of speakers, both for plenary and parallel session talks. The contributions of the Organizing Committee in all aspects, from helping to prepare the academic programme down to arranging local hospitality, were much appreciated. We thank the members of both the committees for making Quark Matter 2008 a very effective and interesting platform for scientific deliberations. Quark Matter 2008 was financially supported by: Air Liquide (New Delhi) Board of Research Nuclear Sciences (Mumbai) Bose

  12. PREFACE: Quark Matter 2008

    NASA Astrophysics Data System (ADS)

    Alam, Jan-e.; Chattopadhyay, Subhasis; Nayak, Tapan; Sinha, Bikash; Viyogi, Yogendra P.

    2008-10-01

    Quark Matter 2008—the 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions was held in Jaipur, the Pink City of India, from 4-10 February, 2008. Organizing Quark Matter 2008 in India itself indicates the international recognition of the Indian contribution to the field of heavy-ion physics, which was initiated and nurtured by Bikash Sinha, Chair of the conference. The conference was inaugurated by the Honourable Chief Minister of Rajasthan, Smt. Vasundhara Raje followed by the key note address by Professor Carlo Rubbia. The scientific programme started with the theoretical overview, `SPS to RHIC and onwards to LHC' by Larry McLerran followed by several theoretical and experimental overview talks on the ongoing experiments at SPS and RHIC. The future experiments at the LHC, FAIR and J-PARC, along with the theoretical predictions, were discussed in great depth. Lattice QCD predictions on the nature of the phase transition and critical point were vigorously debated during several plenary and parallel session presentations. The conference was enriched by the presence of an unprecedented number of participants; about 600 participants representing 31 countries across the globe. This issue contains papers based on plenary talks and oral presentations presented at the conference. Besides invited and contributed talks, there were also a large number of poster presentations. Members of the International Advisory Committee played a pivotal role in the selection of speakers, both for plenary and parallel session talks. The contributions of the Organizing Committee in all aspects, from helping to prepare the academic programme down to arranging local hospitality, were much appreciated. We thank the members of both the committees for making Quark Matter 2008 a very effective and interesting platform for scientific deliberations. Quark Matter 2008 was financially supported by: Air Liquide (New Delhi) Board of Research Nuclear Sciences (Mumbai) Bose

  13. Environmental psychology matters.

    PubMed

    Gifford, Robert

    2014-01-01

    Environmental psychology examines transactions between individuals and their built and natural environments. This includes investigating behaviors that inhibit or foster sustainable, climate-healthy, and nature-enhancing choices, the antecedents and correlates of those behaviors, and interventions to increase proenvironmental behavior. It also includes transactions in which nature provides restoration or inflicts stress, and transactions that are more mutual, such as the development of place attachment and identity and the impacts on and from important physical settings such as home, workplaces, schools, and public spaces. As people spend more time in virtual environments, online transactions are coming under increasing research attention. Every aspect of human existence occurs in one environment or another, and the transactions with and within them have important consequences both for people and their natural and built worlds. Environmental psychology matters.

  14. Language matters: an introduction.

    PubMed

    Leap, William L; Provencher, Denis M

    2011-01-01

    That language and sexuality are closely connected is one of the enduring themes in human sexuality research. The articles in this special issue of the Journal of Homosexuality explore some of these language-centered insights as they apply to same-sex related desires, identities, and practices and to other dimensions of non-normative sexual experiences. The articles address language use over a range of geographic and social locations. The linguistic practices discussed are diverse, including the language associated with Santería, comments viewers make about gay pornography, homophobic discourse, coming out stories, stories where declarations of sexual identity are tacitly withheld, sexual messages in Black hip hop culture, assessments of urban AIDS ministries, and policies that limit transgender subjects' access to urban space. Taken together, these articles demonstrate that language matters in the everyday experience of sexual sameness and they model some of the approaches that are now being explored in language and sexuality studies.

  15. Neutrino signals from dark matter

    NASA Astrophysics Data System (ADS)

    Erkoca, Arif Emre

    Large-scale neutrino telescopes will be powerful tools to observe multitude of mysterious phenomena happening in the Universe. The dark matter puzzle is listed as one of them. In this study, indirect detection of dark matter via neutrino signals is presented. The upward muon, the contained muon and the hadronic shower fluxes are calculated, assuming annihilation/decay of the dark matter in the core of the astrophysical objects and in the Galactic center. Direct neutrino production and secondary neutrino production from the decay of Standard Model particles produced in the annihilation/decay of dark matter are studied. The results are contrasted to the ones previously obtained in the literature, illustrating the importance of properly treating muon propagation and energy loss for the upward muon flux. The dependence of the dark matter signals on the density profile, the dark matter mass and the detector threshold are discussed. Different dark matter models (gravitino, Kaluza-Klein and leptophilic) which can account for recent observations of some indirect searches are analyzed regarding their detection in the kilometer size neutrino detectors in the near future. Muon and shower rates and the minimum observation times in order to reach 2sigma detection significance are evaluated, with the result suggesting that the optimum cone half angles chosen about the Galactic center are about 10° (50°) for the muon (shower) events. A detailed analysis shows that for the annihilating dark matter models such as the leptophilic and Kaluza-Klein models, upward and contained muon as well as showers yield promising signals for dark matter detection in just a few years of observation, whereas for decaying dark matter models, the same observation times can only be reached with showers. The analytical results for the final fluxes are also obtained as well as parametric forms for the muon and shower fluxes for the dark matter models considered in this study.

  16. Does Climate Literacy Matter?

    NASA Astrophysics Data System (ADS)

    Bedford, D. P.

    2014-12-01

    One obstacle to climate science education is the perception that climate literacy plays little or no role in the formation of opinions about the reality and seriousness of anthropogenic global warming (AGW), or that members of the non-specialist public already know enough climate science to hold an informed opinion. Why engage in climate science education if climate literacy does not matter? The idea that resistance to or dismissal of the findings and policy implications of climate science can be addressed simply by providing more and better information—the 'deficit model'—has been heavily critiqued in recent years. However, the pendulum is in danger of swinging too far in the opposite direction, with the view that information deficits either do not exist or are not relevant at all to attitude formation, and that cultural perspectives are sufficient by themselves to explain attitudes to AGW. This paper briefly reviews several recent publications that find a correlation between higher levels of climate literacy and greater acceptance of or concern about AGW, then presents results from a survey completed by 458 students at a primarily undergraduate institution in northern Utah in April-May 2013. These data indicate that attitudes to AGW are largely tribal, based on political outlook, Democrats being more concerned, Republicans less concerned. Overall levels of climate literacy demonstrated by respondents were low, but concern about AGW increased with higher levels of climate literacy among Republicans—though not among Democrats, for whom acceptance of AGW appears to be more an article of faith or badge of identity. Findings such as this suggest that, contrary to some recent critiques of the deficit model, information deficits do exist and do matter for opinion formation on AGW, although cultural factors are clearly also of great importance. Climate science education therefore can potentially help engage members of the public in issues related to AGW.

  17. Dark Matter Searches With GLAST

    SciTech Connect

    Wai, Lawrence; Nuss, E.

    2007-02-05

    Indirect detection of particle dark matter relies upon pair annihilation of Weakly Interaction Massive Particles (WIMPs), which is complementary to the well known techniques of direct detection (WIMP-nucleus scattering) and collider production (WIMP pair production). Pair annihilation of WIMPs results in the production of gamma-rays, neutrinos, and anti-matter. Of the various experiments sensitive to indirect detection of dark matter, the Gamma-ray Large Area Space Telescope (GLAST) may play the most crucial role in the next few years. After launch in late 2007, The GLAST Large Area Telescope (LAT) will survey the gamma-ray sky in the energy range of 20MeV-300GeV. By eliminating charged particle background above 100 MeV, GLAST may be sensitive to as yet to be observed Milky Way dark matter subhalos, as well as WIMP pair annihilation spectral lines from the Milky Way halo. Discovery of gamma-ray signals from dark matter in the Milky Way would not only demonstrate the particle nature of dark matter; it would also open a new observational window on galactic dark matter substructure. Location of new dark matter sources by GLAST would dramatically alter the experimental landscape; ground based gamma ray telescopes could follow up on the new GLAST sources with precision measurements of the WIMP pair annihilation spectrum.

  18. Astronomy Matters for Chemistry Teachers.

    ERIC Educational Resources Information Center

    Huebner, Jay S.; And Others

    1996-01-01

    Describes basic misconceptions about the origin of elements and forms of matter found in chemistry texts that need modification in light of modern observational data and interpretations given in astronomy. Notes that there are forms of matter other than elements and compounds. Confounding examples from astronomy include white dwarfs, neutron…

  19. Soft matter: food for thought

    NASA Astrophysics Data System (ADS)

    Ogborn, Jon

    2004-01-01

    'Soft matter' is a lively current field of research, looking at fundamental theoretical questions about the structure and behaviour of complex forms of matter, and at very practical problems of, for example, improving the performance of glues or the texture of ice cream. Foodstuffs provide an excellent way in to this modern topic, which lies on the boundary between physics and chemistry.

  20. Soft Matter: Food for Thought

    ERIC Educational Resources Information Center

    Ogborn, Jon

    2004-01-01

    "Soft matter" is a lively current field of research, looking at fundamental theoretical questions about the structure and behaviour of complex forms of matter, and at very practical problems of, for example, improving the performance of glues or the texture of ice cream. Foodstuffs provide an excellent way in to this modern topic, which lies on…

  1. Soft Matter: Food for Thought

    ERIC Educational Resources Information Center

    Ogborn, Jon

    2004-01-01

    "Soft matter" is a lively current field of research, looking at fundamental theoretical questions about the structure and behaviour of complex forms of matter, and at very practical problems of, for example, improving the performance of glues or the texture of ice cream. Foodstuffs provide an excellent way in to this modern topic, which lies on…

  2. Quark Matter '87: Concluding remarks

    SciTech Connect

    Gyulassy, M.

    1988-03-01

    This year marked the beginning of the experimental program at BNL and CERN to probe the properties of ultra dense hadronic matter and to search for the quark-gluon plasma phase of matter. Possible implications of the preliminary findings are discussed. Problems needing further theoretical and experimental study are pointed out. 50 refs.

  3. Planetarium Show on Dark Matter

    SciTech Connect

    Barnett, R. Michael

    2016-05-31

    We describe a new planetarium show about Dark Matter entitled “Phantom of the Universe”. When completed in late 2014, it will feature the exciting story of dark matter, from the Big Bang to its anticipated discovery at the Large Hadron Collider.

  4. Reconciling MOND and dark matter?

    NASA Astrophysics Data System (ADS)

    Bruneton, Jean-Philippe; Liberati, Stefano; Sindoni, Lorenzo; Famaey, Benoit

    2009-03-01

    Observations of galaxies suggest a one-to-one analytic relation between the inferred gravity of dark matter at any radius and the enclosed baryonic mass, a relation summarized by Milgrom's law of modified Newtonian dynamics (MOND). However, present-day covariant versions of MOND usually require some additional fields contributing to the geometry, as well as an additional hot dark matter component to explain cluster dynamics and cosmology. Here, we envisage a slightly more mundane explanation, suggesting that dark matter does exist but is the source of MOND-like phenomenology in galaxies. We assume a canonical action for dark matter, but also add an interaction term between baryonic matter, gravity, and dark matter, such that standard matter effectively obeys the MOND field equation in galaxies. We show that even the simplest realization of the framework leads to a model which reproduces some phenomenological predictions of cold dark matter (CDM) and MOND at those scales where these are most successful. We also devise a more general form of the interaction term, introducing the medium density as a new order parameter. This allows for new physical effects which should be amenable to observational tests in the near future. Hence, this very general framework, which can be furthermore related to a generalized scalar-tensor theory, opens the way to a possible unification of the successes of CDM and MOND at different scales.

  5. Astronomy Matters for Chemistry Teachers.

    ERIC Educational Resources Information Center

    Huebner, Jay S.; And Others

    1996-01-01

    Describes basic misconceptions about the origin of elements and forms of matter found in chemistry texts that need modification in light of modern observational data and interpretations given in astronomy. Notes that there are forms of matter other than elements and compounds. Confounding examples from astronomy include white dwarfs, neutron…

  6. The search for dark matter

    NASA Astrophysics Data System (ADS)

    Cline, David B.

    2016-03-01

    We discuss the search for dark matter. We first review the data from LUX that excludes the low-mass WIMP region and slightly lowers the XENON100 limits. We provide a brief review of the problems with the claimed low-mass signals. We discuss the current expectations for SUSY-WIMP dark matter and show why very massive detectors like Darwin may be required. We discuss some theoretical predictions from the meeting. There was compelling evidence from events observed in the Galactic Center by Fermi-LAT of WIMP dark matter at the UCLA meeting. We recount the Richard Arnowitt Lectures at UCLA dark matter symposiums and his role in the development of the strategy to detect SUGRA dark matter. In Honor of Richard Arnowitt.

  7. Multi-Component Dark Matter

    SciTech Connect

    Zurek, Kathryn M.

    2008-11-01

    We explore multi-component dark matter models where the dark sector consists of multiple stable states with different mass scales, and dark forces coupling these states further enrich the dynamics. The multi-component nature of the dark matter naturally arises in supersymmetric models, where both R parity and an additional symmetry, such as a Z{sub 2}, is preserved. We focus on a particular model where the heavier component of dark matter carries lepton number and annihilates mostly to leptons. The heavier component, which is essentially a sterile neutrino, naturally explains the PAMELA, ATIC and synchrotron signals, without an excess in antiprotons which typically mars other models of weak scale dark matter. The lighter component, which may have a mass from a GeV to a TeV, may explain the DAMA signal, and may be visible in low threshold runs of CDMS and XENON, which search for light dark matter.

  8. Inflationary imprints on dark matter

    NASA Astrophysics Data System (ADS)

    Nurmi, Sami; Tenkanen, Tommi; Tuominen, Kimmo

    2015-11-01

    We show that dark matter abundance and the inflationary scale H could be intimately related. Standard Model extensions with Higgs mediated couplings to new physics typically contain extra scalars displaced from vacuum during inflation. If their coupling to Standard Model is weak, they will not thermalize and may easily constitute too much dark matter reminiscent to the moduli problem. As an example we consider Standard Model extended by a Z2 symmetric singlet s coupled to the Standard Model Higgs Φ via λ Φ†Φ s2. Dark matter relic density is generated non-thermally for λ lesssim 10-7. We show that the dark matter yield crucially depends on the inflationary scale. For H~ 1010 GeV we find that the singlet self-coupling and mass should lie in the regime λsgtrsim 10-9 and mslesssim 50 GeV to avoid dark matter overproduction.

  9. 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.

  10. What's the Matter?

    NASA Astrophysics Data System (ADS)

    Berry, L. A.

    2004-11-01

    Virtually all of the visible universe is composed of plasma. Yet, despite the introduction of plasma displays into everyday use, most people still don't know either what a plasma is or the breadth and importance of plasma applications and science. The Coalition for Plasma Science (CPS) is a broadly-based group of institutions and individuals whose goal is to increase the understanding of plasmas for non-technical audiences. CPS activities include maintaining a website, http://www.plasmacoalition.org, developing educational literature, organizing educational luncheon presentations for Members of Congress and their staffs, and responding to questions about plasmas that are received by the CPS e-mail or toll-free number. With the support of the APS/DPP and the IEEE/PSAC, the CPS is working on establishing a science fair prize for plasma related projects. These CPS activities depend on the voluntary labor of CPS members and associates. New participants are needed to enable more people to respond: The matter is plasma! Send an e-mail to the CPS at CPS@plasmacoalition.org for information.

  11. Gray matter heterotopia.

    PubMed

    Barkovich, A J; Kuzniecky, R I

    2000-12-12

    Gray matter heterotopia are common malformations of cortical development. From a clinical perspective, affected patients are best divided into three groups: subependymal, subcortical, and band heterotopia (also called double cortex). Symptomatic women with subependymal heterotopia typically present with partial epilepsy during the second decade of life; development and neurologic examinations up to that point are typically normal. Symptoms in men with subependymal heterotopia vary, depending on whether they have the X-linked or autosomal form. Men with the X-linked form more commonly have associated CNS and visceral anomalies; their development is typically abnormal. Symptomatic men with the autosomal variety have clinical courses similar to symptomatic women. Both men and women with subcortical heterotopia typically have congenital fixed neurologic deficits and develop partial epilepsy during the second half of the first decade of life. The more extensive the subcortical heterotopia, the greater the deficit; bilateral heterotopia are almost invariably associated with severe developmental delay or mental retardation. In general, band heterotopia are seen exclusively in women; men with a mutation of the related gene (called XLIS or DCX) usually die in utero or have a much more severe brain anomaly. Symptoms in affected women vary from normal to severe developmental delay or mental retardation; the severity of the syndrome is related to the thickness of the band of arrested neurons. Nearly all affected patients that come to medical attention have epilepsy, with partial complex and atypical absence epilepsy being the most common syndromes. Some of the more severely affected patients develop attacks.

  12. Probing gravitational dark matter

    NASA Astrophysics Data System (ADS)

    Ren, Jing; He, Hong-Jian

    2015-03-01

    So far all evidences of dark matter (DM) come from astrophysical and cosmological observations, due to the gravitational interactions of DM. It is possible that the true DM particle in the universe joins gravitational interactions only, but nothing else. Such a Gravitational DM (GDM) may act as a weakly interacting massive particle (WIMP), which is conceptually simple and attractive. In this work, we explore this direction by constructing the simplest scalar GDM particle χs. It is a Bbb Z2 odd singlet under the standard model (SM) gauge group, and naturally joins the unique dimension-4 interaction with Ricci curvature, ξsχs2Script R, where ξs is the dimensionless nonminimal coupling. We demonstrate that this gravitational interaction ξsχs2Script R, together with Higgs-curvature nonminimal coupling term ξhH†HScript R, induces effective couplings between χs2 and SM fields, and can account for the observed DM thermal relic abundance. We analyze the annihilation cross sections of GDM particles and derive the viable parameter space for realizing the DM thermal relic density. We further study the direct/indirect detections and the collider signatures of such a scalar GDM. These turn out to be highly predictive and testable.

  13. Probing gravitational dark matter

    SciTech Connect

    Ren, Jing; He, Hong-Jian E-mail: hjhe@tsinghua.edu.cn

    2015-03-01

    So far all evidences of dark matter (DM) come from astrophysical and cosmological observations, due to the gravitational interactions of DM. It is possible that the true DM particle in the universe joins gravitational interactions only, but nothing else. Such a Gravitational DM (GDM) may act as a weakly interacting massive particle (WIMP), which is conceptually simple and attractive. In this work, we explore this direction by constructing the simplest scalar GDM particle χ{sub s}. It is a Z{sub 2} odd singlet under the standard model (SM) gauge group, and naturally joins the unique dimension-4 interaction with Ricci curvature, ξ{sub s}χ{sub s}{sup 2}R, where ξ{sub s} is the dimensionless nonminimal coupling. We demonstrate that this gravitational interaction ξ{sub s}χ{sub s}{sup 2}R, together with Higgs-curvature nonminimal coupling term ξ{sub h}H{sup †}HR, induces effective couplings between χ{sub s}{sup 2} and SM fields, and can account for the observed DM thermal relic abundance. We analyze the annihilation cross sections of GDM particles and derive the viable parameter space for realizing the DM thermal relic density. We further study the direct/indirect detections and the collider signatures of such a scalar GDM. These turn out to be highly predictive and testable.

  14. Probing gravitational dark matter

    SciTech Connect

    Ren, Jing; He, Hong-Jian

    2015-03-27

    So far all evidences of dark matter (DM) come from astrophysical and cosmological observations, due to the gravitational interactions of DM. It is possible that the true DM particle in the universe joins gravitational interactions only, but nothing else. Such a Gravitational DM (GDM) may act as a weakly interacting massive particle (WIMP), which is conceptually simple and attractive. In this work, we explore this direction by constructing the simplest scalar GDM particle χ{sub s}. It is a ℤ{sub 2} odd singlet under the standard model (SM) gauge group, and naturally joins the unique dimension-4 interaction with Ricci curvature, ξ{sub s}χ{sub s}{sup 2}R, where ξ{sub s} is the dimensionless nonminimal coupling. We demonstrate that this gravitational interaction ξ{sub s}χ{sub s}{sup 2}R, together with Higgs-curvature nonminimal coupling term ξ{sub h}H{sup †}HR, induces effective couplings between χ{sub s}{sup 2} and SM fields, and can account for the observed DM thermal relic abundance. We analyze the annihilation cross sections of GDM particles and derive the viable parameter space for realizing the DM thermal relic density. We further study the direct/indirect detections and the collider signatures of such a scalar GDM. These turn out to be highly predictive and testable.

  15. Oscillating asymmetric dark matter

    NASA Astrophysics Data System (ADS)

    Tulin, Sean; Yu, Hai-Bo; Zurek, Kathryn M.

    2012-05-01

    We study the dynamics of dark matter (DM) particle-antiparticle oscillations within the context of asymmetric DM. Oscillations arise due to small DM number-violating Majorana-type mass terms, and can lead to recoupling of annihilation after freeze-out and washout of the DM density. Asymmetric DM oscillations "interpolate" between symmetric and asymmetric DM freeze-out scenarios, and allow for a larger DM model-building parameter space. We derive the density matrix equations for DM oscillations and freeze-out from first principles using nonequilibrium field theory, and our results are qualitatively different than in previous studies. DM dynamics exhibits particle-vs-antiparticle "flavor" effects, depending on the interaction type, analogous to neutrino oscillations in a medium. "Flavor-sensitive" DM interactions include scattering or annihilation through a new vector boson, while "flavor-blind" interactions include scattering or s-channel annihilation through a new scalar boson. In particular, we find that flavor-sensitive annihilation does not recouple when coherent oscillations begin, and that flavor-blind scattering does not lead to decoherence.

  16. Mind and matter

    PubMed Central

    Freris, Leon

    2013-01-01

    In the View Point article of Reference 1, the editor of CIB was kind enough to let me express my views on the topic of Darwinian evolution. Since then and mainly through contacts generated by that article, I felt that there was more to be said on this topic. The editor was kind enough to allow me to air my views again.   I have no qualifications in biology or philosophy, so the readers of CIB may find that some of the material on evolution in this article is well-known territory to them, but for me it was a part of the unfolding story that informed my understanding and led me to some conclusions. My thesis is that the explanations based on the present materialist/reductionist views on how experiential qualities developed out of inert matter are unconvincing and that an alternative viewpoint offers a more parsimonious and logically coherent account. The article presents my rearrangement of material contained or taken from references 2, 4, 5, and 6 linked by my own commentary. For a better-argued and ultimately more convincing exposition of the views in this article the interested reader should study the references. PMID:24505505

  17. Modeling Soft Matter

    NASA Astrophysics Data System (ADS)

    Kremer, Kurt

    Soft matter science or soft materials science is a relatively new term for the science of a huge class of rather different materials such as colloids, polymers (of synthetic or biological origin), membranes, complex molecular assemblies, complex fluids, etc. and combinations thereof. While many of these systems are contained in or are even the essential part of everyday products ("simple" plastics such as yoghurt cups, plastic bags, CDs, many car parts; gels and networks such as rubber, many low fat foods, "gummi" bears; colloidal systems such as milk, mayonnaise, paints, almost all cosmetics or body care products, the border lines between the different applications and systems are of course not sharp) or as biological molecules or assemblies (DNA, proteins, membranes and cytoskeleton, etc.) are central to our existence, others are basic ingredients of current and future high tech products (polymers with specific optical or electronic properties, conducting macromolecules, functional materials). Though the motivation is different in life science rather than in materials science biomolecular simulations, the basic structure of the problems faced in the two fields is very similar.

  18. Astrophysical Probes of Dark Matter

    NASA Astrophysics Data System (ADS)

    Profumo, S.

    2013-08-01

    What is the connection between how the dark matter was produced in the early universe and how we can detect it today? Where does the WIMP miracle come from, and is it really a "WIMP" miracle? What brackets the mass range for thermal relics? Where does <συ> come from, and what does it mean? What is the difference between chemical and kinetic decoupling? Why do some people think that dark matter cannot be lighter than 40 GeV? Why is bbar b such a popular annihilation final state? Why is antimatter a good way to look for dark matter? Why should the cosmic-ray positron fraction decline with energy? How do you calculate the flux of neutrinos from dark matter annihilation in a celestial body, and when is it independent of the dark matter pair-annihilation rate? How does dark matter produce photons? -- Read these lecture notes, do the suggested 10 exercises, and you will find answers to all of these questions (and to many more on what You Always Wanted to Know About Dark Matter But Were Afraid to Ask).

  19. Phases of cannibal dark matter

    DOE PAGES

    Farina, Marco; Pappadopulo, Duccio; Ruderman, Joshua T.; ...

    2016-12-13

    A hidden sector with a mass gap undergoes an epoch of cannibalism if number changing interactions are active when the temperature drops below the mass of the lightest hidden particle. During cannibalism, the hidden sector temperature decreases only logarithmically with the scale factor. We consider the possibility that dark matter resides in a hidden sector that underwent cannibalism, and has relic density set by the freeze-out of two-to-two annihilations. We identify three novel phases, depending on the behavior of the hidden sector when dark matter freezes out. During the cannibal phase, dark matter annihilations decouple while the hidden sector ismore » cannibalizing. During the chemical phase, only two-to-two interactions are active and the total number of hidden particles is conserved. During the one way phase, the dark matter annihilation products decay out of equilibrium, suppressing the production of dark matter from inverse annihilations. We map out the distinct phenomenology of each phase, which includes a boosted dark matter annihilation rate, new relativistic degrees of freedom, warm dark matter, and observable distortions to the spectrum of the cosmic microwave background.« less

  20. Dark matter and dark radiation

    SciTech Connect

    Ackerman, Lotty; Buckley, Matthew R.; Carroll, Sean M.; Kamionkowski, Marc

    2009-01-15

    We explore the feasibility and astrophysical consequences of a new long-range U(1) gauge field ('dark electromagnetism') that couples only to dark matter, not to the standard model. The dark matter consists of an equal number of positive and negative charges under the new force, but annihilations are suppressed if the dark-matter mass is sufficiently high and the dark fine-structure constant {alpha}-circumflex is sufficiently small. The correct relic abundance can be obtained if the dark matter also couples to the conventional weak interactions, and we verify that this is consistent with particle-physics constraints. The primary limit on {alpha}-circumflex comes from the demand that the dark matter be effectively collisionless in galactic dynamics, which implies {alpha}-circumflex < or approx. 10{sup -3} for TeV-scale dark matter. These values are easily compatible with constraints from structure formation and primordial nucleosynthesis. We raise the prospect of interesting new plasma effects in dark-matter dynamics, which remain to be explored.

  1. Phases of cannibal dark matter

    SciTech Connect

    Farina, Marco; Pappadopulo, Duccio; Ruderman, Joshua T.; Trevisan, Gabriele

    2016-12-13

    A hidden sector with a mass gap undergoes an epoch of cannibalism if number changing interactions are active when the temperature drops below the mass of the lightest hidden particle. During cannibalism, the hidden sector temperature decreases only logarithmically with the scale factor. We consider the possibility that dark matter resides in a hidden sector that underwent cannibalism, and has relic density set by the freeze-out of two-to-two annihilations. We identify three novel phases, depending on the behavior of the hidden sector when dark matter freezes out. During the cannibal phase, dark matter annihilations decouple while the hidden sector is cannibalizing. During the chemical phase, only two-to-two interactions are active and the total number of hidden particles is conserved. During the one way phase, the dark matter annihilation products decay out of equilibrium, suppressing the production of dark matter from inverse annihilations. We map out the distinct phenomenology of each phase, which includes a boosted dark matter annihilation rate, new relativistic degrees of freedom, warm dark matter, and observable distortions to the spectrum of the cosmic microwave background.

  2. Skew-flavored dark matter

    DOE PAGES

    Agrawal, Prateek; Chacko, Zackaria; Fortes, Elaine C. F. S.; ...

    2016-05-10

    We explore a novel flavor structure in the interactions of dark matter with the Standard Model. We consider theories in which both the dark matter candidate, and the particles that mediate its interactions with the Standard Model fields, carry flavor quantum numbers. The interactions are skewed in flavor space, so that a dark matter particle does not directly couple to the Standard Model matter fields of the same flavor, but only to the other two flavors. This framework respects minimal flavor violation and is, therefore, naturally consistent with flavor constraints. We study the phenomenology of a benchmark model in whichmore » dark matter couples to right-handed charged leptons. In large regions of parameter space, the dark matter can emerge as a thermal relic, while remaining consistent with the constraints from direct and indirect detection. The collider signatures of this scenario include events with multiple leptons and missing energy. In conclusion, these events exhibit a characteristic flavor pattern that may allow this class of models to be distinguished from other theories of dark matter.« less

  3. Skew-flavored dark matter

    SciTech Connect

    Agrawal, Prateek; Chacko, Zackaria; Fortes, Elaine C. F. S.; Kilic, Can

    2016-05-10

    We explore a novel flavor structure in the interactions of dark matter with the Standard Model. We consider theories in which both the dark matter candidate, and the particles that mediate its interactions with the Standard Model fields, carry flavor quantum numbers. The interactions are skewed in flavor space, so that a dark matter particle does not directly couple to the Standard Model matter fields of the same flavor, but only to the other two flavors. This framework respects minimal flavor violation and is, therefore, naturally consistent with flavor constraints. We study the phenomenology of a benchmark model in which dark matter couples to right-handed charged leptons. In large regions of parameter space, the dark matter can emerge as a thermal relic, while remaining consistent with the constraints from direct and indirect detection. The collider signatures of this scenario include events with multiple leptons and missing energy. In conclusion, these events exhibit a characteristic flavor pattern that may allow this class of models to be distinguished from other theories of dark matter.

  4. Skew-flavored dark matter

    SciTech Connect

    Agrawal, Prateek; Chacko, Zackaria; Fortes, Elaine C. F. S.; Kilic, Can

    2016-05-10

    We explore a novel flavor structure in the interactions of dark matter with the Standard Model. We consider theories in which both the dark matter candidate, and the particles that mediate its interactions with the Standard Model fields, carry flavor quantum numbers. The interactions are skewed in flavor space, so that a dark matter particle does not directly couple to the Standard Model matter fields of the same flavor, but only to the other two flavors. This framework respects minimal flavor violation and is, therefore, naturally consistent with flavor constraints. We study the phenomenology of a benchmark model in which dark matter couples to right-handed charged leptons. In large regions of parameter space, the dark matter can emerge as a thermal relic, while remaining consistent with the constraints from direct and indirect detection. The collider signatures of this scenario include events with multiple leptons and missing energy. In conclusion, these events exhibit a characteristic flavor pattern that may allow this class of models to be distinguished from other theories of dark matter.

  5. Phases of cannibal dark matter

    NASA Astrophysics Data System (ADS)

    Farina, Marco; Pappadopulo, Duccio; Ruderman, Joshua T.; Trevisan, Gabriele

    2016-12-01

    A hidden sector with a mass gap undergoes an epoch of cannibalism if number changing interactions are active when the temperature drops below the mass of the lightest hidden particle. During cannibalism, the hidden sector temperature decreases only logarithmically with the scale factor. We consider the possibility that dark matter resides in a hidden sector that underwent cannibalism, and has relic density set by the freeze-out of two-to-two annihilations. We identify three novel phases, depending on the behavior of the hidden sector when dark matter freezes out. During the cannibal phase, dark matter annihilations decouple while the hidden sector is cannibalizing. During the chemical phase, only two-to-two interactions are active and the total number of hidden particles is conserved. During the one way phase, the dark matter annihilation products decay out of equilibrium, suppressing the production of dark matter from inverse annihilations. We map out the distinct phenomenology of each phase, which includes a boosted dark matter annihilation rate, new relativistic degrees of freedom, warm dark matter, and observable distortions to the spectrum of the cosmic microwave background.

  6. Experimental soft-matter science

    NASA Astrophysics Data System (ADS)

    Nagel, Sidney R.

    2017-04-01

    Soft materials consist of basic units that are significantly larger than an atom but much smaller than the overall dimensions of the sample. The label "soft condensed matter" emphasizes that the large basic building blocks of these materials produce low elastic moduli that govern a material's ability to withstand deformations. Aside from softness, there are many other properties that are also caused by the large size of the constituent building blocks. Soft matter is dissipative, disordered, far from equilibrium, nonlinear, thermal and entropic, slow, observable, gravity affected, patterned, nonlocal, interfacially elastic, memory forming, and active. This is only a partial list of how matter created from large component particles is distinct from "hard matter" composed of constituents at an atomic scale. Issues inherent in soft matter raise problems that are broadly important in diverse areas of science and require multiple modes of attack. For example, far-from-equilibrium behavior is confronted in biology, chemistry, geophysics, astrophysics, and nuclear physics. Similarly, issues dealing with disorder appear broadly throughout many branches of inquiry wherever rugged landscapes are invoked. This article reviews the discussions that occurred during a workshop held on 30-31 January 2016 in which opportunities in soft-matter experiment were surveyed. Soft matter has had an exciting history of discovery and continues to be a fertile ground for future research.

  7. Lectures on Dark Matter Physics

    NASA Astrophysics Data System (ADS)

    Lisanti, Mariangela

    Rotation curve measurements from the 1970s provided the first strong indication that a significant fraction of matter in the Universe is non-baryonic. In the intervening years, a tremendous amount of progress has been made on both the theoretical and experimental fronts in the search for this missing matter, which we now know constitutes nearly 85% of the Universe's matter density. These series of lectures provide an introduction to the basics of dark matter physics. They are geared for the advanced undergraduate or graduate student interested in pursuing research in high-energy physics. The primary goal is to build an understanding of how observations constrain the assumptions that can be made about the astro- and particle physics properties of dark matter. The lectures begin by delineating the basic assumptions that can be inferred about dark matter from rotation curves. A detailed discussion of thermal dark matter follows, motivating Weakly Interacting Massive Particles, as well as lighter-mass alternatives. As an application of these concepts, the phenomenology of direct and indirect detection experiments is discussed in detail.

  8. Condensed Matter Nuclear Science

    NASA Astrophysics Data System (ADS)

    Biberian, Jean-Paul

    2006-02-01

    1. General. A tribute to gene Mallove - the "Genie" reactor / K. Wallace and R. Stringham. An update of LENR for ICCF-11 (short course, 10/31/04) / E. Storms. New physical effects in metal deuterides / P. L. Hagelstein ... [et al.]. Reproducibility, controllability, and optimization of LENR experiments / D. J. Nagel -- 2. Experiments. Electrochemistry. Evidence of electromagnetic radiation from Ni-H systems / S. Focardi ... [et al.]. Superwave reality / I. Dardik. Excess heat in electrolysis experiments at energetics technologies / I. Dardik ... [et al.]. "Excess heat" during electrolysis in platinum/K[symbol]CO[symbol]/nickel light water system / J. Tian ... [et al.]. Innovative procedure for the, in situ, measurement of the resistive thermal coefficient of H(D)/Pd during electrolysis; cross-comparison of new elements detected in the Th-Hg-Pd-D(H) electrolytic cells / F. Celani ... [et al.]. Emergence of a high-temperature superconductivity in hydrogen cycled Pd compounds as an evidence for superstoihiometric H/D sites / A. Lipson ... [et al.]. Plasma electrolysis. Calorimetry of energy-efficient glow discharge - apparatus design and calibration / T. B. Benson and T. O. Passell. Generation of heat and products during plasma electrolysis / T. Mizuno ... [et al.]. Glow discharge. Excess heat production in Pd/D during periodic pulse discharge current in various conditions / A. B. Karabut. Beam experiments. Accelerator experiments and theoretical models for the electron screening effect in metallic environments / A. Huke, K. Czerski, and P. Heide. Evidence for a target-material dependence of the neutron-proton branching ratio in d+d reactions for deuteron energies below 20keV / A. Huke ... [et al.]. Experiments on condensed matter nuclear events in Kobe University / T. Minari ... [et al.]. Electron screening constraints for the cold fusion / K. Czerski, P. Heide, and A. Huke. Cavitation. Low mass 1.6 MHz sonofusion reactor / R. Stringham. Particle detection. Research

  9. Nucleation of quark matter in protoneutron star matter

    SciTech Connect

    Mintz, B. W.; Fraga, E. S.; Pagliara, G.; Schaffner-Bielich, J.

    2010-06-15

    The phase transition from hadronic to quark matter may take place already during the early post-bounce stage of core collapse supernovae when matter is still hot and lepton rich. If the phase transition is of first order and exhibits a barrier, the formation of the new phase occurs via the nucleation of droplets. We investigate the thermal nucleation of a quark phase in supernova matter and calculate its rate for a wide range of physical parameters. We show that the formation of the first droplet of a quark phase might be very fast and therefore the phase transition to quark matter could play an important role in the mechanism and dynamics of supernova explosions.

  10. Mixed dark matter from technicolor

    SciTech Connect

    Belyaev, Alexander; Frandsen, Mads T.; Sarkar, Subir; Sannino, Francesco

    2011-01-01

    We study natural composite cold dark matter candidates which are pseudo-Nambu-Goldstone bosons (pNGB) in models of dynamical electroweak symmetry breaking. Some of these can have a significant thermal relic abundance, while others must be mainly asymmetric dark matter. By considering the thermal abundance alone we find a lower bound of m{sub W} on the pNGB mass when the (composite) Higgs is heavier than 115 GeV. Being pNGBs, the dark matter candidates are in general light enough to be produced at the LHC.

  11. Capturing prokaryotic dark matter genomes.

    PubMed

    Gasc, Cyrielle; Ribière, Céline; Parisot, Nicolas; Beugnot, Réjane; Defois, Clémence; Petit-Biderre, Corinne; Boucher, Delphine; Peyretaillade, Eric; Peyret, Pierre

    2015-12-01

    Prokaryotes are the most diverse and abundant cellular life forms on Earth. Most of them, identified by indirect molecular approaches, belong to microbial dark matter. The advent of metagenomic and single-cell genomic approaches has highlighted the metabolic capabilities of numerous members of this dark matter through genome reconstruction. Thus, linking functions back to the species has revolutionized our understanding of how ecosystem function is sustained by the microbial world. This review will present discoveries acquired through the illumination of prokaryotic dark matter genomes by these innovative approaches. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  12. Mass extinctions and missing matter

    NASA Technical Reports Server (NTRS)

    Stothers, R. B.

    1984-01-01

    The possible influence of 'invisible matter' on the solar system's comet halo, and therefore on quasi-periodic cometary bombardment of the earth and consequent mass extinctions, is briefly addressed. Invisible matter consisting of small or cold interstellar molecular clouds could significantly modulate the comet background flux, while invisible matter consisting of a large population of old, dead stars with a relatively small galactic concentration probably could not. It is also shown that the downward force exerted by the Galaxy will perturb the halo, but will not produce any periodicity.

  13. Mass extinctions and missing matter

    NASA Technical Reports Server (NTRS)

    Stothers, R. B.

    1984-01-01

    The possible influence of 'invisible matter' on the solar system's comet halo, and therefore on quasi-periodic cometary bombardment of the earth and consequent mass extinctions, is briefly addressed. Invisible matter consisting of small or cold interstellar molecular clouds could significantly modulate the comet background flux, while invisible matter consisting of a large population of old, dead stars with a relatively small galactic concentration probably could not. It is also shown that the downward force exerted by the Galaxy will perturb the halo, but will not produce any periodicity.

  14. Detection of cosmic dark matter

    SciTech Connect

    Primack, J.R.; Seckel, D.; Sadoulet, B.

    1988-01-01

    This is a mid-1988 status report on attempts to detect particle dark matter. We have some prejudice in limiting ourselves to dark matter candidates that we feel are especially motivated: weakly interacting massive particles (WIMPs), axions, and light neutrinos. Much of our review centers on the possibility of detecting WIMPs. This is partly because there exist several methods by which WIMPs may be detected in the next decade, whereas for axions the prospects are more uncertain and for light neutrinos essentially nonexistent. In addition, we feel that WIMPs provide a natural way for a critical density of dark matter to occur within the context of plausible particle theories. (AIP)

  15. White matter plasticity in adulthood.

    PubMed

    Wang, S; Young, K M

    2014-09-12

    CNS white matter is subject to a novel form of neural plasticity which has been termed "myelin plasticity". It is well established that oligodendrocyte generation and the addition of new myelin internodes continue throughout normal adulthood. These new myelin internodes maybe required for the de novo myelination of previously unmyelinated axons, myelin sheath replacement, or even myelin remodeling. Each process could alter axonal conduction velocity, but to what end? We review the changes that occur within the white matter over the lifetime, the known regulators and mediators of white matter plasticity in the mature CNS, and the physiological role this plasticity may play in CNS function.

  16. Soliton matter as a model of dense nuclear matter

    SciTech Connect

    Glendenning, N.K.

    1985-01-01

    We employ the hybrid soliton model of the nucleon consisting of a topological meson field and deeply bound quarks to investigate the behavior of the quarks in soliton matter as a function of density. To organize the calculation, we place the solitons on a spatial lattice. The model suggests the transition of matter from a color insulator to a color conductor above a critical density of a few times normal nuclear density. 9 references, 5 figures.

  17. Matter parity as the origin of scalar dark matter

    SciTech Connect

    Kadastik, Mario; Kannike, Kristjan; Raidal, Martti

    2010-01-01

    We extend the concept of matter parity P{sub M}=(-1){sup 3(B-L)} to nonsupersymmetric theories and argue that P{sub M} is the natural explanation to the existence of dark matter of the Universe. We show that the nonsupersymmetric dark matter must be contained in a scalar 16 representation(s) of SO(10), thus the unique low-energy dark matter candidates are P{sub M}-odd complex scalar singlet(s) S and an inert scalar doublet(s) H{sub 2}. We have calculated the thermal relic dark matter (DM) abundance of the model and shown that its minimal form may be testable at LHC via the standard model (SM) Higgs boson decays H{sub 1{yields}}DM DM. The PAMELA anomaly can be explained with the decays DM{yields}{nu}lW induced via seesawlike operator which is additionally suppressed by the Planck scale. Because the SM fermions are odd under matter parity too, the DM sector is just our scalar relative.

  18. Dwarf Dark Matter Halos

    NASA Astrophysics Data System (ADS)

    Colín, P.; Klypin, A.; Valenzuela, O.; Gottlöber, Stefan

    2004-09-01

    We study properties of dark matter halos at high redshifts z=2-10 for a vast range of masses with the emphasis on dwarf halos with masses of 107-109 h-1 Msolar. We find that the density profiles of relaxed dwarf halos are well fitted by the Navarro, Frenk, & White (NFW) profile and do not have cores. We compute the halo mass function and the halo spin parameter distribution and find that the former is very well reproduced by the Sheth & Tormen model, while the latter is well fitted by a lognormal distribution with λ0=0.042 and σλ=0.63. We estimate the distribution of concentrations for halos in a mass range that covers 6 orders of magnitude, from 107 to 1013 h-1 Msolar, and find that the data are well reproduced by the model of Bullock et al. The extrapolation of our results to z=0 predicts that present-day isolated dwarf halos should have a very large median concentration of ~35. We measure the subhalo circular velocity functions for halos with masses that range from 4.6×109 to 1013 h-1 Msolar and find that they are similar when normalized to the circular velocity of the parent halo. Dwarf halos studied in this paper are many orders of magnitude smaller than well-studied cluster- and Milky Way-sized halos. Yet, in all respects the dwarfs are just downscaled versions of the large halos. They are cuspy and, as expected, more concentrated. They have the same spin parameter distribution and follow the same mass function that was measured for large halos.

  19. Cerebral White Matter

    PubMed Central

    Schmahmann, Jeremy D.; Smith, Eric E.; Eichler, Florian S.; Filley, Christopher M.

    2013-01-01

    Lesions of the cerebral white matter (WM) result in focal neurobehavioral syndromes, neuropsychiatric phenomena, and dementia. The cerebral WM contains fiber pathways that convey axons linking cerebral cortical areas with each other and with subcortical structures, facilitating the distributed neural circuits that subserve sensorimotor function, intellect, and emotion. Recent neuroanatomical investigations reveal that these neural circuits are topographically linked by five groupings of fiber tracts emanating from every neocortical area: (1) cortico-cortical association fibers; (2) corticostriatal fibers; (3) commissural fibers; and cortico-subcortical pathways to (4) thalamus and (5) pontocerebellar system, brain stem, and/or spinal cord. Lesions of association fibers prevent communication between cortical areas engaged in different domains of behavior. Lesions of subcortical structures or projection/striatal fibers disrupt the contribution of subcortical nodes to behavior. Disconnection syndromes thus result from lesions of the cerebral cortex, subcortical structures, and WM tracts that link the nodes that make up the distributed circuits. The nature and the severity of the clinical manifestations of WM lesions are determined, in large part, by the location of the pathology: discrete neurological and neuropsychiatric symptoms result from focal WM lesions, whereas cognitive impairment across multiple domains—WM dementia—occurs in the setting of diffuse WM disease. We present a detailed review of the conditions affecting WM that produce these neurobehavioral syndromes, and consider the pathophysiology, clinical effects, and broad significance of the effects of aging and vascular compromise on cerebral WM, in an attempt to help further the understanding, diagnosis, and treatment of these disorders. PMID:18990132

  20. From Matter to Life

    NASA Astrophysics Data System (ADS)

    Imari Walker, Sara; Davies, Paul C. W.; Ellis, George F. R.

    2017-02-01

    1. Introduction Sara Imari Walker, Paul C. W. Davies and F. R. Ellis; Part I. Physics and Life: 2. The 'hard problem' of life Sara Imari Walker and Paul C. W. Davies; 3. Beyond initial conditions and laws of motion: constructor theory of information and life Chiara Marletto; Part II. Bio from Bit: 4. (How) did information emerge? Anne-Marie Grisogono; 5. On the emerging codes for chemical evolution Jillian E. Smith-Carpenter, Sha Li, Jay T. Goodwin, Anil K. Mehta and David G. Lynn; 6. Digital and analogue information in organisms Denis Noble; 7. From entropy to information: biased typewriters and the origin of life Christoph Adami and Thomas Labar; Part III. Life's Hidden Information: 8. Cryptographic nature David Krakauer; 9. Noise and function Steven Weinstein and Theodore Pavlic; 10. The many faces of state space compression David Wolpert, Eric Libby, Joshua Grochow and Simon DeDeo; 11. Causality, information and biological computation: an algorithmic software approach to life, disease and the immune system Hector Zenil, Angelika Schmidt and Jesper Tegnér; Part IV. Complexity and Causality: 12. Life's information hierarchy Jessica Flack; 13. Living through downward causation: from molecules to ecosystems Keith D. Farnsworth, George F. R. Ellis and Luc Jaeger; 14. Automata and animats: from dynamics to cause-effect structures Larissa Albantakis and Giulio Tononi; 15. Biological information, causality and specificity - an intimate relationship Karola Stotz and Paul Griffiths; Part V. From Matter to Mind: 16. Major transitions in political order Simon DeDeo; 17. Bits from biology for computational intelligence Michael Wibral, Joseph Lizier and Viola Priesemann; 18. Machine learning and the questions it raises G. Andrew D. Briggs and Dawid Potgieter.

  1. Integrated coherent matter wave circuits

    DOE PAGES

    Ryu, C.; Boshier, M. G.

    2015-09-21

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through theirmore » electric polarizability. Moreover, the source of coherent matter waves is a Bose–Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry.« less

  2. The Dark Matter of Biology.

    PubMed

    Ross, Jennifer L

    2016-09-06

    The inside of the cell is full of important, yet invisible species of molecules and proteins that interact weakly but couple together to have huge and important effects in many biological processes. Such "dark matter" inside cells remains mostly hidden, because our tools were developed to investigate strongly interacting species and folded proteins. Example dark-matter species include intrinsically disordered proteins, posttranslational states, ion species, and rare, transient, and weak interactions undetectable by biochemical assays. The dark matter of biology is likely to have multiple, vital roles to regulate signaling, rates of reactions, water structure and viscosity, crowding, and other cellular activities. We need to create new tools to image, detect, and understand these dark-matter species if we are to truly understand fundamental physical principles of biology. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  3. The LZ dark matter experiment

    NASA Astrophysics Data System (ADS)

    McKinsey, D. N.; LZ Collaboration

    2016-05-01

    The LUX and ZEPLIN collaborations have merged to construct a 7 tonne two-phase Xe dark matter detector, known as LUX-ZEPLIN or LZ. Chosen as one of the Generation 2 suite of dark matter direct detection experiments, LZ will probe spin-independent WIMP-nucleon cross sections down to 2 × 10-48 cm2 at 50 GeV/c2 within 3 years of operation, covering a substantial range of theoretically-motivated dark matter candidates. Along with dark matter interactions with Xe nuclei, LZ will also be sensitive to solar neutrinos emitted by the pp fusion process in the sun, neutrinos emitted by a nearby supernova and detected by coherent neutrino-nucleus scattering, certain classes of axions and axion-like particles, and neutrinoless double-beta decay of 136Xe. The design of LZ is presented, along with its expected backgrounds and projected sensitivity.

  4. Active matter, then and now.

    PubMed

    Keller, Evelyn Fox

    2016-09-01

    Historically, living was divided from dead, inert matter by its autonomous activity. Today, a number of materials not themselves alive are characterized as having inherent activity, and this activity has become the subject of a hot new field of physics, "Active Matter", or "Soft matter become alive." For active matter scientists, the relation of physics to biology is guaranteed in one direction by the assertion that the cell is a material, and hence its study can be considered a branch of material science, and in the other direction, by the claim that the physical dynamics of this material IS what brings the cell to life, and therefore its study is a proper branch of biology. I will examine these claims in relation to the concerns of nineteenth century scientists on the one hand, and on the other, in relation to future prospects of the division between animate and inanimate.

  5. Thermodynamics of cosmological matter creation

    PubMed Central

    Prigogine, I.; Geheniau, J.; Gunzig, E.; Nardone, P.

    1988-01-01

    A type of cosmological history that includes large-scale entropy production is proposed. These cosmologies are based on reinterpretation of the matter-energy stress tensor in Einstein's equations. This modifies the usual adiabatic energy conservation laws, thereby including irreversible matter creation. This creation corresponds to an irreversible energy flow from the gravitational field to the created matter constituents. This point of view results from consideration of the thermodynamics of open systems in the framework of cosmology. It is shown that the second law of thermodynamics requires that space-time transforms into matter, while the inverse transformation is forbidden. It appears that the usual initial singularity associated with the big bang is structurally unstable with respect to irreversible matter creation. The corresponding cosmological history therefore starts from an instability of the vacuum rather than from a singularity. This is exemplified in the framework of a simple phenomenological model that leads to a three-stage cosmology: the first drives the cosmological system from the initial instability to a de Sitter regime, and the last connects with the usual matter-radiation Robertson-Walker universe. Matter as well as entropy creation occurs during the first two stages, while the third involves the traditional cosmological evolution. A remarkable fact is that the de Sitter stage appears to be an attractor independent of the initial fluctuation. This is also the case for all the physical predictions involving the present Robertson-Walker universe. Most results obtained previously, in the framework of quantum field theory, can now be obtained on a macroscopic basis. It is shown that this description leads quite naturally to the introduction of primeval black holes as the intermediate stage between the Minkowski vacuum and the present matter-radiation universe. The instability at the origin of the universe is the result of fluctuations of the

  6. Thermodynamics of cosmological matter creation.

    PubMed

    Prigogine, I; Geheniau, J; Gunzig, E; Nardone, P

    1988-10-01

    A type of cosmological history that includes large-scale entropy production is proposed. These cosmologies are based on reinterpretation of the matter-energy stress tensor in Einstein's equations. This modifies the usual adiabatic energy conservation laws, thereby including irreversible matter creation. This creation corresponds to an irreversible energy flow from the gravitational field to the created matter constituents. This point of view results from consideration of the thermodynamics of open systems in the framework of cosmology. It is shown that the second law of thermodynamics requires that space-time transforms into matter, while the inverse transformation is forbidden. It appears that the usual initial singularity associated with the big bang is structurally unstable with respect to irreversible matter creation. The corresponding cosmological history therefore starts from an instability of the vacuum rather than from a singularity. This is exemplified in the framework of a simple phenomenological model that leads to a three-stage cosmology: the first drives the cosmological system from the initial instability to a de Sitter regime, and the last connects with the usual matter-radiation Robertson-Walker universe. Matter as well as entropy creation occurs during the first two stages, while the third involves the traditional cosmological evolution. A remarkable fact is that the de Sitter stage appears to be an attractor independent of the initial fluctuation. This is also the case for all the physical predictions involving the present Robertson-Walker universe. Most results obtained previously, in the framework of quantum field theory, can now be obtained on a macroscopic basis. It is shown that this description leads quite naturally to the introduction of primeval black holes as the intermediate stage between the Minkowski vacuum and the present matter-radiation universe. The instability at the origin of the universe is the result of fluctuations of the

  7. Lorentz-violating dark matter

    NASA Astrophysics Data System (ADS)

    Mondragon, Antonio R.

    Observations from the 1930s until the present have established the existence of dark matter with an abundance that is much larger than that of luminous matter. Because none of the known particles of nature have the correct properties to be identified as the dark matter, various exotic candidates have been proposed. The neutralino of supersymmetric theories is the most promising example. Such cold dark matter candidates, however, lead to a conflict between the standard simulations of the evolution of cosmic structure and observations. Simulations predict excessive structure formation on small scales, including density cusps at the centers of galaxies, that is not observed. This conflict still persists in early 2007, and it has not yet been convincingly resolved by attempted explanations that invoke astrophysical phenomena, which would destroy or broaden all small scale structure. We have investigated another candidate that is perhaps more exotic: Lorentz-violating dark matter, which was originally motivated by an unconventional fundamental theory, but which in this dissertation is defined as matter which has a nonzero minimum velocity. Furthermore, the present investigation evolved into the broader goal of exploring the properties of Lorentz-violating matter and the astrophysical consequences-a subject which to our knowledge has not been previously studied. Our preliminary investigations indicated that this form of matter might have less tendency to form small-scale structure. These preliminary calculations certainly established that Lorentz-violating matter which always moves at an appreciable fraction of the speed of light will bind less strongly. However, the much more thorough set of studies reported here lead to the conclusion that, although the binding energy is reduced, the small-scale structure problem is not solved by Lorentz-violating dark matter. On the other hand, when we compare the predictions of Lorentz-violating dynamics with those of classical

  8. A History of Dark Matter

    SciTech Connect

    Bertone, Gianfranco; Hooper, Dan

    2016-05-16

    Although dark matter is a central element of modern cosmology, the history of how it became accepted as part of the dominant paradigm is often ignored or condensed into a brief anecdotical account focused around the work of a few pioneering scientists. The aim of this review is to provide the reader with a broader historical perspective on the observational discoveries and the theoretical arguments that led the scientific community to adopt dark matter as an essential part of the standard cosmological model.

  9. Strongly interacting parton matter equilibration

    SciTech Connect

    Ozvenchuk, V.; Linnyk, O.; Bratkovskaya, E.; Gorenstein, M.; Cassing, W.

    2012-07-15

    We study the kinetic and chemical equilibration in 'infinite' parton matter within the Parton-Hadron-String Dynamics transport approach. The 'infinite' matter is simulated within a cubic box with periodic boundary conditions initialized at different energy densities. Particle abundances, kinetic energy distributions, and the detailed balance of the off-shell quarks and gluons in the strongly-interacting quarkgluon plasma are addressed and discussed.

  10. Did LIGO Detect Dark Matter?

    NASA Astrophysics Data System (ADS)

    Bird, Simeon; Cholis, Ilias; Munoz, Julian; Ali-Haimoud, Yacine; Kamionkowski, Marc; Kovetz, Ely; Raccanelli, Alvise; Riess, Adam

    2017-01-01

    There is a possibility that the recent LIGO detection of gravitational waves originated from the merger of two primordial black holes, making up the dark matter. Thirty solar mass black holes, as detected by LIGO, lie within an allowed mass window for primordial black hole dark matter. Interestingly, our best estimates of the number of observable mergers fall within the range implied by current LIGO data. I will explain these estimates and discuss the (considerable!) theoretical uncertainties.

  11. Dark matter triggers of supernovae

    NASA Astrophysics Data System (ADS)

    Graham, Peter W.; Rajendran, Surjeet; Varela, Jaime

    2015-09-01

    The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to 1.25 M⊙ rules out primordial black holes with masses ˜1019- 1020 gm as a dominant constituent of the local dark matter density. Black holes with masses as large as 1024 gm will be excluded if recent observations by the NuStar Collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range 1020- 1022 gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism proposed in this paper can constrain a variety of other dark matter scenarios such as Q balls, annihilation/collision of large composite states of dark matter and models of dark matter where the accretion of dark matter leads to the formation of compact cores within the star. White dwarfs, with their astronomical lifetimes and sizes, can thus act as large spacetime volume detectors enabling a unique probe of the properties of dark matter, especially of dark matter candidates that have low number density. This mechanism also raises the intriguing possibility that a class of supernova may be triggered through rare events induced by dark matter rather than the conventional mechanism of accreting white dwarfs that explode upon reaching the Chandrasekhar mass.

  12. Dark matter beams at LBNF

    SciTech Connect

    Coloma, Pilar; Dobrescu, Bogdan A.; Frugiuele, Claudia; Harnik, Roni

    2016-04-08

    High-intensity neutrino beam facilities may produce a beam of light dark matter when protons strike the target. Searches for such a dark matter beam using its scattering in a nearby detector must overcome the large neutrino background. We characterize the spatial and energy distributions of the dark matter and neutrino beams, focusing on their differences to enhance the sensitivity to dark matter. We find that a dark matter beam produced by a Z$^{'}$ boson in the GeV mass range is both broader and more energetic than the neutrino beam. The reach for dark matter is maximized for a detector sensitive to hard neutral-current scatterings, placed at a sizable angle off the neutrino beam axis. In the case of the Long-Baseline Neutrino Facility (LBNF), a detector placed at roughly 6 degrees off axis and at a distance of about 200 m from the target would be sensitive to Z$^{'}$ couplings as low as 0.05. This search can proceed symbiotically with neutrino measurements. We also show that the MiniBooNE and MicroBooNE detectors, which are on Fermilab’s Booster beamline, happen to be at an optimal angle from the NuMI beam and could perform searches with existing data. As a result, this illustrates potential synergies between LBNF and the short-baseline neutrino program if the detectors are positioned appropriately.

  13. Dark Matter with Variable Masses

    NASA Astrophysics Data System (ADS)

    García-Bellido, Juan

    String effective theories contain a dilaton scalar field which couples to gravity, matter and radiation. In general, particle masses will have different dilaton couplings. We can always choose a conformal frame in which baryons have constant masses while (nonbaryonic) dark matter have variable masses, in the context of a scalar-tensor gravity theory. We are interested in the phenomenology of this scenario. Dark matter with variable masses could have a measurable effect on the dynamical motion of the halo of spiral galaxies, which may affect cold dark matter models of galaxy formation. As a consequence of variable masses, the energy-momentum tensor is not conserved; there is a dissipative effect, due to the dilaton coupling, associated with a “dark entropy” production. In particular, if axions had variable masses they could be diluted away, thus opening the “axion window.” Assuming that dark matter with variable masses dominates the cosmological evolution during the matter era, it will affect the primordial nucleosynthesis predictions on the abundances of light elements. Furthermore, the dilaton also couples to radiation in the form of a variable gauge coupling. Experimental bounds will constrain the parameters of this model.

  14. Extreme Mechanics of Growing Matter

    NASA Astrophysics Data System (ADS)

    Kuhl, Ellen

    2013-03-01

    Growth is a distinguishing feature of all living things. Unlike standard materials, living matter can autonomously respond to alterations in its environment. As a result of a continuous ultrastructural turnover and renewal of cells and extracellular matrix, living matter can undergo extreme changes in composition, size, and shape within the order of months, weeks, or days. While hard matter typically adapts by increasing its density to grow strong, soft matter adapts by increasing its volume to grow large. Here we provide a state-of-the-art review of growing matter, and compare existing mathematical models for growth and remodeling of living systems. Applications are plentiful ranging from plant growth to tumor growth, from asthma in the lungs to restenosis in the vasculature, from plastic to reconstructive surgery, and from skeletal muscle adaptation to heart failure. Using these examples, we discuss current challenges and potential future directions. We hope to initiate critical discussions around the biophysical modeling of growing matter as a powerful tool to better understand biological systems in health and disease. This research has been supported by the NSF CAREER award CMMI 0952021.

  15. Bootstrapping white matter segmentation, Eve++

    NASA Astrophysics Data System (ADS)

    Plassard, Andrew; Hinton, Kendra E.; Venkatraman, Vijay; Gonzalez, Christopher; Resnick, Susan M.; Landman, Bennett A.

    2015-03-01

    Multi-atlas labeling has come in wide spread use for whole brain labeling on magnetic resonance imaging. Recent challenges have shown that leading techniques are near (or at) human expert reproducibility for cortical gray matter labels. However, these approaches tend to treat white matter as essentially homogeneous (as white matter exhibits isointense signal on structural MRI). The state-of-the-art for white matter atlas is the single-subject Johns Hopkins Eve atlas. Numerous approaches have attempted to use tractography and/or orientation information to identify homologous white matter structures across subjects. Despite success with large tracts, these approaches have been plagued by difficulties in with subtle differences in course, low signal to noise, and complex structural relationships for smaller tracts. Here, we investigate use of atlas-based labeling to propagate the Eve atlas to unlabeled datasets. We evaluate single atlas labeling and multi-atlas labeling using synthetic atlases derived from the single manually labeled atlas. On 5 representative tracts for 10 subjects, we demonstrate that (1) single atlas labeling generally provides segmentations within 2mm mean surface distance, (2) morphologically constraining DTI labels within structural MRI white matter reduces variability, and (3) multi-atlas labeling did not improve accuracy. These efforts present a preliminary indication that single atlas labels with correction is reasonable, but caution should be applied. To purse multi-atlas labeling and more fully characterize overall performance, more labeled datasets would be necessary.

  16. Dark matter beams at LBNF

    DOE PAGES

    Coloma, Pilar; Dobrescu, Bogdan A.; Frugiuele, Claudia; ...

    2016-04-08

    High-intensity neutrino beam facilities may produce a beam of light dark matter when protons strike the target. Searches for such a dark matter beam using its scattering in a nearby detector must overcome the large neutrino background. We characterize the spatial and energy distributions of the dark matter and neutrino beams, focusing on their differences to enhance the sensitivity to dark matter. We find that a dark matter beam produced by a Zmore » $$^{'}$$ boson in the GeV mass range is both broader and more energetic than the neutrino beam. The reach for dark matter is maximized for a detector sensitive to hard neutral-current scatterings, placed at a sizable angle off the neutrino beam axis. In the case of the Long-Baseline Neutrino Facility (LBNF), a detector placed at roughly 6 degrees off axis and at a distance of about 200 m from the target would be sensitive to Z$$^{'}$$ couplings as low as 0.05. This search can proceed symbiotically with neutrino measurements. We also show that the MiniBooNE and MicroBooNE detectors, which are on Fermilab’s Booster beamline, happen to be at an optimal angle from the NuMI beam and could perform searches with existing data. As a result, this illustrates potential synergies between LBNF and the short-baseline neutrino program if the detectors are positioned appropriately.« less

  17. Dark matter and global symmetries

    SciTech Connect

    Mambrini, Yann; Profumo, Stefano; Queiroz, Farinaldo S.

    2016-08-03

    General considerations in general relativity and quantum mechanics are known to potentially rule out continuous global symmetries in the context of any consistent theory of quantum gravity. Assuming the validity of such considerations, we derive stringent bounds from gamma-ray, X-ray, cosmic-ray, neutrino, and CMB data on models that invoke global symmetries to stabilize the dark matter particle. We compute up-to-date, robust model-independent limits on the dark matter lifetime for a variety of Planck-scale suppressed dimension-five effective operators. We then specialize our analysis and apply our bounds to specific models including the Two-Higgs-Doublet, Left-Right, Singlet Fermionic, Zee-Babu, 3-3-1 and Radiative See-Saw models. Here, assuming that (i) global symmetries are broken at the Planck scale, that (ii) the non-renormalizable operators mediating dark matter decay have O(1) couplings, that (iii) the dark matter is a singlet field, and that (iv) the dark matter density distribution is well described by a NFW profile, we are able to rule out fermionic, vector, and scalar dark matter candidates across a broad mass range (keV-TeV), including the WIMP regime

  18. Dark matter and global symmetries

    DOE PAGES

    Mambrini, Yann; Profumo, Stefano; Queiroz, Farinaldo S.

    2016-08-03

    General considerations in general relativity and quantum mechanics are known to potentially rule out continuous global symmetries in the context of any consistent theory of quantum gravity. Assuming the validity of such considerations, we derive stringent bounds from gamma-ray, X-ray, cosmic-ray, neutrino, and CMB data on models that invoke global symmetries to stabilize the dark matter particle. We compute up-to-date, robust model-independent limits on the dark matter lifetime for a variety of Planck-scale suppressed dimension-five effective operators. We then specialize our analysis and apply our bounds to specific models including the Two-Higgs-Doublet, Left-Right, Singlet Fermionic, Zee-Babu, 3-3-1 and Radiative See-Sawmore » models. Here, assuming that (i) global symmetries are broken at the Planck scale, that (ii) the non-renormalizable operators mediating dark matter decay have O(1) couplings, that (iii) the dark matter is a singlet field, and that (iv) the dark matter density distribution is well described by a NFW profile, we are able to rule out fermionic, vector, and scalar dark matter candidates across a broad mass range (keV-TeV), including the WIMP regime« less

  19. Plasma dark matter direct detection

    NASA Astrophysics Data System (ADS)

    Clarke, J. D.; Foot, R.

    2016-01-01

    Dark matter in spiral galaxies like the Milky Way may take the form of a dark plasma. Hidden sector dark matter charged under an unbroken U(1)' gauge interaction provides a simple and well defined particle physics model realising this possibility. The assumed U(1)' neutrality of the Universe then implies (at least) two oppositely charged dark matter components with self-interactions mediated via a massless "dark photon" (the U(1)' gauge boson). In addition to nuclear recoils such dark matter can give rise to keV electron recoils in direct detection experiments. In this context, the detailed physical properties of the dark matter plasma interacting with the Earth is required. This is a complex system, which is here modelled as a fluid governed by the magnetohydrodynamic equations. These equations are numerically solved for some illustrative examples, and implications for direct detection experiments discussed. In particular, the analysis presented here leaves open the intriguing possibility that the DAMA annual modulation signal is due primarily to electron recoils (or even a combination of electron recoils and nuclear recoils). The importance of diurnal modulation (in addition to annual modulation) as a means of probing this kind of dark matter is also emphasised.

  20. Make dark matter charged again

    NASA Astrophysics Data System (ADS)

    Agrawal, Prateek; Cyr-Racine, Francis-Yan; Randall, Lisa; Scholtz, Jakub

    2017-05-01

    We revisit constraints on dark matter that is charged under a U(1) gauge group in the dark sector, decoupled from Standard Model forces. We find that the strongest constraints in the literature are subject to a number of mitigating factors. For instance, the naive dark matter thermalization timescale in halos is corrected by saturation effects that slow down isotropization for modest ellipticities. The weakened bounds uncover interesting parameter space, making models with weak-scale charged dark matter viable, even with electromagnetic strength interaction. This also leads to the intriguing possibility that dark matter self-interactions within small dwarf galaxies are extremely large, a relatively unexplored regime in current simulations. Such strong interactions suppress heat transfer over scales larger than the dark matter mean free path, inducing a dynamical cutoff length scale above which the system appears to have only feeble interactions. These effects must be taken into account to assess the viability of darkly-charged dark matter. Future analyses and measurements should probe a promising region of parameter space for this model.

  1. Plasma dark matter direct detection

    SciTech Connect

    Clarke, J.D.; Foot, R. E-mail: rfoot@unimelb.edu.au

    2016-01-01

    Dark matter in spiral galaxies like the Milky Way may take the form of a dark plasma. Hidden sector dark matter charged under an unbroken U(1)' gauge interaction provides a simple and well defined particle physics model realising this possibility. The assumed U(1)' neutrality of the Universe then implies (at least) two oppositely charged dark matter components with self-interactions mediated via a massless 'dark photon' (the U(1)' gauge boson). In addition to nuclear recoils such dark matter can give rise to keV electron recoils in direct detection experiments. In this context, the detailed physical properties of the dark matter plasma interacting with the Earth is required. This is a complex system, which is here modelled as a fluid governed by the magnetohydrodynamic equations. These equations are numerically solved for some illustrative examples, and implications for direct detection experiments discussed. In particular, the analysis presented here leaves open the intriguing possibility that the DAMA annual modulation signal is due primarily to electron recoils (or even a combination of electron recoils and nuclear recoils). The importance of diurnal modulation (in addition to annual modulation) as a means of probing this kind of dark matter is also emphasised.

  2. Cosmology of fermionic dark matter

    SciTech Connect

    Boeckel, Tillmann; Schaffner-Bielich, Juergen

    2007-11-15

    We explore a model for a fermionic dark matter particle family which decouples from the rest of the particles when at least all standard model particles are in equilibrium. We calculate the allowed ranges for mass and chemical potential to be compatible with big bang nucleosynthesis (BBN) calculations and WMAP data for a flat universe with dark energy ({omega}{sub {lambda}}{sup 0}=0.72, {omega}{sub M}{sup 0}=0.27, h=0.7). Futhermore we estimate the free streaming length for fermions and antifermions to allow comparison to large scale structure data (LSS). We find that for dark matter decoupling when all standard model particles are present even the least restrictive combined BBN calculation and WMAP results allow us to constrain the initial dark matter chemical potential to a highest value of 6.3 times the dark matter temperature. In this case, the resulting mass range is at most 1.8 eV{<=}m{<=}53 eV, where the upper bound scales linearly with g{sub eff}{sup s}(T{sub Dec}). From LSS we find that, similar to ordinary warm dark matter models, the particle mass has to be larger than {approx}500 eV [meaning g{sub eff}{sup s}(T{sub Dec})>10{sup 3}] to be compatible with observations of the Ly {alpha} forest at high redshift, but still the dark matter chemical potential over temperature ratio can exceed unity.

  3. Dark matter and global symmetries

    NASA Astrophysics Data System (ADS)

    Mambrini, Yann; Profumo, Stefano; Queiroz, Farinaldo S.

    2016-09-01

    General considerations in general relativity and quantum mechanics are known to potentially rule out continuous global symmetries in the context of any consistent theory of quantum gravity. Assuming the validity of such considerations, we derive stringent bounds from gamma-ray, X-ray, cosmic-ray, neutrino, and CMB data on models that invoke global symmetries to stabilize the dark matter particle. We compute up-to-date, robust model-independent limits on the dark matter lifetime for a variety of Planck-scale suppressed dimension-five effective operators. We then specialize our analysis and apply our bounds to specific models including the Two-Higgs-Doublet, Left-Right, Singlet Fermionic, Zee-Babu, 3-3-1 and Radiative See-Saw models. Assuming that (i) global symmetries are broken at the Planck scale, that (ii) the non-renormalizable operators mediating dark matter decay have O (1) couplings, that (iii) the dark matter is a singlet field, and that (iv) the dark matter density distribution is well described by a NFW profile, we are able to rule out fermionic, vector, and scalar dark matter candidates across a broad mass range (keV-TeV), including the WIMP regime.

  4. Dark Matter Core Defies Explanation

    NASA Image and Video Library

    2017-09-28

    NASA image release March 2, 2012 This composite image shows the distribution of dark matter, galaxies, and hot gas in the core of the merging galaxy cluster Abell 520, formed from a violent collision of massive galaxy clusters. The natural-color image of the galaxies was taken with NASA's Hubble Space Telescope and with the Canada-France-Hawaii Telescope in Hawaii. Superimposed on the image are "false-colored" maps showing the concentration of starlight, hot gas, and dark matter in the cluster. Starlight from galaxies, derived from observations by the Canada-France-Hawaii Telescope, is colored orange. The green-tinted regions show hot gas, as detected by NASA's Chandra X-ray Observatory. The gas is evidence that a collision took place. The blue-colored areas pinpoint the location of most of the mass in the cluster, which is dominated by dark matter. Dark matter is an invisible substance that makes up most of the universe's mass. The dark-matter map was derived from the Hubble Wide Field Planetary Camera 2 observations, by detecting how light from distant objects is distorted by the cluster galaxies, an effect called gravitational lensing. The blend of blue and green in the center of the image reveals that a clump of dark matter resides near most of the hot gas, where very few galaxies are found. This finding confirms previous observations of a dark-matter core in the cluster. The result could present a challenge to basic theories of dark matter, which predict that galaxies should be anchored to dark matter, even during the shock of a collision. Abell 520 resides 2.4 billion light-years away. To read more go to: www.nasa.gov/mission_pages/hubble/science/dark-matter-cor... Credit: NASA, ESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and

  5. Topological hierarchy matters — topological matters with superlattices of defects

    NASA Astrophysics Data System (ADS)

    He, Jing; Kou, Su-Peng

    2016-11-01

    Topological insulators/superconductors are new states of quantum matter with metallic edge/surface states. In this paper, we review the defects effect in these topological states and study new types of topological matters — topological hierarchy matters. We find that both topological defects (quantized vortices) and non topological defects (vacancies) can induce topological mid-gap states in the topological hierarchy matters after considering the superlattice of defects. These topological mid-gap states have nontrivial topological properties, including the nonzero Chern number and the gapless edge states. Effective tight-binding models are obtained to describe the topological mid-gap states in the topological hierarchy matters. Project supported by the National Basic Research Program of China (Grant Nos. 2011CB921803 and 2012CB921704), the National Natural Science Foundation of China (Grant Nos. 11174035, 11474025, 11404090, and 11674026), the Natural Science Foundation of Hebei Province, China (Grant No. A2015205189), the Hebei Education Department Natural Science Foundation, China (Grant No. QN2014022), and the Specialized Research Fund for the Doctoral Program of Higher Education, China.

  6. 20 CFR 702.371 - Interlocutory matters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Interlocutory matters. 702.371 Section 702... Procedures Interlocutory Matters, Supplementary Orders, and Modifications § 702.371 Interlocutory matters. Compensation orders shall not be made or filed with respect to interlocutory matters of a procedural...

  7. 20 CFR 702.371 - Interlocutory matters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Interlocutory matters. 702.371 Section 702... Procedures Interlocutory Matters, Supplementary Orders, and Modifications § 702.371 Interlocutory matters. Compensation orders shall not be made or filed with respect to interlocutory matters of a procedural...

  8. 20 CFR 702.371 - Interlocutory matters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Interlocutory matters. 702.371 Section 702... Procedures Interlocutory Matters, Supplementary Orders, and Modifications § 702.371 Interlocutory matters. Compensation orders shall not be made or filed with respect to interlocutory matters of a procedural...

  9. 20 CFR 702.371 - Interlocutory matters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Interlocutory matters. 702.371 Section 702... Procedures Interlocutory Matters, Supplementary Orders, and Modifications § 702.371 Interlocutory matters. Compensation orders shall not be made or filed with respect to interlocutory matters of a procedural...

  10. 20 CFR 702.371 - Interlocutory matters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Interlocutory matters. 702.371 Section 702... Procedures Interlocutory Matters, Supplementary Orders, and Modifications § 702.371 Interlocutory matters. Compensation orders shall not be made or filed with respect to interlocutory matters of a procedural...

  11. Adolescent Gender Differences in Mattering and Wellness

    ERIC Educational Resources Information Center

    Rayle, Andrea Dixon

    2005-01-01

    Mattering to others has been associated with psychosocial well-being and overall wellness. The relationship of perceived interpersonal and general mattering to overall wellness was studied with a sample of 462 high school students (229 males and 233 females). The two measures of perceived mattering (the Mattering to Others Questionnaire and the…

  12. Matter and Interactions: A Particle Physics Perspective

    ERIC Educational Resources Information Center

    Organtini, Giovanni

    2011-01-01

    In classical mechanics, matter and fields are completely separated; matter interacts with fields. For particle physicists this is not the case; both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this article we explain why particle physicists believe in…

  13. Matter and Interactions: A Particle Physics Perspective

    ERIC Educational Resources Information Center

    Organtini, Giovanni

    2011-01-01

    In classical mechanics, matter and fields are completely separated; matter interacts with fields. For particle physicists this is not the case; both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this article we explain why particle physicists believe in…

  14. Quality and Safety Matter

    NASA Astrophysics Data System (ADS)

    Manha, William D.

    2010-09-01

    ,(the presenter) 0 injuries, 0 deaths 3. March 18, 1980,(USSR) Vostok 8A92M booster pad explosion, 48 deaths. 4. August 22, 2003,(Brazil) -Alcantara VLS -1, V03. Solid rocket ignited on pad, 21 deaths 5. Summer of 2006(USA) a payload organization inquired about requirements to fly a satellite with a new “safe” SpaceDev hybrid propulsion system using a solid polymer as the fuel and nitrous oxide as the oxidizer. The extensive titanium/nitrous oxide materials compatibility testing that was required discouraged the payload organization from further exploration of using the Shuttle as the launch vehicle. 6. July 26, 2007(USA) SpaceShipTwo nitrous oxide explosion, 3 seriously injured, 3 deaths The above listed catastrophic failures resulted in 210 deaths, but there were none on the Apollo SM explosion because of compliance with CalOSHA. This is an applied lesson learned of the Shuttle. Safety was not jeopardized without extensive materials compatibility testing. On the other hand, the nitrous oxide was erroneously identified as safe for launch from Shuttle or ISS which resulted in a catastrophic explosion and resulted in 3 major injuries, and 3 deaths. This is a testimony of a survivor of a catastrophic failure where safety rules were followed and the application of the lesson learned which confirmed safety and quality, as expressed by Von Braun, PERFECTION and SAFETY do MATTER!

  15. Cryogenic Dark Matter Search (CDMS): The Hunt for Dark Matter

    SciTech Connect

    Sadoulet, Bernard

    2006-03-06

    Deciphering the nature of dark matter has great scientific importance. A leading hypothesis is that dark matter is made of Weakly Interactive Massive Particles (WIMPs), which may result from supersymmetry or additional spatial dimensions. The underground search for elastic scattering of WIMPs on suitable targets (the so-called 'direct detection') is currently led by the Cryogenic Dark Matter Search II (CDMS II) experiment. Its sensitivity is ten times better than any other experiment and we hope to obtain another factor ten in the coming two years. After a brief recall of our recent results, I will describe the complementarity between direct detection experiments, the LHC and the ILC and I will outline the role that SLAC could play in this SuperCDMS program.

  16. Condensed Matter Nuclear Science

    NASA Astrophysics Data System (ADS)

    Takahashi, Akito; Ota, Ken-Ichiro; Iwamura, Yashuhiro

    Preface -- 1. General. Progress in condensed matter nuclear science / A. Takahashi. Summary of ICCF-12 / X. Z. Li. Overview of light water/hydrogen-based low-energy nuclear reactions / G. H. Miley and P. J. Shrestha -- 2. Excess heat and He detection. Development of "DS-reactor" as the practical reactor of "cold fusion" based on the "DS-cell" with "DS-cathode" / Y. Arata and Y.-C. Zhang. Progress in excess of power experiments with electrochemical loading of deuterium in palladium / V. Violante ... [et al.]. Anomalous energy generation during conventional electrolysis / T. Mizuno and Y. Toriyabe. "Excess heat" induced by deuterium flux in palladium film / B. Liu ... [et al.]. Abnormal excess heat observed during Mizuno-type experiments / J.-F. Fauvarque, P. P. Clauzon and G. J.-M. Lallevé. Seebeck envelope calorimetry with a Pd|D[symbol]O + H[symbol]SO[symbol] electrolytic cell / W.-S. Zhang, J. Dash and Q. Wang. Observation and investigation of nuclear fusion and self-induced electric discharges in liquids / A. I. Koldamasov ... [et al.]. Description of a sensitive seebeck calorimeter used for cold fusion studies / E. Storms. Some recent results at ENEA / M. Apicella ... [et al.]. Heat measurement during plasma electrolysis / K. Iizumi ... [et al.]. Effect of an additive on thermal output during electrolysis of heavy water with a palladium cathode / Q. Wang and J. Dash. Thermal analysis of calorimetric systems / L. D'Aulerio ... [et al.]. Surface plasmons and low-energy nuclear reactions triggering / E. Castagna ... [et al.]. Production method for violent TCB jet plasma from cavity / F. Amini. New results and an ongoing excess heat controversy / L. Kowalski ... [et al.] -- 3. Transmutation. Observation of surface distribution of products by X-ray fluorescence spectrometry during D[symbol] gas permeation through Pd Complexes / Y. Iwamura ... [et al.]. Discharge experiment using Pd/CaO/Pd multi-layered cathode / S. Narita ... [et al.]. Producing transmutation

  17. Dark matter, neutron stars, and strange quark matter.

    PubMed

    Perez-Garcia, M Angeles; Silk, Joseph; Stone, Jirina R

    2010-10-01

    We show that self-annihilating weakly interacting massive particle (WIMP) dark matter accreted onto neutron stars may provide a mechanism to seed compact objects with long-lived lumps of strange quark matter, or strangelets, for WIMP masses above a few GeV. This effect may trigger a conversion of most of the star into a strange star. We use an energy estimate for the long-lived strangelet based on the Fermi-gas model combined with the MIT bag model to set a new limit on the possible values of the WIMP mass that can be especially relevant for subdominant species of massive neutralinos.

  18. Did LIGO Detect Dark Matter?

    PubMed

    Bird, Simeon; Cholis, Ilias; Muñoz, Julian B; Ali-Haïmoud, Yacine; Kamionkowski, Marc; Kovetz, Ely D; Raccanelli, Alvise; Riess, Adam G

    2016-05-20

    We consider the possibility that the black-hole (BH) binary detected by LIGO may be a signature of dark matter. Interestingly enough, there remains a window for masses 20M_{⊙}≲M_{bh}≲100M_{⊙} where primordial black holes (PBHs) may constitute the dark matter. If two BHs in a galactic halo pass sufficiently close, they radiate enough energy in gravitational waves to become gravitationally bound. The bound BHs will rapidly spiral inward due to the emission of gravitational radiation and ultimately will merge. Uncertainties in the rate for such events arise from our imprecise knowledge of the phase-space structure of galactic halos on the smallest scales. Still, reasonable estimates span a range that overlaps the 2-53  Gpc^{-3} yr^{-1} rate estimated from GW150914, thus raising the possibility that LIGO has detected PBH dark matter. PBH mergers are likely to be distributed spatially more like dark matter than luminous matter and have neither optical nor neutrino counterparts. They may be distinguished from mergers of BHs from more traditional astrophysical sources through the observed mass spectrum, their high ellipticities, or their stochastic gravitational wave background. Next-generation experiments will be invaluable in performing these tests.

  19. Maverick dark matter at colliders

    NASA Astrophysics Data System (ADS)

    Beltrán, Maria; Hooper, Dan; Kolb, Edward W.; Krusberg, Zosia A. C.; Tait, Tim M. P.

    2010-09-01

    Assuming that dark matter is a weakly interacting massive particle (WIMP) species X produced in the early Universe as a cold thermal relic, we study the collider signal of pp or pbar{p} rightarrow bar{X}X + jets and its distinguishability from standard-model background processes associated with jets and missing energy. We assume that the WIMP is the sole particle related to dark matter within reach of the LHC — a “maverick” particle — and that it couples to quarks through a higher dimensional contact interaction. We simulate the WIMP final-state signal Xbar{X} + jets and dominant standard-model (SM) background processes and find that the dark-matter production process results in higher energies for the colored final state partons than do the standard-model background processes. As a consequence, the detectable signature of maverick dark matter is an excess over standard-model expectations of events consisting of large missing transverse energy, together with large leading jet transverse momentum and scalar sum of the transverse momenta of the jets. Existing Tevatron data and forthcoming LHC data can constrain (or discover!) maverick dark matter.

  20. Inflationary imprints on dark matter

    SciTech Connect

    Nurmi, Sami; Tenkanen, Tommi; Tuominen, Kimmo E-mail: tommi.tenkanen@helsinki.fi

    2015-11-01

    We show that dark matter abundance and the inflationary scale H could be intimately related. Standard Model extensions with Higgs mediated couplings to new physics typically contain extra scalars displaced from vacuum during inflation. If their coupling to Standard Model is weak, they will not thermalize and may easily constitute too much dark matter reminiscent to the moduli problem. As an example we consider Standard Model extended by a Z{sub 2} symmetric singlet s coupled to the Standard Model Higgs Φ via λ Φ{sup †}Φ s{sup 2}. Dark matter relic density is generated non-thermally for λ ∼< 10{sup −7}. We show that the dark matter yield crucially depends on the inflationary scale. For H∼ 10{sup 10} GeV we find that the singlet self-coupling and mass should lie in the regime λ{sub s}∼> 10{sup −9} and m{sub s}∼< 50 GeV to avoid dark matter overproduction.

  1. Exotic States of Nuclear Matter

    NASA Astrophysics Data System (ADS)

    Lombardo, Umberto; Baldo, Marcello; Burgio, Fiorella; Schulze, Hans-Josef

    2008-02-01

    pt. A. Theory of nuclear matter EOS and symmetry energy. Constraining the nuclear equation of state from astrophysics and heavy ion reactions / C. Fuchs. In-medium hadronic interactions and the nuclear equation of state / F. Sammarruca. EOS and single-particle properties of isospin-asymmetric nuclear matter within the Brueckner theory / W. Zuo, U. Lombardo & H.-J. Schulze. Thermodynamics of correlated nuclear matter / A. Polls ... [et al.]. The validity of the LOCV formalism and neutron star properties / H. R. Moshfegh ... [et al.]. Ferromagnetic instabilities of neutron matter: microscopic versus phenomenological approaches / I. Vidaã. Sigma meson and nuclear matter saturation / A. B. Santra & U. Lombardo. Ramifications of the nuclear symmetry energy for neutron stars, nuclei and heavy-ion collisions / A. W. Steiner, B.-A. Li & M. Prakash. The symmetry energy in nuclei and nuclear matter / A. E. L. Dieperink. Probing the symmetry energy at supra-saturation densities / M. Di Toro et al. Investigation of low-density symmetry energy via nucleon and fragment observables / H. H. Wolter et al. Instability against cluster formation in nuclear and compact-star matter / C. Ducoin ... [et al.]. Microscopic optical potentials of nucleon-nucleus and nucleus-nucleus scattering / Z.-Y. Ma, J. Rong & Y.-Q. Ma -- pt. B. The neutron star crust: structure, formation and dynamics. Neutron star crust beyond the Wigner-Seitz approximation / N. Chamel. The inner crust of a neutron star within the Wigner-Seitz method with pairing: from drip point to the bottom / E. E. Saperstein, M. Baldo & S. V. Tolokonnikov. Nuclear superfluidity and thermal properties of neutron stars / N. Sandulescu. Collective excitations: from exotic nuclei to the crust of neutron stars / E. Khan, M. Grasso & J. Margueron. Monte Carlo simulation of the nuclear medium: fermi gases, nuclei and the role of Pauli potentials / M. A. Pérez-García. Low-density instabilities in relativistic hadronic models / C. Provid

  2. Introduction. Cosmology meets condensed matter.

    PubMed

    Kibble, T W B; Pickett, G R

    2008-08-28

    At first sight, low-temperature condensed-matter physics and early Universe cosmology seem worlds apart. Yet, in the last few years a remarkable synergy has developed between the two. It has emerged that, in terms of their mathematical description, there are surprisingly close parallels between them. This interplay has been the subject of a very successful European Science Foundation (ESF) programme entitled COSLAB ('Cosmology in the Laboratory') that ran from 2001 to 2006, itself built on an earlier ESF network called TOPDEF ('Topological Defects: Non-equilibrium Field Theory in Particle Physics, Condensed Matter and Cosmology'). The articles presented in this issue of Philosophical Transactions A are based on talks given at the Royal Society Discussion Meeting 'Cosmology meets condensed matter', held on 28 and 29 January 2008. Many of the speakers had participated earlier in the COSLAB programme, but the strength of the field is illustrated by the presence also of quite a few new participants.

  3. Quark description of nuclear matter

    SciTech Connect

    Berges, Jurgen

    2001-07-01

    We discuss the role of an adjoint chiral condensate for color superconducting quark matter. Its presence leads to color-flavor locking in two-flavor quark matter. Color is broken completely as well as chiral symmetry in the two-flavor theory with coexisting adjoint quark-antiquark and antitriplet quark-quark condensates. The qualitative properties of this phase match the properties of ordinary nuclear matter without strange baryons. This complements earlier proposals by Schaefer and Wilczek for a quark description of hadronic phases. We show for a class of models with effective four-fermion interactions that adjoint chiral and diquark condensates do not compete, in the sense that simultaneous condensation occurs for sufficiently strong interactions in the adjoint chiral channel.

  4. Dark matter in 3D

    DOE PAGES

    Alves, Daniele S. M.; El Hedri, Sonia; Wacker, Jay G.

    2016-03-21

    We discuss the relevance of directional detection experiments in the post-discovery era and propose a method to extract the local dark matter phase space distribution from directional data. The first feature of this method is a parameterization of the dark matter distribution function in terms of integrals of motion, which can be analytically extended to infer properties of the global distribution if certain equilibrium conditions hold. The second feature of our method is a decomposition of the distribution function in moments of a model independent basis, with minimal reliance on the ansatz for its functional form. We illustrate our methodmore » using the Via Lactea II N-body simulation as well as an analytical model for the dark matter halo. Furthermore, we conclude that O(1000) events are necessary to measure deviations from the Standard Halo Model and constrain or measure the presence of anisotropies.« less

  5. Dark matter in 3D

    SciTech Connect

    Alves, Daniele S. M.; El Hedri, Sonia; Wacker, Jay G.

    2016-03-21

    We discuss the relevance of directional detection experiments in the post-discovery era and propose a method to extract the local dark matter phase space distribution from directional data. The first feature of this method is a parameterization of the dark matter distribution function in terms of integrals of motion, which can be analytically extended to infer properties of the global distribution if certain equilibrium conditions hold. The second feature of our method is a decomposition of the distribution function in moments of a model independent basis, with minimal reliance on the ansatz for its functional form. We illustrate our method using the Via Lactea II N-body simulation as well as an analytical model for the dark matter halo. Furthermore, we conclude that O(1000) events are necessary to measure deviations from the Standard Halo Model and constrain or measure the presence of anisotropies.

  6. Cold dark matter heats up.

    PubMed

    Pontzen, Andrew; Governato, Fabio

    2014-02-13

    A principal discovery in modern cosmology is that standard model particles comprise only 5 per cent of the mass-energy budget of the Universe. In the ΛCDM paradigm, the remaining 95 per cent consists of dark energy (Λ) and cold dark matter. ΛCDM is being challenged by its apparent inability to explain the low-density 'cores' of dark matter measured at the centre of galaxies, where centrally concentrated high-density 'cusps' were predicted. But before drawing conclusions, it is necessary to include the effect of gas and stars, historically seen as passive components of galaxies. We now understand that these can inject heat energy into the cold dark matter through a coupling based on rapid gravitational potential fluctuations, explaining the observed low central densities.

  7. Swim pressure of active matter

    NASA Astrophysics Data System (ADS)

    Takatori, Sho; Yan, Wen; Brady, John; Caltech Team

    2014-11-01

    Through their self-motion, all active matter systems generate a unique ``swim pressure'' that is entirely athermal in origin. This new source for the active stress exists at all scales in both living and nonliving active systems, and also applies to larger organisms where inertia is important (i.e., the Stokes number is not small). Here we explain the origin of the swim stress and develop a simple thermodynamic model to study the self-assembly and phase separation in active soft matter. Our new swim stress perspective can help analyze and exploit a wide class of active soft matter, from swimming bacteria and catalytic nanobots, schools of fish and birds, and molecular motors that activate the cellular cytoskeleton.

  8. Dark Matter Hairs Around Earth

    NASA Image and Video Library

    2015-11-23

    This illustration shows Earth surrounded by filaments of dark matter called "hairs," which are proposed in a study in the Astrophysical Journal by Gary Prézeau of NASA's Jet Propulsion Laboratory, Pasadena, California. A hair is created when a stream of dark matter particles goes through the planet. According to simulations, the hair is densest at a point called the "root." When particles of a dark matter stream pass through the core of Earth, they form a hair whose root has a particle density about a billion times greater than average. The hairs in this illustration are not to scale. Simulations show that the roots of such hairs can be 600,000 miles (1 million kilometers) from Earth, while Earth's radius is only about 4,000 miles (6,400 kilometers). http://photojournal.jpl.nasa.gov/catalog/PIA20176

  9. Dark Matter Hairs Around Jupiter

    NASA Image and Video Library

    2015-11-23

    This illustration shows Jupiter surrounded by filaments of dark matter called "hairs," which are proposed in a study in the Astrophysical Journal by Gary Prézeau of NASA's Jet Propulsion Laboratory, Pasadena, California. A hair is created when a stream of dark matter particles goes through the planet. According to simulations, the hair is densest at a point called the "root." When particles of a dark matter stream pass through the core of Jupiter, they form a hair whose root has a particle density about a trillion times greater than average. The size of Jupiter relative to the distance between Jupiter and the hair roots is to scale. http://photojournal.jpl.nasa.gov/catalog/PIA20178

  10. Deuteron distribution in nuclear matter

    NASA Astrophysics Data System (ADS)

    Benhar, O.; Fabrocini, A.; Fantoni, S.; Illarionov, A. Yu.; Lykasov, G. I.

    2002-05-01

    We analyze the properties of deuteron-like structures in infinite, correlated nuclear matter, described by a realistic hamiltonian containing the Urbana v14 two-nucleon and the Urbana TNI many-body potentials. The distribution of neutron-proton pairs, carrying the deuteron quantum numbers, is obtained as a function of the total momentum by computing the overlap between the nuclear matter in its ground state and the deuteron wave functions in correlated basis functions theory. We study the differences between the S- and D-wave components of the deuteron and those of the deuteron-like pair in the nuclear medium. The total number of deuteron type pairs is computed and compared with the predictions of Levinger's quasideuteron model. The resulting Levinger's factor in nuclear matter at equilibrium density is 11.63. We use the local density approximation to estimate the Levinger's factor for heavy nuclei, obtaining results which are consistent with the available experimental data from photoreactions.

  11. Static Response of Neutron Matter.

    PubMed

    Buraczynski, Mateusz; Gezerlis, Alexandros

    2016-04-15

    We generalize the problem of strongly interacting neutron matter by adding a periodic external modulation. This allows us to study from first principles a neutron system that is extended and inhomogeneous, with connections to the physics of both neutron-star crusts and neutron-rich nuclei. We carry out fully nonperturbative microscopic quantum Monte Carlo calculations of the energy of neutron matter at different densities, as well as different strengths and periodicities of the external potential. In order to remove systematic errors, we examine finite-size effects and the impact of the wave function ansatz. We also make contact with energy-density functional theories of nuclei and disentangle isovector gradient contributions from bulk properties. Finally, we calculate the static density-density linear response function of neutron matter and compare it with the response of other physical systems.

  12. Naturality, unification, and dark matter

    SciTech Connect

    Kainulainen, Kimmo; Virkajaervi, Jussi; Tuominen, Kimmo

    2010-08-15

    We consider a model where electroweak symmetry breaking is driven by technicolor dynamics with minimal particle content required for walking coupling and saturation of global anomalies. Furthermore, the model features three additional Weyl fermions singlet under technicolor interactions, two of which provide for a one-loop unification of the standard model gauge couplings. Among these extra matter fields exists a possible candidate for weakly interacting dark matter. We evaluate the relic densities and find that they are sufficient to explain the cosmological observations and avoid the experimental limits from earth-based searches. Hence, we establish a nonsupersymmetric framework where hierarchy and naturality problems are solved, coupling constant unification is achieved, and a plausible dark matter candidate exists.

  13. [Brain function and white matter].

    PubMed

    Wake, Hiroaki; Kato, Daisuke

    2015-04-01

    Accumulated evidence shows that neural information processing takes place in superficial layers of the brain called the gray matter. Synapses, which connect different neurons reside in the gray matter and are considered the major components of information processing and plasticity. On the other hand, myelinated axons lie beneath the gray matter. These bundles of cables connect neurons in the different brain regions to form functional neural circuits. Myelinated axons were of little of interest to neuroscientists and have long been ignored in the formation of functional neuronal circuits. Recent evidence shows that myelin formed by oligodendrocytes shows plastic changes depending on neuronal activity. In this issue, we discuss the plastic changes of myelin and its functional role in learning and training.

  14. Semiclassical cosmology with polymer matter

    NASA Astrophysics Data System (ADS)

    Moeez Hassan, Syed; Husain, Viqar

    2017-04-01

    In loop quantum cosmology, polymer quantization is applied to gravity and Schrödinger quantization to matter. This approach misses interesting cosmological dynamics coming from the polymer quantization of matter. We demonstrate this in semiclassical cosmology with a scalar field and pressureless dust: gravity is kept classical, dust is used to fix the time gauge, and polymer quantization effects are isolated in the scalar field. The resulting dynamics shows a period of inflation, both with and without a scalar potential, and the emergence of a classical universe at late times. Since gravity is not quantized, the cosmological singularity is not resolved, but our results suggest that polymer quantization of both gravity and matter are important for a complete picture.

  15. Dark matter via massive bigravity

    NASA Astrophysics Data System (ADS)

    Blanchet, Luc; Heisenberg, Lavinia

    2015-05-01

    In this work we investigate the existence of relativistic models for dark matter in the context of bimetric gravity, used here to reproduce the modified Newtonian dynamics (MOND) at galactic scales. For this purpose we consider two different species of dark matter particles that separately couple to the two metrics of bigravity. These two sectors are linked together via an internal U (1 ) vector field, and some effective composite metric built out of the two metrics. Among possible models only certain classes of kinetic and interaction terms are allowed without invoking ghost degrees of freedom. Along these lines we explore the number of allowed kinetic terms in the theory and point out the presence of ghosts in a previous model. Finally, we propose a promising class of ghost-free candidate theories that could provide the MOND phenomenology at galactic scales while reproducing the standard cold dark matter model at cosmological scales.

  16. Dark Matter in 3D

    SciTech Connect

    Alves, Daniele S.M.; Hedri, Sonia El; Wacker, Jay G.

    2012-04-01

    We discuss the relevance of directional detection experiments in the post-discovery era and propose a method to extract the local dark matter phase space distribution from directional data. The first feature of this method is a parameterization of the dark matter distribution function in terms of integrals of motion, which can be analytically extended to infer properties of the global distribution if certain equilibrium conditions hold. The second feature of our method is a decomposition of the distribution function in moments of a model independent basis, with minimal reliance on the ansatz for its functional form. We illustrate our method using the Via Lactea II N-body simulation as well as an analytical model for the dark matter halo. We conclude that O(1000) events are necessary to measure deviations from the Standard Halo Model and constrain or measure the presence of anisotropies.

  17. The DAMIC Dark Matter Experiment

    SciTech Connect

    de Mello Neto, J. R.T.

    2015-10-07

    The DAMIC (DArk Matter In CCDs) experiment uses high-resistivity, scientific-grade CCDs to search for dark matter. The CCD’s low electronic noise allows an unprecedently low energy threshold of a few tens of eV; this characteristic makes it possible to detect silicon recoils resulting from interactions of low-mass WIMPs. In addition, the CCD’s high spatial resolution and the excellent energy response results in very effective background identification techniques. The experiment has a unique sensitivity to dark matter particles with masses below 10 GeV/c2. Previous results have motivated the construction of DAMIC100, a 100 grams silicon target detector currently being installed at SNOLAB. The mode of operation and unique imaging capabilities of the CCDs, and how they may be exploited to characterize and suppress backgrounds are discussed, as well as physics results after one year of data taking.

  18. Hydrodynamics of soft active matter

    NASA Astrophysics Data System (ADS)

    Marchetti, M. C.; Joanny, J. F.; Ramaswamy, S.; Liverpool, T. B.; Prost, J.; Rao, Madan; Simha, R. Aditi

    2013-07-01

    This review summarizes theoretical progress in the field of active matter, placing it in the context of recent experiments. This approach offers a unified framework for the mechanical and statistical properties of living matter: biofilaments and molecular motors in vitro or in vivo, collections of motile microorganisms, animal flocks, and chemical or mechanical imitations. A major goal of this review is to integrate several approaches proposed in the literature, from semimicroscopic to phenomenological. In particular, first considered are “dry” systems, defined as those where momentum is not conserved due to friction with a substrate or an embedding porous medium. The differences and similarities between two types of orientationally ordered states, the nematic and the polar, are clarified. Next, the active hydrodynamics of suspensions or “wet” systems is discussed and the relation with and difference from the dry case, as well as various large-scale instabilities of these nonequilibrium states of matter, are highlighted. Further highlighted are various large-scale instabilities of these nonequilibrium states of matter. Various semimicroscopic derivations of the continuum theory are discussed and connected, highlighting the unifying and generic nature of the continuum model. Throughout the review, the experimental relevance of these theories for describing bacterial swarms and suspensions, the cytoskeleton of living cells, and vibrated granular material is discussed. Promising extensions toward greater realism in specific contexts from cell biology to animal behavior are suggested, and remarks are given on some exotic active-matter analogs. Last, the outlook for a quantitative understanding of active matter, through the interplay of detailed theory with controlled experiments on simplified systems, with living or artificial constituents, is summarized.

  19. Matters on a Moving Brane

    NASA Astrophysics Data System (ADS)

    Koivisto, Tomi Sebastian; Wills, Danielle Elizabeth

    2013-10-01

    A novel generalization of the Dirac-Born-Infeld string scenario is described. It is shown that matter residing on the moving brane is dark and has the so-called disformal coupling to gravity. This gives rise to cosmologies where dark matter stems from the oscillations of the open strings along the brane and the transverse oscillations result in dark energy. Furthermore, due to a new screening mechanism that conceals the fifth force from local experiments, one may even entertain the possibility that the visible sector is also moving along the extra dimensions.

  20. Dark matter in modified gravity?

    NASA Astrophysics Data System (ADS)

    Katsuragawa, Taishi; Matsuzaki, Shinya

    2017-02-01

    We explore a new horizon of modified gravity from the viewpoint of particle physics. As a concrete example, we take the F (R ) gravity to raise a question: can a scalar particle ("scalaron") derived from the F (R ) gravity be a dark matter candidate? We place the limit on the parameter in a class of F (R ) gravity model from the constraint on the scalaron as a dark matter. The role of the screening mechanism and compatibility with the dark energy problem are addressed.

  1. Matter effects on neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Mocioiu, Irina; Shrock, Robert

    2000-12-01

    We calculate matter effects on neutrino oscillations in long baseline experiments, using actual density profiles in the Earth. We study the dependence of the signal on E/Δmatm2, the angles in the leptonic mixing matrix and the influence of Δmsol2 and CP phase on the oscillations. The results show quantitatively how matter effects can cause significant changes in the oscillation probabilities. These effects can be useful in amplifying certain neutrino oscillation signals and helping one to obtain measurements of mixing parameters and the magnitude and sign of Δmatm2.

  2. Diquark abundance in stellar matter

    SciTech Connect

    Horvath, J.E.; de Freitas Pacheco, J.A.; de Araujo, J.C.N. )

    1992-11-15

    The clustering of quarks into pairs (diquarks) has been suggested recently to play an important role in dense matter and its astrophysical realization in neutron-star cores. We address in this work the features of diquark matter by employing an accurate equation of state valid for the effective {lambda}{phi}{sup 4} diquark theory, and find milder (although non-negligible) effects than in previous calculations. Some considerations on the very presence of a diquark-dominated region immediately above the deconfinement density are also given.

  3. Condensed Matter Physics - Biology Resonance

    NASA Astrophysics Data System (ADS)

    Baskaran, G.

    The field of condensed matter physics had its genesis this century and it has had a remarkable evolution. A closer look at its growth reveals a hidden aim in the collective consciousness of the field - a part of the development this century is a kind of warm up exercise to understand the nature of living condensed matter, namely the field of biology, by a growing new breed of scientists in the coming century. Through some examples the vitality of this interaction will be pointed out.

  4. Dynamical matter-parity breaking and gravitino dark matter

    SciTech Connect

    Schmidt, Jonas; Weniger, Christoph; Yanagida, Tsutomu T.

    2010-11-15

    Scenarios where gravitinos with GeV masses makeup dark matter are known to be in tension with high reheating temperatures, as required by e.g. thermal leptogenesis. This tension comes from the longevity of the NLSPs (next-to-lightest supersymmetric particle), which can destroy the successful predictions of the standard primordial nucleosynthesis. However, a small violation of matter parity can open new decay channels for the NLSP, avoiding the BBN (standard primordial nucleosynthesis) problems, while being compatible with experimental cosmic-ray constraints. In this paper, we propose a model where matter parity, which we assume to be embedded in the U(1){sub B-L} gauge symmetry, is broken dynamically in a hidden sector at low-scales. This can naturally explain the smallness of the matter parity breaking in the visible sector. We discuss the dynamics of the corresponding pseudo Nambu-Goldstone modes of B-L breaking in the hidden sector, and we comment on typical cosmic-ray and collider signatures in our model.

  5. Gray matter and white matter abnormalities in online game addiction.

    PubMed

    Weng, Chuan-Bo; Qian, Ruo-Bing; Fu, Xian-Ming; Lin, Bin; Han, Xiao-Peng; Niu, Chao-Shi; Wang, Ye-Han

    2013-08-01

    Online game addiction (OGA) has attracted greater attention as a serious public mental health issue. However, there are only a few brain magnetic resonance imaging studies on brain structure about OGA. In the current study, we used voxel-based morphometry (VBM) analysis and tract-based spatial statistics (TBSS) to investigate the microstructural changes in OGA and assessed the relationship between these morphology changes and the Young's Internet Addiction Scale (YIAS) scores within the OGA group. Compared with healthy subjects, OGA individuals showed significant gray matter atrophy in the right orbitofrontal cortex, bilateral insula, and right supplementary motor area. According to TBSS analysis, OGA subjects had significantly reduced FA in the right genu of corpus callosum, bilateral frontal lobe white matter, and right external capsule. Gray matter volumes (GMV) of the right orbitofrontal cortex, bilateral insula and FA values of the right external capsule were significantly positively correlated with the YIAS scores in the OGA subjects. Our findings suggested that microstructure abnormalities of gray and white matter were present in OGA subjects. This finding may provide more insights into the understanding of the underlying neural mechanisms of OGA.

  6. Every Child Mattered in England: But What Matters to Children?

    ERIC Educational Resources Information Center

    Meehan, Catherine

    2016-01-01

    "Every Child Matters" under New Labour provided a framework for services for young children's care and education. It was pushed aside by the Conservative-led coalition and replaced by "More Great Childcare". The UK as a signatory to the United Nations Convention on the Rights of the Child, therefore has obligations for…

  7. Every Child Mattered in England: But What Matters to Children?

    ERIC Educational Resources Information Center

    Meehan, Catherine

    2016-01-01

    "Every Child Matters" under New Labour provided a framework for services for young children's care and education. It was pushed aside by the Conservative-led coalition and replaced by "More Great Childcare". The UK as a signatory to the United Nations Convention on the Rights of the Child, therefore has obligations for…

  8. Multiscatter stellar capture of dark matter

    NASA Astrophysics Data System (ADS)

    Bramante, Joseph; Delgado, Antonio; Martin, Adam

    2017-09-01

    Dark matter may be discovered through its capture in stars and subsequent annihilation. It is usually assumed that dark matter is captured after a single scattering event in the star; however this assumption breaks down for heavy dark matter, which requires multiple collisions with the star to lose enough kinetic energy to become captured. We analytically compute how multiple scatters alter the capture rate of dark matter and identify the parameter space where the effect is largest. Using these results, we then show how multiscatter capture of dark matter on compact stars can be used to probe heavy mX≫TeV dark matter with remarkably small dark matter-nucleon scattering cross sections. As one example, it is demonstrated how measuring the temperature of old neutron stars in the Milky Way's center provides sensitivity to high mass dark matter with dark matter-nucleon scattering cross sections smaller than the xenon direct detection neutrino floor.

  9. Analysis of dark matter and dark energy

    NASA Astrophysics Data System (ADS)

    Yongquan, Han

    2016-05-01

    As the law of unity of opposites of the Philosophy tells us, the bright material exists, the dark matter also exists. Dark matter and dark energy should allow the law of unity of opposites. The Common attributes of the matter is radiation, then common attributes of dark matter must be absorb radiation. Only the rotation speed is lower than the speed of light radiation, can the matter radiate, since the speed of the matter is lower than the speed of light, so the matter is radiate; The rotate speed of the dark matter is faster than the light , so the dark matter doesn't radiate, it absorbs radiation. The energy that the dark matter absorb radiation produced (affect the measurement of time and space distribution of variations) is dark energy, so the dark matter produce dark energy only when it absorbs radiation. Dark matter does not radiate, two dark matters does not exist inevitably forces, and also no dark energy. Called the space-time ripples, the gravitational wave is bent radiation, radiation particles should be graviton, graviton is mainly refers to the radiation particles whose wavelength is small. Dark matter, dark energy also confirms the existence of the law of symmetry.

  10. Quark matter droplets in neutron stars

    NASA Technical Reports Server (NTRS)

    Heiselberg, H.; Pethick, C. J.; Staubo, E. F.

    1993-01-01

    We show that, for physically reasonable bulk and surface properties, the lowest energy state of dense matter consists of quark matter coexisting with nuclear matter in the presence of an essentially uniform background of electrons. We estimate the size and nature of spatial structure in this phase, and show that at the lowest densities the quark matter forms droplets embedded in nuclear matter, whereas at higher densities it can exhibit a variety of different topologies. A finite fraction of the interior of neutron stars could consist of matter in this new phase, which would provide new mechanisms for glitches and cooling.

  11. Quark matter droplets in neutron stars

    NASA Technical Reports Server (NTRS)

    Heiselberg, H.; Pethick, C. J.; Staubo, E. F.

    1993-01-01

    We show that, for physically reasonable bulk and surface properties, the lowest energy state of dense matter consists of quark matter coexisting with nuclear matter in the presence of an essentially uniform background of electrons. We estimate the size and nature of spatial structure in this phase, and show that at the lowest densities the quark matter forms droplets embedded in nuclear matter, whereas at higher densities it can exhibit a variety of different topologies. A finite fraction of the interior of neutron stars could consist of matter in this new phase, which would provide new mechanisms for glitches and cooling.

  12. Hyperon matter at low densities

    NASA Astrophysics Data System (ADS)

    Sulaksono, A.

    2014-09-01

    It was reported recently that hyperons can be present inside PSRJ1614-2230 compact star. This can be realized only if the strength of the ω-hyperons and φ-hyperons coupling of conventional hyperons coupling constant on the extended relativistic mean field (ERMF) model increase by a factor of 1.5 to 3. In the present work, the mass and radius relation of the neutron star that is calculated by using BSR28 parameter set of ERMF model augmented with maximal coupling strength of the ω-hyperons and φ-hyperons (X=1), is compared to the mass and radius relation of the neutron star that is predicted by the same RMF parameter set but by assuming that hyperons do not exist in the matter (No. Hyp) as well as those by assuming the hyperons coupling constant fulfilled the conventional SU(6) and SU(3) symmetry. The consequences of implementing X=1 prescription are also discussed. The potential depths of hyperons in symmetric nuclear matter (SNM), pure neutron matter (PNM) and pure lambda matter (PLM) based on this parameter set are also calculated by using the X=1, SU (6) and SU (3) prescriptions. The results are compared to those obtained from microscopic models, quark meson coupling model (χ QMM) and the QCD sum rule for finite density (QCD SM) result.

  13. Magnetism in Dense Quark Matter

    NASA Astrophysics Data System (ADS)

    Ferrer, Efrain J.; de la Incera, Vivian

    We review the mechanisms via which an external magnetic field can affect the ground state of cold and dense quark matter. In the absence of a magnetic field, at asymptotically high densities, cold quark matter is in the Color-Flavor-Locked (CFL) phase of color superconductivity characterized by three scales: the superconducting gap, the gluon Meissner mass, and the baryonic chemical potential. When an applied magnetic field becomes comparable with each of these scales, new phases and/or condensates may emerge. They include the magnetic CFL (MCFL) phase that becomes relevant for fields of the order of the gap scale; the paramagnetic CFL, important when the field is of the order of the Meissner mass, and a spin-one condensate associated to the magnetic moment of the Cooper pairs, significant at fields of the order of the chemical potential. We discuss the equation of state (EoS) of MCFL matter for a large range of field values and consider possible applications of the magnetic effects on dense quark matter to the astrophysics of compact stars.

  14. Source Testing for Particulate Matter.

    ERIC Educational Resources Information Center

    DeVorkin, Howard

    Developed for presentation at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971, this outline covers procedures for the testing of particulate matter. These are: (1) basic requirements, (2) information required, (3) collection of samples, (4) processing of samples, (5)…

  15. Particulate matter and preterm birth

    EPA Science Inventory

    Particulate matter (PM) has been variably associated with preterm birth (PTB) (gestation <37 weeks), but the role played by specific chemical components of PM has been little studied. We examined the association between ambient PM <2.5 micrometers in aerodynamic diameter (PM2.S) ...

  16. Wino dark matter under siege

    SciTech Connect

    Cohen, Timothy; Lisanti, Mariangela; Pierce, Aaron; Slatyer, Tracy R. E-mail: mlisanti@princeton.edu E-mail: tslatyer@mit.edu

    2013-10-01

    A fermion triplet of SU(2){sub L} — a wino — is a well-motivated dark matter candidate. This work shows that present-day wino annihilations are constrained by indirect detection experiments, with the strongest limits coming from H.E.S.S. and Fermi. The bounds on wino dark matter are presented as a function of mass for two scenarios: thermal (winos constitute a subdominant component of the dark matter for masses less than 3.1 TeV) and non-thermal (winos comprise all the dark matter). Assuming the NFW halo model, the H.E.S.S. search for gamma-ray lines excludes the 3.1 TeV thermal wino; the combined H.E.S.S. and Fermi results completely exclude the non-thermal scenario. Uncertainties in the exclusions are explored. Indirect detection may provide the only probe for models of anomaly plus gravity mediation where the wino is the lightest superpartner and scalars reside at the 100 TeV scale.

  17. Interaction of Radiation with Matter

    SciTech Connect

    Rickards, J.

    2010-09-10

    A flash introductory course in the interaction of ionizing radiation with matter is presented for students starting out in nuclear physics, medical applications of radiation, materials modification, radiation damage, detectors, materials analysis, radiation protection, and other applications. Emphasis is on defining basic concepts and on a simple visualization of ideas for practical applications, rather than on completeness or rigor.

  18. Diphoton resonance confronts dark matter

    NASA Astrophysics Data System (ADS)

    Choi, Soo-Min; Kang, Yoo-Jin; Lee, Hyun Min

    2016-07-01

    As an interpretation of the 750 GeV diphoton excesses recently reported by both ATLAS and CMS collaborations, we consider a simple extension of the Standard Model with a Dirac fermion dark matter where a singlet complex scalar field mediates between dark matter and SM particles via effective couplings to SM gauge bosons and/or Higgs-portal. In this model, we can accommodate the diphoton events through the direct and/or cascade decays of pseudo-scalar and real scalar partners of the complex scalar field. We show that mono-jet searches and gamma-ray observations are complementary in constraining the region where the width of the diphoton resonance can be enhanced due to the couplings of the resonance to dark matter and the correct relic density is obtained. In the case of cascade decay of the resonance, the effective couplings of singlet scalars can be smaller, but the model is still testable by the future discrimination between single photon and photon-jet at the LHC as well as the gamma-ray searches for the cascade annihilation of dark matter.

  19. Wake up, because Math Matters

    ERIC Educational Resources Information Center

    Gilpin, Jeanny

    2010-01-01

    This article presents the author's story, as a teacher, about building a Math Matters club and discusses why her students arrived at school before first bell to participate enthusiastically. The author's students seemed to have a negative attitude about math. In giving that stirring motivational speech, she apparently overlooked one important…

  20. Hyperon matter at low densities

    SciTech Connect

    Sulaksono, A.

    2014-09-25

    It was reported recently that hyperons can be present inside PSRJ1614-2230 compact star. This can be realized only if the strength of the ω-hyperons and φ-hyperons coupling of conventional hyperons coupling constant on the extended relativistic mean field (ERMF) model increase by a factor of 1.5 to 3. In the present work, the mass and radius relation of the neutron star that is calculated by using BSR28 parameter set of ERMF model augmented with maximal coupling strength of the ω-hyperons and φ-hyperons (X=1), is compared to the mass and radius relation of the neutron star that is predicted by the same RMF parameter set but by assuming that hyperons do not exist in the matter (No. Hyp) as well as those by assuming the hyperons coupling constant fulfilled the conventional SU(6) and SU(3) symmetry. The consequences of implementing X=1 prescription are also discussed. The potential depths of hyperons in symmetric nuclear matter (SNM), pure neutron matter (PNM) and pure lambda matter (PLM) based on this parameter set are also calculated by using the X=1, SU (6) and SU (3) prescriptions. The results are compared to those obtained from microscopic models, quark meson coupling model (χ QMM) and the QCD sum rule for finite density (QCD SM) result.

  1. Regional Background Fine Particulate Matter

    EPA Science Inventory

    A modeling system composed of the global model GEOS-Chem providing hourly lateral boundary conditions to the regional model CMAQ was used to calculate the policy relevant background level of fine particulate: matter. Simulations were performed for the full year of 2004 over the d...

  2. Particulate matter and preterm birth

    EPA Science Inventory

    Particulate matter (PM) has been variably associated with preterm birth (PTB) (gestation <37 weeks), but the role played by specific chemical components of PM has been little studied. We examined the association between ambient PM <2.5 micrometers in aerodynamic diameter (PM2.S) ...

  3. The LZ Dark Matter Experiment

    NASA Astrophysics Data System (ADS)

    Bernard, Ethan; LZ Collaboration

    2013-10-01

    Astrophysical and cosmological observations show that dark matter is concentrated in halos around galaxies and is approximately five times more abundant than baryonic matter. Dark matter has evaded direct detection despite a series of increasingly sensitive experiments. The LZ (LUX-ZEPLIN) experiment will use a two-phase liquid-xenon time projection chamber to search for elastic scattering of xenon nuclei by WIMP (weakly interactive massive particle) dark matter. The detector will contain seven tons of liquid xenon shielded by an active organic scintillator veto and a water tank within the Sanford Underground Research Facility (SURF) in Lead, South Dakota. The LZ detector scales up the demonstrated light-sensing, cryogenic, radiopurity and shielding technologies of the LUX experiment. Active shielding, position fiducialization, radiopurity control and signal discrimination will reduce backgrounds to levels subdominant to solar neutrino scattering. This experiment will reach a sensitivity to the WIMP-nucleon spin-independent cross section approaching ~ 2 .10-48 cm2 for a 50 GeV WIMP mass, which is about three orders of magnitude smaller than current limits.

  4. The Particle Theory of Matter

    ERIC Educational Resources Information Center

    Widick, Paul R.

    1969-01-01

    Described are activities that are designed to help elementary children understand the possibility of the particle theory of matter. Children work with beads, marbles, B-B shot and sand; by mixing these materials and others they are led to see that it is highly possible for the existence of particles which are not visible. (BR)

  5. Apparatus for particulate matter analysis

    DOEpatents

    Gundel, Lara A.; Apte, Michael G.; Hansen, Anthony D.; Black, Douglas R.

    2007-01-30

    The apparatus described herein is a miniaturized system for particle exposure assessment (MSPEA) for the quantitative measurement and qualitative identification of particulate content in gases. The present invention utilizes a quartz crystal microbalance (QCM) or other mass-sensitive temperature compensated acoustic wave resonator for mass measurement. Detectors and probes and light sources are used in combination for the qualitative determination of particulate matter.

  6. Z-portal dark matter

    SciTech Connect

    Arcadi, Giorgio; Mambrini, Yann; Richard, Francois E-mail: yann.mambrini@th.u-psud.fr

    2015-03-01

    We propose to generalize the extensions of the Standard Model where the Z boson serves as a mediator between the Standard Model sector and the dark sector χ. We show that, like in the Higgs portal case, the combined constraints from the recent direct searches restrict severely the nature of the coupling of the dark matter to the Z boson and set a limit m{sub χ} ∼> 200 GeV (except in a very narrow region around the Z-pole region). Using complementarity between spin dependent, spin independent and FERMI limits, we predict the nature of this coupling, more specifically the axial/vectorial ratio that respects a thermal dark matter coupled through a Z-portal while not being excluded by the current observations. We also show that the next generation of experiments of the type LZ or XENON1T will test Z-portal scenario for dark matter mass up to 2 TeV . The condition of a thermal dark matter naturally predicts the spin-dependent scattering cross section on the neutron to be σ{sup SD}{sub χn} ≅ 10{sup −40} cm{sup 2}, which then becomes a clear prediction of the model and a signature testable in the near future experiments.

  7. Voyage of Time: Dark Matter

    SciTech Connect

    2016-10-10

    This scene of “Voyage of Time,” contributed by KIPAC’s Ralf Kaehler and Tom Abel, shows how dark matter evolved in the universe to form large-scale structures such as galaxies and galaxy clusters. (SLAC National Accelerator Laboratory)

  8. A Rigorous Curriculum Really Matters

    ERIC Educational Resources Information Center

    Cook, Erika

    2013-01-01

    As every good secondary administrator knows, rigorous curricula matter. Challenging curricula is the factor in lifting each student to reach their potential: "the academic intensity of the student's high school curriculum still counts more than anything else...in providing momentum toward completing a bachelor's degree" (Adelman, 2006,…

  9. Source Testing for Particulate Matter.

    ERIC Educational Resources Information Center

    DeVorkin, Howard

    Developed for presentation at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971, this outline covers procedures for the testing of particulate matter. These are: (1) basic requirements, (2) information required, (3) collection of samples, (4) processing of samples, (5)…

  10. Teacher Working Conditions that Matter

    ERIC Educational Resources Information Center

    Leithwood, Ken; McAdie, Pat

    2007-01-01

    To advance understanding of the issues concerning teachers' working conditions, the Elementary Teachers' Federation of Ontario commissioned one of the authors to do an analytical review of literature on teachers' working conditions. This resulted in the publication, "Teacher Working Conditions That Matter: Evidence for Change." The…

  11. Z-portal dark matter

    SciTech Connect

    Arcadi, Giorgio; Mambrini, Yann; Richard, Francois

    2015-03-11

    We propose to generalize the extensions of the Standard Model where the Z boson serves as a mediator between the Standard Model sector and the dark sector χ. We show that, like in the Higgs portal case, the combined constraints from the recent direct searches restrict severely the nature of the coupling of the dark matter to the Z boson and set a limit m{sub χ}≳200 GeV (except in a very narrow region around the Z-pole region). Using complementarity between spin dependent, spin independent and FERMI limits, we predict the nature of this coupling, more specifically the axial/vectorial ratio that respects a thermal dark matter coupled through a Z-portal while not being excluded by the current observations. We also show that the next generation of experiments of the type LZ or XENON1T will test Z-portal scenario for dark matter mass up to 2 TeV. The condition of a thermal dark matter naturally predicts the spin-dependent scattering cross section on the neutron to be σ{sub χn}{sup SD}≃10{sup −40} cm{sup 2}, which then becomes a clear prediction of the model and a signature testable in the near future experiments.

  12. MSSM Dark Matter Without Prejudice

    SciTech Connect

    Gainer, James S.; /SLAC

    2009-12-11

    Recently we examined a large number of points in a 19-dimensional parameter subspace of the CP-conserving MSSM with Minimal Flavor Violation. We determined whether each of these points satisfied existing theoretical, experimental, and observational constraints. Here we discuss the properties of the parameter space points allowed by existing data that are relevant for dark matter searches.

  13. MSSM Dark Matter Without Prejudice

    SciTech Connect

    Gainer, James S.

    2010-02-10

    Recently we examined a large number of points in a 19-dimensional parameter subspace of the CP-conserving MSSM with Minimal Flavor Violation. We determined whether each of these points satisfied existing theoretical, experimental, and observational constraints. Here we discuss the properties of the parameter space points allowed by existing data that are relevant for dark matter searches.

  14. MSSM Dark Matter Without Prejudice

    NASA Astrophysics Data System (ADS)

    Gainer, James S.

    2010-02-01

    Recently we examined a large number of points in a 19-dimensional parameter subspace of the CP-conserving MSSM with Minimal Flavor Violation. We determined whether each of these points satisfied existing theoretical, experimental, and observational constraints. Here we discuss the properties of the parameter space points allowed by existing data that are relevant for dark matter searches.

  15. The Electrical Property of Matter.

    ERIC Educational Resources Information Center

    DeMeo, Stephen; Lythcott, Jean

    2001-01-01

    Describes a demonstration of static charge using balloons and crystals to illustrate the electrical nature of matter. Building on the classic physics demonstration that uses pieces of paper and a plastic rod, this approach adds a new dimension of chemistry. Offers suggestions for how to discuss the observed phenomenon. (DLH)

  16. Dark matter signals in space

    NASA Astrophysics Data System (ADS)

    Salati, Pierre

    2010-01-01

    The confirmation by the PAMELA collaboration of a positron excess above 10 GeV has triggered a lot of excitement in the field of particle astrophysics. This excess could be the first long waited hint of the presence of massive and weakly interacting species in the halo of the Milky Way. If so, the nature of the astronomical dark matter is about to be unveiled after more than seventy years of unsuccessful searches. This review summarizes the state of the art, a year of bubbling activity after the PAMELA announcement. The dark matter candidates which can potentially lead to a positron excess have quite special properties. They are severely constrained by radio and gamma observations unless they are tightly packed inside unprobable or bizarre dark matter clumps. These species could also be unstable with abnormally long lifetimes. Although the positron excess could be generated by annihilating and/or decaying dark matter particles, William of Ockham would warn us that a more natural explanation is to be found in pulsars for instance, and that entia non sunt multiplicanda praeter necessitatem.

  17. Dark matter in NGC 4472

    NASA Technical Reports Server (NTRS)

    Loewenstein, Michael

    1992-01-01

    An attempt is made to constrain the total mass distribution of the giant elliptical galaxy NGC 4472 by constructing simultaneous equilibrium models for the gas and stars. Emphasis is given to reconciling the value of the emission-weighted average value of kT derived from the Ginga spectrum with the amount of dark matter needed to account for velocity dispersion observations.

  18. Z-portal dark matter

    NASA Astrophysics Data System (ADS)

    Arcadi, Giorgio; Mambrini, Yann; Richard, Francois

    2015-03-01

    We propose to generalize the extensions of the Standard Model where the Z boson serves as a mediator between the Standard Model sector and the dark sector χ. We show that, like in the Higgs portal case, the combined constraints from the recent direct searches restrict severely the nature of the coupling of the dark matter to the Z boson and set a limit mχ gtrsim 200 GeV (except in a very narrow region around the Z-pole region). Using complementarity between spin dependent, spin independent and FERMI limits, we predict the nature of this coupling, more specifically the axial/vectorial ratio that respects a thermal dark matter coupled through a Z-portal while not being excluded by the current observations. We also show that the next generation of experiments of the type LZ or XENON1T will test Z-portal scenario for dark matter mass up to 2 TeV . The condition of a thermal dark matter naturally predicts the spin-dependent scattering cross section on the neutron to be σSDχn simeq 10-40 cm2, which then becomes a clear prediction of the model and a signature testable in the near future experiments.

  19. Extraterrestrial Matter Chronometry of Sediments

    NASA Astrophysics Data System (ADS)

    Peucker-Ehrenbrink, B.; Waters, C. A.; Hoffman, P. F.; Kurz, M. D.

    2010-12-01

    Tracer records of extraterrestrial matter (ET) accumulation in sediments suggest that ET accretion rates are reasonable constant on time scales relevant to sediment accumulation in terrestrial and marine environments (1000-100,000 years), except during impact events. Geochemical tracers of ET matter in sediments are therefore informative rate indicators applicable to individual samples. This alleviates the need for interpolating rates between known chronometric tie points. The most sensitive tracers of ET accretion include noble gases, particularly helium, and the heavy platinum group elements osmium, iridium and platinum. Helium and osmium have tell-tale isotope signatures that are sensitive indicators of terrestrial vs. extraterrestrial pedigree. Here we investigate the use of coupled helium-osmium isotope and helium, osmium, iridium and platinum concentration analyses to determine sedimentation rates across Neoproterozoic glacial terminations. Bodiselitsch et al. (Science 308, 2005, 239ff) suggested that significant iridium anomalies at transitions from glacial to postglacial sediments constrain the duration of Neoproterozoic Marinoan glaciation to at least 3, and most likely 12 million years. Our data on Marinoan sections from NW Canada and Namibia reveal no large ET matter anomaly, and support a more nuanced interpretation of coupled geochemical indicators of accretion of ET matter across those transitions. Our records provide insights into environmental changes during periods of Neoproterozoic climate change.

  20. Accountability for What Matters Most

    ERIC Educational Resources Information Center

    Wagner, Tony

    2012-01-01

    During the author's travels all over the United States speaking to a wide variety of audiences, and his visits with leadership groups in the Middle East and Far East, he has encountered diverse audiences who share his concern that the majority of students are leaving high school without the skills that matter most--even in those school districts…

  1. The Particle Theory of Matter

    ERIC Educational Resources Information Center

    Widick, Paul R.

    1969-01-01

    Described are activities that are designed to help elementary children understand the possibility of the particle theory of matter. Children work with beads, marbles, B-B shot and sand; by mixing these materials and others they are led to see that it is highly possible for the existence of particles which are not visible. (BR)

  2. Wake up, because Math Matters

    ERIC Educational Resources Information Center

    Gilpin, Jeanny

    2010-01-01

    This article presents the author's story, as a teacher, about building a Math Matters club and discusses why her students arrived at school before first bell to participate enthusiastically. The author's students seemed to have a negative attitude about math. In giving that stirring motivational speech, she apparently overlooked one important…

  3. The Electrical Property of Matter.

    ERIC Educational Resources Information Center

    DeMeo, Stephen; Lythcott, Jean

    2001-01-01

    Describes a demonstration of static charge using balloons and crystals to illustrate the electrical nature of matter. Building on the classic physics demonstration that uses pieces of paper and a plastic rod, this approach adds a new dimension of chemistry. Offers suggestions for how to discuss the observed phenomenon. (DLH)

  4. Warm Dense Matter: An Overview

    SciTech Connect

    Kalantar, D H; Lee, R W; Molitoris, J D

    2004-04-21

    This document provides a summary of the ''LLNL Workshop on Extreme States of Materials: Warm Dense Matter to NIF'' which was held on 20, 21, and 22 February 2002 at the Wente Conference Center in Livermore, CA. The warm dense matter regime, the transitional phase space region between cold material and hot plasma, is presently poorly understood. The drive to understand the nature of matter in this regime is sparking scientific activity worldwide. In addition to pure scientific interest, finite temperature dense matter occurs in the regimes of interest to the SSMP (Stockpile Stewardship Materials Program). So that obtaining a better understanding of WDM is important to performing effective experiments at, e.g., NIF, a primary mission of LLNL. At this workshop we examined current experimental and theoretical work performed at, and in conjunction with, LLNL to focus future activities and define our role in this rapidly emerging research area. On the experimental front LLNL plays a leading role in three of the five relevant areas and has the opportunity to become a major player in the other two. Discussion at the workshop indicated that the path forward for the experimental efforts at LLNL were two fold: First, we are doing reasonable baseline work at SPLs, HE, and High Energy Lasers with more effort encouraged. Second, we need to plan effectively for the next evolution in large scale facilities, both laser (NIF) and Light/Beam sources (LCLS/TESLA and GSI) Theoretically, LLNL has major research advantages in areas as diverse as the thermochemical approach to warm dense matter equations of state to first principles molecular dynamics simulations. However, it was clear that there is much work to be done theoretically to understand warm dense matter. Further, there is a need for a close collaboration between the generation of verifiable experimental data that can provide benchmarks of both the experimental techniques and the theoretical capabilities. The conclusion of this

  5. Alternative to particle dark matter

    NASA Astrophysics Data System (ADS)

    Khoury, Justin

    2015-01-01

    We propose an alternative to particle dark matter that borrows ingredients of modified Newtonian dynamics (MOND) while adding new key components. The first new feature is a dark matter fluid, in the form of a scalar field with small equation of state and sound speed. This component is critical in reproducing the success of cold dark matter for the expansion history and the growth of linear perturbations, but does not cluster significantly on nonlinear scales. Instead, the missing mass problem on nonlinear scales is addressed by a modification of the gravitational force law. The force law approximates MOND at large and intermediate accelerations, and therefore reproduces the empirical success of MOND at fitting galactic rotation curves. At ultralow accelerations, the force law reverts to an inverse-square law, albeit with a larger Newton's constant. This latter regime is important in galaxy clusters and is consistent with their observed isothermal profiles, provided the characteristic acceleration scale of MOND is mildly varying with scale or mass, such that it is 12 times higher in clusters than in galaxies. We present an explicit relativistic theory in terms of two scalar fields. The first scalar field is governed by a Dirac-Born-Infeld action and behaves as a dark matter fluid on large scales. The second scalar field also has single-derivative interactions and mediates a fifth force that modifies gravity on nonlinear scales. Both scalars are coupled to matter via an effective metric that depends locally on the fields. The form of this effective metric implies the equality of the two scalar gravitational potentials, which ensures that lensing and dynamical mass estimates agree. Further work is needed in order to make both the acceleration scale of MOND and the fraction at which gravity reverts to an inverse-square law explicitly dynamical quantities, varying with scale or mass.

  6. Dark matter in the Universe

    SciTech Connect

    Turner, M.S. Chicago Univ., IL . Enrico Fermi Inst.)

    1991-03-01

    What is the quantity and composition of material in the universe This is one of the most fundamental questions we can ask about the universe, and its answer bears on a number of important issues including the formation of structure in the universe, and the ultimate fate and the earliest history of the universe. Moreover, answering this question could lead to the discovery of new particles, as well as shedding light on the nature of the fundamental interactions. At present, only a partial answer is at hand: most of the material in the universe does not give off detectable radiation, i.e., is dark;'' the dark matter associated with bright galaxies contributes somewhere between 10% and 30% of the critical density (by comparison luminous matter contributes less than 1%); baryonic matter contributes between 1.1% and 12% of critical. The case for the spatially-flat, Einstein-de Sitter model is supported by three compelling theoretical arguments -- structure formation, the temporal Copernican principle, and inflation -- and by some observational data. If {Omega} is indeed unity--or even just significantly greater than 0.1--then there is a strong case for a universe comprised of nonbaryonic matter. There are three well motivated particle dark-matter candidates: an axion of mass 10{sup {minus}6} eV to 10{sup {minus}4} eV; a neutralino of mass 10 GeV to about 3 TeV; or a neutrino of mass 20 eV to 90 eV. All three possibilities can be tested by experiments that are either being planned or are underway. 71 refs., 6 figs.

  7. Dark matter in the universe

    SciTech Connect

    Turner, M.S. Chicago Univ., IL . Enrico Fermi Inst.)

    1990-11-01

    What is the quantity and composition of material in the Universe This is one of the most fundamental questions we can ask about the Universe, and its answer bears on a number of important issues including the formation of structure in the Universe, and the ultimate fate and the earliest history of the Universe. Moreover, answering this question could lead to the discovery of new particles, as well as shedding light on the nature of the fundamental interactions. At present, only a partial answer is at hand: Most of the material in the Universe does not give off detectable radiation, i.e., is dark;'' the dark matter associated with bright galaxies contributes somewhere between 10% and 30% of the critical density (by comparison luminous matter contributes less than 1%); baryonic matter contributes between 1.1% and 12% of critical. The case for the spatially-flat, Einstein-de Sitter model is supported by three compelling theoretical arguments--structure formation, the temporal Copernican principle, and inflation--and by some observational data. If {Omega} is indeed unity--or even just significantly greater than 0.1--then there is a strong case for a Universe comprised of nonbaryonic matter. There are three well motivated particle dark-matter candidates: an axion of mass 10{sup {minus}6} eV to 10{sup {minus}4} eV; a neutralino of mass 10 GeV to about 3 TeV; or a neutrino of mass 20 eV to 90 eV. All three possibilities can be tested by experiments that are either being planned or are underway. 63 refs.

  8. EOS of neutron-rich matter and pure neutron matter

    NASA Astrophysics Data System (ADS)

    Manisa, Kaan

    2012-03-01

    We report the equation of state (EOS) of pure neutron matter (PNM) and neutron-rich matter (NRM) for the realistic Urbana V14 two nucleon interaction, obtained by using a Variational Monte Carlo (VMC) method. Also, many body interactions are included as a phenomenological density dependent term in the potential. The binding energy per nucleon is calculated for different densities and various isospin asymmetry parameters. Our results on NRM and PNM are compared with relativistic Brueckner-Hartree-Fock theory and relativistic Hartree-Fock model with the unitary correlation operator method. The results obtained in this study show reasonable agreement with both of these relativistic Hartree-Fock approaches. We also compare the binding energies obtained in this study with those obtained by various authors employing different methods and techniques.

  9. 48 CFR 232.503 - Postaward matters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Postaward matters. 232.503 Section 232.503 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....503 Postaward matters....

  10. 48 CFR 232.503 - Postaward matters.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Postaward matters. 232.503 Section 232.503 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....503 Postaward matters....

  11. 48 CFR 232.502 - Preaward matters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Preaward matters. 232.502 Section 232.502 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....502 Preaward matters....

  12. 48 CFR 232.502 - Preaward matters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Preaward matters. 232.502 Section 232.502 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....502 Preaward matters....

  13. 48 CFR 232.503 - Postaward matters.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Postaward matters. 232.503 Section 232.503 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....503 Postaward matters....

  14. 48 CFR 232.503 - Postaward matters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Postaward matters. 232.503 Section 232.503 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....503 Postaward matters....

  15. 48 CFR 232.503 - Postaward matters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Postaward matters. 232.503 Section 232.503 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....503 Postaward matters....

  16. 48 CFR 232.502 - Preaward matters.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Preaward matters. 232.502 Section 232.502 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....502 Preaward matters....

  17. 48 CFR 232.502 - Preaward matters.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Preaward matters. 232.502 Section 232.502 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....502 Preaward matters....

  18. 48 CFR 232.502 - Preaward matters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Preaward matters. 232.502 Section 232.502 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT....502 Preaward matters....

  19. Strongly Interacting Matter at High Energy Density

    SciTech Connect

    McLerran,L.

    2008-09-07

    This lecture concerns the properties of strongly interacting matter (which is described by Quantum Chromodynamics) at very high energy density. I review the properties of matter at high temperature, discussing the deconfinement phase transition. At high baryon density and low temperature, large N{sub c} arguments are developed which suggest that high baryonic density matter is a third form of matter, Quarkyonic Matter, that is distinct from confined hadronic matter and deconfined matter. I finally discuss the Color Glass Condensate which controls the high energy limit of QCD, and forms the low x part of a hadron wavefunction. The Glasma is introduced as matter formed by the Color Glass Condensate which eventually thermalizes into a Quark Gluon Plasma.

  20. Dark matter axions and caustic rings

    SciTech Connect

    Sikivie, P.

    1997-11-01

    This report contains discussions on the following topics: the strong CP problem; dark matter axions; the cavity detector of galactic halo axions; and caustic rings in the density distribution of cold dark matter halos.

  1. Thermodynamics of neutron-rich nuclear matter

    SciTech Connect

    López, Jorge A.; Porras, Sergio Terrazas Gutiérrez, Araceli Rodríguez

    2016-07-07

    This manuscript presents methods to obtain properties of neutron-rich nuclear matter from classical molecular dynamics. Some of these are bulk properties of infinite nuclear matter, phase information, the Maxwell construction, spinodal lines and symmetry energy.

  2. Dark matter and the equivalence principle

    NASA Technical Reports Server (NTRS)

    Frieman, Joshua A.; Gradwohl, Ben-Ami

    1993-01-01

    A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.

  3. Dark matter and the equivalence principle

    NASA Technical Reports Server (NTRS)

    Frieman, Joshua A.; Gradwohl, Ben-Ami

    1993-01-01

    A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.

  4. Dark Matter Annihilation at the Galactic Center

    SciTech Connect

    Linden, Timothy Ryan

    2013-06-01

    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 ve times as much dark matter as baryonic matter. However, e orts 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 rst multiwavelength analysis of the GC, with suitable e ective 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 e orts which have successfully detected an excess in -ray emission from the region immediately surrounding the GC, which is di cult to describe in terms of standard di use 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

  5. New Frontiers in Dark Matter Detection

    NASA Astrophysics Data System (ADS)

    Thaler, Jesse

    2017-01-01

    Dark matter, detected thus far only through its couplings to gravity, remains an enigma. It is therefore essential to pursue a broad portfolio of search strategies to test for non-gravitational interactions between dark matter and visible matter. In this talk, I give an overview of recent progress in detecting dark matter and related particles, ranging from ultralight axion-like particles to hidden sector dark forces.

  6. Dark matter in a bouncing universe

    SciTech Connect

    Cheung, Yeuk-Kwan E.; Kang, Jin U; Li, Changhong E-mail: jin.u.kang2@gmail.com

    2014-11-01

    We investigate a new scenario of dark matter production in a bouncing universe, in which dark matter was produced completely out of equilibrium in the contracting as well as expanding phase. We explore possibilities of using dark matter as a probe of the bouncing universe, focusing on the relationship between a critical temperature of the bouncing universe and the present relic abundance of dark matter.

  7. PREFACE: Polymers and Complex Matter

    NASA Astrophysics Data System (ADS)

    von Ferber, Christian

    2005-05-01

    This special issue, in honour of Lothar Schäfer on the occasion of his 60th birthday, focuses on polymers and complex matter and covers a broad range of topics both in terms of subject matter and methods applied. This reflects the wide and open minded interests of the honoree. Lothar Schäfer began his career in Heidelberg working on theoretical nuclear physics with H A Weidenmüller. Following a stay at the CEN Saclay in 1974, he turned to the field of critical phenomena. He made fundamental contributions to the subject of disordered systems, in particular on Goldstone modes with F J Wegner and on Anderson localization with A U Pruisken. With T A Witten he formulated a truly field theoretic description of general polymer solutions. Polymers in solution and the renormalization group approach to their experimentally accessible properties have, since 1980 in Hannover and 1983 in Essen, been his primary field of research summarized in his book Excluded Volume Effects in Polymer Solutions as Explained by the Renormalization Group covering `all you ought to know' on the subject. This work is complemented by analytical studies of polymer dynamics. The subjects contained in this special issue encompass soft matter and its rheology, polymers in confinement and their role in short- and long-range colloidal interactions: discussing lenses, dumbbells, rods and dendrimers. Special topics are short chains, directed molecules and gas permeation through polymers. Applications of polymer theory to biological systems include the interactions between DNA molecules and between DNA and proteins and the polymerization of the actin skeleton. Work on random matrix theory, functional renormalization and ageing is devoted to the implications of disorder. Finally, more general aspects of the field theory of polymers and complex matter are discussed, like the Hubbard-Stratonovich transformation, renormalization of polymer field theory, exact renormalization group equations, percolation and

  8. 7 CFR 201.19 - Inert matter.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Inert matter. 201.19 Section 201.19 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.19 Inert matter. The label shall show the percentage by weight of inert matter....

  9. 10 CFR 820.8 - Evidentiary matters.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Evidentiary matters. 820.8 Section 820.8 Energy DEPARTMENT OF ENERGY PROCEDURAL RULES FOR DOE NUCLEAR ACTIVITIES General § 820.8 Evidentiary matters. (a... matter related to a DOE nuclear activity or for any decision required by this part. A DOE Official...

  10. 49 CFR 1104.8 - Objectionable matter.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 8 2013-10-01 2013-10-01 false Objectionable matter. 1104.8 Section 1104.8..., GENERALLY § 1104.8 Objectionable matter. The Board may order that any redundant, irrelevant, immaterial, impertinent, or scandalous matter be stricken from any document....

  11. 10 CFR 820.8 - Evidentiary matters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Evidentiary matters. 820.8 Section 820.8 Energy DEPARTMENT OF ENERGY PROCEDURAL RULES FOR DOE NUCLEAR ACTIVITIES General § 820.8 Evidentiary matters. (a... matter related to a DOE nuclear activity or for any decision required by this part. A DOE Official...

  12. 48 CFR 32.503 - Postaward matters.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Postaward matters. 32.503... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.503 Postaward matters. This section covers matters that are generally relevant only after award of a contract. This does not preclude taking...

  13. 48 CFR 32.502 - Preaward matters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Preaward matters. 32.502... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.502 Preaward matters. This section covers matters that generally are relevant only before contract award. This does not preclude taking...

  14. 46 CFR 201.181 - General matters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false General matters. 201.181 Section 201.181 Shipping... PROCEDURE Judicial Standards of Practice (Rule 19) § 201.181 General matters. (a) In general, the functions... after notice and opportunity for hearing, or in the case of other matters from the time of notice by...

  15. 48 CFR 32.502 - Preaward matters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Preaward matters. 32.502... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.502 Preaward matters. This section covers matters that generally are relevant only before contract award. This does not preclude taking...

  16. 46 CFR 201.181 - General matters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false General matters. 201.181 Section 201.181 Shipping... PROCEDURE Judicial Standards of Practice (Rule 19) § 201.181 General matters. (a) In general, the functions... after notice and opportunity for hearing, or in the case of other matters from the time of notice by...

  17. 49 CFR 1104.8 - Objectionable matter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Objectionable matter. 1104.8 Section 1104.8..., GENERALLY § 1104.8 Objectionable matter. The Board may order that any redundant, irrelevant, immaterial, impertinent, or scandalous matter be stricken from any document....

  18. 49 CFR 1104.8 - Objectionable matter.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 8 2014-10-01 2014-10-01 false Objectionable matter. 1104.8 Section 1104.8..., GENERALLY § 1104.8 Objectionable matter. The Board may order that any redundant, irrelevant, immaterial, impertinent, or scandalous matter be stricken from any document....

  19. 46 CFR 201.181 - General matters.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false General matters. 201.181 Section 201.181 Shipping... PROCEDURE Judicial Standards of Practice (Rule 19) § 201.181 General matters. (a) In general, the functions... after notice and opportunity for hearing, or in the case of other matters from the time of notice by...

  20. 48 CFR 32.503 - Postaward matters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Postaward matters. 32.503... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.503 Postaward matters. This section covers matters that are generally relevant only after award of a contract. This does not preclude taking...

  1. 10 CFR 603.600 - Administrative matters.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Administrative matters. 603.600 Section 603.600 Energy... Affecting Participants' Financial, Property, and Purchasing Systems § 603.600 Administrative matters. This subpart addresses “systemic” administrative matters that place requirements on the operation of...

  2. 40 CFR 1508.19 - Matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Matter. 1508.19 Section 1508.19 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.19 Matter. Matter includes for purposes of part 1504: (a) With respect to the Environmental Protection Agency, any...

  3. 10 CFR 603.600 - Administrative matters.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Administrative matters. 603.600 Section 603.600 Energy... Affecting Participants' Financial, Property, and Purchasing Systems § 603.600 Administrative matters. This subpart addresses “systemic” administrative matters that place requirements on the operation of...

  4. 10 CFR 603.600 - Administrative matters.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Administrative matters. 603.600 Section 603.600 Energy... Affecting Participants' Financial, Property, and Purchasing Systems § 603.600 Administrative matters. This subpart addresses “systemic” administrative matters that place requirements on the operation of...

  5. 10 CFR 603.600 - Administrative matters.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Administrative matters. 603.600 Section 603.600 Energy... Affecting Participants' Financial, Property, and Purchasing Systems § 603.600 Administrative matters. This subpart addresses “systemic” administrative matters that place requirements on the operation of...

  6. 40 CFR 1508.19 - Matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Matter. 1508.19 Section 1508.19 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.19 Matter. Matter includes for purposes of part 1504: (a) With respect to the Environmental Protection Agency, any...

  7. 10 CFR 820.8 - Evidentiary matters.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Evidentiary matters. 820.8 Section 820.8 Energy DEPARTMENT OF ENERGY PROCEDURAL RULES FOR DOE NUCLEAR ACTIVITIES General § 820.8 Evidentiary matters. (a... matter related to a DOE nuclear activity or for any decision required by this part. A DOE Official...

  8. 46 CFR 201.181 - General matters.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false General matters. 201.181 Section 201.181 Shipping... PROCEDURE Judicial Standards of Practice (Rule 19) § 201.181 General matters. (a) In general, the functions... after notice and opportunity for hearing, or in the case of other matters from the time of notice by...

  9. 10 CFR 820.8 - Evidentiary matters.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Evidentiary matters. 820.8 Section 820.8 Energy DEPARTMENT OF ENERGY PROCEDURAL RULES FOR DOE NUCLEAR ACTIVITIES General § 820.8 Evidentiary matters. (a... matter related to a DOE nuclear activity or for any decision required by this part. A DOE Official...

  10. 48 CFR 32.503 - Postaward matters.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Postaward matters. 32.503... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.503 Postaward matters. This section covers matters that are generally relevant only after award of a contract. This does not preclude taking...

  11. 10 CFR 603.600 - Administrative matters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Administrative matters. 603.600 Section 603.600 Energy... Affecting Participants' Financial, Property, and Purchasing Systems § 603.600 Administrative matters. This subpart addresses “systemic” administrative matters that place requirements on the operation of...

  12. 7 CFR 201.19 - Inert matter.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Inert matter. 201.19 Section 201.19 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.19 Inert matter. The label shall show the percentage by weight of inert matter. [5 FR 31, Jan. 4, 1940]...

  13. 46 CFR 201.181 - General matters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false General matters. 201.181 Section 201.181 Shipping... PROCEDURE Judicial Standards of Practice (Rule 19) § 201.181 General matters. (a) In general, the functions... after notice and opportunity for hearing, or in the case of other matters from the time of notice by...

  14. 48 CFR 32.502 - Preaward matters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Preaward matters. 32.502... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.502 Preaward matters. This section covers matters that generally are relevant only before contract award. This does not preclude taking...

  15. 49 CFR 1104.8 - Objectionable matter.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 false Objectionable matter. 1104.8 Section 1104.8..., GENERALLY § 1104.8 Objectionable matter. The Board may order that any redundant, irrelevant, immaterial, impertinent, or scandalous matter be stricken from any document....

  16. 49 CFR 1104.8 - Objectionable matter.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 8 2012-10-01 2012-10-01 false Objectionable matter. 1104.8 Section 1104.8..., GENERALLY § 1104.8 Objectionable matter. The Board may order that any redundant, irrelevant, immaterial, impertinent, or scandalous matter be stricken from any document....

  17. 10 CFR 820.8 - Evidentiary matters.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Evidentiary matters. 820.8 Section 820.8 Energy DEPARTMENT OF ENERGY PROCEDURAL RULES FOR DOE NUCLEAR ACTIVITIES General § 820.8 Evidentiary matters. (a... matter related to a DOE nuclear activity or for any decision required by this part. A DOE Official...

  18. 48 CFR 32.502 - Preaward matters.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Preaward matters. 32.502... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.502 Preaward matters. This section covers matters that generally are relevant only before contract award. This does not preclude taking...

  19. 7 CFR 201.19 - Inert matter.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Inert matter. 201.19 Section 201.19 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.19 Inert matter. The label shall show the percentage by weight of inert matter....

  20. 40 CFR 1508.19 - Matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Matter. 1508.19 Section 1508.19 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.19 Matter. Matter includes for purposes of part 1504: (a) With respect to the Environmental Protection Agency, any...

  1. 40 CFR 1508.19 - Matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Matter. 1508.19 Section 1508.19 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.19 Matter. Matter includes for purposes of part 1504: (a) With respect to the Environmental Protection Agency, any...

  2. 48 CFR 32.503 - Postaward matters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Postaward matters. 32.503... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.503 Postaward matters. This section covers matters that are generally relevant only after award of a contract. This does not preclude taking...

  3. 7 CFR 201.19 - Inert matter.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Inert matter. 201.19 Section 201.19 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.19 Inert matter. The label shall show the percentage by weight of inert matter....

  4. 48 CFR 32.503 - Postaward matters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Postaward matters. 32.503... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.503 Postaward matters. This section covers matters that are generally relevant only after award of a contract. This does not preclude taking...

  5. 7 CFR 201.19 - Inert matter.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Inert matter. 201.19 Section 201.19 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.19 Inert matter. The label shall show the percentage by weight of inert matter. [5 FR 31, Jan. 4, 1940]...

  6. 48 CFR 32.502 - Preaward matters.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Preaward matters. 32.502... REQUIREMENTS CONTRACT FINANCING Progress Payments Based on Costs 32.502 Preaward matters. This section covers matters that generally are relevant only before contract award. This does not preclude taking...

  7. Variational Theory of Hot Dense Matter

    ERIC Educational Resources Information Center

    Mukherjee, Abhishek

    2009-01-01

    We develop a variational theory of hot nuclear matter in neutron stars and supernovae. It can also be used to study charged, hot nuclear matter which may be produced in heavy-ion collisions. This theory is a generalization of the variational theory of cold nuclear and neutron star matter based on realistic models of nuclear forces and pair…

  8. Nonthermal dark matter in mirage mediation

    SciTech Connect

    Nagai, Minoru; Nakayama, Kazunori

    2007-12-15

    In mirage-mediation models there exists a modulus field whose mass is O(1000) TeV and its late decay may significantly change the standard thermal relic scenario of the dark matter. We study nonthermal production of the dark matter directly from the modulus decay, and find that for some parameter regions nonthermally produced neutralinos can become the dark matter.

  9. Variational Theory of Hot Dense Matter

    ERIC Educational Resources Information Center

    Mukherjee, Abhishek

    2009-01-01

    We develop a variational theory of hot nuclear matter in neutron stars and supernovae. It can also be used to study charged, hot nuclear matter which may be produced in heavy-ion collisions. This theory is a generalization of the variational theory of cold nuclear and neutron star matter based on realistic models of nuclear forces and pair…

  10. 40 CFR 1508.19 - Matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Matter. 1508.19 Section 1508.19 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.19 Matter. Matter includes for purposes of part 1504: (a) With respect to the Environmental Protection Agency, any proposed...

  11. An Inquiry into the Phases of Matter

    ERIC Educational Resources Information Center

    Young, Sarah

    2010-01-01

    The "What's the "matter" With XOD" activity addresses students' misconceptions and refines their ideas about phases of matter. This activity introduces the characteristics for solids, liquids, and gases, and begins a discussion about physical and chemical changes and how matter can cycle through different phases. Depending on class size and…

  12. An Inquiry into the Phases of Matter

    ERIC Educational Resources Information Center

    Young, Sarah

    2010-01-01

    The "What's the "matter" With XOD" activity addresses students' misconceptions and refines their ideas about phases of matter. This activity introduces the characteristics for solids, liquids, and gases, and begins a discussion about physical and chemical changes and how matter can cycle through different phases. Depending on class size and…

  13. Matter from G(2) Manifolds

    NASA Astrophysics Data System (ADS)

    Berglund, Per; Brandhuber, Andreas

    2003-04-01

    We describe how chiral matter charged under SU(N) and SO(2N) gauge groups arises from codimension seven singularities in compactifications of M-theory on manifolds with G(2) holonomy. The geometry of these spaces is that of a cone over a six-dimensional Einstein space which can be constructed by (multiple) unfolding of hyper-Kahler quotient spaces. In type IIA the corresponding picture is given by stacks of intersecting D6-branes and chiral matter arises from open strings stretching between them. Usually one obtains (bi)fundamental representations but by including orientifold six-planes in the type IIA picture we find more exotic representations like the anti-symmetric, which is important for the study of SU(5) grand unification, and trifundamental representations. We also exhibit many cases where the G(2) metrics can be described explicitly, although in general the metrics on the spaces constructed via unfolding are not known.

  14. Swift Heavy Ions in Matter

    NASA Astrophysics Data System (ADS)

    Rothard, Hermann; Severin, Daniel; Trautmann, Christina

    2015-12-01

    The present volume contains the proceedings of the Ninth International Symposium on Swift Heavy Ions in Matter (SHIM). This conference was held in Darmstadt, from 18 to 21 May 2015. SHIM is a triennial series, which started about 25 years ago by a joint initiative of CIRIL - Caen and GSI - Darmstadt, with the aim of promoting fundamental and applied interdisciplinary research in the field of high-energy, heavy-ion interaction processes with matter. SHIM was successively organized in Caen (1989), Bensheim (1992), Caen (1995), Berlin (1998), Catania (2002), Aschaffenburg (2005), Lyon (2008), and Kyoto (2012). The conference attracts scientists from many different fields using high-energy heavy ions delivered by large accelerator facilities and characterized by strong and short electronic excitations.

  15. DPIS for warm dense matter

    SciTech Connect

    Kondo, K.; Kanesue, T.; Horioka, K.; Okamura, M.

    2010-05-23

    Warm Dense Matter (WDM) offers an challenging problem because WDM, which is beyond ideal plasma, is in a low temperature and high density state with partially degenerate electrons and coupled ions. WDM is a common state of matter in astrophysical objects such as cores of giant planets and white dwarfs. The WDM studies require large energy deposition into a small target volume in a shorter time than the hydrodynamical time and need uniformity across the full thickness of the target. Since moderate energy ion beams ({approx} 0.3 MeV/u) can be useful tool for WDM physics, we propose WDM generation using Direct Plasma Injection Scheme (DPIS). In the DPIS, laser ion source is connected to the Radio Frequency Quadrupole (RFQ) linear accelerator directly without the beam transport line. DPIS with a realistic final focus and a linear accelerator can produce WDM.

  16. Dark matter in axion landscape

    NASA Astrophysics Data System (ADS)

    Daido, Ryuji; Kobayashi, Takeshi; Takahashi, Fuminobu

    2017-02-01

    If there are a plethora of axions in nature, they may have a complicated potential and create an axion landscape. We study a possibility that one of the axions is so light that it is cosmologically stable, explaining the observed dark matter density. In particular we focus on a case in which two (or more) shift-symmetry breaking terms conspire to make the axion sufficiently light at the potential minimum. In this case the axion has a flat-bottomed potential. In contrast to the case in which a single cosine term dominates the potential, the axion abundance as well as its isocurvature perturbations are significantly suppressed. This allows an axion with a rather large mass to serve as dark matter without fine-tuning of the initial misalignment, and further makes higher-scale inflation to be consistent with the scenario.

  17. Matter Effects On Neutrino Oscillations

    NASA Astrophysics Data System (ADS)

    Gordon, Michael

    An introduction to neutrino oscillations in vacuum is presented, followed by a survey of various techniques for obtaining either exact or approximate expressions for numu → nue oscillations in matter. The method developed by Arafune, Koike, and Sato uses a perturbative analysis to find an approximation for the evolution operator. The method used by Freund yields an approximate oscillation probability by diagonalizing the Hamiltonian, finding the eigenvalues and eigenvectors, and then using those to find modified mixing angles with the matter effect taken into account. The method devised by Mann, Kafka, Schneps, and Altinok produces an exact expression for the oscillation by determining explicitly the evolution operator. These methods are compared to each other using the T2K, MINOS, NOnuA, and LBNE parameters.

  18. Machine learning phases of matter

    NASA Astrophysics Data System (ADS)

    Carrasquilla, Juan; Melko, Roger G.

    2017-02-01

    Condensed-matter physics is the study of the collective behaviour of infinitely complex assemblies of electrons, nuclei, magnetic moments, atoms or qubits. This complexity is reflected in the size of the state space, which grows exponentially with the number of particles, reminiscent of the `curse of dimensionality' commonly encountered in machine learning. Despite this curse, the machine learning community has developed techniques with remarkable abilities to recognize, classify, and characterize complex sets of data. Here, we show that modern machine learning architectures, such as fully connected and convolutional neural networks, can identify phases and phase transitions in a variety of condensed-matter Hamiltonians. Readily programmable through modern software libraries, neural networks can be trained to detect multiple types of order parameter, as well as highly non-trivial states with no conventional order, directly from raw state configurations sampled with Monte Carlo.

  19. Characterising exotic matter driving wormholes

    NASA Astrophysics Data System (ADS)

    Chianese, Marco; Di Grezia, Elisabetta; Manfredonia, Mattia; Miele, Gennaro

    2017-04-01

    In this paper, we develop an iterative approach to span the whole set of exotic matter models able to drive a traversable wormhole. The method, based on a Taylor expansion of metric and stress-energy tensor components in a neighbourhood of the wormhole throat, reduces the Einstein equation to an infinite set of algebraic conditions, which can be satisfied order by order. The approach easily allows the implementation of further conditions linking the stress-energy tensor components among each other, like symmetry conditions or equations of state. The method is then applied to some relevant examples of exotic matter characterised by a constant energy density and that also show an isotropic behaviour in the stress-energy tensor or obeying to a quintessence-like equation of state.

  20. Creep dynamics in soft matter

    NASA Astrophysics Data System (ADS)

    Cabriolu, Raffaela

    Detecting any precursors of failure in Soft Matter Systems (SMS) is an inter-disciplinary topic with important applications (e.g. prediction of failure in engineering processes). Further, it provides an ideal benchmark to understand how mechanical stress and failure impacts the flow properties of amorphous condensed matter. Furthermore, some SMS are viscoelastic, flowing like viscous liquids or deforming like a solid according to applied forces. Often SMS are fragile and local rearrangements trigger catastrophic macroscopic failure. Despite the importance of the topic little is known on the local creep dynamics before the occurrence of such catastrophic events. To study creep and failure at an atomic/molecular level and at time scales that are not easily accessible by experiments we chose to carry out microscopic simulations. In this work we present the response of a colloidal system to uniaxial tensile stress applied and we compare our results to experimental works [8].

  1. Stochastic thermodynamics for active matter

    NASA Astrophysics Data System (ADS)

    Speck, Thomas

    2016-05-01

    The theoretical understanding of active matter, which is driven out of equilibrium by directed motion, is still fragmental and model oriented. Stochastic thermodynamics, on the other hand, is a comprehensive theoretical framework for driven systems that allows to define fluctuating work and heat. We apply these definitions to active matter, assuming that dissipation can be modelled by effective non-conservative forces. We show that, through the work, conjugate extensive and intensive observables can be defined even in non-equilibrium steady states lacking a free energy. As an illustration, we derive the expressions for the pressure and interfacial tension of active Brownian particles. The latter becomes negative despite the observed stable phase separation. We discuss this apparent contradiction, highlighting the role of fluctuations, and we offer a tentative explanation.

  2. Scalar graviton as dark matter

    SciTech Connect

    Pirogov, Yu. F.

    2015-06-15

    The basics of the theory of unimodular bimode gravity built on the principles of unimodular gauge invariance/relativity and general covariance are exposed. Besides the massless tensor graviton of General Relativity, the theory includes an (almost) massless scalar graviton treated as the gravitational dark matter. A spherically symmetric vacuum solution describing the coherent scalar-graviton field for the soft-core dark halos, with the asymptotically flat rotation curves, is demonstrated as an example.

  3. A matter of fried onions.

    PubMed

    Friedman, D B

    1992-12-01

    In the 1946 film 'A Matter of Life and Death', complex partial seizures were portrayed in detail and with surprising accuracy. This study was conducted to determine the nature of the medical collaboration in the preparation of the film as well as the reasons why the creative team of Michael Powell and Emeric Pressburger included these details, but elected to make them invisible to all but those with medical educations.

  4. Dark matter in the universe

    NASA Technical Reports Server (NTRS)

    Turner, Michael S.

    1991-01-01

    What is the quantity and composition of material in the Universe? This is one of the most fundamental questions we can ask about the Universe, and its answer bears on a number of important issues including the formation of structure in the Universe, and the ultimate fate and the earliest history of the Universe. Moreover, answering this question could lead to the discovery of new particles, as well as shedding light on the nature of the fundamental interactions. At present, only a partial answer is at hand. Most of the radiation in the Universe does not give off detectable radiation; it is dark. The dark matter associated with bright galaxies contributes somewhere between 10 and 30 percent of the critical density; baryonic matter contributes between 1.1 and 12 percent of the critical. The case for the spatially flat, Einstein-de Sitter model is supported by three compelling theoretical arguments - structure formation, the temporal Copernican principle, and inflation - and by some observational data. If Omega is indeed unity, or even just significantly greater than 0.1, then there is a strong case for a Universe comprised of nonbaryonic matter. There are three well motivated particle dark matter candidates: an axion of mass 10 (exp -6) eV to 10 (exp -4) eV; a neutrino of mass 10 GeV to about 3 TeV; or a neutrino of mass 20 eV to 90 eV. All three possibilities can be tested by experiments that are either planned or are underway.

  5. Scalar graviton as dark matter

    NASA Astrophysics Data System (ADS)

    Pirogov, Yu. F.

    2015-06-01

    The basics of the theory of unimodular bimode gravity built on the principles of unimodular gauge invariance/relativity and general covariance are exposed. Besides the massless tensor graviton of General Relativity, the theory includes an (almost) massless scalar graviton treated as the gravitational dark matter. A spherically symmetric vacuum solution describing the coherent scalar-graviton field for the soft-core dark halos, with the asymptotically flat rotation curves, is demonstrated as an example.

  6. Strange-quark-matter stars

    SciTech Connect

    Glendenning, N.K.

    1989-11-01

    We investigate the implications of rapid rotation corresponding to the frequency of the new pulsar reported in the supernovae remnant SN1987A. It places very stringent conditions on the equation of state if the star is assumed to be bound by gravity alone. We find that the central energy density of the star must be greater than 13 times that of nuclear density to be stable against the most optimistic estimate of general relativistic instabilities. This is too high for the matter to consist of individual hadrons. We conclude that it is implausible that the newly discovered pulsar, if its half-millisecond signals are attributable to rotation, is a neutron star. We show that it can be a strange quark star, and that the entire family of strange stars can sustain high rotation if strange matter is stable at an energy density exceeding about 5.4 times that of nuclear matter. We discuss the conversion of a neutron star to strange star, the possible existence of a crust of heavy ions held in suspension by centrifugal and electric forces, the cooling and other features. 34 refs., 10 figs., 1 tab.

  7. Heavy spin-2 Dark Matter

    SciTech Connect

    Babichev, Eugeny; Marzola, Luca; Raidal, Martti; Schmidt-May, Angnis; Urban, Federico; Veermäe, Hardi; Strauss, Mikael von

    2016-09-12

    We provide further details on a recent proposal addressing the nature of the dark sectors in cosmology and demonstrate that all current observations related to Dark Matter can be explained by the presence of a heavy spin-2 particle. Massive spin-2 fields and their gravitational interactions are uniquely described by ghost-free bimetric theory, which is a minimal and natural extension of General Relativity. In this setup, the largeness of the physical Planck mass is naturally related to extremely weak couplings of the heavy spin-2 field to baryonic matter and therefore explains the absence of signals in experiments dedicated to Dark Matter searches. It also ensures the phenomenological viability of our model as we confirm by comparing it with cosmological and local tests of gravity. At the same time, the spin-2 field possesses standard gravitational interactions and it decays universally into all Standard Model fields but not into massless gravitons. Matching the measured DM abundance together with the requirement of stability constrains the spin-2 mass to be in the 1 to 100 TeV range.

  8. Isocurvature cold dark matter fluctuations

    NASA Technical Reports Server (NTRS)

    Efstathiou, G.; Bond, J. R.

    1986-01-01

    According to Preskill et al. (1983), the axion field represents a particularly attractive candidate for the dark matter in the universe. In many respects it behaves like other forms of cold dark matter, such as massive gravitinos, photinos, and monopoles. It is, however, a pseudo-Goldstone boson of very low mass, and it is only because of rapid coherent oscillations of the field that it can dominate the mass density of the universe. In the present paper it is assumed that the isocurvature mode is dominant. The linear evolution calculations conducted do not depend upon specific details of particle physics. For this reason, the conducted discussion is applicable to any cold dark matter model with isocurvature perturbations. The results of the study lead to the conclusion that scale-invariant isocurvature perturbations do not seem an attractive possibility for the origin of large-scale structure. The findings strengthen the review that primordial adiabatic perturbations were the dominant fluctuations in the early stages of the Big Bang.

  9. Carbonaceous Matter in Growing Nanoparticles

    NASA Astrophysics Data System (ADS)

    Johnston, M. V.; Stangl, C. M.; Horan, A. J.

    2015-12-01

    Atmospheric nanoparticles constitute the greatest portion of ambient aerosol loading by number. A major source of atmospheric nanoparticles is new particle formation (NPF), a gas to particle conversion process whereby clusters nucleate from gas phase precursors to form clusters on the order of one or a few nanometers and then grow rapidly to climatically relevant sizes. A substantial fraction of cloud condensation nuclei (CCN) are thought to arise from NPF. In order to better predict the frequency, growth rates, and climatic impacts of NPF, knowledge of the chemical mechanisms by which nucleated nanoparticles grow is needed. The two main contributors to particle growth are (neutralized) sulfate and carbonaceous matter. Particle growth by sulfuric acid condensation is generally well understood, though uncertainty remains about the extent of base neutralization and the relative roles of ammonia and amines. Much less is known about carbonaceous matter, and field measurements suggest that nitrogen-containing species are important. In this presentation, recent work by our group will be described that uses a combination of ambient measurements, laboratory experiments and computational work to study carbonaceous matter in growing nanoparticles. These studies span a range of particle sizes from the initial adsorption of molecules onto a nanometer-size ammonium bisulfate seed cluster to reactions in particles that are large enough to support condensed-phase chemistry.

  10. Matter-Wave Tractor Beams

    NASA Astrophysics Data System (ADS)

    Gorlach, Alexey A.; Gorlach, Maxim A.; Lavrinenko, Andrei V.; Novitsky, Andrey

    2017-05-01

    Optical and acoustic tractor beams are currently the focus of intense research due to their counterintuitive property of exerting a pulling force on small scattering objects. In this Letter we propose a matter-wave tractor beam and utilize the de Broglie waves of nonrelativistic matter particles in analogy to "classical" tractor beams. We reveal the presence of the quantum-mechanical pulling force for the variety of quantum mechanical potentials observing the resonant enhancement of the pulling effect under the conditions of the suppressed scattering known as the Ramsauer-Townsend effect. We also derive the sufficient conditions on the scattering potential for the emergence of the pulling force and show that, in particular, a Coulomb scatterer is always shoved, while a Yukawa (screened Coulomb) scatterer can be drawn. Pulling forces in optics, acoustics, quantum mechanics, and classical mechanics are compared, and the matter-wave pulling force is found to have exclusive properties of dragging slow particles in short-range potentials. We envisage that the use of tractor beams could lead to the unprecedented precision in manipulation with atomic-scale quantum objects.

  11. Matter-Wave Tractor Beams.

    PubMed

    Gorlach, Alexey A; Gorlach, Maxim A; Lavrinenko, Andrei V; Novitsky, Andrey

    2017-05-05

    Optical and acoustic tractor beams are currently the focus of intense research due to their counterintuitive property of exerting a pulling force on small scattering objects. In this Letter we propose a matter-wave tractor beam and utilize the de Broglie waves of nonrelativistic matter particles in analogy to "classical" tractor beams. We reveal the presence of the quantum-mechanical pulling force for the variety of quantum mechanical potentials observing the resonant enhancement of the pulling effect under the conditions of the suppressed scattering known as the Ramsauer-Townsend effect. We also derive the sufficient conditions on the scattering potential for the emergence of the pulling force and show that, in particular, a Coulomb scatterer is always shoved, while a Yukawa (screened Coulomb) scatterer can be drawn. Pulling forces in optics, acoustics, quantum mechanics, and classical mechanics are compared, and the matter-wave pulling force is found to have exclusive properties of dragging slow particles in short-range potentials. We envisage that the use of tractor beams could lead to the unprecedented precision in manipulation with atomic-scale quantum objects.

  12. Astronomy Matters for Chemistry Teachers

    NASA Astrophysics Data System (ADS)

    Huebner, Jay S.; Vergenz, Robert A.; Smith, Terry L.

    1996-11-01

    The purpose of this paper is to encourage more chemistry teachers to become familiar with some of the basic ideas described in typical introductory astronomy courses (1 - 9), including those about the origin of elements and forms of matter. These ideas would enrich chemistry courses and help resolve some basic misconceptions that are expressed in many introductory texts (10 - 16) and journal articles for chemistry teachers (17, 18). These misconceptions are typified by statements such as "we can classify all substances as either elements or compounds," and "nature has provided 92 elements out of which all matter is composed." If students accept these misconceptions, they could be deprived of (i) an appreciation of the history of elements and knowing that the elemental composition of the universe continues to evolve, (ii) knowing that of the first 92 elements in the periodic table, technetium and promethium do not occur naturally on Earth, and (iii) understanding that there are forms of matter other than elements and compounds. This paper briefly explores these ideas.

  13. Nuclear matter physics at NICA

    NASA Astrophysics Data System (ADS)

    Senger, P.

    2016-08-01

    The exploration of the QCD phase diagram is one of the most exciting and challenging projects of modern nuclear physics. In particular, the investigation of nuclear matter at high baryon densities offers the opportunity to find characteristic structures such as a first-order phase transition with a region of phase coexistence and a critical endpoint. The experimental discovery of these prominent landmarks of the QCD phase diagram would be a major breakthrough in our understanding of the properties of nuclear matter. Equally important is the quantitative experimental information on the properties of hadrons in dense matter which may shed light on chiral symmetry restoration and the origin of hadron masses. Worldwide, substantial efforts at the major heavy-ion accelerators are devoted to the clarification of these fundamental questions, and new dedicated experiments are planned at future facilities like CBM at FAIR in Darmstadt and MPD at NICA/JINR in Dubna. In this article the perspectives for MPD at NICA will be discussed.

  14. Dark matter near the sun

    NASA Technical Reports Server (NTRS)

    Bahcall, J. N.

    1986-01-01

    The amount of dark matter in the disk of the Galaxy at the solar position is determined by comparing the observed distributions of tracer stars with the predictions obtained from different assumptions of how the unseen matter is distributed. The major uncertainties, observational and theoretical, are estimated. For all the observed samples, typical models imply that about half of the mass in the solar vicinity must be in the form of unobserved matter. The volume density of unobserved material near the sun is about 0.1 solar mass/cu pc; the corresponding column density is about 30 solar masses/cu pc. This, so far unseen, material must be in a disk with an exponential scale height of less than 0.7 kpc. All the existing observations are consistent with the unseen disk material being in the form of stars not massive enough to burn hydrogen. It is suggested that the unseen material that is required to hold up the rotation curves of galaxies and to satisfy the virial theorem for clusters of galaxies might also be in the form of low-mass stars.

  15. Isocurvature cold dark matter fluctuations

    NASA Technical Reports Server (NTRS)

    Efstathiou, G.; Bond, J. R.

    1986-01-01

    According to Preskill et al. (1983), the axion field represents a particularly attractive candidate for the dark matter in the universe. In many respects it behaves like other forms of cold dark matter, such as massive gravitinos, photinos, and monopoles. It is, however, a pseudo-Goldstone boson of very low mass, and it is only because of rapid coherent oscillations of the field that it can dominate the mass density of the universe. In the present paper it is assumed that the isocurvature mode is dominant. The linear evolution calculations conducted do not depend upon specific details of particle physics. For this reason, the conducted discussion is applicable to any cold dark matter model with isocurvature perturbations. The results of the study lead to the conclusion that scale-invariant isocurvature perturbations do not seem an attractive possibility for the origin of large-scale structure. The findings strengthen the review that primordial adiabatic perturbations were the dominant fluctuations in the early stages of the Big Bang.

  16. Heavy hadrons in nuclear matter

    NASA Astrophysics Data System (ADS)

    Hosaka, Atsushi; Hyodo, Tetsuo; Sudoh, Kazutaka; Yamaguchi, Yasuhiro; Yasui, Shigehiro

    2017-09-01

    Current studies on heavy hadrons in nuclear medium are reviewed with a summary of the basic theoretical concepts of QCD, namely chiral symmetry, heavy quark spin symmetry, and the effective Lagrangian approach. The nuclear matter is an interesting place to study the properties of heavy hadrons from many different points of view. We emphasize the importance of the following topics: (i) charm/bottom hadron-nucleon interaction, (ii) structure of charm/bottom nuclei, and (iii) QCD vacuum properties and hadron modifications in nuclear medium. We pick up three different groups of heavy hadrons, quarkonia (J / ψ, ϒ), heavy-light mesons (D/ D ¯ , B ¯ / B) and heavy baryons (Λc, Λb). The modifications of those hadrons in nuclear matter provide us with important information to investigate the essential properties of heavy hadrons. We also give the discussions about the heavy hadrons, not only in infinite nuclear matter, but also in finite-size atomic nuclei with finite baryon numbers, to serve future experiments.

  17. Superconducting Detectors for Superlight Dark Matter.

    PubMed

    Hochberg, Yonit; Zhao, Yue; Zurek, Kathryn M

    2016-01-08

    We propose and study a new class of superconducting detectors that are sensitive to O(meV) electron recoils from dark matter-electron scattering. Such devices could detect dark matter as light as the warm dark-matter limit, m(X)≳1  keV. We compute the rate of dark-matter scattering off of free electrons in a (superconducting) metal, including the relevant Pauli blocking factors. We demonstrate that classes of dark matter consistent with terrestrial and cosmological or astrophysical constraints could be detected by such detectors with a moderate size exposure.

  18. Dark matter: Observational manifestation and experimental searches

    NASA Astrophysics Data System (ADS)

    Vavilova, I. B.; Bolotin, Yu. L.; Boyarsky, A. M.; Danevich, F. A.; Kobychev, V. V.; Tretyak, V. I.; Babyk, Iu. V.; Iakubovskyi, D. A.; Hnatyk, B. I.; Sergeev, S. G

    2015-08-01

    This monograph is the third issue of a three volume edition under the general title "Dark Energy and Dark Matter in the Universe". The authors discuss the astrophysical direct and indirect manifestation and properties of dark matter in galaxies, galaxy clusters and groups; the different mechanisms of energy exchange between dark energy and dark matter that expand the capabilities of the Standard Cosmological Model; the experimental search for dark matter particle candidates (including the sterile neutrinos, solar axions,weakly-interacting massive particles, and superheavy dark matter particles) using space, ground-based, and underground observatories.

  19. Large Extra Dimension and Dark Matter Detection

    NASA Astrophysics Data System (ADS)

    Qin, Bo; Starkman, Glenn D.; Silk, Joseph

    2008-01-01

    If our space has the large extra dimensions as proposed by Arkani-Hamed, Dimopoulos and Dvali (ADD), then gravity would start to deviate from Newtonian gravity and be greatly enhanced in sub-millimeter scales. Here we show that in the ADD scenario, gravity could play an important role (compared to the weak interaction) in the interactions between dark matter particles and the electron. We find that for typical WIMP dark matter, such dark matter-electron ``gravitational'' scattering cross section may be much larger than the dark matter-nucleon cross section constrained by current dark matter experiments.

  20. Neutrino propagation in color superconducting quark matter

    NASA Astrophysics Data System (ADS)

    Carter, Gregory W.; Reddy, Sanjay

    2000-11-01

    We calculate the neutrino mean free path in color superconducting quark matter, and employ it to study the cooling of matter via neutrino diffusion in the superconducting phase as compared to a free quark phase. The cooling process slows when quark matter undergoes a second order phase transition to a superconducting phase at the critical temperature Tc. Cooling subsequently accelerates as the temperature decreases below Tc. This will directly impact the early evolution of a newly born neutron star, should its core contain quark matter. Consequently, there may be observable changes in the early neutrino emission which would provide evidence for superconductivity in hot and dense matter.