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Sample records for superheavy matter strange

  1. 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.

  2. Superheavy dark matter with discrete gauge symmetries

    NASA Astrophysics Data System (ADS)

    Hamaguchi, K.; Nomura, Yasunori; Yanagida, T.

    1998-11-01

    We show that there are discrete gauge symmetries which naturally protect heavy X particles from decaying into ordinary light particles in the supersymmetric standard model. This makes the proposal that superheavy X particles constitute part of the dark matter in the present universe very attractive. It is more interesting that there is a class of discrete gauge symmetries which naturally accommodates a long-lived unstable X particle. We find that in some discrete Z10 models, for example, a superheavy X particle has a lifetime of τX~=1011-1026 yr for a mass of MX~=1013-1014 GeV. This long lifetime is guaranteed by the absence of lower dimensional operators (of light particles) coupled to the X. We briefly discuss a possible explanation for the recently observed ultrahigh-energy cosmic ray events by the decay of this unstable X particle.

  3. Superheavy thermal dark matter and primordial asymmetries

    NASA Astrophysics Data System (ADS)

    Bramante, Joseph; Unwin, James

    2017-02-01

    The early universe could feature multiple reheating events, leading to jumps in the visible sector entropy density that dilute both particle asymmetries and the number density of frozen-out states. In fact, late time entropy jumps are usually required in models of Affleck-Dine baryogenesis, which typically produces an initial particle-antiparticle asymmetry that is much too large. An important consequence of late time dilution, is that a smaller dark matter annihilation cross section is needed to obtain the observed dark matter relic density. For cosmologies with high scale baryogenesis, followed by radiation-dominated dark matter freeze-out, we show that the perturbative unitarity mass bound on thermal relic dark matter is relaxed to 1010 GeV. We proceed to study superheavy asym-metric dark matter models, made possible by a sizable entropy injection after dark matter freeze-out, and identify how the Affleck-Dine mechanism would generate the baryon and dark asymmetries.

  4. Strange hadronic matter

    SciTech Connect

    Schafner, J. |; Dover, C.B. |; Gal, A. ||; Greiner, C. |; Stoecker, H. |

    1993-02-01

    In an extended mean field theory, there is found a large class of bound multi-strange objects, formed from combinations of (p,n,{Lambda} {Xi}{sup 0} {Xi}{sup {minus}}, baryons, which are stable against strong decay. A maximal binding energy per baryon of E{sub B}/A {approx} {minus}21 MeV, strangeness per baryon of {integral}{sub s} {approx} 1--1.2, charge per baryon of {integral}{sub q} {approx} {minus}-0.1 to 0.1, and baryon density of 2.5--3 times that of ordinary nuclei are predicted. For A {ge} 6, stable combinations involving only ({Lambda},{Xi}{sup 0},{Xi}) hyperons are obtained.

  5. 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.

  6. Strangeness in hadronic stellar matter

    NASA Astrophysics Data System (ADS)

    Knorren, R.; Prakash, M.; Ellis, P. J.

    1995-12-01

    We examine the presence of strangeness-bearing components, hyperons and kaons, in dense neutron star matter. Calculations are performed using relativistic mean field models, in which both the baryon-baryon and kaon-baryon interactions are mediated by meson exchange. Results of kaon condensation are found to be qualitatively similar to previous work with chiral models, if compatibility of the kaon optical potentials is required. The presence of strangeness, be it in the form of hyperons or kaons, implies a reduction in the maximum mass and a relatively large number of protons, sufficient to allow rapid cooling to take place. The need to improve upon the poorly known couplings of the strange particles, which determine the composition and structure of neutron stars, is stressed. We also discuss generic problems with effective masses in mean field theories.

  7. Strange stars, strange dwarfs, and planetary-like strange-matter objects

    SciTech Connect

    Weber, F.; Schaab, C.; Weigel, M.K.; Glendenning, N.K.

    1995-05-01

    This paper gives an overview of the properties of all possible equilibrium sequences of compact strange-matter stars with nuclear crusts, which range from strange stars to strange dwarfs. In contrast to their non-strange counterparts--neutron stars and white dwarfs--their properties are determined by two (rather than one) parameters, the central star density and the density at the base of the nuclear crust. This leads to stellar strange-matter configurations whose properties are much more complex than those of the conventional sequence. As an example, two generically different categories of stable strange dwarfs are found, which could be the observed white dwarfs. Furthermore the authors find very-low-mass strange stellar objects, with masses as small as those of Jupiter or even lighter planets. Such objects, if abundant enough, should be seen by the presently performed gravitational microlensing searches.

  8. Strange quark matter fragmentation in astrophysical events

    NASA Astrophysics Data System (ADS)

    Paulucci, L.; Horvath, J. E.

    2014-06-01

    The conjecture of Bodmer-Witten-Terazawa suggesting a form of quark matter (Strange Quark Matter) as the ground state of hadronic interactions has been studied in laboratory and astrophysical contexts by a large number of authors. If strange stars exist, some violent events involving these compact objects, such as mergers and even their formation process, might eject some strange matter into the interstellar medium that could be detected as a trace signal in the cosmic ray flux. To evaluate this possibility, it is necessary to understand how this matter in bulk would fragment in the form of strangelets (small lumps of strange quark matter in which finite effects become important). We calculate the mass distribution outcome using the statistical multifragmentation model and point out several caveats affecting it. In particular, the possibility that strangelets fragmentation will render a tiny fraction of contamination in the cosmic ray flux is discussed.

  9. Bottom-strange mesons in hyperonic matter

    NASA Astrophysics Data System (ADS)

    Pathak, Divakar; Mishra, Amruta

    2014-11-01

    The in-medium behavior of bottom-strange pseudoscalar mesons in hot, isospin asymmetric and dense hadronic environment is studied using a chiral effective model. The same was recently generalized to the heavy quark sector and employed to study the behavior of open-charm and open-bottom mesons. The heavy quark (anti-quark) is treated as frozen and all medium modifications of these bottom-strange mesons are due to their strange anti-quark (quark) content. We observe a pronounced dependence of their medium mass on baryonic density and strangeness content of the medium. Certain aspects of these in-medium interactions are similar to those observed for the strange-charmed mesons in a preceding investigation, such as the lifting of mass-degeneracy of BS0 and {\\bar B}S0 mesons in hyperonic matter, while the same is respected in vacuum as well as in nuclear matter. In general, however, there is a remarkable distinction between the two species, even though the formalism predicts a completely analogous in-medium interaction Lagrangian density. We discuss in detail the reason for different in-medium behavior of these bottom-strange mesons as compared to charmed-strange mesons, despite the dynamics of the heavy quark being treated as frozen in both cases.

  10. Strange Baryonic Matter and Kaon Condensation

    NASA Astrophysics Data System (ADS)

    Gazda, D.; Friedman, E.; Gal, A.; Mareš, J.

    In this contribution we address the question whether kaon condensation could occur in strongly interacting self-bound strange hadronic matter. In our comprehensive dynamical relativistic mean-field (RMF) calculations of nuclear and hypernuclear systems containing several antikaons we found saturation of bar K separation energy as well as the associated nuclear and bar K density distributions upon increasing the number of bar K mesons. The saturation pattern was found to be a universal feature of these multi-strangeness configurations. Since in all cases the bar K separation energy does not exceed 200 MeV, we conclude that bar K mesons do not provide the physical "strangeness" degrees of freedom for self-bound strange hadronic matter.

  11. Seismic Search for Strange Quark Matter

    NASA Technical Reports Server (NTRS)

    Teplitz, Vigdor

    2004-01-01

    Two decades ago, Witten suggested that the ground state of matter might be material of nuclear density made from up, down and strange quarks. Since then, much effort has gone into exploring astrophysical and other implications of this possibility. For example, neutron stars would almost certainly be strange quark stars; dark matter might be strange quark matter. Searches for stable strange quark matter have been made in various mass ranges, with negative, but not conclusive results. Recently, we [D. Anderson, E. Herrin, V. Teplitz, and I. Tibuleac, Bull. Seis. Soc. of Am. 93, 2363 (2003)] reported a positive result for passage through the Earth of a multi-ton "nugget" of nuclear density in a search of about a million seismic reports, to the U.S. Geological Survey for the years 1990-93, not associated with known Earthquakes. I will present the evidence (timing of first signals to the 9 stations involved, first signal directions, and unique waveform characteristics) for our conclusion and discuss potential improvements that could be obtained from exploiting the seismologically quieter environments of the moon and Mars.

  12. Long lived superheavy dark matter with discrete gauge symmetries

    NASA Astrophysics Data System (ADS)

    Hamaguchi, K.; Nomura, Yasunori; Yanagida, T.

    1999-03-01

    The recently observed ultrahigh energy (UHE) cosmic rays beyond the Greisen-Zatsepin-Kuzmin bound can be explained by the decays of some superheavy X particles forming a part of dark matter in our universe. We consider various discrete gauge symmetries ZN to ensure the required long lifetime (τX~=1010-1022 yr) of the X particle to explain the UHE cosmic rays in the minimal supersymmetric standard model (MSSM) with massive Majorana neutrinos. We show that there is no anomaly-free discrete gauge symmetry to make the lifetime of the X particle sufficiently long in the MSSM with the X particle. We find, however, possible solutions to this problem especially by enlarging the particle contents in the MSSM. We show a number of solutions introducing an extra pair of singlets Y and Y¯ which have fractional ZN(N=2,3) charges. The present experimental constraints on the X particle are briefly discussed.

  13. Strange Quark Matter Status and Prospects

    NASA Technical Reports Server (NTRS)

    Sandweiss, J.

    2004-01-01

    The existence of quark states with more than three quarks is allowed in QCD. The stability of such quark matter states has been studied with lattice QCD and phenomenological bag models, but is not well constrained by theory. The addition of strange quarks to the system allows the quarks to be in lower energy states despite the additional mass penalty. There is additional stability from reduced Coulomb repulsion. SQM is expected to have a low Z/A. Stable or metastable massive multiquark states contain u, d, and s quarks.

  14. Nucleation of strange matter in dense stellar cores

    SciTech Connect

    Horvath, J.E. Sao Paulo, Sao Paulo ); Benvenuto, O.G. La Plata ); Vucetich, H. La Plata )

    1992-05-15

    We investigate the nucleation of strange quark matter inside hot, dense nuclear matter. Applying Zel'dovich's kinetic theory of nucleation we find a lower limit of the temperature {ital T} for strange-matter bubbles to appear, which happens to be satisfied inside the Kelvin-Helmholtz cooling era of a compact star life but not much after it. Our bounds thus suggest that a prompt conversion could be achieved, giving support to earlier expectations for nonstandard type-II supernova scenarios.

  15. Examination of strangeness instabilities and effects of strange meson couplings in dense strange hadronic matter and compact stars

    NASA Astrophysics Data System (ADS)

    Torres, James R.; Gulminelli, Francesca; Menezes, Débora P.

    2017-02-01

    Background: The emergence of hyperon degrees of freedom in neutron star matter has been associated to first-order phase transitions in some phenomenological models, but conclusions on the possible physical existence of an instability in the strangeness sector are strongly model dependent. Purpose: The purposes of the present study are to assess whether strangeness instabilities are related to specific values of the largely unconstrained hyperon interactions and to study the effect of the strange meson couplings on phenomenological properties of neutron stars and supernova matter, once these latter are fixed to fulfill the constraints imposed by hypernuclear data. Method: We consider a phenomenological relativistic mean field model (RMF) model sufficiently simple to allow a complete exploration of the parameter space. Results: We show that no instability at supersaturation density exists for the RMF model, as long as the parameter space is constrained by basic physical requirements. This is at variance with a nonrelativistic functional, with a functional behavior fitted through ab initio calculations. Once the study is extended to include the full octet, we show that the parameter space allows reasonable radii for canonical neutron stars as well as massive stars above two-solar mass, together with an important strangeness content of the order of 30%, slightly decreasing with increasing entropy, even in the absence of a strangeness-driven phase transition. Conclusions: We conclude that the hyperon content of neutron stars and supernova matter cannot be established with present constraints, and is essentially governed by the unconstrained coupling to the strange isoscalar meson.

  16. K meson-nucleus interactions: strangeness and nuclear matter

    SciTech Connect

    Kahana, S.

    1985-01-01

    A brief review is provided of some straightforward K-nuclear and ..lambda..-hypernuclear systems. A discussion of less straightforward speculations on H-dibaryons and strange quark matter by many authors, is also given. 28 refs., 6 figs.

  17. PREFACE: Strangeness in Quark Matter (SQM2009) Strangeness in Quark Matter (SQM2009)

    NASA Astrophysics Data System (ADS)

    Fraga, Eduardo; Kodama, Takeshi; Padula, Sandra; Takahashi, Jun

    2010-09-01

    The 14th International Conference on Strangeness in Quark Matter (SQM2009) was held in Brazil from 27 September to 2 October 2009 at Hotel Atlântico, Búzios, Rio de Janeiro. The conference was jointly organized by Universidade Federal do Rio de Janeiro, Universidade Estadual de Campinas, Centro Brasileiro de Pesquisas Físicas, Universidade de São Paulo, Universidade Estadual Paulista and Universidade Federal do Rio Grande do Sul. Over 120 scientists from Argentina, Brazil, China, France, Germany, Hungary, Italy, Japan, Mexico, The Netherlands, Norway, Poland, Russia, Slovakia, South Africa, Switzerland, the UK and the USA gathered at the meeting to discuss the physics of hot and dense matter through the signals of strangeness and also the behavior of heavy quarks. Group photograph The topics covered were strange and heavy quark production in nuclear collisions, strange and heavy quark production in elementary processes, bulk matter phenomena associated with strange and heavy quarks, and strangeness in astrophysics. In view of the LHC era and many other upcoming new machines, together with recent theoretical developments, sessions focused on `New developments and new facilities' and 'Open questions' were also included. A stimulating round-table discussion on 'Physics opportunities in the next decade in the view of strangeness and heavy flavor in matter' was chaired in a relaxed atmosphere by Grazyna Odyniec and conducted by P Braun-Munzinger, W Florkowski, K Redlich, K Šafařík and H Stöcker, We thank these colleagues for pointing out to young participants new physics directions to be pursued. We also thank J Dunlop and K Redlich for excellent introductory lectures given on the Sunday evening pre-conference session. In spite of the not-so-helpful weather, the beauty and charm of the town of Búzios helped to make the meeting successful. Nevertheless, the most important contributions were the excellent talks, whose contents are part of these proceedings, given

  18. Strange and heavy mesons in hadronic matter

    NASA Astrophysics Data System (ADS)

    Cabrera, Daniel; Abreu, Luciano M.; Bratkovskaya, Elena; Ilner, Andrej; Llanes-Estrada, Felipe J.; Ramos, Angels; Tolos, Laura; Torres-Rincon, Juan M.

    2014-04-01

    We present selected results on the properties of strange and heavy-flavoured mesons in a hot and dense nuclear medium, with emphasis in selfconsistent coupled-channel approaches based on the chiral Lagrangian. In the strangeness sector, we discuss how the enhanced reactivity of light strange vectors at FAIR conditions can be tied to in-medium effects on their predominant decay modes (e.g. bar K* → bar Kπ) and to the excitation of strange baryons in vector-meson nucleon interactions. In the heavy-flavour sector, we focus on recent determinations of the transport coefficients of charmed and bottomed mesons in a hadron gas at vanishing baryonic chemical potential. We comment on the role of microscopic transport simulations to establish a connection between theoretical models and experimental observables from heavy-ion collisions (HICs).

  19. Mass spectrometric searches for superheavy elements in terrestrial matter

    NASA Astrophysics Data System (ADS)

    Korschinek, Gunther; Kutschera, Walter

    2015-12-01

    Recent searches for traces of long-lived superheavy elements (SHEs) in terrestrial materials by mass spectrometric means are reviewed. Positive evidence for long-lived neutron-deficient Th isotopes in Th and Rg isotopes in Au, and a possible A = 292, Z ∼ 122 nuclide in Th was reported from experiments with Inductively Coupled Plasma Sector Field Mass Spectrometry (ICP-SF-MS). These findings were not confirmed with Accelerator Mass Spectrometry (AMS), with abundance limits lower by several orders of magnitude. In addition, the extensive AMS searches for 42 SHE nuclides (A = 288- 310) around the much discussed "island of stability" (Z = 114, N = 184) in natural Pt, Au, Pb, Bi materials are reviewed. Due to the flatness of the mass distribution and the relatively large bandwidth of the mass acceptance in AMS searches, an effectively much larger number of SHE nuclides was scanned in the respective materials. No positive evidence for the existence of long-lived SHEs (t1/2 >108 yr) with abundance limits of 10-12 to 10-16 was found.

  20. Kaon condensation and multi-strange matter

    NASA Astrophysics Data System (ADS)

    Gazda, D.; Friedman, E.; Gal, A.; Mareš, J.

    2010-04-01

    We report on dynamical calculations of multi- K¯ hypernuclei, which were performed by adding K¯ mesons to particle-stable configurations of nucleons, Λ and Ξ hyperons. The K¯ separation energy as well as the baryonic densities saturate with the number of antikaons. We demonstrate that the saturation is a robust feature of multi- K¯ hypernuclei. Because the K¯ separation energy B does not exceed 200 MeV, we conclude that kaon condensation is unlikely to occur in finite strong-interaction self-bound {N,Λ,Ξ} strange hadronic systems.

  1. Effect of hyperons on phase coexistence in strange matter

    NASA Astrophysics Data System (ADS)

    Das, P.; Mallik, S.; Chaudhuri, G.

    2017-01-01

    The study of the liquid gas phase transition in the fragmentation of nuclei in heavy ion collisions has been extended to the strangeness sector using the statistical model for multifragmentation. Helmholtz's free energy, specific heat, and a few other thermodynamic observables have been analyzed in order to examine the occurrence of phase transition in the strange matter. The bimodal behavior of the largest cluster formed in fragmentation also strongly indicates a coexistence of both the phases. The presence of hyperons strengthens the signals and also shifts the transition temperature to lower values.

  2. Surface effects in color superconducting strange-quark matter

    SciTech Connect

    Oertel, Micaela; Urban, Michael

    2008-04-01

    Surface effects in strange-quark matter play an important role for certain observables which have been proposed in order to identify strange stars, and color superconductivity can strongly modify these effects. We study the surface of color superconducting strange-quark matter by solving the Hartree-Fock-Bogoliubov equations for finite systems ('strangelets') within the MIT bag model, supplemented with a pairing interaction. Because of the bag-model boundary condition, the strange-quark density is suppressed at the surface. This leads to a positive surface charge, concentrated in a layer of {approx}1 fm below the surface, even in the color-flavor locked (CFL) phase. However, since in the CFL phase all quarks are paired, this positive charge is compensated by a negative charge, which turns out to be situated in a layer of a few tens of fm below the surface, and the total charge of CFL strangelets is zero. We also study the surface and curvature contributions to the total energy. Because of the strong pairing, the energy as a function of the mass number is very well reproduced by a liquid-drop type formula with curvature term.

  3. Bulk viscosity of strange quark matter: Urca versus nonleptonic processes

    SciTech Connect

    Sa'd, Basil A.; Shovkovy, Igor A.; Rischke, Dirk H.

    2007-06-15

    A general formalism for calculating the bulk viscosity of strange quark matter is developed. Contrary to the common belief that the nonleptonic processes alone give the dominant contribution to the bulk viscosity, the inclusion of the Urca processes is shown to play an important role at intermediate densities when the characteristic r-mode oscillation frequencies are not too high. The interplay of nonleptonic and Urca processes is analyzed in detail.

  4. Strangeness as a probe to baryon-rich QCD matter at NICA

    NASA Astrophysics Data System (ADS)

    Fukushima, Kenji

    2016-08-01

    We elucidate a prospect of strangeness fluctuation measurements in the heavy-ion collision at NICA energies. The strangeness fluctuation is sensitive to quark deconfinement. At the same time strangeness has a strong correlation with the baryon number under the condition of vanishing net strangeness, which leads to an enhancement of Λ0, Ξ0, Ξ-, and K+ at high baryon density. The baryon density is maximized around the NICA energies, and strangeness should be an ideal probe to investigate quark deconfinement phenomena of baryon-rich QCD matter created at NICA. We also utilize the hadron resonance gas model to estimate a mixed fluctuation of strangeness and baryon number.

  5. Bottomonium states in hot asymmetric strange hadronic matter

    NASA Astrophysics Data System (ADS)

    Mishra, Amruta; Pathak, Divakar

    2014-08-01

    We calculate the in-medium masses of the bottomonium states [Υ(1S),Υ(2S),Υ(3S), and Υ (4S)] in isospin asymmetric strange hadronic matter at finite temperatures. The medium modifications of the masses arise due to the interaction of these heavy quarkonium states with the gluon condensates of QCD. The gluon condensates in the hot hadronic matter are computed from the medium modification of a scalar dilaton field within a chiral SU(3) model, introduced in the hadronic model to incorporate the broken scale invariance of QCD. There is seen to be a drop in the masses of the bottomonium states and mass shifts are observed to be quite considerable at high densities for the excited states. The effects of density, isospin asymmetry, strangeness, as well as temperature of the medium on the masses of the Υ states are investigated. The effects of the isospin asymmetry as well as strangeness fraction of the medium are seen to be appreciable at high densities and small temperatures. The density effects are the most dominant medium effects which should have observable consequences in the compressed baryonic matter (CBM) in the heavy ion collision experiments in the future facility at FAIR, GSI. The study of the Υ states will, however, require access to energies higher than the energy regime planned at CBM experiment. The density effects on the bottomonium masses should also show up in the dilepton spectra at the Super Proton Synchrotron (SPS) energies, especially for the excited states for which the mass drop is observed to quite appreciable.

  6. Detectability of strange matter in heavy ion experiments

    SciTech Connect

    Schaffner, J., ||; Diener, A.; Stocker, H.,; Greiner, C.,

    1997-06-01

    We discuss the properties of two distinct forms of hypothetical strange matter, small lumps of strange quark matter (strangelets) and of hyperon matter [metastable exotic multihypernuclear objects (MEMO{close_quote}s)], with special emphasis on their relevance for present and future heavy ion experiments. The masses of small strangelets up to A{sub B}=40 are calculated using the MIT bag model with shell mode filling for various bag parameters. The strangelets are checked for possible strong and weak hadronic decays, also taking into account multiple hadron decays. It is found that strangelets which are stable against strong decay are most likely highly negatively charged, contrary to previous findings. Strangelets can be stable against weak hadronic decay but their masses and charges are still rather high. This has serious impact on the present high sensitivity searches in heavy ion experiments at the AGS and CERN facilities. On the other hand, highly charged MEMO{close_quote}s are predicted on the basis of an extended relativistic mean-field model. Those objects could be detected in future experiments searching for short-lived, rare composites. It is demonstrated that future experiments can be sensitive to a much wider variety of strangelets. {copyright} {ital 1997} {ital The American Physical Society}

  7. Strange quark matter and quark stars with the Dyson-Schwinger quark model

    NASA Astrophysics Data System (ADS)

    Chen, H.; Wei, J.-B.; Schulze, H.-J.

    2016-09-01

    We calculate the equation of state of strange quark matter and the interior structure of strange quark stars in a Dyson-Schwinger quark model within rainbow or Ball-Chiu vertex approximation. We emphasize constraints on the parameter space of the model due to stability conditions of ordinary nuclear matter. Respecting these constraints, we find that the maximum mass of strange quark stars is about 1.9 solar masses, and typical radii are 9-11km. We obtain an energy release as large as 3.6 × 10^{53} erg from conversion of neutron stars into strange quark stars.

  8. Search for Stable Strange Quark Matter in Lunar Soil

    SciTech Connect

    Han, K.; Chikanian, A.; Emmet, W.; Finch, L. E.; Majka, R. D.; Sandweiss, J.; Ashenfelter, J.; Heinz, A.; Madsen, J.; Monreal, B.

    2009-08-28

    We report results from a search for strangelets (small chunks of strange quark matter) in lunar soil using the Yale WNSL accelerator as a mass spectrometer. We have searched over a range in mass from A=42 to A=70 amu for nuclear charges 5, 6, 8, 9, and 11. No strangelets were found in the experiment. For strangelets with nuclear charge 8, a concentration in lunar soil higher than 10{sup -16} is excluded at the 95% confidence level. The implied limit on the strangelet flux in cosmic rays is the most sensitive to date for the covered range and is relevant to both recent theoretical flux predictions and a strangelet candidate event found by the AMS-01 experiment.

  9. A new form of strange matter and new hope for finding it

    SciTech Connect

    Flam, F.

    1993-10-08

    Deep in the dense cores of collapsed stars even atoms don't survive. The force of gravity crushes them into particle mushes weighing megatons per teaspoon. But even these alien forms of matter don't hold a candle to another possible end product of a collapsing star: something physicists justifiably call strange matter. This strangeness comes from an exotic particle not associated with ordinary matter: the strange quark. It belongs to a six-member quark family, along with up, down, charm, top, and bottom, each of which carries a different combination of charge and mass. The only ones that make up matter as we know it are up and down quarks, but in theory, matter could form out of strange quarks as well. In nature, it would turn up most probably in interiors of collapsed stars. Scientists originally imagined strange matter as a sort of disorganized mixed bag of strange quarks, but this summer a group proposed that the quarks could form a sort of mutant atomic nucleus that could conceivably grow to the size of a star. For the moment this is speculation, but it may not be theoretical musing for long. Physicists are preparing to try making strange matter here on Earth, in experiments at Brookhaven National Laboratory in New York and Switzerland's CERN, next summer.

  10. In Medium Properties of Charmed Strange Mesons in Dense Hadron ic Matter

    NASA Astrophysics Data System (ADS)

    Kumar, Sushil

    2015-05-01

    The medium modifications of the charmed strange mesons in the dense hadronic matter are investigated within chiral S U(4) model. The charmed strange meson properties modifies due to their interactions with the nucleons, hyperons and the scalar mesons (scalar-isoscalar mesons ( σ, ζ), scalar isovector meson ( δ)) in the dense hadronic medium. The various parameters used in the chiral model are obtained by fitting the vacuum baryon masses and saturation properties of nuclear matter. The non-linear coupled equations of the scalar fields are solved to obtain their baryon density, isospin and strangeness dependent values. Furthermore, the dispersion relations are derived for charmed strange mesons. Effects of isospin asymmetry and strangeness on the energies of charmed strange mesons are investigated. The in medium properties of charmed strange mesons can be particularly relevant to the experiments with neutron rich beams at the Facility for Antiproton and Ion Research (FAIR) at GSI, Germany, as well as to experiments at the Rare Isotope Accelerator (RIA) laboratory, USA. The present study of the in medium properties of charmed strange mesons will be of direct relevance for the observables from the compressed baryonic matter, resulting from the heavy ion collision experiments.

  11. Numerical simulation of the hydrodynamical combustion to strange quark matter

    SciTech Connect

    Niebergal, Brian; Ouyed, Rachid; Jaikumar, Prashanth

    2010-12-15

    We present results from a numerical solution to the burning of neutron matter inside a cold neutron star into stable u,d,s quark matter. Our method solves hydrodynamical flow equations in one dimension with neutrino emission from weak equilibrating reactions, and strange quark diffusion across the burning front. We also include entropy change from heat released in forming the stable quark phase. Our numerical results suggest burning front laminar speeds of 0.002-0.04 times the speed of light, much faster than previous estimates derived using only a reactive-diffusive description. Analytic solutions to hydrodynamical jump conditions with a temperature-dependent equation of state agree very well with our numerical findings for fluid velocities. The most important effect of neutrino cooling is that the conversion front stalls at lower density (below {approx_equal}2 times saturation density). In a two-dimensional setting, such rapid speeds and neutrino cooling may allow for a flame wrinkle instability to develop, possibly leading to detonation.

  12. PREFACE: SQM2007 International Conference on Strangeness in Quark Matter

    NASA Astrophysics Data System (ADS)

    Šafařík, Karel; Šándor, Ladislav; Tomášik, Boris

    2008-04-01

    The International Conference on `Strangeness in Quark Matter' (SQM) was held from 24-29 June 2007 at the Congress Hall of the city cultural centre in the charming mediaeval town of Levoča in north-eastern Slovakia. The Institute of Experimental Physics of the Slovak Academy of Science and the Faculty of Science of the P J Šafárik University in Košice shared the duties of main organizers of the conference. SQM2007 was attended by more than 100 participants from about 20 countries. The natural beauty and the rich cultural and historical monuments of the surrounding Spiš (Scepusium) region created an inspiring setting for the scientific, social and cultural framework of the conference. Continuing the trend started at the SQM2006 conference, heavy flavour physics in heavy-ion collisions was a topic given equal importance in the SQM2007 programme alongside strange quark physics. The Symposium for Students, from Students, organized by Christian Klein-Boesing and Boris Tomášik on the basis of the contributed abstracts, was again an integral and successful part of the conference. The jury, drawn from the organizers, awarded William A Horowitz (Columbia University) the title of best student contribution. The good news is that many students and younger researchers attended the conference. This could not have happened without generous support from our sponsors whom we would like to thank for valuable financial support: CERN, Journal of Physics G, the Prešov self-governing region authorities and the Slovak Physical Society. The kind assistance of the mayor of the town of Levoča is also warmly acknowledged. We would like to extend our gratitude to our colleagues and students from the organizing institutions for their diligent work prior to and during the conference, which ensured that everything worked smoothly. Our special thanks go to our secretaries, Adri Chomičová and Mery Šemš'aková, as well as to the management of the SATEL Hotel in Levoča for their highly

  13. Simulation of electromagnetic and strange probes of dense nuclear matter at NICA/MPD

    NASA Astrophysics Data System (ADS)

    Zinchenko, A.; Kolesnikov, V.; Vasendina, V.

    2016-01-01

    The main task of the NICA/MPD physics program is a study of the properties of nuclear matter under extreme conditions achieved in collisions of heavy ions. These properties can reveal themselves through different probes, the most promising among those being the lepton-antilepton pairs and strange hadrons. In this paper the MPD performance for measuring the electron-positron pairs and strange hyperons in central Au+Au collisions at NICA energies is presented.

  14. Curvature energy effects on strange quark matter nucleation at finite density

    SciTech Connect

    Horvath, J.E. Department of Space Physics and Astronomy, Rice University, P.O. Box 1892, Houston, Texas 77251 )

    1994-05-15

    We consider the effects of the curvature energy term on thermal strange quark matter nucleation in dense neutron matter. Lower bounds on the temperature at which this process can take place are given and compared to those without the curvature term.

  15. Constraining the equation of state of nuclear matter from fusion hindrance in reactions leading to the production of superheavy elements

    NASA Astrophysics Data System (ADS)

    Veselsky, M.; Klimo, J.; Ma, Yu-Gang; Souliotis, G. A.

    2016-12-01

    The mechanism of fusion hindrance, an effect preventing the synthesis of superheavy elements in the reactions of cold and hot fusion, is investigated using the Boltzmann-Uehling-Uhlenbeck equation, where Coulomb interaction is introduced. A strong sensitivity is observed both to the modulus of incompressibility of symmetric nuclear matter, controlling the competition of surface tension and Coulomb repulsion, and to the stiffness of the density-dependence of symmetry energy, influencing the formation of the neck prior to scission. The experimental fusion probabilities were for the first time used to derive constraints on the nuclear equation of state. A strict constraint on the modulus of incompressibility of nuclear matter K0=240 -260 MeV is obtained while the stiff density-dependences of the symmetry energy (γ >1 ) are rejected.

  16. Superheavy Elements

    ERIC Educational Resources Information Center

    Tsang, Chin Fu

    1975-01-01

    Discusses the possibility of creating elements with an atomic number of around 114. Describes the underlying physics responsible for the limited extent of the periodic table and enumerates problems that must be overcome in creating a superheavy nucleus. (GS)

  17. Toroidal Nuclear Matter Distributions of Superheavy Nuclei from Constrained Skyrme-HFB Calculations

    SciTech Connect

    Kosior, Amelia; Staszczak, A.; Wong, Cheuk-Yin

    2017-01-01

    Using the Hartree Fock Bogoliubov (HFB) self-consistent mean-field theory with the SkM* Skyrme energy-density functional, we study nuclear structure properties of even even superheavy nuclei (SHN) of Z = 120 isotopes and N = 184 isotones. The shape of the nucleus along the lowest energy curve as a function of the quadrupole moment Q20 makes a sud- den transition from the oblate spheroids (biconcave discs) to the toroidal shapes, in the region of large oblate quadrupole moments.

  18. Nonextensive statistical effects and strangeness production in hot and dense nuclear matter

    NASA Astrophysics Data System (ADS)

    Lavagno, A.; Pigato, D.

    2012-12-01

    By means of an effective relativistic nuclear equation of state in the framework of the nonextensive statistical mechanics, characterized by power-law quantum distributions, we study the phase transition from hadronic matter to quark-gluon plasma at finite temperature and baryon density. The analysis is performed by requiring the Gibbs conditions on the global conservation of baryon number, electric charge fraction and zero net strangeness. We show that nonextensive statistical effects strongly influence the strangeness production during the pure hadronic phase and the hadron-quark-gluon mixed phase transition, also for small deviations from the standard Boltzmann-Gibbs statistics.

  19. Strange stars

    NASA Technical Reports Server (NTRS)

    Alcock, Charles; Farhi, Edward; Olinto, Angela

    1986-01-01

    Strange matter, a form of quark matter that is postulated to be absolute stable, may be the true ground stage of the hadrons. If this hypothesis is correct, neutron stars may convert to 'strange stars'. The mass-radius relation for strange stars is very different from that of neutron stars; there is no minimum mass, and for mass of 1 solar mass or less, mass is proportional to the cube of the radius. For masses between 1 solar mass and 2 solar masses, the radii of strange stars are about 10 km, as for neutron stars. Strange stars may have an exposed quark surface, which is capable of radiating at rates greatly exceeding the Eddington limit, but has a low emissivity for X-ray photons. The stars may have a thin crust with the same composition as the preneutron drip outer layer of a conventional neutron star crust. Strange stars cool efficiently via neutrino emission.

  20. Stable strange quark matter objects with running masses and coupling constant

    NASA Astrophysics Data System (ADS)

    Xia, Cheng-Jun; Zhou, Shan-Gui

    2017-03-01

    We improve our recently proposed unified description for strange quark matter (SQM) objects, in the way that analytical expressions are derived and used to calculate the distribution of particles inside an SQM object. In the improved model, the computational time is greatly reduced without losing accuracy. The properties of SQM objects are then investigated by adopting perturbative quantum chromodynamics (pQCD) with running quark masses and coupling constant. Aside from the increase of masses and radii of strange stars, it is found that the perturbative interactions also make the electric field on the surface stronger and extends deeper into the core, while small SQM objects become less compact and more positively charged. These may affect the experimental searches of SQM.

  1. Probing the stability of superheavy dark matter particles with high-energy neutrinos

    SciTech Connect

    Esmaili, Arman; Peres, Orlando L.G.; Ibarra, Alejandro E-mail: ibarra@tum.de

    2012-11-01

    Two of the most fundamental properties of the dark matter particle, the mass and the lifetime, are only weakly constrained by the astronomical and cosmological evidence of dark matter. We derive in this paper lower limits on the lifetime of dark matter particles with masses in the range 10TeV−10{sup 15}TeV from the non-observation of ultrahigh energy neutrinos in the AMANDA, IceCube, Auger and ANITA experiments. For dark matter particles which produce neutrinos in a two body or a three body leptonic decay, we find that the dark matter lifetime must be longer than O(10{sup 26}−10{sup 28})s for masses between 10 TeV and the Grand Unification scale. Finally, we also calculate, for concrete particle physics scenarios, the limits on the strength of the interactions that induce the dark matter decay.

  2. The parametric transition of strange matter rings to a black hole

    NASA Astrophysics Data System (ADS)

    Labranche, Hendrick; Petroff, David; Ansorg, Marcus

    2007-02-01

    It is shown numerically that strange matter rings permit a continuous transition to the extreme Kerr black hole. The multipoles as defined by Geroch and Hansen are studied and suggest a universal behaviour for bodies approaching the extreme Kerr solution parametrically. The appearance of a ‘throat region’, a distinctive feature of the extreme Kerr spacetime, is observed. With regard to stability, we verify for a large class of rings, that a particle sitting on the surface of the ring never has enough energy to escape to infinity along a geodesic.

  3. Strange quark matter in the presence of explicit symmetry breaking interactions

    NASA Astrophysics Data System (ADS)

    Moreira, J.; Morais, J.; Hiller, B.; Osipov, A. A.; Blin, A. H.

    2015-06-01

    It is shown that a first-order transition associated with a jump in the strange-quark mass appears in a generalized three-flavor Nambu-Jona-Lasinio treatment of quark matter. The generalization of the Lagrangian displays the complete set of spin-0 interactions at leading and subleading orders (LO and NLO) in 1/Nc counting, including the recently derived NLO explicit chiral symmetry breaking interactions which are of the same order as the 't Hooft flavor determinant. The parameters of the model are tightly constrained by the low-energy characteristics in both the pseudoscalar and scalar meson sectors. The transition occurs in a moderate chemical potential region (μ ≃400 MeV for zero temperature) in addition to the usual chiral transition associated with the light-quark sector. This feature has at its root the inclusion of the explicit chiral symmetry breaking interactions, which therefore can be seen to act as a catalyst in the production of strange-quark matter when compared to the conventional version of the model that takes only into account the 't Hooft interaction in the NLO. It can be traced back to the effect of the interactions which do not violate the Okubo-Zweig-Iizuka rule, without which the empirical ordering of the scalars (mK⋆

  4. Are superheavy stable quark clusters viable candidates for the dark matter?

    NASA Astrophysics Data System (ADS)

    Borštnik, Norma Mankoč; Rosina, Mitja

    2015-08-01

    The explanation for the origin of families of quarks and leptons and their properties is one of the most promising ways to understand the assumptions of the Standard Model. The Spin-Charge-Family theory [N. S. M. Borštnik, Phys. Lett. B 292 (1992) 25; J. Math. Phys. 34 (1993) 3731; Int. J. Theor. Phys. 40 (2001) 315; Mod. Phys. Lett. A 10 (1995) 587; J. Modern Phys. 4 (2013) 823; arXiv:1312.15; Phys. Rev. D 91 (2015) 065004; [arXiv:1409.7791; arXiv:1312.1542; arXiv:1502.06786v1, http://arXiv.org/abs/1409.4981; A. Borštnik and N. S. M. Borštnik, Phys. Rev. D 74 (2006) 073013, arXiv:hep-ph/0512062, arXiv:hep-ph/0401043, arXiv:hep-ph/0401055, arXiv:hep-ph/0301029; G. Bregar and N. S. M. Borštnik, arXiv:1412.5866; G. Bregar et al., New J. Phys. 10 (2008) 093002; G. Bregar and N. S. M. Borštnik, arXiv:1502.06786v1, arXiv:1412.5866; N. S. M. Borštnik, Proc. 13th Workshop "What Comes Beyond the Standard Models", Bled, 12-22 July 2010, eds. N. S. M. Borštnik et al., DMFA Založništvo, Ljubljana, December 2010, pp. 105-129], which does propose the mechanism for the appearance of families and offers an explanation for all the assumptions of the Standard Model, predicts two decoupled groups of four families. The lightest of the upper four families has stable members, which are correspondingly candidates to constitute the dark matter [G. Bregar and N. S. M. Borštnik, Phys. Rev. D 80 (2009) 083534, arXiv:1412.5866]. In this paper, we study the weak and the "nuclear" (determined by the color interaction among the heavy fifth family quarks) scattering of such a very heavy baryon by ordinary nucleons in order to show that the cross-section is very small and consistent with the observation in most experiments so far, provided that the quark mass of this baryon is about 100TeV or above.

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

    SciTech Connect

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

    2015-02-24

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

  6. New upper limit on strange quark matter abundance in cosmic rays with the PAMELA space experiment.

    PubMed

    Adriani, O; Barbarino, G C; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Bruno, A; Cafagna, F; Campana, D; Carlson, P; Casolino, M; Castellini, G; De Donato, C; De Santis, C; De Simone, N; Di Felice, V; Formato, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S; Krutkov, S Y; Kvashnin, A N; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Mergè, M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Palma, F; Panico, B; Papini, P; Pearce, M; Picozza, P; Ricci, M; Ricciarini, S B; Sarkar, R; Scotti, V; Simon, M; Sparvoli, R; Spillantini, P; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N

    2015-09-11

    In this work we present results of a direct search for strange quark matter (SQM) in cosmic rays with the PAMELA space spectrometer. If this state of matter exists it may be present in cosmic rays as particles, called strangelets, having a high density and an anomalously high mass-to-charge (A/Z) ratio. A direct search in space is complementary to those from ground-based spectrometers. Furthermore, it has the advantage of being potentially capable of directly identifying these particles, without any assumption on their interaction model with Earth's atmosphere and the long-term stability in terrestrial and lunar rocks. In the rigidity range from 1.0 to ∼1.0×10^{3}  GV, no such particles were found in the data collected by PAMELA between 2006 and 2009. An upper limit on the strangelet flux in cosmic rays was therefore set for particles with charge 1≤Z≤8 and mass 4≤A≤1.2×10^{5}. This limit as a function of mass and as a function of magnetic rigidity allows us to constrain models of SQM production and propagation in the Galaxy.

  7. New Upper Limit on Strange Quark Matter Abundance in Cosmic Rays with the PAMELA Space Experiment

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Boezio, M.; Bogomolov, E. A.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Castellini, G.; de Donato, C.; de Santis, C.; de Simone, N.; di Felice, V.; Formato, V.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S.; Krutkov, S. Y.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Menn, W.; Mergè, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Munini, R.; Osteria, G.; Palma, F.; Panico, B.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Sarkar, R.; Scotti, V.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.; Pamela Collaboration

    2015-09-01

    In this work we present results of a direct search for strange quark matter (SQM) in cosmic rays with the PAMELA space spectrometer. If this state of matter exists it may be present in cosmic rays as particles, called strangelets, having a high density and an anomalously high mass-to-charge (A /Z ) ratio. A direct search in space is complementary to those from ground-based spectrometers. Furthermore, it has the advantage of being potentially capable of directly identifying these particles, without any assumption on their interaction model with Earth's atmosphere and the long-term stability in terrestrial and lunar rocks. In the rigidity range from 1.0 to ˜1.0 ×103 GV , no such particles were found in the data collected by PAMELA between 2006 and 2009. An upper limit on the strangelet flux in cosmic rays was therefore set for particles with charge 1 ≤Z ≤8 and mass 4 ≤A ≤1.2 ×105 . This limit as a function of mass and as a function of magnetic rigidity allows us to constrain models of SQM production and propagation in the Galaxy.

  8. Converting neutron stars into strange stars

    NASA Technical Reports Server (NTRS)

    Olinto, A. V.

    1991-01-01

    If strange matter is formed in the interior of a neutron star, it will convert the entire neutron star into a strange star. The proposed mechanisms are reviewed for strange matter seeding and the possible strange matter contamination of neutron star progenitors. The conversion process that follows seeding and the recent calculations of the conversion timescale are discussed.

  9. PREFACE: 14th International Conference on Strangeness in Quark Matter (SQM2013)

    NASA Astrophysics Data System (ADS)

    2014-05-01

    The 2013 Strangeness in Quark Matter conference took place at the University of Birmingham in July 2013, in a period of remarkably good weather that gave a very welcome boost to the event. 158 physicists from 25 countries gathered for a week of discussions on the production of strangeness and heavy flavour in heavy ion collisions. The dates for the meeting had been set two years earlier in Cracow, so as to allow it to offer the first major examination of proton-lead collisions from the Large Hadron Collider. It had originally been thought that these collisions would be recorded by the end of 2012, but in the event it turned out that the running period was postponed until January and February of 2013, giving the LHC collaborations - all four major collaborations since LHCb also took part in pPb data taking - very little time to prepare their results. Nevertheless, new results were provided, and their presentation and interpretation formed one of the highlights of the conference. In addition, there was a more detailed assessment of the RHIC beam energy scan, many new heavy flavour results from the RHIC and LHC heavy ion runs and detailed discussions of the future FAIR and NICA programmes. The conference also hosted a good cross-section of current topics in theoretical talks. In the last few years there has been much interest in thermalization and in the use of hydrodynamics to describe the fluctuations visible in higher-order flow coefficients. Discussions of both of these features were well represented, indicating the maturing of this field. We gratefully acknowledge support from The University of Birmingham, CERN, The Extreme Matter Institute (EMMI), the Institute for Particle Physics Phenomenology (IPPP), Institute of Physics Publishing and from the UK Science and Technology Facilities Council (STFC). This assistance allowed us to support over twenty young physicists, and allowed us to ensure that we had the breadth of programme needed for a successful conference

  10. Relating the strangeness content of the nucleon with the mass shift of the ϕ meson in nuclear matter

    SciTech Connect

    Gubler, Philipp; Ohtani, Keisuke

    2016-01-22

    The behavior of the ϕ meson at finite density is studied, making use of a QCD sum rule approach in combination with the maximum entropy method. It is demonstrated that a possible mass shift of the ϕ in nuclear matter is strongly correlated to the strangeness content of the nucleon, which is proportional to the strange sigma term, σ{sub sN}. In contrast to earlier studies, our results show that, depending on the value of σ{sub sN}, the ϕ meson could receive both a positive or negative mass shift at nuclear matter density. We find that these results depend only weakly on potential modifications of the width of the ϕ meson peak and on assumptions made on the behavior of four-quark condensates at finite density.

  11. Plane Symmetric Cosmological Model with Quark and Strange Quark Matter in f ( R, T) Theory of Gravity

    NASA Astrophysics Data System (ADS)

    Agrawal, P. K.; Pawar, D. D.

    2017-03-01

    We studied plane symmetric cosmological model in the presence of quark and strange quark matter with the help of f( R, T) theory. To decipher solutions of plane symmetric space-time, we used power law relation between scale factor and deceleration parameter. We considered the special law of variation of Hubble's parameter proposed by Berman ( Nuovo Cimento B74, 182, 1983) which yields constant deceleration parameter. We also discussed the physical behavior of the solutions by using some physical parameters.

  12. PREFACE: 15th International Conference on Strangeness in Quark Matter (SQM2015)

    NASA Astrophysics Data System (ADS)

    Alvarez-Castillo, D.; Blaschke, D.; Kekelidze, V.; Matveev, V.; Sorin, A.

    2016-01-01

    The 15th International Conference Strangeness in Quark Matter (SQM) took place at the Veksler and Baldin Laboratory of High Energy Physics (VBLHEP) of the Joint Institute for Nuclear Research (JINR) in Dubna in the period July 6 -11, with a record participation of 244 people from 31 countries! The previous meeting of the series in Birmingham 2013 had collected 158 physicists from 25 countries [J. Phys. Conf. Ser. 509, 011001 (2014)]. At SQM-2015, there was also a record participation of young scientist; every 4th conference attendee did not yet hold a PhD degree! There was a special program of 4 general lectures, a devoted session of parallel talks for Young Talents and the Helmholtz International Summer School (HISS) with 16 lecturers on the topics regarding Dense Matter (29.06.-11.07.) as a satellite event at the Bogoliubov Laboratory of Theoretical Physics (BLTP) and at VBLHEP. Another satellite event was the Round TableWorkshop on Physics at NICA, jointly organized by JINR and the Republic of South Africa on July 5, 2015. The selection of Dubna as the place for SQM-2015 conference by the International Advisory Committee (IAC) demonstrates the broad interest of the community in the progress of the Russian Megascience Project on the Nuclotron-based Ion Collider Facility (NICA) hosted at JINR Dubna. In a few years from now the experiments planned at NICA will produce data that provide new information of unprecedented accuracy which will help to answer some of the key questions which are topical at this conference. The SQM-2015 conference had an ambitious scientific program with 38 plenary talks, 97 parallel talks in 7 topical directions and 39 posters reporting the state of the research and the future directions in the fields of strangeness, heavy avors and bulk physics, suggested by the IAC to be the subtitle of the conference from 2016 onwards. Most of the contributions are represented in these Proceedings which we recommend to the community! We gratefully

  13. PREFACE: SQM2004 The 8th International Conference on Strangeness in Quark Matter

    NASA Astrophysics Data System (ADS)

    Cleymans, Jean; Steinberg, Peter; Vilakazi, Zeblon

    2005-06-01

    The 8th International Conference on Strangeness in Quark Matter (SQM2004) was held at at the Breakwater Lodge, which is part of the Graduate School of Business of the University of Cape Town. The architecture of the Breakwater Lodge is a stark reminder of the fact that its original purpose was to serve as a municipal jail. It appears that the spectacular background of Table Mountain and the V&A Waterfront and an excellent set of speakers were sufficient to keep the lecture rooms full to capacity, despite the numerous temptations of Cape Town. This is the first time a major heavy ion conference has been held in South Africa, and the timing is fortuitous, with a long-delayed MoU between South Africa and CERN at last being signed and finalized. At last, funding is being made available for South African scientists to play a meaningful role and make contributions to the international effort in heavy ion physics. Despite the substantial distance from the major cities in the northern hemisphere, the conference was very well attended and the number of participants was about 50% larger than originally anticipated. Participants came from China, India, Japan, the United States, Brazil and many European countries. We would like to thank all of the SQM2004 participants for their efforts and, in particlular, all of the plenary and parallel speakers for their hard work in making this conference such a success. Of course, even more thanks go to all the chairpersons of the various sessions who struggled to keep the conference program on the (admittedly tight) schedule. For future conferences, we recommend keeping a bell handy! Photograph Participants gather on the UCT campus with Table Mountain in the backgound. We would like to thank Professor Tony Fairall for a most entertaining after-dinner talk about all that is unusual and fascinating about the southern hemisphere. It could not be emphasized enough that the daily working of the meeting would have ground to a halt without the

  14. Exact solutions of bulk viscous with string cloud attached to strange quark matter for higher dimensional FRW universe in Lyra geometry

    NASA Astrophysics Data System (ADS)

    Ćaǧlar, Halife; Aygün, Sezgin

    2016-03-01

    In this study, we have investigated bulk viscous with strange quark matter attached to the string cloud for higher dimensional Friedman-Robertson-Walker (FRW) universe in Lyra geometry. By using varying deceleration parameter and conservation equations we have solved Einstein Field Equations (EFE's) and obtained generalized exact solutions for our model. Also we have found that string is not survived for bulk viscous with strange quark matter attached to the string cloud in framework higher dimensional FRW universe in Lyra geometry. This result agrees with Kiran and Reddy, Krori et al, Sahoo and Mishra and Mohanty et al. in four and five dimensions.

  15. Strange stars at finite temperature

    NASA Astrophysics Data System (ADS)

    Ray, Subharthi; Bagchi, Manjari; Dey, Jishnu; Dey, Mira

    2006-03-01

    We calculate strange star properties, using large Nc approximation with built-in chiral symmetry restoration (CSM). We used a relativistic Hartree Fock meanfield approximation method, using a modi.ed Richardson potential with two scale parameters Λ and Λ', to find a new set of equation of state (EOS) for strange quark matter. We take the effect of temperature (T) on gluon mass, in addition to the usual density dependence, and find that the transition T from hadronic matter to strange matter is 80 MeV. Therefore formation of strange stars may be the only signal for formation of QGP with asymptotic freedom (AF) and CSM.

  16. Chemistry of superheavy elements.

    PubMed

    Schädel, Matthias

    2006-01-09

    The number of chemical elements has increased considerably in the last few decades. Most excitingly, these heaviest, man-made elements at the far-end of the Periodic Table are located in the area of the long-awaited superheavy elements. While physical techniques currently play a leading role in these discoveries, the chemistry of superheavy elements is now beginning to be developed. Advanced and very sensitive techniques allow the chemical properties of these elusive elements to be probed. Often, less than ten short-lived atoms, chemically separated one-atom-at-a-time, provide crucial information on basic chemical properties. These results place the architecture of the far-end of the Periodic Table on the test bench and probe the increasingly strong relativistic effects that influence the chemical properties there. This review is focused mainly on the experimental work on superheavy element chemistry. It contains a short contribution on relativistic theory, and some important historical and nuclear aspects.

  17. Lunar Seismic Detector to Advance the Search for Strange Quark Matter

    NASA Technical Reports Server (NTRS)

    Galitzki, Nicholas B.

    2005-01-01

    Detection of small seismic signals on the Moon are needed to study lunar internal structure and to detect possible signals from Strange Quark m&er transit events. The immediate objective is to create a prototype seismic detector using a tunnel diode oscillator with a variable capacitor attached to a proof mass. The device is designed to operate effectively on the Moon, which requires a low power consumption to operate through lunar night, while preserving sensitivity. The goal is capacitance resolution of better than 1 part in 10' and power consumption of less than 1 watt.

  18. Strange Baryon Physics in Full Lattice QCD

    SciTech Connect

    Huey-Wen Lin

    2007-11-01

    Strange baryon spectra and form factors are key probes to study excited nuclear matter. The use of lattice QCD allows us to test the strength of the Standard Model by calculating strange baryon quantities from first principles.

  19. Chemistry of the superheavy elements.

    PubMed

    Schädel, Matthias

    2015-03-13

    The quest for superheavy elements (SHEs) is driven by the desire to find and explore one of the extreme limits of existence of matter. These elements exist solely due to their nuclear shell stabilization. All 15 presently 'known' SHEs (11 are officially 'discovered' and named) up to element 118 are short-lived and are man-made atom-at-a-time in heavy ion induced nuclear reactions. They are identical to the transactinide elements located in the seventh period of the periodic table beginning with rutherfordium (element 104), dubnium (element 105) and seaborgium (element 106) in groups 4, 5 and 6, respectively. Their chemical properties are often surprising and unexpected from simple extrapolations. After hassium (element 108), chemistry has now reached copernicium (element 112) and flerovium (element 114). For the later ones, the focus is on questions of their metallic or possibly noble gas-like character originating from interplay of most pronounced relativistic effects and electron-shell effects. SHEs provide unique opportunities to get insights into the influence of strong relativistic effects on the atomic electrons and to probe 'relativistically' influenced chemical properties and the architecture of the periodic table at its farthest reach. In addition, they establish a test bench to challenge the validity and predictive power of modern fully relativistic quantum chemical models.

  20. Observational signatures of the macroscopic formation of strange matter during core collapse supernovae

    NASA Astrophysics Data System (ADS)

    Zach, Juergen Johann

    2003-12-01

    The consequences of a first order QCD phase transition in the protoneutronstar remnant of a core collapse supernova are presented with a special focus on the effects on neutrino transport. A secondary focus is the detection of these neutrinos in terrestrial detectors. Hybrid stars are constructed such that a coexistence region of QCD-confined and deconfined phases forms in the protoneutronstar interior with possibly a pure deconfined phase in the center. The resulting Coulomb lattice (1D, 2D and 3D) in the coexistence region is shown to crystallize for temperatures relevant in supernova cores seconds after bounce. Droplet deformation modes freeze out in the same range. For the outermost ˜1 km of the coexistence region, the stability of the 3D lattice to shear stresses falls below the critical range of mechanical energy densities provided by hydrodynamical flow. This can lead to a non-spherical relief structure which, together with the enhanced neutrino opacity of the coexistence lattice; can result in anisotropic neutrino transport and therefore neutron star kicks. A computer model for neutrino diffusion coupled with quasistatic evolution of a solid lattice phase and hydrodynamical treatment of the confined matter envelope was developed to address the kick model and other problems. The state of newly formed hybrid stars is determined using a self- consistent approach of integrating the stellar structure equations with the constraint of heat flow equilibrium, resulting in relatively cool energy spheres (T ˜ 1 MeV) compared to T ˜ 10 MeV in the interior. Typical cooling timescales of hybrid stars are then τ ˜ 100 sec. This is shown to result in a statistically significant signal in a Pb-neutron spallation detector. In exploratory calculations, observed kick speeds were reproduced and the presence of a sustainable convective flow pattern to maintain a crater in the coexistence region was verified. The Pb and Fe components of a proposed neutron spallation neutrino

  1. Current trends in non-accelerator particle physics: 1, Neutrino mass and oscillation. 2, High energy neutrino astrophysics. 3, Detection of dark matter. 4, Search for strange quark matter. 5, Magnetic monopole searches

    SciTech Connect

    He, Yudong |

    1995-07-01

    This report is a compilation of papers reflecting current trends in non-accelerator particle physics, corresponding to talks that its author was invited to present at the Workshop on Tibet Cosmic Ray Experiment and Related Physics Topics held in Beijing, China, April 4--13, 1995. The papers are entitled `Neutrino Mass and Oscillation`, `High Energy Neutrino Astrophysics`, `Detection of Dark Matter`, `Search for Strange Quark Matter`, and `Magnetic Monopole Searches`. The report is introduced by a survey of the field and a brief description of each of the author`s papers.

  2. Maximum rotation frequency of strange stars

    SciTech Connect

    Zdunik, J.L.; Haensel, P. )

    1990-07-15

    Using the MIT bag model of strange-quark matter, we calculate the maximum angular frequency of the uniform rotation of strange stars. After studying a broad range of the MIT bag-model parameters, we obtain an upper bound of 12.3 kHz.

  3. Heavy and Superheavy Atomic Nuclei

    NASA Astrophysics Data System (ADS)

    Sobiczewski, Adam

    2008-10-01

    The appearance and development of the concept of super-heavy atomic nuclei are described. The concept appeared during the studies of the limits of the nuclear chart and of the periodic table of the chemical elements. The article concentrates on theoretical studies of the properties of heaviest nuclei. Results of these studies are illustrated and discussed. Prospects for a nearest future of the research of heaviest nuclei are outlined.

  4. Structural and decay properties of Z = 132, 138 superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Rather, Asloob A.; Ikram, M.; Usmani, A. A.; Kumar, Bharat; Patra, S. K.

    2016-12-01

    In this paper, we analyze the structural properties of Z = 132 and Z = 138 superheavy nuclei within the ambit of axially deformed relativistic mean-field framework with NL3 * parametrization and calculate the total binding energies, radii, quadrupole deformation parameter, separation energies, density distributions. We also investigate the phenomenon of shape coexistence by performing the calculations for prolate, oblate and spherical configurations. For clear presentation of nucleon distributions, the two-dimensional contour representation of individual nucleon density and total matter density has been made. Further, a competition between possible decay modes such as α-decay, β-decay and spontaneous fission of the isotopic chain of superheavy nuclei with Z = 132 within the range 312 ≤ A ≤ 392 and 318 ≤ A ≤ 398 for Z = 138 is systematically analyzed within self-consistent relativistic mean-field model. From our analysis, we inferred that the α-decay and spontaneous fission are the principal modes of decay in majority of the isotopes of superheavy nuclei under investigation apart from β-decay as dominant mode of decay in 318-322138 isotopes.

  5. Superheavy elements and r-process

    SciTech Connect

    Panov, I. V. Korneev, I. Yu.; Thielemann, F.-K.

    2009-06-15

    The probability for the production of superheavy elements in the astrophysical r-process is discussed. The dependence of the estimated superheavy-element yields on input data is estimated. Preliminary calculations revealed that the superheavy-element yields at the instant of completion of the r-process may be commensurate with the uranium yield, but the former depend strongly on the models used to forecast the properties of beta-delayed, neutron-induced, and spontaneous fission. This study is dedicated to the 80th anniversary of V.S. Imshennik's birth.

  6. Chemical experiments with superheavy elements.

    PubMed

    Türler, Andreas

    2010-01-01

    Unnoticed by many chemists, the Periodic Table of the Elements has been extended significantly in the last couple of years and the 7th period has very recently been completed with eka-Rn (element 118) currently being the heaviest element whose synthesis has been reported. These 'superheavy' elements (also called transactinides with atomic number > or = 104 (Rf)) have been artificially synthesized in fusion reactions at accelerators in minute quantities of a few single atoms. In addition, all isotopes of the transactinide elements are radioactive and decay with rather short half-lives. Nevertheless, it has been possible in some cases to investigate experimentally chemical properties of transactinide elements and even synthesize simple compounds. The experimental investigation of superheavy elements is especially intriguing, since theoretical calculations predict significant deviations from periodic trends due to the influence of strong relativistic effects. In this contribution first experiments with hassium (Hs, atomic number 108), copernicium (Cn, atomic number 112) and element 114 (eka-Pb) are reviewed.

  7. New dimensions of the periodic system: superheavy, superneutronic, superstrange, antimatter nuclei

    NASA Astrophysics Data System (ADS)

    Greiner, Walter

    2010-12-01

    The possibilities for the extension of the periodic system into the islands of superheavy (SH) elements, to and beyond the neutron drip line and to the sectors of strangeness and antimatter are discussed. The multi-nucleon transfer processes in low-energy damped collisions of heavy actinide nuclei may help us to fill the gap between the nuclei produced in the "hot" fusion reactions and the continent of known nuclei. In these reactions we may also investigate the "island of stability". In many such collisions the lifetime of the composite giant system consisting of two touching nuclei turns out to be rather long (≥10-20 s); sufficient for observing line structure in spontaneous positron emission from super-strong electric fields (vacuum decay), a fundamental QED process not observed yet experimentally. At the neutron-rich sector near the drip line islands and extended ridges of quasistable nuclei are predicted by HF calculations. Such nuclei, as well as very long living superheavy nuclei may be provided in double atomic bomb explosions. A tremendously rich scenario of new nuclear structure emerges with new magic numbers in the strangeness domain. Various production mechanisms are discussed for these objects and for antinuclei in high energy heavy-ion collisions.

  8. New dimensions of the periodic system: superheavy, superneutronic, superstrange, antimatter nuclei

    SciTech Connect

    Greiner, Walter

    2010-12-23

    The possibilities for the extension of the periodic system into the islands of superheavy (SH) elements, to and beyond the neutron drip line and to the sectors of strangeness and antimatter are discussed. The multi-nucleon transfer processes in low-energy damped collisions of heavy actinide nuclei may help us to fill the gap between the nuclei produced in the ''hot'' fusion reactions and the continent of known nuclei. In these reactions we may also investigate the ''island of stability''. In many such collisions the lifetime of the composite giant system consisting of two touching nuclei turns out to be rather long ({>=}10{sup -20} s); sufficient for observing line structure in spontaneous positron emission from super-strong electric fields (vacuum decay), a fundamental QED process not observed yet experimentally. At the neutron-rich sector near the drip line islands and extended ridges of quasistable nuclei are predicted by HF calculations. Such nuclei, as well as very long living superheavy nuclei may be provided in double atomic bomb explosions. A tremendously rich scenario of new nuclear structure emerges with new magic numbers in the strangeness domain. Various production mechanisms are discussed for these objects and for antinuclei in high energy heavy-ion collisions.

  9. Problems of design and development of advanced superheavy launch vehicles

    NASA Astrophysics Data System (ADS)

    Daniluk, A. Yu.; Klyushnikov, V. Yu.; Kuznetsov, I. I.; Osadchenko, A. S.

    2016-12-01

    The article analyzes problems of design and development of advanced superheavy launch vehicles. Mass and energy characteristics and design layout of launch vehicles are substantiated. Delivery methods of bulky superheavy launch vehicle components to the spacecraft launch site are discussed. Methods of reduction of financial and technical risks of development and operation of superheavy launch vehicles are analyzed. The problem of environmental impacts of superheavy launch vehicle launches is posed.

  10. Search for possible superheavy particles in sodium nuclei

    NASA Astrophysics Data System (ADS)

    Dick, W. J.; Greenlees, G. W.; Kaufman, S. L.

    1986-01-01

    A search has been made for isotopes of sodium of mass >100 amu. Such heavy isotopes could arise from the presence of superheavy particles in the primordial soup which became constituents of nuclear matter. The experimental technique involved studying the isotopic mass shift of the Na D2 atomic transition using high-resolution laser spectroscopy and the photon-burst method. An upper limit for the heavy-particle-to-nucleon ratio of 5×10-12 was found. Cosmological-model predictions for this ratio in nuclear matter are ~=10-10. Any comparison of these two values assumes no mass fractionation has occurred in the geophysical disposition and subsequent extraction of the sodium forming the atomic beam and also no differences in the distribution of heavy isotopes among the elements, compared to normal isotopes, during their astrophysical formation. Making these assumptions enables limits to be placed on the heavy-particle annihilation cross sections in the formation process.

  11. Searches for superheavy elements in nature: Cosmic-ray nuclei; spontaneous fission

    NASA Astrophysics Data System (ADS)

    Ter-Akopian, G. M.; Dmitriev, S. N.

    2015-12-01

    There is little chance that superheavy nuclei with lifetimes of no less than 100 million years are present on the stability island discovered at present. Also, pessimistic are the results of estimates made about their nucleosynthesis in r-process. Nevertheless, the search for these nuclei in nature is justified in view of the fundamental importance of this topic. The first statistically significant data set was obtained by the LDEF Ultra-Heavy Cosmic-Ray Experiment, consisting of 35 tracks of actinide nuclei in galactic cosmic rays. Because of their exceptionally long exposure time in Galaxy, olivine crystals extracted from meteorites generate interest as detectors providing unique data regarding the nuclear composition of ancient cosmic rays. The contemporary searches for superheavy elements in the earth matter rely on knowledge obtained from chemical studies of artificially synthesized superheavy nuclei. New results finding out the chemical behavior of superheavy elements should be employed to obtain samples enriched in their homologues. The detection of rare spontaneous fission events and the technique of accelerator mass spectrometry are employed in these experiments.

  12. Chemical signatures for superheavy elementary particles.

    PubMed

    Cahn, R N; Glashow, S L

    1981-08-07

    Models of unified fundamental interactions suggest the existence of many particles in the mass range 10 x 10(9) to 100 x 10(12) electron volts. Among these may be charged particles, X(+/-), that are stable or nearly so. The X(+,)s would form superheavy hydrogen, while the X(-,)s would bind to nuclei. Chemical isolation of naturally occurring technetium, promethium, actinium, protactinium, neptunium, or americium would indicate the presence of superheavy particles in the forms RuX(-), SmX(-), (232)ThX(-), (235,236,238)UX(-), (244)PuX(-), or (247)CmX(-). Other substances worth searching for include superheavy elements with the chemical properties of boron, fluorine, manganese, beryllium, scandium, vanadium, lithium, neon, and thallium.

  13. Superheavy element chemistry at GARIS

    NASA Astrophysics Data System (ADS)

    Haba, Hiromitsu

    2016-12-01

    A gas-jet transport system has been installed to the RIKEN GAs-filled Recoil Ion Separator, GARIS to start up SuperHeavy Element (SHE) chemistry. This system is a promising approach for exploring new frontiers in SHE chemistry: background radioactivities from unwanted by-products are suppressed, a high gas-jet transport yield is achieved, and new chemical reactions can be investigated. Useful radioisotopes of 261Rfa,b, 262Db, and 265Sga,b for chemical studies were produced in the reactions of 248Cm(18O,5n)261Rfa,b, 248Cm(19F,5n)262Db, and 248Cm(22Ne,5n)265Sga,b, respectively. They were successfully extracted to a chemistry laboratory by the gas-jet method. Production and decay properties of 261Rfa,b, 262Db, and 265Sga,b were investigated in detail with the rotating wheel apparatus for α- and spontaneous fission spectrometry. Present status and perspectives of the SHE chemistry at GARIS are also briefly presented.

  14. {gamma}-vibrational states in superheavy nuclei

    SciTech Connect

    Sun Yang; Long Guilu; Al-Khudair, Falih; Sheikh, Javid A.

    2008-04-15

    Recent experimental advances have made it possible to study excited structure in superheavy nuclei. The observed states have often been interpreted as quasiparticle excitations. We show that in superheavy nuclei collective vibrations systematically appear as low-energy excitation modes. By using the microscopic Triaxial Projected Shell Model, we make a detailed prediction on {gamma}-vibrational states and their E2 transition probabilities to the ground state band in fermium and nobelium isotopes where active structure research is going on, and in {sup 270}Ds, the heaviest isotope where decay data have been obtained for the ground-state and for an isomeric state.

  15. Foreword [Special Issue on Superheavy Elements

    SciTech Connect

    Düllmann, Christoph E.; Herzberg, Rolf -Dietmar; Nazarewicz, Witold; Oganessian, Yuri

    2015-12-07

    Reflecting the breadth of research opportunities in the field of superheavy element research, this special issue covers the range of topics in a comprehensive way, including synthesis of superheavy isotopes, nuclear structure, atomic shell structure, and chemical properties. The contributions detail the status of the field and lay out perspectives for the future. The prospects are bright: new isotopes are awaiting discovery, completing the landscape of superheavy nuclei and bridging the currently existing gap between nuclei synthesized in cold fusion reactions and those from 48Ca induced fusion reactions. The possibility that the limits of nuclear structure studies can be pushed even further in mass and charge has greatly motivated a number of new facilities. Advances in experimental techniques will allow studies on isotopes produced significantly below the 1 pb level. Chemical studies progressing to elements never studied to date are already being prepared. Ultra-fast chemistry setups are under development and it will be fascinating to see them at work, elucidating the influence of relativistic effects on superheavy elements. The richness of chemical systems available for transactinides will expand further, giving access to new chemical systems, giving more information on the architecture of the periodic table.

  16. Foreword [Special Issue on Superheavy Elements

    DOE PAGES

    Düllmann, Christoph E.; Herzberg, Rolf -Dietmar; Nazarewicz, Witold; ...

    2015-12-07

    Reflecting the breadth of research opportunities in the field of superheavy element research, this special issue covers the range of topics in a comprehensive way, including synthesis of superheavy isotopes, nuclear structure, atomic shell structure, and chemical properties. The contributions detail the status of the field and lay out perspectives for the future. The prospects are bright: new isotopes are awaiting discovery, completing the landscape of superheavy nuclei and bridging the currently existing gap between nuclei synthesized in cold fusion reactions and those from 48Ca induced fusion reactions. The possibility that the limits of nuclear structure studies can be pushedmore » even further in mass and charge has greatly motivated a number of new facilities. Advances in experimental techniques will allow studies on isotopes produced significantly below the 1 pb level. Chemical studies progressing to elements never studied to date are already being prepared. Ultra-fast chemistry setups are under development and it will be fascinating to see them at work, elucidating the influence of relativistic effects on superheavy elements. The richness of chemical systems available for transactinides will expand further, giving access to new chemical systems, giving more information on the architecture of the periodic table.« less

  17. Transfer-induced fission of superheavy nuclei

    SciTech Connect

    Adamian, G. G.; Antonenko, N. V.; Zubov, A. S.; Sargsyan, V. V.; Scheid, W.

    2010-07-15

    Possibilities of transfer-induced fission of new isotopes of superheavy nuclei with charge numbers 103-108 are studied for the first time in the reactions {sup 48}Ca+{sup 244,246,248}Cm at energies near the corresponding Coulomb barriers. The predicted cross sections are found to be measurable with the detection of three-body final states.

  18. Effects of non-Newtonian gravity on the properties of strange stars

    NASA Astrophysics Data System (ADS)

    Lu, Zhen-Yan; Peng, Guang-Xiong; Zhou, Kai

    2017-02-01

    The properties of strange star matter are studied in the equivparticle model with inclusion of non-Newtonian gravity. It is found that the inclusion of non-Newtonian gravity makes the equation of state stiffer if Witten’s conjecture is true. Correspondingly, the maximum mass of strange stars becomes as large as two times the solar mass, and the maximum radius also becomes bigger. The coupling to boson mass ratio has been constrained within the stability range of strange quark matter.

  19. Strange nonchaotic stars.

    PubMed

    Lindner, John F; Kohar, Vivek; Kia, Behnam; Hippke, Michael; Learned, John G; Ditto, William L

    2015-02-06

    The unprecedented light curves of the Kepler space telescope document how the brightness of some stars pulsates at primary and secondary frequencies whose ratios are near the golden mean, the most irrational number. A nonlinear dynamical system driven by an irrational ratio of frequencies generically exhibits a strange but nonchaotic attractor. For Kepler's "golden" stars, we present evidence of the first observation of strange nonchaotic dynamics in nature outside the laboratory. This discovery could aid the classification and detailed modeling of variable stars.

  20. Superheavy Element Research at Tasca at GSI

    NASA Astrophysics Data System (ADS)

    Düllmann, Christoph E.

    2014-09-01

    Experiments on the synthesis of the heaviest elements are in the center of the current research program on superheavy elements at GSI Darmstadt. At the gas-filled recoil separator TASCA, search experiments for the new elements 119 and 120 have been performed in the reactions 50Ti + 249Bk and 50Ti + 249Cf, respectively, and the production of element 117 in the reaction 48Ca + 249Bk was studied. The experiments were performed successfully and the data are currently under analysis.

  1. Last orbits of binary strange quark stars

    SciTech Connect

    Limousin, Francois; Gourgoulhon, Eric; Gondek-Rosinska, Dorota

    2005-03-15

    We present the first relativistic calculations of the final phase of inspiral of a binary system consisting of two stars built predominantly of strange quark matter (strange quark stars). We study the precoalescing stage within the Isenberg-Wilson-Mathews approximation of general relativity using a multidomain spectral method. A hydrodynamical treatment is performed under the assumption that the flow is either rigidly rotating or irrotational, taking into account the finite density at the stellar surface--a distinctive feature with respect to the neutron star case. The gravitational-radiation driven evolution of the binary system is approximated by a sequence of quasiequilibrium configurations at fixed baryon number and decreasing separation. We find that the innermost stable circular orbit (ISCO) is given by an orbital instability both for synchronized and irrotational systems. This contrasts with neutron stars for which the ISCO is given by the mass-shedding limit in the irrotational case. The gravitational wave frequency at the ISCO, which marks the end of the inspiral phase, is found to be {approx}1400 Hz for two irrotational 1.35 M{sub {center_dot}} strange stars and for the MIT bag model of strange matter with massless quarks and a bag constant B=60 MeV fm{sup -3}. Detailed comparisons with binary neutrons star models, as well as with third order post-Newtonian point-mass binaries are given.

  2. Tennessine Announced As Provisional Name For Superheavy Element 117

    SciTech Connect

    Roberto, Jim

    2016-06-08

    The International Union of Pure and Applied Chemistry (IUPAC) Inorganic Chemistry Division has published a Provisional Recommendation for the names and symbols of the recently discovered superheavy elements 113, 115, 117, and 118. Tennessine (Ts) is proposed for element 117, recognizing the contribution of Tennessee research centers ORNL, Vanderbilt and the University of Tennessee to superheavy element research.

  3. Tennessine Announced As Provisional Name For Superheavy Element 117

    ScienceCinema

    Roberto, Jim

    2016-07-12

    The International Union of Pure and Applied Chemistry (IUPAC) Inorganic Chemistry Division has published a Provisional Recommendation for the names and symbols of the recently discovered superheavy elements 113, 115, 117, and 118. Tennessine (Ts) is proposed for element 117, recognizing the contribution of Tennessee research centers ORNL, Vanderbilt and the University of Tennessee to superheavy element research.

  4. Using the Moon As A Low-Noise Seismic Detector For Strange Quark Nuggets

    NASA Technical Reports Server (NTRS)

    Banerdt, W. Bruce; Chui, Talso; Griggs, Cornelius E.; Herrin, Eugene T.; Nakamura, Yosio; Paik, Ho Jung; Penanen, Konstantin; Rosenbaum, Doris; Teplitz, Vigdor L.; Young, Joseph

    2006-01-01

    Strange quark matter made of up, down and strange quarks has been postulated by Witten [1]. Strange quark matter would be nearly charge neutral and would have density of nuclear matter (10(exp 14) gm/cu cm). Witten also suggested that nuggets of strange quark matter, or strange quark nuggets (SQNs), could have formed shortly after the Big Bang, and that they would be viable candidates for cold dark matter. As suggested by de Rujula and Glashow [2], an SQN may pass through a celestial body releasing detectable seismic energy along a straight line. The Moon, being much quieter seismically than the Earth, would be a favorable place to search for such events. We review previous searches for SQNs to illustrate the parameter space explored by using the Moon as a low-noise detector of SQNs. We also discuss possible detection schemes using a single seismometer, and using an International Lunar Seismic Network.

  5. Penta-Quark States with Strangeness, Hidden Charm and Beauty

    NASA Astrophysics Data System (ADS)

    Wu, Jia-Jun; Zou, Bing-Song

    The classical quenched quark models with three constituent quarks provide a good description for the baryon spatial ground states, but fail to reproduce the spectrum of baryon excited states. More and more evidences suggest that unquenched effects with multi-quark dynamics are necessary ingredients to solve the problem. Several new hyperon resonances reported recently could fit in the picture of penta-quark states. Based on this picture, some new hyperon excited states were predicted to exist; meanwhile with extension from strangeness to charm and beauty, super-heavy narrow N* and Λ* resonances with hidden charm or beauty were predicted to be around 4.3 and 11 GeV, respectively. Recently, two of such N* with hidden charm might have been observed by the LHCb experiment. More of those states are expected to be observed in near future. This opens a new window in order to study hadronic dynamics for the multi-quark states.

  6. Strangeness at SIS energies

    SciTech Connect

    Koch, Volker

    2005-09-28

    In this contribution the authors discuss the physics of strange hadrons in low energy ({approx_equal} 1-2 AGeV) heavy ion collision. In this energy range the relevant strange particle are the kaons and anti-kaons. The most interesting aspect concerning these particles are so called in-medium modifications. They will attempt to review the current status of understanding of these in medium modifications. In addition they briefly discuss other issues related with kaon production, such as the nuclear equation of state and chemical equilibrium.

  7. Superheavy magnetic monopoles and the standard cosmology

    NASA Astrophysics Data System (ADS)

    Turner, M. S.

    1984-10-01

    The superheavy magnetic monopoles predicted to exist in grand unified theories (GUTs) are for particle physics, astrophysics and cosmology. Astrophysical and cosmological considerations are invaluable in the study of the properties of GUT monopoles. Because of the glut of monopoles predicted in the standard cosmology for the simplest GUTs. The simplest GUTs and the standard cosmology are not compatible. This is a very important piece of information about physics at unification energies and about the earliest movements of the Universe. The cosmological consequences of GUT monopoles within the context of the standard hot big bang model are reviewed.

  8. Self-Consistency Effects In Superheavy Nuclei

    SciTech Connect

    Afanasjev, A.V.; Frauendorf, S.

    2005-04-05

    The influence of the central depression in the density distribution of spherical superheavy nuclei on the shell structure is studied within the relativistic mean field theory. Large depression leads to the shell gaps at the proton Z = 120 and neutron N = 172 numbers, while flatter density distribution favors N = 184 for neutrons and leads to the appearance of a Z 126 shell gap and to the decrease of the size of the Z = 120 shell gap. The correlations between the magic shell gaps and the magnitude of central depression are discussed for relativistic and non-relativistic mean field theories.

  9. Electronic structure and properties of superheavy elements

    NASA Astrophysics Data System (ADS)

    Pershina, V.

    2015-12-01

    Spectacular developments in the relativistic quantum theory and computational algorithms in the last few decades allowed for accurate calculations of properties of the superheavy elements (SHE) and their compounds. Often conducted in a close link to the experimental research, these investigations helped predict and interpret an outcome of sophisticated and expensive experiments with single atoms. Most of the works, particularly those related to the experimental studies, are overviewed in this publication. The role of relativistic effects being of paramount importance for the heaviest elements is elucidated.

  10. Two alternative versions of strangeness

    PubMed Central

    Nishijima, Kazuhikoa

    2008-01-01

    The concept of strangeness emerged from the low energy phenomenology before the entry of quarks in particle physics. The connection between strangeness and isospin is rather accidental and loose and we recognize later that the definition of strangeness is model-dependent. Indeed, in Gell-Mann’s triplet quark model we realize that there is a simple alternative representation of strangeness. When the concept of generations is incorporated into the quark model we find that only the second alternative version of strangeness remains meaningful, whereas the original one does no longer keep its significance. PMID:18997448

  11. Strange Nonchaotic Stars

    NASA Astrophysics Data System (ADS)

    Lindner, John F.; Kohar, Vivek; Kia, Behnam; Hippke, Michael; Learned, John G.; Ditto, William L.

    2015-08-01

    Exploiting the unprecedented capabilities of the planet-hunting Kepler space telescope, which stared at 150 000 stars for four years, we discuss recent evidence that certain stars dim and brighten in complex patterns with fractal features. Such stars pulsate at primary and secondary frequencies whose ratios are near the famous golden mean, the most irrational number. A nonlinear system driven by an irrational ratio of frequencies is generically attracted toward a “strange” behavior that is geometrically fractal without displaying the “butterfly effect” of chaos. Strange nonchaotic attractors have been observed in laboratory experiments and have been hypothesized to describe the electrochemical activity of the brain, but a bluish white star 16 000 light years from Earth in the constellation Lyra may manifest, in the scale-free distribution of its minor frequency components, the first strange nonchaotic attractor observed in the wild. The recognition of stellar strange nonchaotic dynamics may improve the classification of these stars and refine the physical modeling of their interiors. We also discuss nonlinear analysis of other RR Lyrae stars in Kepler field of view and discuss some toy models for modeling these stars.References: 1) Hippke, Michael, et al. "Pulsation period variations in the RRc Lyrae star KIC 5520878." The Astrophysical Journal 798.1 (2015): 42.2) Lindner, John F., et al. "Strange nonchaotic stars." Phys. Rev. Lett. 114, 054101 (2015)

  12. Superheavy nuclei: from predictions to discovery

    NASA Astrophysics Data System (ADS)

    Oganessian, Yu Ts; Sobiczewski, A.; Ter-Akopian, G. M.

    2017-02-01

    A fundamental outcome of modern nuclear microscopic theory is the prediction of the ‘islands of stability’ in the region of hypothetical superheavy elements (SHEs). In a heavy nucleus, going through the large-scale deformation on the way to fission, the motion of single nucleons is coupled with the collective degrees of freedom of the whole system. The most striking effect of this coupling is obtained for the case of fission of the heaviest nuclei, whose existence is defined entirely by the nuclear structure, i.e. by the shell effect. From this point of view, the synthesis and study of properties of superheavy nuclei (SHN) is a direct way for checking the basic statements of the microscopic nuclear theory. On the nuclide map, SHN outline the border of the heaviest nuclear masses. SHN set the limits of the periodic system of chemical elements. The study of possible existence of SHN in nature offers a way for testing different scenarios of astrophysical nucleosynthesis. The paper elucidates experimental approaches, used for testing the theory predictions made about the SHN, and presents the results of the discovery of the ‘stability island’ of SHEs.

  13. Potential energy surfaces of superheavy nuclei

    SciTech Connect

    Bender, M.; Rutz, K.; Maruhn, J.A.; Greiner, W.; Reinhard, P.-G. Rutz, K.; Maruhn, J.A.; Greiner, W.

    1998-10-01

    We investigate the structure of the potential energy surfaces of the superheavy nuclei {sub 158}{sup 258}Fm{sub 100}, {sub 156}{sup 264}Hs{sub 108}, {sub 166}{sup 278}112, {sub 184}{sup 298}114, and {sub 172}{sup 292}120 within the framework of self-consistent nuclear models, i.e., the Skyrme-Hartree-Fock approach and the relativistic mean-field model. We compare results obtained with one representative parametrization of each model which is successful in describing superheavy nuclei. We find systematic changes as compared to the potential energy surfaces of heavy nuclei in the uranium region: there is no sufficiently stable fission isomer any more, the importance of triaxial configurations to lower the first barrier fades away, and asymmetric fission paths compete down to rather small deformation. Comparing the two models, it turns out that the relativistic mean-field model gives generally smaller fission barriers. {copyright} {ital 1998} {ital The American Physical Society}

  14. Ground state properties of superheavy nuclei with Z=117 and Z=119

    SciTech Connect

    Ren Zhongzhou; Chen Dinghan; Xu Chang

    2006-11-02

    We review the current studies on the ground-state properties of superheavy nuclei. It is shown that there is shape coexistence for the ground state of many superheavy nuclei from different models and many superheavy nuclei are deformed. This can lead to the existence of isomers in superheavy region and it plays an important role for the stability of superheavy nuclei. Some new results on Z=117 and Z=119 isotopes are presented. The agreement between theoretical results and experimental data clearly demonstrates the validity of theoretical models for the ground-state properties of superheavy nuclei.

  15. Measurement of strange particle production in the NICA fixed-target programme

    NASA Astrophysics Data System (ADS)

    Friese, Volker

    2016-08-01

    Strange particles provide a sensitive tool to study the dense and hot matter created in relativistic nuclear collisions. Although strangeness production in such collisions has been a topic of experimental and theoretical research for many years, its understanding is far from being complete. This holds in particular for multi-strange hyperons and for lower collision energies as relevant for NICA and FAIR. Multi-strange particles, being sensitive to both the mechanism of strangeness production and the net-baryon density, are expected to shed light on the state of the created matter and to indicate possible transitions to new phases of strongly interacting matter. We thus advocate the measurement of hyperons and φ mesons in a fixed-target experiment at NICA (BM@N), which can be achieved by a relatively compact detector system.

  16. TORSIONAL OSCILLATIONS OF NONBARE STRANGE STARS

    SciTech Connect

    Mannarelli, Massimo; Pagliaroli, Giulia; Parisi, Alessandro; Pilo, Luigi; Tonelli, Francesco

    2015-12-20

    Strange stars are one of the possible compact stellar objects that can form after a supernova collapse. We consider a model of a strange star having an inner core in the color-flavor locked phase surmounted by a crystalline color superconducting (CCSC) layer. These two phases constitute the quarksphere, which we assume to be the largest and heaviest part of the strange star. The next layer consists of standard nuclear matter forming an ionic crust, hovering on the top of the quarksphere and prevented from falling by a strong dipolar electric field. The dipolar electric field arises because quark matter is confined in the quarksphere by the strong interaction, but electrons can leak outside forming an electron layer a few hundred fermi thick separating the ionic crust from the underlying quark matter. The ionic matter and the CCSC matter constitute two electromagnetically coupled crust layers. We study the torsional oscillations of these two layers. Remarkably, we find that if a fraction larger than 10{sup −4} of the energy of a Vela-like glitch is conveyed to a torsional oscillation, the ionic crust will likely break. The reason is that the very rigid and heavy CCSC crust layer will absorb only a small fraction of the glitch energy, leading to a large-amplitude torsional oscillation of the ionic crust. The maximum stress generated by the torsional oscillation is located inside the ionic crust and is very close to the star’s surface. This peculiar behavior leads to a much easier crust cracking than in standard neutron stars.

  17. Strange skyrmion molecules

    NASA Astrophysics Data System (ADS)

    Kopeliovich, Vladimir B.; Stern, Boris E.

    1997-05-01

    Composed skyrmions with B=2, strangeness content close to 0.5 and the binding energy of several tens of Mev are described. These skyrmions are obtained starting from the system of two B=1 hedgehogs located in different SU(2) subgroups of SU(3) and have the mass and baryon number distribution of molecular (dipole) type. The quantization of zero modes of skyrmion molecules and physics consequences of their existence are discussed.

  18. Strange skyrmion molecules

    SciTech Connect

    Kopeliovich, Vladimir B.; Stern, Boris E.

    1997-05-20

    Composed skyrmions with B=2, strangeness content close to 0.5 and the binding energy of several tens of Mev are described. These skyrmions are obtained starting from the system of two B=1 hedgehogs located in different SU(2) subgroups of SU(3) and have the mass and baryon number distribution of molecular (dipole) type. The quantization of zero modes of skyrmion molecules and physics consequences of their existence are discussed.

  19. Superheavy Elements -- Synthesis, Structure and Reaction Mechanism

    SciTech Connect

    Ackermann, Dieter

    2006-08-14

    The exciting results search for superheavy elements which have been achieved in the recent years have triggered a broad range of activities. Apart from experiments to attempt the synthesis of new elements, nuclear structure investigations in the transactinide region has become possibly for Z up to 108 or 110. Heavy element chemistry has successfully placed Hs in the periodic table and is no attacking element 112. The development of accelerators and experimental methods promises advances to enable the extension of these investigations in regions closer to the ''island of stability''. Mass measurements using ion traps and neutron rich unstable beam species for the systematic investigation of nuclear structure and reaction mechanisms for heavy neutron rich system are believed to complete the variety of tools in future.

  20. Nonaxial-octupole effect in superheavy nuclei

    SciTech Connect

    Chen, Y.-S.; Sun, Yang; Gao Zaochun

    2008-06-15

    The triaxial-octupole Y{sub 32} correlation in atomic nuclei has long been expected to exist but experimental evidence has not been clear. We find, in order to explain the very low-lying 2{sup -} bands in the transfermium mass region, that this exotic effect may manifest itself in superheavy elements. Favorable conditions for producing triaxial-octupole correlations are shown to be present in the deformed single-particle spectrum, which is further supported by quantitative Reflection Asymmetric Shell Model calculations. It is predicted that the strong nonaxial-octupole effect may persist up to the element 108. Our result thus represents the first concrete example of spontaneous breaking of both axial and reflection symmetries in the heaviest nuclear systems.

  1. Entrance channel effects in superheavy element production

    NASA Astrophysics Data System (ADS)

    Nasirov, Avazbek; Giardina, Giorgio; Mandaglio, Giuseppe; Muminov, Akhtam

    2016-12-01

    The difference between evaporation residue cross sections measured in the cold (X+208Pb, 209Bi) and hot (48Ca+actinides) fusion reactions can be related to the stage of compound nucleus (CN) formation and/or to the stage of its survival against fission. The cold fusion reactions are favorable in synthesis of the superheavy elements (SHE) with charge numbers Z < 112 in comparison with the hot fusion reactions due to small excitation energy and large fission barrier of the CN formed in these reactions. The strong decrease of the cross sections of the synthesis of the SHE Z = 113 in the cold fusion reactions in comparison with the ones in the hot fusion reactions is the result of the increase of hindrance to the CN formation in the cold fusion reactions. The origin of the intrinsic fusion barrier, B, causing the strong decrease of the probability PCN in the cold fusion is discussed.

  2. Strange experiments at the AGS

    SciTech Connect

    Chrien, R.

    1990-01-01

    The purpose of this review is to report recent progress in nuclear experiments involving strangeness which have been carried out at the Brookhaven Alternating Gradient Synchrotron over the past three years. These recent developments are noted in three areas: few body systems and dibaryons; strange probes of the nucleus; and associated production of hypernuclei. 9 refs., 3 figs.

  3. Electroproduction of Strange Nuclei

    SciTech Connect

    E.V. Hungerford

    2002-06-01

    The advent of high-energy, CW-beams of electrons now allows electro-production and precision studies of nuclei containing hyperons. Previously, the injection of strangeness into a nucleus was accomplished using secondary beams of mesons, where beam quality and target thickness limited the missing mass resolution. We review here the theoretical description of the (e, e'K+) reaction mechanism, and discuss the first experiment demonstrating that this reaction can be used to precisely study the spectra of light hypernuclei. Future experiments based on similar techniques, are expected to attain even better resolutions and rates.

  4. COALESCENCE OF STRANGE-QUARK PLANETS WITH STRANGE STARS: A NEW KIND OF SOURCE FOR GRAVITATIONAL WAVE BURSTS

    SciTech Connect

    Geng, J. J.; Huang, Y. F.; Lu, T.

    2015-05-01

    Strange-quark matter (SQM) may be the true ground state of hadronic matter, indicating that the observed pulsars may actually be strange stars (SSs), but not neutron stars. According to the SQM hypothesis, the existence of a hydrostatically stable sequence of SQM stars has been predicted, ranging from 1 to 2 solar mass SSs, to smaller strange dwarfs and even strange planets. While gravitational wave (GW) astronomy is expected to open a new window to the universe, it will shed light on the search for SQM stars. Here we show that due to their extreme compactness, strange planets can spiral very close to their host SSs without being tidally disrupted. Like inspiraling neutron stars or black holes, these systems would serve as new sources of GW bursts, producing strong GWs at the final stage. The events occurring in our local universe can be detected by upcoming GW detectors, such as Advanced LIGO and the Einstein Telescope. This effect provides a unique probe to SQM objects and is hopefully a powerful tool for testing the SQM hypothesis.

  5. Coalescence of Strange-quark Planets with Strange Stars: a New Kind of Source for Gravitational Wave Bursts

    NASA Astrophysics Data System (ADS)

    Geng, J. J.; Huang, Y. F.; Lu, T.

    2015-05-01

    Strange-quark matter (SQM) may be the true ground state of hadronic matter, indicating that the observed pulsars may actually be strange stars (SSs), but not neutron stars. According to the SQM hypothesis, the existence of a hydrostatically stable sequence of SQM stars has been predicted, ranging from 1 to 2 solar mass SSs, to smaller strange dwarfs and even strange planets. While gravitational wave (GW) astronomy is expected to open a new window to the universe, it will shed light on the search for SQM stars. Here we show that due to their extreme compactness, strange planets can spiral very close to their host SSs without being tidally disrupted. Like inspiraling neutron stars or black holes, these systems would serve as new sources of GW bursts, producing strong GWs at the final stage. The events occurring in our local universe can be detected by upcoming GW detectors, such as Advanced LIGO and the Einstein Telescope. This effect provides a unique probe to SQM objects and is hopefully a powerful tool for testing the SQM hypothesis.

  6. Stability of charged strange quark stars

    SciTech Connect

    Arbañil, José D. V.; Malheiro, Manuel

    2015-12-17

    We investigate the hydrostatic equilibrium and the stability of charged stars made of a charged perfect fluid. The matter contained in the star follows the MIT bag model equation of state and the charge distribution to a power-law of the radial coordinate. The hydrostatic equilibrium and the stability of charged strange stars are analyzed using the Tolman-Oppenheimer-Volkoff equation and the Chandrasekhar’s equation pulsation, respectively. These two equation are modified from their original form to the inclusion of the electric charge. We found that the stability of the star decreases with the increment of the central energy density and with the increment of the amount of charge.

  7. Seismic search for strange quark nuggets

    SciTech Connect

    Herrin, Eugene T.; Rosenbaum, Doris C.; Teplitz, Vigdor L.

    2006-02-15

    Bounds on masses and abundances of Strange Quark Nuggets (SQNs) are inferred from a seismic search on Earth. Potential SQN bounds from a possible seismic search on the Moon are reviewed and compared with Earth capabilities. Bounds are derived from the data taken by seismometers implanted on the Moon by the Apollo astronauts. We show that the Apollo data implies that the abundance of SQNs in the region of 10 kg to 1 ton must be at least an order of magnitude less than would saturate the dark matter in the solar neighborhood.

  8. Theoretical studies on the modes of decay of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Nithya, C.

    2016-11-01

    The decay modes of recently synthesized superheavy nuclei are investigated by comparing the α -decay half-lives with the spontaneous fission half-lives. α -decay half-lives are calculated using the Coulomb and proximity potential model for deformed nuclei (CPPMDN). The agreement between theoretical and experimental α half-lives shows the predictability of the CPPMDN in the superheavy region. A modified formula is proposed for calculating the spontaneous fission half-lives including the shell correction. The agreement between theoretical predictions and experimental results of spontaneous fission half-lives is satisfactory for heavy and superheavy nuclei ranging from Th to Fl. A comparison between the spontaneous fission half-lives computed using eight different formalisms is performed for even-even superheavy nuclei in the range of 108 ≤Z ≤120 . Even though all these models can reproduce the experimental spontaneous fission half-lives, model-to-model variations in predicting the fission half-lives in superheavy region is evident from the study.

  9. The Universe is a Strange Place

    NASA Astrophysics Data System (ADS)

    Wilczek, Frank

    Our understanding of ordinary matter is remarkably accurate and complete, but it is based on principles that are very strange and unfamiliar. As I'll explain, we've come to understand matter to be a Music of the Void, in a remarkably literal sense. Just as we physicists finalized that wonderful understanding, towards the end of the twentieth century, astronomers gave us back our humility, by informing us that ordinary matter - what we, and chemists and biologists, and astronomers themselves, have been studying all these centuries constitutes only about 5% of the mass of the universe as a whole. I'll describe some of our promising attempts to rise to this challenge by improving, rather than merely complicating, our description of the world.

  10. ``Towards Strange Metallic Holography'

    SciTech Connect

    Hartnoll, Sean A.; Polchinski, Joseph; Silverstein, Eva; Tong, David; /Cambridge U., DAMTP /Santa Barbara, KITP /UC, Santa Barbara

    2010-08-26

    We initiate a holographic model building approach to 'strange metallic' phenomenology. Our model couples a neutral Lifshitz-invariant quantum critical theory, dual to a bulk gravitational background, to a finite density of gapped probe charge carriers, dually described by D-branes. In the physical regime of temperature much lower than the charge density and gap, we exhibit anomalous scalings of the temperature and frequency dependent conductivity. Choosing the dynamical critical exponent z appropriately we can match the non-Fermi liquid scalings, such as linear resistivity, observed in strange metal regimes. As part of our investigation we outline three distinct string theory realizations of Lifshitz geometries: from F theory, from polarized branes, and from a gravitating charged Fermi gas. We also identify general features of renormalization group flow in Lifshitz theories, such as the appearance of relevant charge-charge interactions when z {ge} 2. We outline a program to extend this model building approach to other anomalous observables of interest such as the Hall conductivity.

  11. Isomers and Enhanced Stability of Superheavy Elements

    NASA Astrophysics Data System (ADS)

    Kondev, Filip; Anl, Lbnl, Anu, Csnsm, Llnl, Usna, U. Of Edinburgh, U. Of Jyväskylä, U. Of Massachusetts, Lowell Collaboration

    2014-09-01

    There has been continuing activity addressing the complex question of whether excited isomeric states would lead to enhanced stability of superheavy nuclei, given changes in the fission barriers, α-decay probabilities and the effects of nuclear structure (such as K-hindrance). Recently, we have carried out new studies of the 254Rf isotope using the 50Ti + 206Pb reaction at Argonne National Laboratory and Lawrence Berkeley National Laboratory. A digital data acquisition system was deployed in both experiments, which allowed the identification of implant and decay events that were separated by time as short as hundreds of nanoseconds. Two isomeric states were discovered in 254Rf with half-lives of ~4 μs and ~300 μs, the latter being an order of magnitude longer lived than the ground state. In addition, K-isomers in 244Cm and 246Cm were also studied following β- decays of 244Am (Kπ = 6+) and 246Am (Kπ = 7-) mass-separated sources, respectively. The emphasis was on elucidating details of the level schemes, which allowed reliable values for the strength of the K-forbidden transitions to be determined and compared with systematics in other regions of the nuclear chart. There has been continuing activity addressing the complex question of whether excited isomeric states would lead to enhanced stability of superheavy nuclei, given changes in the fission barriers, α-decay probabilities and the effects of nuclear structure (such as K-hindrance). Recently, we have carried out new studies of the 254Rf isotope using the 50Ti + 206Pb reaction at Argonne National Laboratory and Lawrence Berkeley National Laboratory. A digital data acquisition system was deployed in both experiments, which allowed the identification of implant and decay events that were separated by time as short as hundreds of nanoseconds. Two isomeric states were discovered in 254Rf with half-lives of ~4 μs and ~300 μs, the latter being an order of magnitude longer lived than the ground state. In

  12. Summary of recent experimental results on strangeness production

    NASA Astrophysics Data System (ADS)

    Kalweit, Alexander

    2017-01-01

    This article summarises the highlights of the recent experimental findings on strangeness production presented at the 16th edition of the International Conference on Strangeness in Quark Matter in Berkeley. Results obtained by eight large experimental collaborations (ALICE, ATLAS, CMS, HADES, LHCb, NA-61, PHENIX, STAR) spanning a large range in centre-of-mass energy and a variety of collision systems were presented at the conference. The article does not aim at being a complete review, but rather at connecting the experimental highlights of the different collaborations and at pointing towards questions which should be addressed by these experiments in future.

  13. Using the Moon as a Strange Quark Nugget Detector

    NASA Astrophysics Data System (ADS)

    Herrin, Eugene T.; Rosenbaum, Doris C.; Teplitz, Vigdor L.

    2007-11-01

    We review the romance and mystery of strange quark matter (SQM), including: its basics, our recent work on bounds on the abundance of ton-range strange quark nuggets (SQNs) from Earth seismology, potential SQN bounds from a possible seismic search on the Moon, and our recent bounds on SQNs in the 10 kilogram to ton range from the data of Apollo-implanted seismometers. Finally, we speculate a bit on using the sun or the solar system to detect passage of SQNs of much greater mass than the aforementioned.

  14. Baryon number and strangeness: signals of a deconfinedantecedent

    SciTech Connect

    Majumder, A.; Koch, V.; Randrup, J.

    2005-06-29

    The correlation between baryon number and strangeness is used to discern the nature of the deconfined matter produced at vanishing chemical potential in high-energy nuclear collisions at the BNL RHIC. Comparisons of results of various phenomenological models with correlations extracted from lattice QCD calculations suggest that a quasi-particle picture applies. At finite baryon densities, such as those encountered at the CERN SPS, it is demonstrated that the presence of a first-order phase transition and the accompanying development of spinodal decomposition would significantly enhance the number of strangeness carriers and the associated fluctuations.

  15. Quasifission in heavy and superheavy element formation reactions

    NASA Astrophysics Data System (ADS)

    Hinde, D. J.; Dasgupta, M.; Jeung, D. Y.; Mohanto, G.; Prasad, E.; Simenel, C.; Walshe, J.; Wahkle, A.; Williams, E.; Carter, I. P.; Cook, K. J.; Kalkal, Sunil; Rafferty, D. C.; Rietz, R. du; Simpson, E. C.; David, H. M.; Düllmann, Ch. E.; Khuyagbaatar, J.

    2016-12-01

    Superheavy elements are created in the laboratory by the fusion of two heavy nuclei. The large Coulomb repulsion that makes superheavy elements decay also makes the fusion process that forms them very unlikely. Instead, after sticking together for a short time, the two nuclei usually come apart, in a process called quasifission. Mass-angle distributions give the most direct information on the characteristics and time scales of quasifission. A systematic study of carefully chosen mass-angle distributions has provided information on the global trends of quasifission. Large deviations from these systematics reveal the major role played by the nuclear structure of the two colliding nuclei in determining the reaction outcome, and thus implicitly in hindering or favouring superheavy element production.

  16. Actinide targets for the synthesis of super-heavy elements

    SciTech Connect

    Roberto, J.; Alexander, Charles W.; Boll, Rose Ann; Ezold, Julie G.; Felker, Leslie Kevin; Rykaczewski, Krzysztof Piotr; Hogle, Susan L.

    2015-06-18

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249Bk, 251Cf, and 254Es are described.

  17. How good are superheavy element Z and A assignments?

    NASA Astrophysics Data System (ADS)

    Gregorich, Kenneth

    2016-12-01

    Proton number, Z, and mass number,A, assignments for newly discovered heavy element nuclides have historically been made by observing α decay to a daughter with well-established Z and A, and then observing the well-know decay of that daughter. For all of the new superheavy element isotopes observed in 48Ca irradiations of actinide targets, this correlation technique has not been possible, because the α-decay chains end in spontaneous fission of previously unknown isotopes. Consequently, Z and A assignments have been made by less-direct means. The superheavy element Z and A assignment methods are summarized, and possibilities for how they may be incorrect are explored. While it is highly likely that most of the superheavy element Z and A assignments are correct, there is a real need for a direct proof.

  18. Actinide targets for the synthesis of super-heavy elements

    DOE PAGES

    Roberto, J.; Alexander, Charles W.; Boll, Rose Ann; ...

    2015-06-18

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing themore » production of rare actinides including 249Bk, 251Cf, and 254Es are described.« less

  19. Actinide targets for the synthesis of super-heavy elements

    NASA Astrophysics Data System (ADS)

    Roberto, J. B.; Alexander, C. W.; Boll, R. A.; Burns, J. D.; Ezold, J. G.; Felker, L. K.; Hogle, S. L.; Rykaczewski, K. P.

    2015-12-01

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249Bk, 251Cf, and 254Es are described.

  20. The Superheavy Elements and Anti-Gravity

    SciTech Connect

    Anastasovski, Petar K.

    2004-02-04

    The essence of any propulsion concept is to overcome gravity. Anti-gravity is a natural means to achieve this. Thus, the technology to pursue anti-gravity, by using superheavy elements, may provide a new propulsion paradigm. The theory of superluminal relativity provides a hypothesis for existence of elements with atomic number up to Z = 145, some of which may possess anti-gravity properties. Analysis results show that curved space-time exists demonstrating both gravitic and anti-gravitic properties not only around nuclei but inside the nuclei as well. Two groups of elements (Z < 64 and 63 < Z <145) exist that demonstrate these capabilities. The nuclei of the first group of elements have the masses with only the property of gravity. The nuclei of the elements of the second group have the masses with both properties: gravity and anti-gravity in two different ranges of curved space-time around the nuclei.. The hypothetical element with Z = 145 is the unique among all elements whose nucleus has only anti-gravity property. It is proposed that this element be named Hawking, in honour of Stephen W. Hawking.

  1. Superheavy Element Nuclear Chemistry at RIKEN

    SciTech Connect

    Haba, Hiromitsu; Kaji, Daiya; Kasamatsu, Yoshitaka; Kudou, Yuki; Morimoto, Kouji; Morita, Kosuke; Ozeki, Kazutaka; Yoneda, Akira; Kikunaga, Hidetoshi; Komori, Yukiko; Ooe, Kazuhiro; Shinohara, Atsushi; Yoshimura, Takashi; Sato, Nozomi; Toyoshima, Atsushi; Yokoyama, Akihiko

    2010-05-12

    A gas-jet transport system has been coupled to the RIKEN gas-filled recoil ion separator GARIS to startup superheavy element (SHE) chemistry at RIKEN. The performance of the system was appraised using an isotope of element 104, {sup 261}Rf, produced in the {sup 248}Cm({sup 18}O,5n){sup 261}Rf reaction. Alpha-particles of {sup 261}Rf separated with GARIS and extracted to a chemistry laboratory were successfully identified with a rotating wheel apparatus for alpha spectrometry. The setting parameters such as the magnetic field of the separator and the gas-jet conditions were optimized. The present results suggest that the GARIS/gas-jet system is a promising approach for exploring new frontiers in SHE chemistry: (i) the background radioactivities of unwanted reaction products are strongly suppressed, (ii) the intense beam is absent in the gas-jet chamber and hence high gas-jet efficiency is achieved, and (iii) the beam-free condition also allows for investigations of new chemical systems.

  2. Nuclear Reactions Used For Superheavy Element Research

    SciTech Connect

    Stoyer, Mark A.

    2008-04-17

    Some of the most fascinating questions about the limits of nuclear stability are confronted in the heaviest nuclei. How many more new elements can be synthesized? What are the nuclear and chemical properties of these exotic nuclei? Does the 'Island of Stability' exist and can we ever explore the isotopes inhabiting that nuclear region? This paper will focus on the current experimental research on the synthesis and characterization of superheavy nuclei with Z>112 from the Dubna/Livermore collaboration. Reactions using {sup 48}Ca projectiles from the U400 cyclotron and actinide targets ({sup 233,238}U, {sup 237}Np, {sup 242,244}Pu, {sup 243}Am, {sup 245,248}Cm, {sup 249}Cf) have been investigated using the Dubna Gas Filled Recoil Separator in Dubna over the last 8 years. In addition, several experiments have been performed to investigate the chemical properties of some of the observed longer-lived isotopes produced in these reactions. Some comments will be made on nuclear reactions used for the production of the heaviest elements. A summary of the current status of the upper end of the chart of nuclides will be presented.

  3. The Superheavy Elements and Anti-Gravity

    NASA Astrophysics Data System (ADS)

    Anastasovski, Petar K.

    2004-02-01

    The essence of any propulsion concept is to overcome gravity. Anti-gravity is a natural means to achieve this. Thus, the technology to pursue anti-gravity, by using superheavy elements, may provide a new propulsion paradigm. The theory of superluminal relativity provides a hypothesis for existence of elements with atomic number up to Z = 145, some of which may possess anti-gravity properties. Analysis results show that curved space-time exists demonstrating both gravitic and anti-gravitic properties not only around nuclei but inside the nuclei as well. Two groups of elements (Z < 64 and 63 < Z <145) exist that demonstrate these capabilities. The nuclei of the first group of elements have the masses with only the property of gravity. The nuclei of the elements of the second group have the masses with both properties: gravity and anti-gravity in two different ranges of curved space-time around the nuclei.. The hypothetical element with Z = 145 is the unique among all elements whose nucleus has only anti-gravity property. It is proposed that this element be named Hawking, in honour of Stephen W. Hawking.

  4. Nuclear reactions used for superheavy element research

    SciTech Connect

    Stoyer, M A

    2008-02-26

    Some of the most fascinating questions about the limits of nuclear stability are confronted in the heaviest nuclei. How many more new elements can be synthesized? What are the nuclear and chemical properties of these exotic nuclei? Does the 'Island of Stability' exist and can we ever explore the isotopes inhabiting that nuclear region? This paper will focus on the current experimental research on the synthesis and characterization of superheavy nuclei with Z > 112 from the Dubna/Livermore collaboration. Reactions using 48Ca projectiles from the U400 cyclotron and actinide targets ({sup 233,238}U, {sup 237}Np, {sup 242,244}Pu, {sup 243}Am, {sup 245,248}Cm, {sup 249}Cf) have been investigated using the Dubna Gas Filled Recoil Separator in Dubna over the last 8 years. In addition, several experiments have been performed to investigate the chemical properties of some of the observed longer-lived isotopes produced in these reactions. Some comments will be made on nuclear reactions used for the production of the heaviest elements. A summary of the current status of the upper end of the chart of nuclides will be presented.

  5. Superheavy magnetic monopoles and the standard cosmology

    SciTech Connect

    Turner, M.S.

    1984-10-01

    The superheavy magnetic monopoles predicted to exist in grand unified theories (GUTs) are very interesting obsects, both from the point of view of particle physics, as well as from astrophysics and cosmology. Astrophysical and cosmological considerations have proved to be invaluable in studying the properties of GUT monopoles. Because of the glut of monopoles predicted in the standard cosmology for the simplest GUTs (so many that the Universe should have reached a temperature of 3/sup 0/K at the tender age of approx. = 10,000 yrs), the simplest GUTs and the standard cosmology are not compatible. This is a very important piece of information about physics at unification energies (E greater than or equal to 10/sup 14/ GeV) and about the earliest moments (t less than or equal to 10/sup -34/ s) of the Universe. In this talk the author reviews the cosmological consequences of GUT monopoles within the context of the standard hot big bang model. 46 references.

  6. Magnetic Field of Strange Dwarfs

    NASA Astrophysics Data System (ADS)

    Baghdasaryan, D. S.

    2016-03-01

    The generation of a magnetic field in a strange quark star owing to differential rotation of the superfluid and superconducting quark core relative to the normal electron-nuclear crust of the star is examined. The maximum possible magnetic field on the surface is estimated for various models of strange dwarfs. Depending on the configuration parameters, i.e., the mass M and radius R of the star, a range of 103-105 G is found. These values of the magnetic field may be an additional condition for identification of strange dwarfs among the extensive class of observed white dwarfs.

  7. Grammatical complexity of strange sets

    NASA Astrophysics Data System (ADS)

    Auerbach, Ditza; Procaccia, Itamar

    1990-06-01

    Chaotic dynamical systems can be organized around an underlying strange set, which is comprised of all the unstable periodic orbits. In this paper, we quantify the complexity of such an organization; this complexity addresses the difficulty of predicting the structure of the strange set from low-order data and is independent of the entropy and the algorithmic complexity. We refer to the new measure as the grammatical complexity. The notion is introduced, discussed, and illustrated in the context of simple dynamical systems. In addition, the grammatical complexity is generalized to include metric properties arising due to the nonuniform distribution of the invariant measure on the strange set.

  8. Atomic properties of superheavy elements No, Lr, and Rf

    NASA Astrophysics Data System (ADS)

    Dzuba, V. A.; Safronova, M. S.; Safronova, U. I.

    2014-07-01

    The combination of the configuration interaction method and all-order single-double coupled-cluster technique is used to calculate excitation energies, ionization potentials, and static dipole polarizabilities of superheavy elements nobelium, lawrencium, and rutherfordium. Breit and quantum electrodynamic corrections are also included. The results for the superheavy elements are compared with earlier calculations where available. Similar calculations for lighter analogs, ytterbium, lutetium, and hafnium, are used to study the accuracy of the calculations. The estimated uncertainties of the final results are discussed.

  9. Strange Stars, Neutron Stars and Pulsar Emission

    NASA Astrophysics Data System (ADS)

    Benvenuto, O. G.; Horvath, J. E.

    1990-11-01

    RESUMEN. Se ha conjeturado que una partlecula de dieciocho quarks, sin Carga, sin espi'n y sin colar (quark-alfa) podri'a ser estable a ba5as tern peraturas y presiones aiTh COfl respecto a materia extrafla. Presentamos en este trabajo la estmctura de estrellas extraflas incluyendo los efectos y apariencia de parti'culas uark-alfa en las capas exteriores. La estruc tura interna ya no es hoinogenea del centro a la superficie, sino que muestra un centro de materia extrafla, capas s6lidas y una costra delgada de materia normal en la superficie. La superficie de materia nonnal permite la fornaci6n de una magnetosfera, la que se piensa sea el sitlo en donde ocurre la emisi6n del pulsar. La superficie de superflui'do ayuda a explicar el fen6rneno de `glitch', el cual ba sido observado en muchos pulsares. Se discute la ecuaci6n de estado para rnateria quark-alfa relevante en este regimen. ABSTIZACT:It has been conjectured that an quark, uncharged, spinless and colorless particle Cquark-alpha) could be stable at low pressures and temperatures even with respect to strange matter. We present in work tlie structure of stars including the effects of the appearance of quark-alpi' particles ii their outer layers. The internal structure is no longer from tlie center to the surface, but show a strange matter core, a solid and superfluid layers and a thin crust of normal matter at the surface. The normal matter surface allows tlie fon tion of a magnetosphere, whicl is to be tl place where pulsar emission occurs. A superfluid layer helps to explain tlie glitch , wlflch has been observed in . equation of state for quark-alpha matter relevant in regime is also discussed. Keq LA)OtL : ARY S - OF STATF - ?.ACT

  10. Strangeness and onset of deconfinement

    SciTech Connect

    Becattini, F.

    2012-05-15

    I will review the current status of global strangeness production in relativistic heavy-ion collisions with particular emphasis on recent results from core-corona model. I will discuss its relevance for the detection of the onset of deconfinement.

  11. Strangeness and onset of deconfinement

    NASA Astrophysics Data System (ADS)

    Becattini, F.

    2012-05-01

    I will review the current status of global strangeness production in relativistic heavy-ion collisions with particular emphasis on recent results from core-corona model. I will discuss its relevance for the detection of the onset of deconfinement.

  12. Electronic structure theory of the superheavy elements

    NASA Astrophysics Data System (ADS)

    Eliav, Ephraim; Fritzsche, Stephan; Kaldor, Uzi

    2015-12-01

    High-accuracy calculations of atomic properties of the superheavy elements (SHE) up to element 122 are reviewed. The properties discussed include ionization potentials, electron affinities and excitation energies, which are associated with the spectroscopic and chemical behavior of these elements, and are therefore of considerable interest. Accurate predictions of these quantities require high-order inclusion of relativity and electron correlation, as well as large, converged basis sets. The Dirac-Coulomb-Breit Hamiltonian, which includes all terms up to second order in the fine-structure constant α, serves as the framework for the treatment; higher-order Lamb shift terms are considered in some selected cases. Electron correlation is treated by either the multiconfiguration self-consistent-field approach or by Fock-space coupled cluster theory. The latter is enhanced by the intermediate Hamiltonian scheme, allowing the use of larger model (P) spaces. The quality of the calculations is assessed by applying the same methods to lighter homologs of the SHEs and comparing with available experimental information. Very good agreement is obtained, within a few hundredths of an eV, and similar accuracy is expected for the SHEs. Many of the properties predicted for the SHEs differ significantly from what may be expected by straightforward extrapolation of lighter homologs, demonstrating that the structure and chemistry of SHEs are strongly affected by relativity. The major scientific challenge of the calculations is to find the electronic structure and basic atomic properties of the SHE and assign its proper place in the periodic table. Significant recent developments include joint experimental-computational studies of the excitation spectrum of Fm and the ionization energy of Lr, with excellent agreement of experiment and theory, auguring well for the future of research in the field.

  13. Adiabatic fission barriers in superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Jachimowicz, P.; Kowal, M.; Skalski, J.

    2017-01-01

    Using the microscopic-macroscopic model based on the deformed Woods-Saxon single-particle potential and the Yukawa-plus-exponential macroscopic energy, we calculated static fission barriers Bf for 1305 heavy and superheavy nuclei 98 ≤Z ≤126 , including even-even, odd-even, even-odd and odd-odd systems. For odd and odd-odd nuclei, adiabatic potential-energy surfaces were calculated by a minimization over configurations with one blocked neutron or/and proton on a level from the 10th below to the 10th above the Fermi level. The parameters of the model that have been fixed previously by a fit to masses of even-even heavy nuclei were kept unchanged. A search for saddle points has been performed by the "imaginary water flow" method on a basic five-dimensional deformation grid, including triaxiality. Two auxiliary grids were used for checking the effects of the mass asymmetry and hexadecapole nonaxiality. The ground states (g.s.) were found by energy minimization over configurations and deformations. We find that the nonaxiality significantly changes first and second fission saddle in many nuclei. The effect of the mass asymmetry, known to lower the second, very deformed saddles in actinides, in the heaviest nuclei appears at the less deformed saddles in more than 100 nuclei. It happens for those saddles in which the triaxiality does not play any role, which suggests a decoupling between effects of the mass asymmetry and triaxiality. We studied also the influence of the pairing interaction strength on the staggering of Bf for odd- and even-particle numbers. Finally, we provide a comparison of our results with other theoretical fission barrier evaluations and with available experimental estimates.

  14. Chemical Investigations of Superheavy Elements - Current Results and New Techniques

    SciTech Connect

    Duellmann, Christoph E.

    2007-02-26

    Chemical studies of the superheavy elements have progressed tremendously in recent years. This is illustrated here using the following four examples: (i) gas chemical studies of element 112, (ii) radiochemical investigations of the reaction 248Cm(26Mg,xn)274-xHs, (iii) complexation studies of rutherfordium, and (iv) the development of the technique of physical preseparation.

  15. Foundations of strangeness nuclear physics derived from chiral effective field theory

    NASA Astrophysics Data System (ADS)

    Meißner, Ulf-G.; Haidenbauer, Johann

    Dense compact objects like neutron stars or black holes have always been one of Gerry Brown’s favorite research topics. This is closely related to the effects of strangeness in nuclear physics. Here, we review the chiral Effective Field Theory approach to interactions involving nucleons and hyperons, the possible existence of strange dibaryons, the fate of hyperons in nuclear matter and the present status of three-body forces involving hyperons and nucleons.

  16. Strangeness asymmetry in the proton

    NASA Astrophysics Data System (ADS)

    Alberg, Mary

    2015-04-01

    Strangeness asymmetry in the proton may arise from fluctuations of the proton into meson-baryon pairs. The leading contributions to proton strangeness are from the KΛ , KΣ , K* Λ and K* Σ states. We use a Fock state expansion of the proton in terms of these pairs to represent the strange meson cloud. We determine the strangeness distributions of the proton in a hybrid convolution model, in which the fluctuations are represented either by light-cone wave functions or meson-baryon splitting functions. For the parton distributions of the s(s) quarks in the bare baryons(mesons) of the Fock states, we use light cone wave functions or our statistical model, which expands the bare hadrons in terms of quark-gluon states. The momentum distributions of the s and s quarks in each Fock state differ because they are constituents of different hadrons. We present our results for proton strangeness asymmetry, and compare them to NuTeV and to global parton distributions. This research has been supported in part by NSF Award 1205686.

  17. Radial stability of anisotropic strange quark stars

    NASA Astrophysics Data System (ADS)

    Arbañil, José D. V.; Malheiro, M.

    2016-11-01

    The influence of the anisotropy in the equilibrium and stability of strange stars is investigated through the numerical solution of the hydrostatic equilibrium equation and the radial oscillation equation, both modified from their original version to include this effect. The strange matter inside the quark stars is described by the MIT bag model equation of state. For the anisotropy two different kinds of local anisotropic σ = pt-pr are considered, where pt and pr are respectively the tangential and the radial pressure: one that is null at the star's surface defined by pr(R) = 0, and one that is nonnull at the surface, namely, σs = 0 and σs ≠ 0. In the case σs = 0, the maximum mass value and the zero frequency of oscillation are found at the same central energy density, indicating that the maximum mass marks the onset of the instability. For the case σs ≠ 0, we show that the maximum mass point and the zero frequency of oscillation coincide in the same central energy density value only in a sequence of equilibrium configurations with the same value of σs. Thus, the stability star regions are determined always by the condition dM/dρc > 0 only when the tangential pressure is maintained fixed at the star surface's pt(R). These results are also quite important to analyze the stability of other anisotropic compact objects such as neutron stars, boson stars and gravastars.

  18. Strangeness production at high baryon density

    NASA Astrophysics Data System (ADS)

    Satz, Helmut

    2016-08-01

    We propose to measure strange and non-strange hadron abundances at NICA in both AA and pp collisions, in order to test the validity range and possible extension schemes for present explanations of the energy and collision dependence of strange particle suppression.

  19. Strange hadron production at SIS energies: an update from HADES

    NASA Astrophysics Data System (ADS)

    Lorenz, M.; Adamczewski-Musch, J.; Arnold, O.; Atomssa, E. T.; Behnke, C.; Berger-Chen, J. C.; Biernat, J.; Blanco, A.; Blume, C.; Böhmer, M.; Bordalo, P.; Chernenko, S.; Deveaux, C.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Fonte, P.; Franco, C.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gill, K.; Golubeva, M.; Guber, F.; Gumberidze, M.; Harabasz, S.; Hennino, T.; Hlavac, S.; Höhne, C.; Holzmann, R.; Ierusalimov, A.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Kardan, B.; Koenig, I.; Koenig, W.; Kolb, B. W.; Korcyl, G.; Kornakov, G.; Kotte, R.; Krása, A.; Krebs, E.; Kuc, G.; Kugler, A.; Kunz, T.; Kurepin, A.; Kurilkin, A.; Kurilkin, P.; Ladygin, V.; Lalik, R.; Lapidus, K.; Lebedev, A.; Lopes, L.; Mahmoud, T.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michel, J.; Müntz, C.; Münzer, R.; Naumann, L.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Petousis, V.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Rehnisch, L.; Reshetin, A.; Rost, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Scheib, T.; Schmidt-Sommerfeld, K.; Schuldes, H.; Sellheim, P.; Siebenson, J.; Silva, L.; Sobolev, Yu. G.; Spataro, S.; Ströbele, H.; Stroth, J.; Strzempek, P.; Sturm, C.; Svoboda, O.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Tsertos, H.; Vasiliev, T.; Wagner, V.; Wendisch, C.; Wirth, J.; Wüstenfeld, J.; Zanevsky, Y.; Zumbruch, P.

    2016-01-01

    We present and discuss recent experimental activities of the HADES collaboration on open and hidden strangeness production close or below the elementary NN threshold. Special emphasis is put on the feed-down from ϕ mesons to antikaons, the presence of the Ξ- excess in cold nuclear matter and the comparison of statistical model rates to elementary p+p data. The implications for the interpretation of heavy-ion data are discussed as well.

  20. A realistic model for charged strange quark stars

    NASA Astrophysics Data System (ADS)

    Thirukkanesh, S.; Ragel, F. C.

    2017-01-01

    We report a general approach to solve an Einstein-Maxwell system to describe a static spherically symmetric anisotropic strange matter distribution with linear equation of state in terms of two generating functions. It is examined by choosing Tolmann IV type potential for one of the gravitational potentials and a physically reasonable choice for the electric field. Hence, the generated model satisfies all the required major physical properties of a realistic star. The effect of electric charge on physical properties is highlighted.

  1. Strange nonchaotic self-oscillator

    NASA Astrophysics Data System (ADS)

    Jalnine, Alexey Yu.; Kuznetsov, Sergey P.

    2016-08-01

    An example of strange nonchaotic attractor (SNA) is discussed in a dissipative system of mechanical nature driven by a constant torque applied to one of the elements of the construction. So the external force is not oscillatory, and the system is autonomous. Components of the motion with incommensurable frequencies emerge due to the irrational ratio of the sizes of the involved rotating elements. We regard the phenomenon as strange nonchaotic self-oscillations, and its existence sheds new light on the question of feasibility of SNA in autonomous systems.

  2. Quark-hadron phase transition and strangeness conservation constraints

    NASA Astrophysics Data System (ADS)

    Saeed-Uddin

    1999-01-01

    The implications of the strangeness conservation in a hadronic resonance gas (HRG) on the expected phase transition to the quark gluon plasma (QGP) are investigated. It is assumed that under favourable conditions a first order hadron-quark matter phase transition may occur in the hot hadronic matter such as those produced in the ultra-relativistic heavy-ion collisions at CERN and BNL. It is however shown that the criteria of strict strangeness conservation in the HRG may not permit the occurrence of a strict first order equilibrium quark-hadron phase transition unlike a previous study. This emerges as a consequence of the application of a realistic equation of state (EOS) for the HRG and QGP phases, which account for the finite-size effect arising from the short range hard-core hadronic repulsion in the HRG phase and the perturbative QCD interactions in the QGP phase. For a first order hadron-quark matter phase transition to occur one will therefore require large fluctuations in the critical thermal parameters, which might arise due to superheating, supercooling or other nonequlibrium effects. We also discuss a scenario proposed earlier, leading to a possible strangeness separation process during hadronization.

  3. Atomic Properties of Superheavy Elements No, Lr, and Rf

    NASA Astrophysics Data System (ADS)

    Safronova, Marianna; Dzuba, Vladimir; Safronova, Ulyana

    2014-05-01

    The study of the superheavy elements (nuclear charge Z > 100) is an important multidisciplinary area of research involving nuclear and atomic physics and chemistry. Atomic calculations help to understand the role of the relativistic and many-body effects and provide important information for the planning and interpreting the measurements. The need to treat relativistic and correlation effects to high level of accuracy makes the calculations a very challenging task. In this work, the combination of the configuration interaction technique and all-order linearized coupled-cluster method is used to calculate excitation energies, ionization potentials, and static dipole polarizabilities of superheavy elements nobelium, lawrencium and rutherfordium. Breit and QED corrections are also included. The same calculations are carried out for similar but lighter elements Hf, Lu, and Yb where experimental data are available to test the accuracy of the calculations.

  4. Actinide Isotopes for the Synthesis of Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Roberto, J. B.; Alexander, C. W.; Boll, R. A.; Dean, D. J.; Ezold, J. G.; Felker, L. K.; Rykaczewski, K. P.

    2014-09-01

    Recent research resulting in the synthesis of isotopes of new elements 113-118 has demonstrated the importance of actinide targets in superheavy element research. Oak Ridge National Laboratory (ORNL) has unique facilities for the production and processing of actinide target materials, including the High Flux Isotope Reactor (HFIR) and the Radiochemical Engineering Development Center (REDC). These facilities have provided actinide target materials that have been used for the synthesis of all superheavy (SHE) elements above Copernicium (element 112). In this paper, the use of actinide targets for SHE research and discovery is described, including recent results for element 117 using 249Bk target material from ORNL. ORNL actinide capabilities are reviewed, including production and separation/purification, availabilities of actinide materials, and future opportunities including novel target materials such as 251Cf.

  5. Superheavy Elements Production in High Intensive Neutron Fluxes

    NASA Astrophysics Data System (ADS)

    Lutostansky, Yu. S.; Lyashuk, V. I.; Panov, I. V.

    2013-06-01

    The possibility of superheavy elements production in high intensive neutron fluxes is being studied. A model of the transuranium isotopes production under conditions of pulse nucleosynthesis in a neutron flux with densities of up to ~1025 neutron/cm2 is considered. The pulse process allows us to divide it in time into two stages: the process of multiple neutron captures (with t < 10-6 s) and the subsequent β-decay of neutron-rich nuclei. The modeling of the transuranium yields takes into account the adiabatic character of the process, the probability of delayed fission, and the emission of delayed neutrons. A target with a binary composition of 238U and 239Pu, 248Cm, and 251Cf isotopes is used to predict the yields of heavy and superheavy isotopes.

  6. Formation of superheavy elements in cold fusion reactions

    NASA Astrophysics Data System (ADS)

    Smolańczuk, Robert

    2001-04-01

    We calculate the formation cross sections of transactinides (superheavy elements), as well as heavy actinides (No and Lr), which have been or might be obtained in fusion reactions with the evaporation of only one neutron. We use both more realistic fusion barrier and survival probability of the compound nucleus in comparison with the original phenomenological model [Phys. Rev. C 59, 2634 (1999)] that prompted the Berkeley experiment on the synthesis of a new superheavy element 118 [Phys. Rev. Lett. 83, 1104 (1999)]. Calculations are performed for asymmetric and symmetric target-projectile combinations and for reactions with stable and radioactive-ion beams. The formation cross sections measured at GSI-Darmstadt for transactinides and heavy actinides, as well as that for superheavy element 118 reported by the LBNL-Berkeley group, are reproduced within a factor of 2.4, on average. Based on the obtained relatively large cross sections, we predict that optimal reactions with stable beams for the synthesis of so far unobserved superheavy elements 119, 120, and 121 are 209Bi(86Kr, 1n)294119, 208Pb(88Sr, 1n)295120, and 209Bi(88Sr, 1n)296121, respectively. This is because of the magic of both the target and the projectile that leads to larger Q value and, consequently, lower effective fusion barrier with larger transmission probability. The same effect is responsible for relatively large cross sections predicted for the symmetric reactions 136Xe(124Sn, 1n)259Rf, 136Xe(136Xe, 1n)271Hs,138Ba(136Xe, 1n)273110, and 140Ce(136Xe, 1n)275112. Although shell effects in the magic nuclei 124Sn, 136Xe, 138Ba, and 140Ce are not as strong as in 208Pb and 209Bi, they act on both the target and the projectile and lead to the prediction of measurable cross sections.

  7. Identification of Heavy and Superheavy Nuclides Using Chemical Separator Systems

    SciTech Connect

    Turler, Andreas

    1999-12-31

    With the recent synthesis of superheavy nuclides produced in the reactions {sup 48}Ca+{sup 238}U and {sup 48}Ca+{sup 242,244}Pu, much longer-lived nuclei than the previously known neutron-deficient isotopes of the heaviest elements have been identified. Half-lives of several hours and up to several years have been predicted for the longest-lived isotopes of these elements. Thus, the sensitivity of radiochemical separation techniques may present a viable alternative to physical separator systems for the discovery of some of the predicted longer-lived heavy and superheavy nuclides. The advantages of chemical separator systems in comparison to kinematic separators lie in the possibility of using thick targets, high beam intensities spread over larger target areas and in providing access to nuclides emitted under large angles and low velocities. Thus, chemical separator systems are ideally suited to study also transfer and (HI, axn) reaction products. In the following, a study of (HI, axn) reactions will be presented and prospects to chemically identify heavy and superheavy elements discussed.

  8. Will strangeness win the prize?

    NASA Astrophysics Data System (ADS)

    Kapusta, Joseph I.

    2001-03-01

    Five groups have made predictions involving the production of strange hadrons and entered them in a competition set up by Barbara Jacak, Xin-Nian Wang and myself in the spring of 1998 for the purpose of comparing with first-year physics results from RHIC. These predictions are summarized and evaluated.

  9. A strange cat in Dublin

    NASA Astrophysics Data System (ADS)

    O'Raifeartaigh, Cormac

    2012-11-01

    Not many life stories in physics involve Nazis, illicit sex, a strange cat and the genetic code. Thus, a new biography of the great Austrian physicist Erwin Schrödinger is always of interest, and with Erwin Schrödinger and the Quantum Revolution, veteran science writer John Gribbin does not disappoint.

  10. The Peculiarities of the Production and Decay of Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Itkis, M. G.; Beghini, S.; Behera, B. R.; Bogachev, A. A.; Bouchat, V.; Corradi, L.; Dorvaux, O.; Fioretto, E.; Hanappe, F.; Itkis, I. M.; Jandel, M.; Kliman, J.; Knyazheva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Krupa, L.; Latina, A.; Materna, T.; Montagnoli, G.; Oganessian, Yu. Ts.; Pokrovsky, I. V.; Prokhorova, E. V.; Rowley, N.; Rusanov, A. Ya.; Sagaidak, R. N.; Scarlassara, F.; Schmitt, C.; Stefanini, A. M.; Stuttge, L.; Szilner, S.; Trotta, M.

    2006-08-01

    The interest in the study of the fission process of superheavy nuclei mainly deals with the opportunity to obtain information about the cross-section of the compound nucleus (CN) formation at excitation energies E*≈15-30 MeV. It allows one to estimate the survival probability of the superheavy composite system after evaporation of 1-3 neutrons, i.e. in "cold" or "warm" fusion reactions. However, in order to solve this problem deeper understanding of the coalescence processes between colliding nuclei, the competition between fusion-fission and quasi-fission processes is needed. The characteristics of both processes, their manifestation in the experimental observables and the relative contribution to the capture cross-section in dependence on the excitation energies, reaction entrance channel etc were investigated for a wide range of target-projectile combinations. Results of the experiments devoted to the study of the fusion-fission and quasi-fission processes in the reactions of the formation of the superheavy nuclei with Z = 102-122 are presented. The heavy ions 26Mg, 48Ca, 50Ti, 58Fe and 64Ni were used as projectiles. The choice of the reactions with 48Ca and actinide-targets was inspired by the experiments on the production of the isotopes 283112, 289114 and 283116 in Dubna using the same reactions. The 50Ti, 58Fe and 64Ni projectiles were chosen since the corresponding projectile-target combinations lead to the synthesis of even heavier elements. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Russia) and the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy) using the time-of-flight spectrometer of fission fragments CORSET. The role of the shell effects, the influence of the entrance channel asymmetry and the deformations of colliding nuclei on the mechanism of the fusion-fission and the competitive process of quasi-fission are discussed. The recent results on synthesis of

  11. Probing strange stars and color superconductivity by r-mode instabilities in millisecond pulsars

    PubMed

    Madsen

    2000-07-03

    r-mode instabilities in rapidly rotating quark matter stars (strange stars) lead to specific signatures in the evolution of pulsars with periods below 2.5 msec, and may explain the apparent lack of very rapid pulsars. Existing data seem consistent with pulsars being strange stars with a normal quark matter phase surrounded by an insulating nuclear crust. In contrast, quark stars in a color-flavor-locked phase are ruled out. Two-flavor color superconductivity is marginally inconsistent with pulsar data.

  12. Strangeness in ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Bellini, Francesca; ALICE Collaboration

    2017-01-01

    Strangeness production has been measured by the ALICE experiment in different collision systems at the unprecedented center-of-mass energies available at the CERN Large Hadron Collider. In Pb–Pb collisions at TeV the relative production of strange and multi-strange baryons relative to pions is observed to follow a saturating trend with increasing centrality, and reaching values that are consistent with those predicted by thermal model calculations in the Grand-Canonical ensemble. More recently, the multiplicity dependence of strangeness production in small systems such as pp and p–Pb has also been investigated. An overview of the most recent results on strangeness production is reported, including the first observation of strangeness enhancement with charged particle multiplicity in pp collisions.

  13. Optimal reaction for synthesis of superheavy element 117

    SciTech Connect

    Liu, Z. H.; Bao Jingdong

    2009-09-15

    Fusion reactions leading to the formation of superheavy element 117 are systematically analyzed. Among the reactions considered, the {sup 250}Bk({sup 48}Ca,4n){sup 294}117 reaction has the largest evaporation residue (ER) cross section of about 2 pb. However, this reaction is hard to realize experimentally because it is difficult to accumulate sufficient amount of target material due to the short lifetime of {sup 250}Bk nucleus. For the reaction {sup 48}Ca+{sup 249}Bk, our estimation shows that the ER cross sections in 3n and 4n channels may be expected to be greater than 1 pb. Therefore, {sup 48}Ca and {sup 249}Bk should be the optimal projectile-target combination for synthesis of superheavy element 117 in practice. In addition, as a main result of systematic analysis, we find that the ER cross section exponentially depends on the mass difference (in unit of temperature) of fission and neutron emission saddle points. Therefore, it is of essential importance for the successful synthesis of superheavy nuclei to select the isotopic composition of projectile and/or target so as the mass difference of fission and neutron emission saddle points as large as possible. Entrance channel effects are examined by means of a comparison of the reactions {sup 48}Ca+{sup 245}Bk, {sup 50}Ti+{sup 243}Am, and {sup 55}Mn+{sup 238}U leading to the same compound nucleus {sup 293}117. The ER cross sections of the reactions {sup 50}Ti+{sup 243}Am and {sup 55}Mn+{sup 238}U are much smaller than that of {sup 48}Ca+{sup 245}Bk.

  14. FIONA: A new mass analyzer for superheavy elements

    NASA Astrophysics Data System (ADS)

    Esker, Nicholas; Gates, Jacklyn; Gregorich, Kenneth; Pang, Gregory; Nitsche, Heino

    2014-09-01

    Six new superheavy elements (SHE, Z = 112 - 118) and over fifty new transactinide isotopes (Z > 104) have been synthesized in compound nuclear reactions using 48 Ca on actinides. These SHE are short-lived; their decay chains end in spontaneous fission before reaching a known mass region. Direct mass determination was unavailable and their A assignments remain unconfirmed. At LBNL, we use the 88''-cyclotron to produce high intensity beams (1013 particles per second) and the Berkeley Gas-Filled Separator (BGS) to isolate and study such transactinides at a rate of atoms per week. Unfortunately, the BGS's high beam suppression comes at the cost of mass resolution. Ongoing upgrades to the BGS, including beam thermalization and fast ion transport, will allow us to couple a dedicated mass analyzer to the BGS. This Facility for Identification Of Nuclide A (FIONA) is a novel mass separator based on an unbalanced Wien velocity filter. It has been designed for 100% transmission with an expected mass resolution of ~2000 A/ ΔA. We present the current progress in commissioning the FIONA mass analyzer using a nat Xe ion source and the future directions of the project, including the first direct mass measurement of a superheavy element.

  15. Status and perspectives of the Dubna superheavy element factory

    NASA Astrophysics Data System (ADS)

    Dmitriev, Sergey; Itkis, Mikhail; Oganessian, Yuri

    2016-12-01

    In the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research (FLNR JINR), construction of a new experimental complex is currently in progress (Superheavy Element Factory), aimed at the synthesis of new superheavy nuclides and the detailed study of those already synthesized. The project includes the construction of a new accelerator of stable and long-lived isotopes in the mass range A = 10-100 with an intensity of up to 10 pμ A and energy up to 8 MeV/nucleon; con-struction of a new experimental building and infrastructure for housing the accelerator with five channels for the transportation of beams to a 1200-m2 experimental hall that is equipped with systems of shielding and control for operations with radioactive materials; development of new separators of reaction products; upgrade of the existing separators and development of the new detection modules for the study of nuclear, atomic, and chemical properties of new elements. The first experiments are planned for 2018.

  16. Collisions of deformed nuclei and superheavy-element production

    SciTech Connect

    Iwamoto, Akira; Moeller, P. |||; Nix, J.R.; Sagawa, Hiroyuki, Sagawa

    1995-09-01

    A detailed understanding of complete fusion cross sections in heavy-ion collisions requires a consideration of the effects of the deformation of the projectile and target. The aim here is to show that deformation and orientation of the colliding nuclei have a very significant effect on the fusion-barrier height and on the compactness of the touching configuration. To facilitate discussions of fusion configurations of deformed nuclei, the authors develop a classification scheme and introduce a notation convention for these configurations. They discuss particular deformations and orientations that lead to compact touching configurations and to fusion-barrier heights that correspond to fairly low excitation energies of the compound systems. Such configurations should be the most favorable for producing superheavy elements. They analyze a few projectile-target combinations whose deformations allow favorable entrance-channel configurations and whose proton and neutron numbers lead to compound systems in a part of the superheavy region where a half-lives are calculated to be observable, that is, longer than 1 {micro}s.

  17. Additional strange hadrons from QCD thermodynamics and strangeness freezeout in heavy ion collisions.

    PubMed

    Bazavov, A; Ding, H-T; Hegde, P; Kaczmarek, O; Karsch, F; Laermann, E; Maezawa, Y; Mukherjee, Swagato; Ohno, H; Petreczky, P; Schmidt, C; Sharma, S; Soeldner, W; Wagner, M

    2014-08-15

    We compare lattice QCD results for appropriate combinations of net strangeness fluctuations and their correlations with net baryon number fluctuations with predictions from two hadron resonance gas (HRG) models having different strange hadron content. The conventionally used HRG model based on experimentally established strange hadrons fails to describe the lattice QCD results in the hadronic phase close to the QCD crossover. Supplementing the conventional HRG with additional, experimentally uncharted strange hadrons predicted by quark model calculations and observed in lattice QCD spectrum calculations leads to good descriptions of strange hadron thermodynamics below the QCD crossover. We show that the thermodynamic presence of these additional states gets imprinted in the yields of the ground-state strange hadrons leading to a systematic 5-8 MeV decrease of the chemical freeze-out temperatures of ground-state strange baryons.

  18. Strangeness detection in ALICE experiment at LHC

    SciTech Connect

    Safarik, K.

    1995-07-15

    The authors present some parameters of the ALICE detector which concern the detection of strange particles. The results of a simulation for neutral strange particles and cascades, together with estimated rates are presented. They also briefly discuss the detection of charged K-mesons. Finally, they mention the possibility of open charm particle detection.

  19. Strangeness production with protons and pions

    SciTech Connect

    Dover, C.B.

    1993-04-01

    We discuss the spectrum of physics questions related to strangeness which could be addressed with intense beams of protons and pions in the few GeV region. We focus on various aspects of strangeness production, including hyperon production in pp collisions, studies of hyperon-nucleon scattering, production of hypernuclei in proton and pion-nucleus collisions, and spin phenomena in hypernuclei.

  20. The Maximum Mass of Rotating Strange Stars

    NASA Astrophysics Data System (ADS)

    Szkudlarek, M.; Gondek-Rosiń; ska, D.; Villain, L.; Ansorg, M.

    2012-12-01

    Strange quark stars are considered as a possible alternative to neutron stars as compact objects (e.g. Weber 2003). A hot compact star (a proto-neutron star or a strange star) born in a supernova explosion or a remnant of neutron stars binary merger are expected to rotate differentially and be important sources of gravitational waves. We present results of the first relativistic calculations of differentially rotating strange quark stars for broad ranges of degree of differential rotation and maximum densities. Using a highly accurate, relativistic code we show that rotation may cause a significant increase of maximum allowed mass of strange stars, much larger than in the case of neutron stars with the same degree of differential rotation. Depending on the maximum allowed mass a massive neutron star (strange star) can be temporarily stabilized by differential rotation or collapse to a black hole.

  1. Mendeleev's principle against Einstein's relativity: news from the chemistry of superheavy elements

    NASA Astrophysics Data System (ADS)

    Gäggeler, Heinz W.

    2009-12-01

    The review briefly considers the problems of synthesis and chemical identification of superheavy elements. The specific features of their properties are determined by the relativistic effects. The synthesis and chemical investigations into bohrium and element 112 are discussed as examples.

  2. Super-heavy electron material as metallic refrigerant for adiabatic demagnetization cooling.

    PubMed

    Tokiwa, Yoshifumi; Piening, Boy; Jeevan, Hirale S; Bud'ko, Sergey L; Canfield, Paul C; Gegenwart, Philipp

    2016-09-01

    Low-temperature refrigeration is of crucial importance in fundamental research of condensed matter physics, because the investigations of fascinating quantum phenomena, such as superconductivity, superfluidity, and quantum criticality, often require refrigeration down to very low temperatures. Currently, cryogenic refrigerators with (3)He gas are widely used for cooling below 1 K. However, usage of the gas has been increasingly difficult because of the current worldwide shortage. Therefore, it is important to consider alternative methods of refrigeration. We show that a new type of refrigerant, the super-heavy electron metal YbCo2Zn20, can be used for adiabatic demagnetization refrigeration, which does not require (3)He gas. This method has a number of advantages, including much better metallic thermal conductivity compared to the conventional insulating refrigerants. We also demonstrate that the cooling performance is optimized in Yb1-x Sc x Co2Zn20 by partial Sc substitution, with x ~ 0.19. The substitution induces chemical pressure that drives the materials to a zero-field quantum critical point. This leads to an additional enhancement of the magnetocaloric effect in low fields and low temperatures, enabling final temperatures well below 100 mK. This performance has, up to now, been restricted to insulators. For nearly a century, the same principle of using local magnetic moments has been applied for adiabatic demagnetization cooling. This study opens new possibilities of using itinerant magnetic moments for cryogen-free refrigeration.

  3. Super-heavy electron material as metallic refrigerant for adiabatic demagnetization cooling

    DOE PAGES

    Tokiwa, Yoshifumi; Piening, Boy; Jeevan, Hirale S.; ...

    2016-09-09

    Low-temperature refrigeration is of crucial importance in fundamental research of condensed matter physics, because the investigations of fascinating quantum phenomena, such as superconductivity, superfluidity, and quantum criticality, often require refrigeration down to very low temperatures. Currently, cryogenic refrigerators with 3He gas are widely used for cooling below 1 Kelvin. However, usage of the gas has been increasingly difficult because of the current world-wide shortage. Therefore, it is important to consider alternative methods of refrigeration. We show that a new type of refrigerant, the super-heavy electron metal YbCo2Zn20, can be used for adiabatic demagnetization refrigeration, which does not require 3He gas.more » This method has a number of advantages, including much better metallic thermal conductivity compared to the conventional insulating refrigerants. We also demonstrate that the cooling performance is optimized in Yb1$-$xScxCo2Zn20 by partial Sc substitution, with x ~ 0.19. The substitution induces chemical pressure that drives the materials to a zero-field quantum critical point. This leads to an additional enhancement of the magnetocaloric effect in low fields and low temperatures, enabling final temperatures well below 100 mK. This performance has, up to now, been restricted to insulators. For nearly a century, the same principle of using local magnetic moments has been applied for adiabatic demagnetization cooling. Lastly, this study opens new possibilities of using itinerant magnetic moments for cryogen-free refrigeration.« less

  4. Super-heavy electron material as metallic refrigerant for adiabatic demagnetization cooling

    PubMed Central

    Tokiwa, Yoshifumi; Piening, Boy; Jeevan, Hirale S.; Bud’ko, Sergey L.; Canfield, Paul C.; Gegenwart, Philipp

    2016-01-01

    Low-temperature refrigeration is of crucial importance in fundamental research of condensed matter physics, because the investigations of fascinating quantum phenomena, such as superconductivity, superfluidity, and quantum criticality, often require refrigeration down to very low temperatures. Currently, cryogenic refrigerators with 3He gas are widely used for cooling below 1 K. However, usage of the gas has been increasingly difficult because of the current worldwide shortage. Therefore, it is important to consider alternative methods of refrigeration. We show that a new type of refrigerant, the super-heavy electron metal YbCo2Zn20, can be used for adiabatic demagnetization refrigeration, which does not require 3He gas. This method has a number of advantages, including much better metallic thermal conductivity compared to the conventional insulating refrigerants. We also demonstrate that the cooling performance is optimized in Yb1−xScxCo2Zn20 by partial Sc substitution, with x ~ 0.19. The substitution induces chemical pressure that drives the materials to a zero-field quantum critical point. This leads to an additional enhancement of the magnetocaloric effect in low fields and low temperatures, enabling final temperatures well below 100 mK. This performance has, up to now, been restricted to insulators. For nearly a century, the same principle of using local magnetic moments has been applied for adiabatic demagnetization cooling. This study opens new possibilities of using itinerant magnetic moments for cryogen-free refrigeration. PMID:27626073

  5. 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.

  6. Ionization potentials of superheavy elements No, Lr, and Rf and their ions

    PubMed Central

    Dzuba, V. A.; Safronova, M. S.; Safronova, U. I.; Kramida, A.

    2016-01-01

    We predict ionization potentials of superheavy elements No, Lr, and Rf and their ions using a relativistic hybrid method that combines configuration interaction (CI) with the linearized coupled-cluster approach. Extensive study of the completeness of the four-electron CI calculations for Hf and Rf was carried out. As a test of theoretical accuracy, we also calculated ionization potential of Yb, Lu, Hf, and their ions, which are homologues of the superheavy elements of this study. PMID:28058290

  7. Ionization potentials of superheavy elements No, Lr, and Rf and their ions

    NASA Astrophysics Data System (ADS)

    Dzuba, V. A.; Safronova, M. S.; Safronova, U. I.; Kramida, A.

    2016-10-01

    We predict ionization potentials of superheavy elements No, Lr, and Rf and their ions using a relativistic hybrid method that combines configuration interaction (CI) with the linearized coupled-cluster approach. Extensive study of the completeness of the four-electron CI calculations for Hf and Rf was carried out. As a test of theoretical accuracy, we also calculated ionization potential of Yb, Lu, Hf, and their ions, which are homologues of the superheavy elements of this study.

  8. Superheavy elements - An early solar system upper limit for elements 107 to 110

    NASA Technical Reports Server (NTRS)

    Nozette, S.; Boynton, W. V.

    1981-01-01

    The abundance of samarium-152 in the Santa Clara iron meteorite is found to be 108 x 10 to the 7th atoms per gram. This quantity, if attributed to fission of a superheavy element with atomic number 107 to 109, limits the amount of superheavy elements in the early solar system to 0.000017 times the abundance of uranium-238. For element 110, the limit is 0.000034.

  9. QED corrections for the valence electron in the heavy and superheavy metal atoms from the 11 and 12 groups

    NASA Astrophysics Data System (ADS)

    Goidenko, I. A.

    2009-10-01

    The first-order QED corrections for valence electron are investigated for the neutral Ag, Rg and their neighbours of the Mendeleev Periodic Table within the framework of the Dirac-Hartree-Fock method. The including of SE effects in such procedure was done first for superheavy atoms. The obtained results provide the limit of the accuracy for the modern relativistic theoretical calculations for the superheavy elements and open the discussion about the accuracy of the QED corrections in the superheavy elements themselves.

  10. Using the Moon and Mars as Giant Detectors for Strange Quark Nuggets

    NASA Technical Reports Server (NTRS)

    Chui, Talso; Penanen, Konstantin; Strayer, Don; Banerdt, Bruce; Tepliz, Vigdor; Herrin, Eugene

    2004-01-01

    On the Earth, the detectability of small seismic signals is limited by pervasive seismic background noise, caused primarily by interactions of the atmosphere and oceans with the solid surface. Mars, with a very thin atmosphere and no ocean is expected to have a noise level at least an order of magnitude lower than the Earth, and the airless Moon is even quieter still. These pristine low-vibration environments are ideal for searching for nuggets of "strange quark matter." Strange quark matter was postulated by Edward Witten [Phys. Rev. D30, 272, 1984] as the lowest possible energy state of matter. It would be made of up, down, and strange quarks, instead of protons and neutrons made only of up and down quarks. It would have nuclear densities, and hence be difficult to detect. Micron-sized nuggets would weigh in the ton range. As suggested by de Rujula and Glashow [Nature 312 (5996): 734, 1984], a massive strange quark nugget can generate a trail of seismic waves, as it traverses a celestial body. We discuss the mission concept for deploying a network of sensitive seismometers on Mars and on the Moon for such a search.

  11. Q-value effects on the production of superheavy nuclei

    SciTech Connect

    Liu, Z. H.; Bao, Jing-Dong

    2006-11-15

    The formation of superheavy nucleus {sup 270}Hs via the 4n evaporation channel of fusion reactions {sup 26}Mg+{sup 248}Cm, {sup 30}Si+{sup 244}Pu, {sup 36}S+{sup 238}U, and {sup 48}Ca+{sup 226}Ra is studied using a two-parameter Smoluchowski equation. The evaporation residual cross sections of the reactions {sup 48}Ca+{sup 226}Ra and {sup 36}S+{sup 238}U are obviously enhanced because of their large negative Q values. The enhancement is due to the fact that the excitation energy corresponding to the maximum yield of the evaporation residue depends on the reaction Q value, and the maximum cross section sensitively depends on the increment of this excitation energy relative to the effective threshold energy of which the channel for fission after 4n emission opens.

  12. Nuclear spectroscopy with Geant4. The superheavy challenge

    NASA Astrophysics Data System (ADS)

    Sarmiento, Luis G.

    2016-12-01

    The simulation toolkit Geant4 was originally developed at CERN for high-energy physics. Over the years it has been established as a swiss army knife not only in particle physics but it has seen an accelerated expansion towards nuclear physics and more recently to medical imaging and γ- and ion- therapy to mention but a handful of new applications. The validity of Geant4 is vast and large across many particles, ions, materials, and physical processes with typically various different models to choose from. Unfortunately, atomic nuclei with atomic number Z > 100 are not properly supported. This is likely due to the rather novelty of the field, its comparably small user base, and scarce evaluated experimental data. To circumvent this situation different workarounds have been used over the years. In this work the simulation toolkit Geant4 will be introduced with its different components and the effort to bring the software to the heavy and superheavy region will be described.

  13. Nuclear inertia and the decay modes of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Poenaru, D. N.; Gherghescu, R. A.; Greiner, Walter

    2013-10-01

    Superheavy nuclei produced up to now decay mainly by α emission and spontaneous fission. For atomic numbers larger than 121 cluster decay has a good chance to compete. While calculated α decay half-lives are in agreement with experimental data within one order of magnitude and cluster decay experiments are also very well accounted for, the discrepancy between theory and experiment can be as high as ten orders of magnitude for spontaneous fission. We analyze some ways of improving the accuracy: using a semiempirical formula for α decay and changing the parameters of analytical superasymmetric fission and of the universal curve for cluster decay. For spontaneous fission we act on nuclear dynamics based on potential barriers computed by the macroscopic-microscopic method and employing various nuclear inertia variation laws. Applications are illustrated for 284Cn and Z = 118-124 even-even parent nuclei. Communicated by Steffen Bass

  14. Formation of super-heavy elements in astrophysical nucleosynthesis

    SciTech Connect

    Zagrebaev, V. I.; Karpov, A. V.; Mishustin, I. N.; Greiner, Walter

    2012-10-20

    The unexplored area of heavy neutron-rich nuclides is extremely important for the understanding of the r process of astrophysical nucleogenesis. For elements with Z>100 only neutron deficient isotopes (located to the left of the stability line) have been synthesized so far. The 'north-east' area of the nuclear map can be reached neither in fusion reactions nor in fragmentation processes. Low energy multi-nucleon transfer reactions are quite promising for the production and study of neutron-rich heavy nuclei including those located at the superheavy (SH) island of stability [1]. The neutron capture process is considered here as an alternative method for the production of SH nuclei. Requirements for the pulsed reactors of the next generation that could be used for the synthesis of long-living neutron rich SH nuclei are formulated. Formation of SH nuclei in supernova explosions is also discussed and the abundance of SH elements in nature is estimated.

  15. and : candidates for charmed-strange mesons

    NASA Astrophysics Data System (ADS)

    Song, Qin-Tao; Chen, Dian-Yong; Liu, Xiang; Matsuki, Takayuki

    2015-01-01

    Newly observed two charmed-strange resonances, and , are investigated by calculating their Okubo-Zweig-Iizuka-allowed strong decays, which shows that they are suitable candidates for the and states in the charmed-strange meson family. Our study also predicts other main decay modes of and , which can be accessible at the future experiment. In addition, the decay behaviors of the spin partners of and , i.e., and , are predicted in this work, which are still missing at present. The experimental search for the missing and charmed-strange mesons is an intriguing and challenging task for further experiments.

  16. Strangeness production in p–Pb and Pb–Pb collisions with ALICE at LHC

    NASA Astrophysics Data System (ADS)

    Colella, Domenico; ALICE Collaboration

    2017-01-01

    The main goal of the ALICE experiment is to study the properties of the hot and dense medium created in ultra-relativistic heavy-ion collisions. The measurement of the (multi-)strange particles is an important tool to understand particle production mechanisms and the dynamics of the quark-gluon plasma (QGP). We report on the production of in proton-lead (p–Pb) collisions at and lead-lead (Pb–Pb) collisions at measured by ALICE at the LHC. The comparison of the hyperon-to-pion ratios in the two colliding systems may provide insight into strangeness production mechanisms, while the comparison of the nuclear modification factors helps to determine the contribution of initial state effects and the suppression from strange quark energy loss in nuclear matter.

  17. Condensed-matter trio scoop Dirac prize

    NASA Astrophysics Data System (ADS)

    Durrani, Matin

    2012-09-01

    Three condensed-matter physicists, who have advanced our understanding of a strange type of material known as a "topological insulator", have won this year's Dirac medal from the International Centre for Theoretical Physics (ICTP) in Trieste, Italy.

  18. Ultrarelativistic cascades and strangeness production

    SciTech Connect

    Kahana, D.E.; Kahana, S.H.

    1998-02-01

    A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS.

  19. Strange Creatures: An Additive Wood Sculpture Project.

    ERIC Educational Resources Information Center

    Wales, Andrew

    2002-01-01

    Describes an art project where students create strange creatures using scraps of wood. Discusses how the students use the wood and other materials. Explains that the students also write about the habitat characteristics of their creatures. Includes learning objectives. (CMK)

  20. Strangeness contributions to nucleon form factors

    SciTech Connect

    Ross Young

    2006-09-11

    We review a recent theoretical determination of the strange quark content of the electromagnetic form factors of the nucleon. These are compared with a global analysis of current experimental measurements in parity-violating electron scattering.

  1. Strangeness Physics with CLAS at Jefferson Lab

    SciTech Connect

    Burkert, Volker

    2009-10-01

    A brief overview of strangeness physics with the CLAS detector at JLab is given, mainly covering the domain of nucleon resonances. Several excited states predicted by the symmetric constituent quark model may have signiffcant couplings to the K+ or K0 channels. I will discuss data that are relevant in the search for such states in the strangeness channel, and give an outlook on the future prospects of the N* program at JLab with electromagnetic probes.

  2. 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.

  3. Theoretical perspectives on strange physics

    SciTech Connect

    Ellis, J.

    1983-04-01

    Kaons are heavy enough to have an interesting range of decay modes available to them, and light enough to be produced in sufficient numbers to explore rare modes with satisfying statistics. Kaons and their decays have provided at least two major breakthroughs in our knowledge of fundamental physics. They have revealed to us CP violation, and their lack of flavor-changing neutral interactions warned us to expect charm. In addition, K/sup 0/-anti K/sup 0/ mixing has provided us with one of our most elegant and sensitive laboratories for testing quantum mechanics. There is every reason to expect that future generations of kaon experiments with intense sources would add further to our knowledge of fundamental physics. This talk attempts to set future kaon experiments in a general theoretical context, and indicate how they may bear upon fundamental theoretical issues. A survey of different experiments which would be done with an Intense Medium Energy Source of Strangeness, including rare K decays, probes of the nature of CP isolation, ..mu.. decays, hyperon decays and neutrino physics is given. (WHK)

  4. Super-heavy electron material as metallic refrigerant for adiabatic demagnetization cooling

    SciTech Connect

    Tokiwa, Yoshifumi; Piening, Boy; Jeevan, Hirale S.; Bud'ko, Sergey L.; Canfield, Paul C.; Gegenwart, Philipp

    2016-09-09

    Low-temperature refrigeration is of crucial importance in fundamental research of condensed matter physics, because the investigations of fascinating quantum phenomena, such as superconductivity, superfluidity, and quantum criticality, often require refrigeration down to very low temperatures. Currently, cryogenic refrigerators with 3He gas are widely used for cooling below 1 Kelvin. However, usage of the gas has been increasingly difficult because of the current world-wide shortage. Therefore, it is important to consider alternative methods of refrigeration. We show that a new type of refrigerant, the super-heavy electron metal YbCo2Zn20, can be used for adiabatic demagnetization refrigeration, which does not require 3He gas. This method has a number of advantages, including much better metallic thermal conductivity compared to the conventional insulating refrigerants. We also demonstrate that the cooling performance is optimized in Yb1$-$xScxCo2Zn20 by partial Sc substitution, with x ~ 0.19. The substitution induces chemical pressure that drives the materials to a zero-field quantum critical point. This leads to an additional enhancement of the magnetocaloric effect in low fields and low temperatures, enabling final temperatures well below 100 mK. This performance has, up to now, been restricted to insulators. For nearly a century, the same principle of using local magnetic moments has been applied for adiabatic demagnetization cooling. Lastly, this study opens new possibilities of using itinerant magnetic moments for cryogen-free refrigeration.

  5. Strangeness asymmetry in the proton sea

    NASA Astrophysics Data System (ADS)

    Alberg, Mary

    2015-10-01

    Meson cloud models describe the proton sea in terms of fluctuations of the proton into meson-baryon pairs. The leading contributions to proton strangeness are from states which contain a kaon and a Lambda or Sigma hyperon. We use a Fock state expansion of the proton in terms of these states to determine the strangeness distributions of the proton in a convolution model, in which the fluctuations are represented by meson-baryon splitting functions, which determine the total strangeness of the proton. Strangeness asymmetry, the difference between momentum distributions of the s and sbar quarks in the proton, arises because the quarks are constituents of different hadrons. For the parton distributions of the s(sbar) quarks in the bare baryons(mesons) of the Fock states, we use light cone wave functions or our statistical model, which expands the bare hadrons in terms of quark-gluon states. We show that strangeness asymmetry depends strongly on the parton distributions used for the hadrons in the cloud. We compare our results to NuTeV and to global parton distributions. This research has been supported in part by NSF Award 1205686.

  6. Momentum distributions of strange and anti-strange quarks in the proton

    NASA Astrophysics Data System (ADS)

    Hansen, Chase; Raschko, David; Netzel, Greg

    2013-10-01

    Strangeness in the proton has been confirmed by experiment. We are using the statistical method of Zhang et al., which explained the u - d asymmetry in the proton. We expand the model to include strange quarks, to explain the existence of strangeness in the proton. We used RAMBO in order to create a Bjorken-x distribution for the partons in the proton. We adjusted RAMBO to include the strange quark mass. In order to suppress the transitions to states that include s - s pairs, we calculate energy distributions for the gluons and allow gluons to split into s - s pairs only if the gluon is above the energy threshold of twice the mass of a strange quark. We expand our view to include the meson cloud model, attempting a different approach at explaining strangeness in the proton. After Q2 evolution, we compare our calculations of strangeness probability and S+ (x) to HERMES and ATLAS data, as well as global parton distribution fits. Supported in part by NSF Grants No. 0855656 and 1205686.

  7. Correlation between {alpha}-Decay Energies of Superheavy Nuclei Involving the Effects of Symmetry Energy

    SciTech Connect

    Dong Jianmin; Zuo Wei; Scheid, Werner

    2011-07-01

    A formula for the relationship between the {alpha}-decay energies (Q values) of superheavy nuclei (SHN) is presented, which is composed of the effects of Coulomb energy and symmetry energy. It can be employed not only to validate the experimental observations and measurements to a large extent, but also to predict the Q values of heaviest SHN with a high accuracy generally which will be very useful for future experiments. Furthermore, the shell closures in superheavy region and the effect of the symmetry energy on the stability of SHN against {alpha} decay are discussed with the help of this formula.

  8. Electron structure of superheavy elements Uut, Fl and Uup ( Z=113 to 115)

    NASA Astrophysics Data System (ADS)

    Dzuba, V. A.; Flambaum, V. V.

    2016-12-01

    We use recently developed method of accurate atomic calculations which combines linearized single-double coupled cluster method with the configuration interaction technique to calculate ionisation potentials, excitation energies, static polarizabilities and valence electron densities for superheavy elements Uut, Fl and Uup ( Z=113 to 115) and their ions. The accuracy of the calculations is controlled by comparing similar calculations for lighter analogs of the superheavy elements, Tl, Pb and Bi with experiment. The role of relativistic effects and correlations is discussed and comparison with earlier calculations is presented.

  9. Electric dipole moments of superheavy elements: A case study on copernicium

    NASA Astrophysics Data System (ADS)

    RadžiÅ«tÄ--, Laima; Gaigalas, Gediminas; Jönsson, Per; Bieroń, Jacek

    2016-06-01

    The multiconfiguration Dirac-Hartree-Fock method was employed to calculate the atomic electric dipole moments (EDMs) of the superheavy element copernicium (Cn, Z =112 ). The EDM enhancement factors of Cn, calculated here, are about one order of magnitude larger than those of Hg. The exponential dependence of the enhancement factors on the atomic number Z along group 12 of the periodic table was derived from the EDMs of the entire homologous series, Zn, Cd, Hg, Cn, and Uhb. These results show that superheavy elements with sufficiently long half-lives are potential candidates for EDM searches.

  10. Measurements of strangeness production in the STAR experiment at RHIC

    SciTech Connect

    Wilson, W.K.

    1995-07-15

    Simulations of the ability of the STAR (Solenoidal Tracker at RHIC) detector to measure strangeness production in central Au+Au collisions at RHIC are presented. Emphasis is placed on the reconstruction of short lived particles using a high resolution inner tracker. The prospects for performing neutral kaon interferometry are discussed. Simulation results for measurements of strange and multi-strange baryons are presented.

  11. Characterization of strange attractors as inhomogeneous fractals

    NASA Astrophysics Data System (ADS)

    Paladin, G.; Vulpiani, A.

    1984-09-01

    The geometry of strange attractors of chaotic dynamical systems is investigated analytically within the framework of fractal theory. A set of easily computable exponents which generalize the fractal dimensionality and characterize the inhomogeneity of the fractals of strange attractors is derived, and sample computations are shown. It is pointed out that the fragmentation process described is similar to models of intermittency in fully developed turbulence. The exponents for the sample problems are computed in the same amount of CPU time as the computation of nu by the method of Grassberger and Procaccia (1983) but provide more information; less time is required than for the nu(n) computation of Hentschel and Procaccia (1983).

  12. Recent results from strangeness in transport models

    NASA Astrophysics Data System (ADS)

    Steinheimer, J.; Botvina, A. S.; Bleicher, M.

    2016-01-01

    In these proceedings we discuss recent developments in the microscopic description of strange particle production in nuclear collisions. We put a special emphasis on the production of hypernuclei at the upcoming FAIR and NICA facilities as well as the deep sub threshold, ϕ and Ξ- production yields measured with the HADES experiment. Employing new resonance decay channels we obtain a satisfactory description of ϕ and Ξ- production in deep sub threshold Ar+KCl reactions. Our results implicate that no new medium effects are required to describe the rare strange particle production data from low energy nuclear collisions.

  13. Strange fireball as an explanation of the muon excess in Auger data

    NASA Astrophysics Data System (ADS)

    Anchordoqui, Luis A.; Goldberg, Haim; Weiler, Thomas J.

    2017-03-01

    We argue that ultrahigh-energy cosmic-ray collisions in Earth's atmosphere can probe the strange quark density of the nucleon. These collisions have center-of-mass energies ≳1 04.6A GeV , where A ≥14 is the nuclear baryon number. We hypothesize the formation of a deconfined thermal fireball which undergoes a sudden hadronization. At production the fireball has a very high matter density and consists of gluons and two flavors of light quarks (u , d ). Because the fireball is formed in the baryon-rich projectile fragmentation region, the high baryochemical potential damps the production of u u ¯ and d d ¯ pairs, resulting in gluon fragmentation mainly into s s ¯. The strange quarks then become much more abundant and upon hadronization the relative density of strange hadrons is significantly enhanced over that resulting from a hadron gas. Assuming the momentum distribution functions can be approximated by Fermi-Dirac and Bose-Einstein statistics, we estimate a kaon-to-pion ratio of about 3 and expect a similar (total) baryon-to-pion ratio. We show that, if this were the case, the excess of strange hadrons would suppress the fraction of energy which is transferred to decaying π0's by about 20%, yielding an ˜40 % enhancement of the muon content in atmospheric cascades, in agreement with recent data reported by the Pierre Auger Collaboration.

  14. An experimental paradigm opening the world of superheavy elements

    NASA Astrophysics Data System (ADS)

    Armbruster, P.; Münzenberg, Gottfried

    2012-07-01

    The history of the discovery of the six elements Z = 107 - 112, bohrium, hassium, meitnerium, darmstadtium, roentgenium, and copernicium goes back to the early 1960s. An experimental method to separate and identify rare nuclear reaction products, the recoil separation, was developed and optimised for beams of fission products at European research reactors. Chemical elements beyond the then first transactinides (Z = 104), which owe their stability to the internal structure of atomic nuclei, were predicted theoretically. A big brother of the shell-stabilised nucleus 208Pb, a spherical magic nucleus at Z = 114-126 and N = 184, might reach lifetimes long enough to be detected. In the seventies, hunting superheavy elements (SHE) was on the agenda of nuclear chemistry. Could the Periodic Table of Elements be extended to Z = 120, and is the order of electrons in the atom still following the laws established for lighter elements? In Germany, the heavy ion accelerator (UNILAC) was built by Christoph Schmelzer and his team at GSI, Darmstadt. SHE and UNILAC met the recoil separators in 1968, and SHIP (Separator for Heavy Ion reaction Products) was ready together with the first UNILAC-beams in 1976. Recoil separation is orders of magnitude more sensitive, selective, and faster than earlier methods used to synthesise elements up to seaborgium, Z = 106. The experimental paradigm we introduced opened the world of SHEs. At SHIP we discovered and investigated the elements Z = 107-112 in the years 1980-2000. Our laboratory was the world champion during this time. Today our experimental method is used worldwide in the search for SHEs, but the leadership went to the Russian laboratory JINR in Dubna, which extended the Periodic Table by 6 more elements to Z = 118, the candidate for the next rare gas.

  15. Nuclear isomers in superheavy elements as stepping stones towards the island of stability.

    PubMed

    Herzberg, R-D; Greenlees, P T; Butler, P A; Jones, G D; Venhart, M; Darby, I G; Eeckhaudt, S; Eskola, K; Grahn, T; Gray-Jones, C; Hessberger, F P; Jones, P; Julin, R; Juutinen, S; Ketelhut, S; Korten, W; Leino, M; Leppänen, A-P; Moon, S; Nyman, M; Page, R D; Pakarinen, J; Pritchard, A; Rahkila, P; Sarén, J; Scholey, C; Steer, A; Sun, Y; Theisen, Ch; Uusitalo, J

    2006-08-24

    A long-standing prediction of nuclear models is the emergence of a region of long-lived, or even stable, superheavy elements beyond the actinides. These nuclei owe their enhanced stability to closed shells in the structure of both protons and neutrons. However, theoretical approaches to date do not yield consistent predictions of the precise limits of the 'island of stability'; experimental studies are therefore crucial. The bulk of experimental effort so far has been focused on the direct creation of superheavy elements in heavy ion fusion reactions, leading to the production of elements up to proton number Z = 118 (refs 4, 5). Recently, it has become possible to make detailed spectroscopic studies of nuclei beyond fermium (Z = 100), with the aim of understanding the underlying single-particle structure of superheavy elements. Here we report such a study of the nobelium isotope 254No, with 102 protons and 152 neutrons--the heaviest nucleus studied in this manner to date. We find three excited structures, two of which are isomeric (metastable). One of these structures is firmly assigned to a two-proton excitation. These states are highly significant as their location is sensitive to single-particle levels above the gap in shell energies predicted at Z = 114, and thus provide a microscopic benchmark for nuclear models of the superheavy elements.

  16. Ways to produce new superheavy isotopes with Z = 111-117 in charged particle evaporation channels

    NASA Astrophysics Data System (ADS)

    Hong, Juhee; Adamian, G. G.; Antonenko, N. V.

    2017-01-01

    The excitation functions of the production of new heaviest isotopes of superheavy nuclei with charge numbers 111-117 in the pxn and αxn evaporation channels of the 48Ca-induced hot fusion reactions are predicted for the first time for future experiments.

  17. 'Strange money': risk, finance and socialized debt.

    PubMed

    Dodd, Nigel

    2011-03-01

    This paper explores an essential but neglected aspect of recent discussions of the banking and financial system, namely money itself. Specifically, I take up a distinction drawn by Susan Strange which has never been fully elaborated: between a financial system that is global, and an international monetary system that remains largely territorial. I propose a sociological elaboration of this distinction by examining each category, 'finance' and 'money', in terms of its distinctive orientation to risk and debt. Money is distinguished by its high degree of liquidity and low degree of risk, corresponding to expectations that derive from its status as a 'claim upon society'- a form of socialized debt. But as Strange argued, these features of money are being undermined by the proliferation of sophisticated instruments of financial risk management -'strange money'- that, as monetary substitutes, both weaken states' capacity to manage money, and more broadly, contribute to 'overbanking'. The ultimate danger, according to Strange, is the 'death of money'. The paper concludes by exploring the implications of the distinction for sociological arguments about the changing nature of money.

  18. The mystery of the strange formulae

    NASA Astrophysics Data System (ADS)

    Bracken, Tony

    2016-10-01

    On a recent visit to the Wilhelm Röntgen memorial in Wurzburg, Germany, I noticed two strange trigonometric formulae set in the terrazzo floor at the western entrance to the building that houses Röntgen's X-ray laboratory.

  19. 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.

  20. 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

  1. 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.

  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. Phenomenology of strangeness production at high energies

    NASA Astrophysics Data System (ADS)

    Nasser Tawfik, Abdel; Yassin, Hayam; Abo Elyazeed, Eman R.; Maher, Muhammad; Magied Diab, Abdel; Abdel Wahab, Magda; Abou El Dahab, Eiman

    2016-12-01

    The strange-quark occupation factor (γ_s) is determined from the statistical fit of the multiplicity ratio {K}^+/π+ in a wide range of nucleon-nucleon center-of-mass energies (\\sqrt{sNN} ). From this single-strange-quark subsystem, γ_s(\\sqrt{sNN}) was parametrized as a damped trigonometric functionality and successfully implemented into the hadron resonance gas model, at chemical semi-equilibrium. Various particle ratios including {K}^-/ π- , Λ/π- , and \\barΛ/π- are well reproduced. The phenomenology of γ_s(\\sqrt{sNN}) suggests that the hadrons (γs rises) at \\sqrt{sNN} ≃ 7 \\text{GeV} seem to undergo a phase transition to a mixed phase (γs decreases), which is then derived into partons (γs remains unchanged with increasing \\sqrt{sNN} ), at \\sqrt{sNN} ≃ 20 \\text{GeV} .

  4. Unique signatures for QGP in strangeness sector

    NASA Astrophysics Data System (ADS)

    Tiwari, V. K.; Singh, C. P.

    1998-03-01

    We suggest that the variations of certain strange particle ratios either with the energy density or with the baryon density constitute a significant signal for identification of the QGP formation in ultra-relativistic nucleus-nucleus collisions. We use realistic equations of state (EOS) for the QGP as well as for dense, hot hadron gas (HG) scenarios. We suggest that a direct comparison of the ratios obtained in the QGP and HG scenarios will be immensely helpful in identifying the QGP formation.

  5. Charmed-strange mesons revisited: Mass spectra and strong decays

    NASA Astrophysics Data System (ADS)

    Song, Qin-Tao; Chen, Dian-Yong; Liu, Xiang; Matsuki, Takayuki

    2015-03-01

    Inspired by the present experimental status of charmed-strange mesons, we perform a systematic study of the charmed-strange meson family in which we calculate the mass spectra of the charmed-strange meson family by taking a screening effect into account in the Godfrey-Isgur model and investigate the corresponding strong decays via the quark pair creation model. These phenomenological analyses of charmed-strange mesons not only shed light on the features of the observed charmed-strange states, but also provide important information on future experimental search for the missing higher radial and orbital excitations in the charmed-strange meson family, which will be a valuable task in LHCb, the forthcoming Belle II, and PANDA.

  6. Complete strangeness measurements in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Tomášik, Boris; Kolomeitsev, Evgeni E.

    2016-08-01

    We discuss strangeness production in heavy-ion collisions within and around the energy range of the planned NICA facility. We describe a minimal statistical model, in which the total strangeness yield is fixed by the observed or calculated K+ multiplicity. We show how the exact strangeness conservation can be taken into account on event-by-event basis in such a model. We argue that from strange particle yields one can reveal information about the collision dynamics and about possible modifications of particle properties in medium. This can be best achieved if the complete strangeness measurement is performed, i.e. kaons, antikaons, hyperons and multistrange hyperons are registered in the same experimental setup. In particular, production of hadrons containing two and more strange quarks, like Ξ and Ω baryons could be of interest.

  7. Strangeness production in antiproton annihilation on nuclei

    NASA Astrophysics Data System (ADS)

    Cugnon, J.; Deneye, P.; Vandermeulen, J.

    1990-04-01

    The strangeness production in antiproton annihilation on nuclei is investigated by means of a cascade-type model, within the frame of the conventional picture of the annihilation on a single nucleon followed by subsequent rescattering proceeding in the hadronic phase. The following hadrons are introduced: N, Λ, Σ, Λ¯, π, η, ω, K, and K¯ and, as far as possible, the experimental reaction cross sections are used in our simulation. The numerical results are compared with experimental data up to 4 GeV/c. The Λ¯ yield is correctly reproduced, while the Λ and Ks yields are overestimated in the p¯Ta and p¯Ne cases. On the other hand, the rapidity and perpendicular momentum distributions are well reproduced. It is shown that total strange yield is not very much affected by the associated production taking place during the rescattering process. It is also shown that the Λ/Ks ratio is largely due to the strangeness exchange reactions induced by antikaons. In particular, values of the order of 1 to 3 are expected in the energy range investigated here, independently of the detail of the hadronic phase dynamics. Finally, it is stressed that rapidity distributions are consistent with the rescattering process. Comparison with other works and implications of our results are examined.

  8. Strangeness in the baryon ground states

    NASA Astrophysics Data System (ADS)

    Semke, A.; Lutz, M. F. M.

    2012-10-01

    We compute the strangeness content of the baryon octet and decuplet states based on an analysis of recent lattice simulations of the BMW, PACS, LHPC and HSC groups for the pion-mass dependence of the baryon masses. Our results rely on the relativistic chiral Lagrangian and large-Nc sum rule estimates of the counter terms relevant for the baryon masses at N3LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. A simultaneous description of the lattice results of the BMW, LHPC, PACS and HSC groups is achieved. From a global fit we determine the axial coupling constants F ≃ 0.45 and D ≃ 0.80 in agreement with their values extracted from semi-leptonic decays of the baryons. Moreover, various flavor symmetric limits of baron octet and decuplet masses as obtained by the QCDSF-UKQCD group are recovered. We predict the pion- and strangeness sigma terms and the pion-mass dependence of the octet and decuplet ground states at different strange quark masses.

  9. Strangeness production in AA and pp collisions

    NASA Astrophysics Data System (ADS)

    Castorina, Paolo; Satz, Helmut

    2016-07-01

    Boost-invariant hadron production in high-energy collisions occurs in causally disconnected regions of finite space-time size. As a result, globally conserved quantum numbers (charge, strangeness, baryon number) are conserved locally in spatially restricted correlation clusters. Their size is determined by two time scales: the equilibration time specifying the formation of a quark-gluon plasma, and the hadronization time, specifying the onset of confinement. The expected values for these scales provide the theoretical basis for the suppression observed for strangeness production in elementary interactions ( pp , e^+e^- below LHC energies. In contrast, the space-time superposition of individual collisions in high-energy heavy-ion interactions leads to higher energy densities, resulting in much later hadronization and hence much larger hadronization volumes. This largely removes the causality constraints and results in an ideal hadronic resonance gas in full chemical equilibrium. In the present paper, we determine the collision energies needed for that; we also estimate when pp collisions reach comparable hadronization volumes and thus determine when strangeness suppression should disappear there as well.

  10. COMMITTEES: SQM 2007 - International Conference On Strangeness In Quark Matter SQM 2007 - International Conference On Strangeness In Quark Matter

    NASA Astrophysics Data System (ADS)

    2008-04-01

    Local Organising Committee Ivan Králik (IEP SAS, Košice) Vojtěch Petráček (Czechoslovakia Technical University, Prague) Ján Pišút (Comenius University, Bratislava) Emanuele Quercigh (CERN) Karel Šafařík (CERN), Co-chair Ladislav v Sándor (IEP SAS, Košice), Co-chair Boris Tomášik (Mateja Bela University, Banská Bystrica) Jozef Urbán (UPJŠ Košice) International Advisory Committee Jörg Aichelin, Nantes Federico Antinori, Padova Tamás Biró, Budapest Peter Braun-Munzinger, GSI Jean Cleymans, Cape Town László Csernai, Bergen Timothy Hallman, BNL Huan Zhong Huang, UCLA Sonja Kabana, Nantes Roy A Lacey, Stony Brook Carlos Lourenço, CERN Yu-Gang Ma, Shanghai Jes Masden, Aarhus Yasuo Miake, Tsukuba Berndt Müller, Duke Grazyna Odyniec, LBNL Helmut Oeschler, Darmstadt Jan Rafelski, Arizona Hans Georg Ritter, LBNL Jack Sandweiss, Yale George S F Stephans, MIT Horst Stöcker, Frankfurt Thomas Ullrich, BNL Orlando Villalobos-Baillie, Birmingham William A Zajc, Columbia

  11. COMMITTEES: SQM2008-International Conference on Strangeness in Quark Matter SQM2008-International Conference on Strangeness in Quark Matter

    NASA Astrophysics Data System (ADS)

    2008-04-01

    Local Organising Committee Xiangzhou Cai (SINPA) Weiqin Chao (CCAST) Liewen Chen (SJTU) Jianping Cheng (Tsinghua University) Jinghua Fu (CCNU) Yuanning Gao (Tsinghua University) Xiaomei Li (CIAE) Zuotang Liang (Shandong University) Feng Liu (CCNU), Co-chair Yuxin Liu (PKU) Qing Wang (Tsinghua University) Qun Wang (USTC) Hushan Xu (IMP) Daicui Zhou (CCNU) Pengfei Zhuang (Tsinghua University), Co-chair Bingsong Zou (IHEP) International Advisory Committee Jörg Aichelin, Nantes Federico Antinori, Padova Tamás Biró, Budapest Peter Braun-Munzinger, GSI Jean Cleymans, Cape Town László Csernai, Bergen Timothy Hallman, BNL Huan Zhong Huang, UCLA Takeshi Kodama, Rio de Janeiro Carlos Lourenço, CERN Yu-Gang Ma, Shanghai Jes Masden, Aarhus Yasuo Miake, Tsukuba Berndt Müller, Duke Grazyna Odyniec, LBNL Helmut Oeschler, Darmstadt Johann Rafelski, Arizona Hans Georg Ritter, LBNL Karel Šafařík, CERN Jack Sandweiss, Yale George S F Stephans, MIT Horst Stöcker, Frankfurt Thomas Ullrich, BNL Nu Xu, LBNL William A Zajc, Columbia

  12. Transfer reaction studies in the region of heavy and superheavy nuclei at SHIP

    NASA Astrophysics Data System (ADS)

    Heinz, S.; Comas, V.; Hofmann, S.; Ackermann, D.; Heredia, J.; Heβberger, F. P.; Khuyagbaatar, J.; Kindler, B.; Lommel, B.; Mann, R.

    2011-02-01

    We studied multi-nucleon transfer reactions in the region of heavy and superheavy nuclei. The goal was to investigate these reactions as possibility to create new superheavy neutron-rich isotopes, which cannot be produced in fusion reactions. The experiments have been performed at the velocity filter SHIP at GSI. At SHIP we can detect and identify the heavy, target-like, transfer products. Due to the low background at the focal plane detector and the isotope identification via radioactive decays, the setup allows to reach an upper cross-section limit of 10 pb/sr within one day of beamtime. We investigated the systems 58,64Ni + 207Pb and 48Ca + 248Cm at beam energies below and up to 20% above the Coulomb barrier. At all energies we observed a massive transfer of protons and neutrons, where transfer products with up to eight neutrons more than the target nucleus could be identified.

  13. New Superheavy Element Isotopes: 242Pu(48Ca,5n)285114

    SciTech Connect

    Ellison, Paul A; Gregorich, Kenneth E.; Berryman, Jill S.; Bleuel, Darren L.; Clark, Roderick M.; Dragojevic, Irena; Dvorak, Jan; Fallon, Paul; Fineman-Sotomayor, Carolina; Gates, Jacklyn M.; Gothe, Oliver R.; Lee, I-Yang; Loveland, Walter D.; McLaughlin, Joseph P.; Paschalis, Stefanos; Petri, Marina-Kalliopi; Qian, Jing; Stavsetra, Liv; Wiedeking, Mathis; Nitsche, Heino

    2010-10-22

    The new, neutron-deficient, superheavy element isotope {sup 285}114 was produced in {sup 48}Ca irradiations of {sup 242}Pu targets at a center-of-target beam energy of 256 MeV (E* = 50 MeV). The {alpha} decay of {sup 285}114 was followed by the sequential {alpha} decay of four daughter nuclides, {sup 281}Cn, {sup 277}Ds, {sup 273}Hs, and {sup 269}Sg. {sup 265}Rf was observed to decay by spontaneous fission. The measured {alpha}-decay Q values were compared with those from a macroscopic-microscopic nuclear mass model to give insight into superheavy element shell effects. The {sup 242}Pu({sup 48}Ca,5n){sup 285}114 cross section was 0.6{sub -0.5}{sup +0.9} pb.

  14. Microscopic Analysis of the α-DECAY in Heavy and Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Delion, D. S.; Sandulescu, A.; Greiner, W.

    2004-09-01

    We analyze the α-decay along N - Z chains in heavy and superheavy nuclei. The α-particle preformation amplitude is estimated within the pairing model, while the penetration part by the deformed WKB approach. We show that for N > 126 the plateau condition is not fulfilled along any α-chain, namely the logarithmic derivative of the Coulomb function changes much faster in comparison with that of the preformation factor. We correct this deficiency by considering an α-cluster factor in the preformation amplitude, depending upon the Coulomb parameter. For superheavy region an additional dependence upon the number of interacting α-particles indicates a clustering feature connected with a larger radial component.

  15. Fusion-fission probabilities, cross sections, and structure notes of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Kowal, Michał; Cap, Tomasz; Jachimowicz, Piotr; Skalski, Janusz; Siwek-Wilczyńska, Krystyna; Wilczyński, Janusz

    2016-12-01

    Fusion - fission probabilities in the synthesis of heaviest elements are discussed in the context of the latest experimental reports. Cross sections for superheavy nuclei are evaluated using the "Fusion by Diffusion" (FBD) model. Predictive power of this approach is shown for experimentally known Lv and Og isotopes and predictions given for Z = 119, 120. Ground state and saddle point properties as masses, shell corrections, pairing energies, and deformations necessary for cross-section estimations are calculated systematically within the multidimensional microscopic-macroscopic method based on the deformed Woods-Saxon single-particle potential. In the frame of the FBD approach predictions for production of elements heavier than Z = 118 are not too optimistic. For this reason, and because of high instability of superheavy nuclei, we comment on some structure effects, connected with the K-isomerism phenomenon which could lead to a significant increase in the stability of these systems.

  16. Gluon effects on the equation of state of color superconducting strange stars

    NASA Astrophysics Data System (ADS)

    Ferrer, E. J.; de la Incera, V.; Paulucci, L.

    2015-08-01

    Compact astrophysical objects are a window for the study of strongly interacting nuclear matter given the conditions in their interiors, which are not reproduced in a laboratory environment. Much has been debated about their composition with possibilities ranging from a simple mixture of mostly protons and neutrons to deconfined quark matter. Recent observations on the mass of two pulsars, PSR J 1614 -2230 and PSR J 0348 +0432 , have posed a great restriction on their composition, since the equation of state must be hard enough to support masses of about at least two solar masses. The onset of quarks tends to soften the equation of state, but it can get substantially stiffer since in the high-dense medium a repulsive vector interaction channel is opened. Nevertheless, we show that once gluon effects are considered, the equation of state of strange stars formed by quark matter in the color-flavor-locked (CFL) phase of color superconductivity becomes softer decreasing the maximum stellar mass that can be reached. This may indicate that strange stars made entirely of CFL matter can only be favored if other interactions, as the one corresponding to the vector channel, are taken into consideration and are large enough.

  17. Calculation of the hyperfine structure of the superheavy elements Z=119 and Z=120{sup +}

    SciTech Connect

    Dinh, T. H.; Dzuba, V. A.; Flambaum, V. V.

    2009-10-15

    The hyperfine-structure constants of the lowest s and p{sub 1/2} states of superheavy elements Z=119 and Z=120{sup +} are calculated using ab initio approach. Core polarization and dominating correlation effects are included to all orders. Breit and quantum electrodynamic effects are also considered. Similar calculations for Cs, Fr, Ba{sup +}, and Ra{sup +} are used to control the accuracy. The dependence of the hyperfine-structure constants on the nuclear radius is discussed.

  18. Relativistic effects on the bonding of heavy and superheavy hydrogen halides

    NASA Astrophysics Data System (ADS)

    Saue, Trond; Faegri, Knut; Gropen, Odd

    1996-12-01

    The bonding in the hydrogen halides HI, HAt and HUus (Uus = element 117) has been studied using four-component Dirac-Hartree-Fock calculations and finite basis sets. The calculations show that the effect of spin-orbit splitting on the valence p-orbital dominates the bonding for the compound of the superheavy element, and even for the sixth row the spin-orbit interaction should be treated self-consistently for an accurate description of the electronic structure.

  19. Stability and synthesis of superheavy elements: Fighting the battle against fission - example of 254No

    NASA Astrophysics Data System (ADS)

    Lopez-Martens, A.; Henning, G.; Khoo, T. L.; Seweryniak, D.; Alcorta, M.; Asai, M.; Back, B. B.; Bertone, P.; Boilley, D.; Carpenter, M. P.; Chiara, C. J.; Chowdhury, P.; Gall, B.; Greenlees, P. T.; Gurdal, G.; Hauschild, K.; Heinz, A.; Hoffman, C. R.; Janssens, R. V. F.; Karpov, A. V.; Kay, B. P.; Kondev, F. G.; Lakshmi, S.; Lauristen, T.; Lister, C. J.; McCutchan, E. A.; Nair, C.; Piot, J.; Potterveld, D.; Reiter, P.; Rowley, N.; Rogers, A. M.; Zhu, S.

    2016-12-01

    Superheavy nuclei exist solely due to quantum shell effects, which create a pocket in the potential-energy surface of the nucleus, thus providing a barrier against spontaneous fission. Determining the height of the fission barrier and its angular-momentum dependence is important to quantify the role that microscopic shell corrections play in enhancing and extending the limits of nuclear stability. In this talk, the first measurement of a fission barrier in the very heavy nucleus 254No will be presented.

  20. Superheavy Element Studies with TASCA at GSI: Spectroscopy of Element 115 Decay Chains

    NASA Astrophysics Data System (ADS)

    Rudolph, Dirk

    Experimental campaigns on investigations of the superheavy elements 115, 117, 119, and 120 were conducted 2011 and 2012 at the gas-filled "TransActinide Separator and Chemistry Apparatus" (TASCA) at the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. Nuclear structure implications of first-ever α-photon coincidence spectroscopy on element 115 and its daughters obtained with the TASISpec set-up are discussed, likewise possible connections between decay chains associated with elements 115 and 117.

  1. Design of a new in-flight separator for heavy and superheavy fusion and transfer products

    NASA Astrophysics Data System (ADS)

    Heinz, S.; Barth, W.; Franczak, B.; Geissel, H.; Gupta, M.; Hofmann, S.; Mickat, S.; Münzenberg, G.; Plaß, W. R.; Scheidenberger, C.; Weick, H.; Winkler, M.

    2013-12-01

    We are developing a new velocity filter which is foreseen for separation of fusion and deep inelastic transfer products in the region of heavy and superheavy nuclei. The device is developed in collaboration with GSI Darmstadt, the University of Giessen and the Manipal University, India. In parallel to the separator design we are developing new techniques for particle detection and identification, especially for heavy nuclei which are not accessible with the presently available techniques.

  2. Barium isotopes in Allende meteorite - Evidence against an extinct superheavy element

    NASA Technical Reports Server (NTRS)

    Lewis, R. S.; Anders, E.; Shimamura, T.; Lugmair, G. W.

    1983-01-01

    Carbon and chromite fractions from the Allende meteorite that contain isotopically anomalous xenon-131 to xenon-136 (carbonaceous chondrite fission or CCF xenon) at up to 5 x 10 to the 11th atoms per gram show no detectable isotopic anomalies in barium-130 to barium-138. This rules out the possibility that the CCF xenon was formed by in situ fission of an extinct superheavy element. Apparently the CCF xenon and its carbonaceous carrier are relics from stellar nucleosynthesis.

  3. Alpha-decay energies of superheavy nuclei for the Fayans functional

    NASA Astrophysics Data System (ADS)

    Tolokonnikov, S. V.; Borzov, I. N.; Kortelainen, M.; Lutostansky, Yu. S.; Saperstein, E. E.

    2017-02-01

    Alpha-decay energies for several chains of superheavy nuclei are calculated within the self-consistent mean-field approach by using the Fayans functional FaNDF0. They are compared to the experimental data and predictions of two Skyrme functionals, SLy4 and SkM*, and of the macro-micro method as well. The corresponding lifetimes are calculated with the use of the semi-phenomenological formulas by Parkhomenko and Sobiczewski and by Royer and Zhang.

  4. Advanced Quantum Mechanical Calculation of Superheavy Ions: Energy Levels, Radiation and Finite Nuclear Size Effects

    SciTech Connect

    Glushkov, Alexander V.; Gurnitskaya, E.P.; Loboda, A.V.

    2005-10-26

    Advanced quantum approach to calculation of spectra for superheavy ions with an account of relativistic, correlation, nuclear, radiative effects is developed and based on the gauge invariant quantum electrodynamics (QED) perturbation theory (PT). The Lamb shift polarization part is calculated in the Ueling approximation, self-energy part is defined within a new non-PT procedure of Ivanov-Ivanova. Calculation results for energy levels, hyperfine structure parameters of some heavy elements ions are presented.

  5. Correlations between neutrons and protons near the Fermi surface and Qα of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Wang, Ning; Liu, Min; Wu, Xizhen; Meng, Jie

    2016-01-01

    The shell corrections and shell gaps in nuclei are systematically studied with the latest Weizsäcker-Skyrme (WS4) mass model. We find that most of asymmetric nuclei with (sub)shell closures locate along the shell stability line (SSL), N =1.37 Z +13.5 , which might be due to a strong correlation between neutrons and protons near the Fermi surface. The double magicity of nuclei 46Si and 78Ni is predicted according to the corresponding shell gaps, shell corrections, and nuclear deformations. The unmeasured superheavy nuclei, 296118 and 298120, with relatively large shell gaps and shell corrections, also locate along the SSL, whereas the traditional magic nucleus 298Fl evidently deviates from the line. The α -decay energies of superheavy nuclei with Z =113 -126 are simultaneously investigated by using the WS4 model together with the radial basis function corrections. For superheavy nuclei with large shell corrections, the smallest α -decay energy for elements Z =116 , 117, and 118 in their isotope chains locates at N =178 rather than 184.

  6. Disappearance of Z=120 & 126 magicity and presence of hyper deformations in superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Sharma, M. M.; Farhan, A. R.

    2012-10-01

    Conventional wisdom has it that Z=120 and especially Z=126 are predicted to be magic numbers for extreme superheavy nuclei. We have undertaken a study of structure of superheavy nuclei in the region of Z=120 to Z=126 within the framework of the deformed relativistic Hartree-Bogoliubov (DRHB) approach. Nuclei in this region entail a large density of states and are thus susceptible to a coupling to the continuum especially those which are close to being proton unbound. The DRHB approach which takes into account the coupling to the continuum is suitable for nuclei in the end of the periodic table. Additionally, the pairing in this approach is included within the Bogoliubov quasi-particle scheme, which takes into account the shell gap at the Fermi surface appropriately. Using the successful Lagrangian model NL-SV1 [1] based upon the vector self-coupling of φ-meson, it is shown that the perceived shell gaps at Z=120 and Z=126 disappear, thus making these proton numbers as non-magic. It is also shown that due to very large Coulomb force acting in these nuclei which are virtually at the end of the periodic table, stability to the nuclei in this region is brought about by extremely large elongated shapes with β2 ˜ 0.70-0.80. Consequences on formation of superheavy nuclei in this region will be discussed.

  7. Theoretical prediction of probable isotopes of superheavy nuclei of Z = 122

    NASA Astrophysics Data System (ADS)

    Manjunatha, H. C.

    2016-11-01

    We have studied the α-decay half-life and spontaneous fission half-lives of isotopes of superheavy element Z = 122 in the range 275 ≤ A ≥ 326. A comparison of calculated alpha half-lives with the literature [D. N. Poenaru, R. A. Gherghescu and W. Greiner, Phys. Rev. C 83 (2011) 014601, D. N. Poenaru, R. A. Gherghescu and W. Greiner, Phys. Rev. C 85 (2012) 034615] and the analytical formulas of Royer [G. Royer, J. Phys. G; Nucl. Part. Phys. 26 (2000) 1149] shows good agreement with each other. To identify the mode of decay of these isotopes, the spontaneous-fission half-lives were also evaluated using the semiempirical relation given by [C. Xu, Z. Ren and Y. Guo, Phys. Rev. C 78 (2008) 044329]. A comparative study on the competition of alpha decay versus spontaneous fission of superheavy nuclei (SHN) reveals that around eight isotopes (307-314122) survive fission and have alpha decay channel as the prominent mode of decay and hold the possibility to be synthesized in the laboratory. The alpha decay half-lives and spontaneous fission half-lives of SHN with Z = 122, A = 299-306, with Z = 120, A = 294-300, and with Z = 119, A = 292-297 are also studied. The present study will be useful in the synthesis of superheavy elements Z > 118 by using the actinide based reactions with stable projectiles heavier than 48Ca.

  8. Influence of hexadecapole deformation on production cross sections of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Bao, X. J.; Guo, S. Q.; Zhang, H. F.; Li, J. Q.

    2016-12-01

    The current heaviest superheavy nuclei (SHN) are experimentally synthesized by using 48Ca to bombard actinide nuclei via fusion reactions. Actinide nuclei often have considerable hexadecapole deformation in addition to quadrupole deformation, which was not considered in previous theoretical studies. With the dinuclear system concept, and by taking the hexadecapole deformation in to consideration in addition to the quadrupole deformation, the hot fusion probability leading to the synthesis of SHN is investigated systematically. Synthesis of superheavy elements 296118 and 295118 by using the 48Ca+251Cf reaction channel is evaluated and discussed, and the maximal evaporation residue cross sections (ERCSs) of the 3n and 4n channels are predicted to be 1.90 and 0.11 pb, respectively. The predicted maximum ERCSs in 3n and 4n evaporation channels of the 249Bk(50Ti,xn){}299-x119 reaction are 0.12 and 0.04 pb, respectively. The most favorable reaction to synthesize the element Z = 120 turns out to be 251Cf(50Ti,xn){}301-x120, but the predicted maximum cross section for this reaction is only 67 fb. Therefore, superheavy element 119 may be the most hopeful new element for Z\\gt 118 to be synthesized under some improved experimental conditions in the near future.

  9. Exotic decay modes of odd-Z (105-119) superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Rajeswari, N. S.; Balasubramaniam, M.

    2014-06-01

    Half-lives of proton emission for proton emitters with Z = 51 to 83 are calculated, in the frame-work of unified fission model with the penetrability calculated using the WKB approximation. For all the ground and isomeric state of the proton, the deformation degree of freedom is included. Calculated half-lives are in good agreement with the experimental ones. Experimentally for a few isotopes, proton and alpha branches are reported. Hence we have calculated the half-lives of alpha decay for these elements. For parent nuclei 157Ta, 166Ir, 167Ir, 176Tl and 177Tl, the alpha decay mode is preferred over the proton emission. Further, the calculations are extended to find half-lives of superheavy element with odd proton number in the range Z = 105 to 119, for both proton, alpha and for a few cluster decays. Calculations on superheavy elements reveal that cluster radioactivity has half-lives comparable with proton emissions. It is found that proton emission is the primary competing decay mode with respect to alpha decay for superheavy elements. Among considered clusters, 12C, 20Ne and 24Mg are found to have lowest half-lives among other N = Z clusters and for a few clusters the half-lives are found to be comparable with that of proton emission.

  10. Strange baryonic resonances and resonances coupling to strange hadrons at SIS energies

    NASA Astrophysics Data System (ADS)

    Fabbietti, L.

    2016-01-01

    The role played by baryonic resonances in the production of final states containing strangeness for proton-proton reactions at 3.5 GeV measured by HADES is discussed by means of several very different measurements. First the associate production of Δ resonances accompanying final states with strange hadrons is presented, then the role of interferences among N* resonances, as measured by HADES for the first time, is summarised. Last but not least the role played by heavy resonances, with a mass larger than 2 GeV/c2 in the production of strange and non-strange hadrons is discussed. Experimental evidence for the presence of a Δ(2000)++ are presented and hypotheses are discussed employing the contribution of similar objects to populate the excesses measured by HADES for the Ξ in A+A and p+A collisions and in the dilepton sector for A+A collisions. This extensive set of results helps to better understand the dynamic underlaying particle production in elementary reactions and sets a more solid basis for the understanding of heavy ion collisions at the same energies and even higher as planned at the FAIR facility.

  11. Strange baryonic resonances and resonances coupling to strange hadrons at SIS energies

    SciTech Connect

    Fabbietti, L.

    2016-01-22

    The role played by baryonic resonances in the production of final states containing strangeness for proton-proton reactions at 3.5 GeV measured by HADES is discussed by means of several very different measurements. First the associate production of Δ resonances accompanying final states with strange hadrons is presented, then the role of interferences among N{sup *} resonances, as measured by HADES for the first time, is summarised. Last but not least the role played by heavy resonances, with a mass larger than 2 GeV/c{sup 2} in the production of strange and non-strange hadrons is discussed. Experimental evidence for the presence of a Δ(2000){sup ++} are presented and hypotheses are discussed employing the contribution of similar objects to populate the excesses measured by HADES for the Ξ in A+A and p+A collisions and in the dilepton sector for A+A collisions. This extensive set of results helps to better understand the dynamic underlaying particle production in elementary reactions and sets a more solid basis for the understanding of heavy ion collisions at the same energies and even higher as planned at the FAIR facility.

  12. Strangeness in nuclei and neutron stars

    NASA Astrophysics Data System (ADS)

    Lonardoni, Diego

    2017-01-01

    The presence of exotic particles in the core of neutron stars (NS) has been questioned for a long time. At present, it is still an unsolved problem that drives intense research efforts, both theoretical and experimental. The appearance of strange baryons in the inner regions of a NS, where the density can exceed several times the nuclear saturation density, is likely to happen due to energetic considerations. The onset of strange degrees of freedom is considered as an effective mechanism to soften the equation of state (EoS). This softening affects the entire structure of the star, reducing the pressure and therefore the maximum mass that the star can stably support. The observation of two very massive NS with masses of the order of 2M⊙ seems instead to rule out soft EoS, apparently excluding the possibility of hyperon formation in the core of the star. This inconsistency, usually referred to as the hyperon puzzle, is based on what we currently know about the interaction between strange particles and normal nucleons. The combination of a poor knowledge of the hypernuclear interactions and the difficulty of obtaining clear astrophysical evidence of the presence of hyperons in NS makes the understanding of the behavior of strange degrees of freedom in NS an intriguing theoretical challenge. We give our contribution to the discussion by studying the general problem of the hyperon-nucleon interaction. We attack this issue by employing a quantum Monte Carlo (QMC) technique, that has proven to be successful in the description of strongly correlated Fermion systems, to the study of finite size nuclear systems including strange degrees of freedom, i.e. hypernuclei. We show that many-body hypernuclear forces are fundamental to properly reproduce the ground state physics of Λ hypernuclei from light- to medium-heavy. However, the poor abundance of experimental data on strange nuclei leaves room for a good deal of indetermination in the construction of hypernuclear

  13. Strangeness and charm production in high energy heavy ion collisions

    SciTech Connect

    Xu, Nu

    2001-01-01

    We discuss the dynamical effects of strangeness and charm production in high energy nuclear collisions. In order to understand the early stage dynamical evolution, it is necessary to study the transverse momentum distributions of multi-strange hadrons like {Xi} and {Omega} and charm mesons like J/{Psi} as a function of collision centrality.

  14. Associated strangeness production on light nuclei

    NASA Astrophysics Data System (ADS)

    Ernst, J.; Kingler, J.; Lippert, C.

    1991-04-01

    The study of light hyper-nuclei via associated strangeness production in (p, K+) reactions is discussed. Though the process is characterized by a very large momentum transfer the presence of short range correlations is expected to rise the cross section up to the order of nb/sr. Two approved proposals for high resolution studies of this reaction are discussed and respective detection limits are presented. The first is scheduled for October 1990 at the SPES4 spectrometer at the SATURNE acclerator (LNS Saclay). The second deals with the planned upgrading of the BIG KARL magnetic spectrograph at the cooled beam facility COSY being bulit at Forschungsanlage Jülich.

  15. New Fragment Separation Technology for Superheavy Element Research

    SciTech Connect

    Shaughnessy, D A; Moody, K J; Henderson, R A; Kenneally, J M; Landrum, J H; Lougheed, R W; Patin, J B; Stoyer, M A; Stoyer, N J; Wild, J F; Wilk, P A

    2008-01-28

    This project consisted of three major research areas: (1) development of a solid Pu ceramic target for the MASHA separator, (2) chemical separation of nuclear decay products, and (3) production of new isotopes and elements through nuclear reactions. There have been 16 publications as a result of this project, and this collection of papers summarizes our accomplishments in each of the three areas of research listed above. The MASHA (Mass Analyzer for Super-Heavy Atoms) separator is being constructed at the U400 Cyclotron at the Flerov Laboratory of Nuclear Reactions in Dubna, Russia. The purpose of the separator is to physically separate the products from nuclear reactions based on their isotopic masses rather than their decay characteristics. The separator was designed to have a separation between isotopic masses of {+-}0.25 amu, which would enable the mass of element 114 isotopes to be measured with outstanding resolution, thereby confirming their discovery. In order to increase the production rate of element 114 nuclides produced via the {sup 244}Pu+{sup 48}Ca reaction, a new target technology was required. Instead of a traditional thin actinide target, the MASHA separator required a thick, ceramic-based Pu target that was thick enough to increase element 114 production while still being porous enough to allow reaction products to migrate out of the target and travel through the separator to the detector array located at the back end. In collaboration with UNLV, we began work on development of the Pu target for MASHA. Using waste-form synthesis technology, we began by creating zirconia-based matrices that would form a ceramic with plutonium oxide. We used samarium oxide as a surrogate for Pu and created ceramics that had varying amounts of the starting materials in order to establish trends in material density and porosity. The results from this work are described in more detail in Refs. [1,4,10]. Unfortunately, work on MASHA was delayed in Russia because it was

  16. Small scale anisotropies of UHECRs from super-heavy halo dark matter

    SciTech Connect

    P. Blasi; R. K. Sheth

    2001-10-23

    The decay of very heavy metastable relics of the Early Universe can produce ultra-high energy cosmic rays (UHECRs) in the halo of our own Galaxy. In this model, no Greisen-Zatsepin-Kuzmin cutoff is expected because of the short propagation distances. They show here that, as a consequence of the hierarchical build up of the halo, this scenario predicts the existence of small scale anisotropies in the arrival directions of UHECRs, in addition to a large scale anisotropy, known from previous studies. They also suggest some other observable consequences of this scenario which will be testable with upcoming experiments, as Auguer, EUSO and OWL.

  17. Dilepton and strangeness production probed with HADES

    SciTech Connect

    Rustamov, A.

    2012-05-15

    With the High Acceptance Di-Electron Spectrometer (HADES) at GSI we have studied dilepton production in the few-GeV energy regime in various collisions systems, from elementary NN, over pA, up to the medium-heavy Ar + KCl system. We have thus confirmed the puzzling results of the former DLS Collaboration at the Bevalac. While we have traced the origin of the excess pair yield in CC collisions to elementary pp and pn processes, in our Ar + KCl data a contribution from the dense phase of the collision has been identified. Together with the e{sup +}e{sup -} pairs, we have also obtained in the Ar + KCl system at 1.76 A GeV a high-statistics data set on open and hidden strangeness, i.e. K{sup {+-}}, K{sub s}{sup 0}, {Lambda}, {phi}, and {Xi}{sup -}, allowing for a comprehensive discussion of strangeness production in this system.

  18. Singularity-free anisotropic strange quintessence star

    NASA Astrophysics Data System (ADS)

    Bhar, Piyali

    2015-04-01

    Present paper provides a new model of anisotropic strange star corresponding to the exterior Schwarzschild metric. The Einstein field equations have been solved by utilizing the Krori-Barua (KB) ansatz (Krori and Barua in J. Phys. A, Math. Gen. 8:508, 1975) in presence of quintessence field characterized by a parameter ω q with . The obtained solutions are free from central singularity. Our model is potentially stable. The numerical values of mass of the different strange stars SAXJ1808.4-3658(SS1) (radius=7.07 km), 4U1820-30 (radius=10 km), Vela X-12 (radius=9.99 km), PSR J 1614-2230 (radius=10.3 km) obtained from our model is very close to the observational data that confirms the validity of our proposed model. The interior solution is also matched to the exterior Schwarzschild spacetime in presence of thin shell where negative surface pressure is required to hold the thin shell against collapsing.

  19. Strange Particles and Heavy Ion Physics

    SciTech Connect

    Bassalleck, Bernd; Fields, Douglas

    2016-04-28

    This very long-running grant has supported many experiments in nuclear and particle physics by a group from the University of New Mexico. The gamut of these experiments runs from many aspects of Strangeness Nuclear Physics, to rare Kaon decays, to searches for exotic Hadrons such as Pentaquark or H-Dibaryon, and finally to Spin Physics within the PHENIX collaboration at RHIC. These experiments were performed at a number of laboratories worldwide: first and foremost at Brookhaven National Lab (BNL), but also at CERN, KEK, and most recently at J-PARC. In this Final Technical Report we summarize progress and achievements for this award since our last Progress Report, i.e. for the period of fall 2013 until the award’s termination on November 30, 2015. The report consists of two parts, representing our two most recent experimental efforts, participation in the Nucleon Spin Physics program of the PHENIX experiment at RHIC, the Relativistic Heavy Ion Collider at BNL – Task 1, led by Douglas Fields; and participation in several Strangeness Nuclear Physics experiments at J-PARC, the Japan Proton Accelerator Research Center in Tokai-mura, Japan – Task 2, led by Bernd Bassalleck.

  20. Strangeness in STAR experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Shi, Shusu; STAR collaboration

    2017-01-01

    We present the recent results of strangeness production at the mid-rapidity in Au + Au collisions at RHIC, from to 200 GeV. Elliptic asymmetry v 2 of multi-strange baryon Ω and φ mesons are similar to that of pions and protons in the intermediate pT range (2 - 5 GeV/c) in GeV Au + Au collisions, indicating that the major part of collective ow has been built up at partonic stage. The breaking of mass ordering between φ mesons and protons in the low pT range (< 1 GeV/c) is consistent with a picture that φ mesons are less sensitive to later hadronic interaction. The nuclear modification factor R CP and baryon to meson ratio change dramatically when the collision energy is lower than 19.6 GeV. It suggests a possible change of the created QCD medium properties at lower energies compared to those from high energies.

  1. Strange-face illusions during inter-subjective gazing.

    PubMed

    Caputo, Giovanni B

    2013-03-01

    In normal observers, gazing at one's own face in the mirror for a few minutes, at a low illumination level, triggers the perception of strange faces, a new visual illusion that has been named 'strange-face in the mirror'. Individuals see huge distortions of their own faces, but they often see monstrous beings, archetypal faces, faces of relatives and deceased, and animals. In the experiment described here, strange-face illusions were perceived when two individuals, in a dimly lit room, gazed at each other in the face. Inter-subjective gazing compared to mirror-gazing produced a higher number of different strange-faces. Inter-subjective strange-face illusions were always dissociative of the subject's self and supported moderate feeling of their reality, indicating a temporary lost of self-agency. Unconscious synchronization of event-related responses to illusions was found between members in some pairs. Synchrony of illusions may indicate that unconscious response-coordination is caused by the illusion-conjunction of crossed dissociative strange-faces, which are perceived as projections into each other's visual face of reciprocal embodied representations within the pair. Inter-subjective strange-face illusions may be explained by the subject's embodied representations (somaesthetic, kinaesthetic and motor facial pattern) and the other's visual face binding. Unconscious facial mimicry may promote inter-subjective illusion-conjunction, then unconscious joint-action and response-coordination.

  2. a Conceptual Design Study of a Next Generation Separator for the In-Flight Separation of Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Münzenberg, Gottfried; Gupta, Mohini; Geissel, Hans; Heinz, Sophia; Hofmann, Sigurd; Plass, Wolfgang R.; Scheidenberger, Christoph; Weick, Helmut; Winkler, Martin

    2013-06-01

    After more than 25 years of the successful operation of SHIP in heavy-and superheavy element research, it is due time for the development of a next-generation in-flight separator for fusion and transfer products, primarily for heavy and superheavy elements. This work is triggered by new developments including accelerators for beams of highest intensity, the availability of strong beams of radioactive isotopes at near Coulomb barrier energies, and the recent developments for efficient ion catcher-cooler systems with the capability of mass identification and measurement.

  3. Systematic study of probable projectile-target combinations for the synthesis of the superheavy nucleus 302120

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Safoora, V.

    2016-08-01

    Probable projectile-target combinations for the synthesis of the superheavy element 302120 have been studied taking the Coulomb and proximity potential as the interaction barrier. The probabilities of the compound nucleus formation PCN for the projectile-target combinations found in the cold reaction valley of 302120 are estimated. At energies near and above the Coulomb barrier, we have calculated the capture, fusion, and evaporation residue cross sections for the reactions of all probable projectile-target combinations so as to predict the most promising projectile-target combinations for the synthesis of the superheavy element 302120 in heavy-ion fusion reactions. The calculated fusion and evaporation cross sections for the more asymmetric ("hotter") projectile-target combination is found to be higher than the less asymmetric ("colder") combination. It can be seen from the nature of the quasifission barrier height, mass asymmetry, the probability of compound nucleus formation, survival probability, and excitation energy, the systems 44Ar+258No , 46Ar+256No , 48Ca+254Fm , 50Ca+252Fm , 54Ti+248Cf , and 58Cr+244Cm in deep region I of the cold reaction valley and the systems 62Fe+240Pu , 64Fe+238Pu , 68Ni+234U , 70Ni+232U , 72Ni+230U , and 74Zn+228Th in the other cold valleys are identified as the better projectile-target combinations for the synthesis of 302120. Our predictions on the synthesis of 302120 superheavy nuclei using the combinations 54Cr+248Cm , 58Fe+244Pu , 64Ni+238U , and 50Ti+249Cf are compared with available experimental data and other theoretical predictions.

  4. K -shell ionization during α decay of polonium isotopes and superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Trzhaskovskaya, M. B.; Nikulin, V. K.

    2016-03-01

    The theory of K -shell ionization during α decay of the 84Po isotopes is considered in detail as a part of our general study of the inner shell ionization probability of heavy and superheavy nuclei. Calculations of K -shell ionization with allowance made for the α -particle tunneling through the atomic Coulomb barrier have been performed in the framework of the fully quantum mechanical treatment developed for the first time by Anholt and Amundsen. Further information is available [Anholt and Amundsen, Phys. Rev. A 25, 169 (1982), 10.1103/PhysRevA.25.169]. As distinct from all previous the K -shell ionization calculations where the Dirac hydrogenlike wave functions have been used, we have found the discrete and continuum electron wave functions in the framework of the relativistic self-consistent Dirac-Fock method. In addition, we have taken into consideration accurately terms associated with the α -particle tunneling. Our exact calculations show that the tunneling contribution to the ionization probability is of great importance while Anholt and Amundsen have asserted that the contribution is small. We have obtained that the K -shell ionization probability during α decay of five isotopes of 84Po correlate better with the available experimental data providing the tunneling is included in calculations. New calculations for K -shell ionization during α decay of superheavy elements Fm249100,No253102,Rg272111, as well as Rn22286 are also presented. The data may be of importance in the combined α ,γ , and conversion-electron spectroscopy used in the superheavy element synthesis analysis.

  5. Central depression in nuclear density and its consequences for the shell structure of superheavy nuclei

    SciTech Connect

    Afanasjev, A.V.; Frauendorf, S.

    2005-02-01

    The influence of the central depression in the density distribution of spherical superheavy nuclei on the shell structure is studied within the relativistic mean-field theory. A large depression leads to the shell gaps at the proton Z=120 and neutron N=172 numbers, whereas a flatter density distribution favors N=184 and leads to the appearance of a Z=126 shell gap and to the decrease of the size of the Z=120 shell gap. The correlations between the magic shell gaps and the magnitude of the central depression are discussed for relativistic and nonrelativistic mean field theories.

  6. Rotational 2+ states of superheavy elements in the Skyrme-Hartree-Fock-Bogoliubov model

    NASA Astrophysics Data System (ADS)

    Baran, A.; Staszczak, A.

    2013-05-01

    The Skyrme-Hartree-Fock-Bogoliubov calculations of the energies of first 2+ rotational states of deformed superheavy (SH) elements in the region of 108 ⩽ Z ⩽ 126 and 148 ⩽ N ⩽ 180 are reported. The results agree well in the case of fermium isotopes after a proper scaling of the moment of inertia. The scaling factor equals 1.3. The extension of the model to the region of SH elements gives a possibility of better estimation of the Q-values of α-decay, which is a dominant decay mode of SH elements.

  7. Strangeness production in small and large collision systems at RHIC

    NASA Astrophysics Data System (ADS)

    Heinz, Mark T.

    2006-07-01

    We present measurements of strange and multi-strange hadrons in p+p collisions at √s =200 GeV measured by STAR. We will compare these preliminary results to leading-order (LO) and next-to-leading order (NLO) perturbative QCD models widely believed to describe the production mechanisms. In particular we will point out recent changes of the model calculations which improve the agreement with our data significantly and will discuss the physics consequences. In larger collision systems, produced with heavy ions at RHIC, we observe the centrality dependence of strange and multi-strange particle production. The non-linear dependency between (anti)-hyperon yields and the system size Npart seems to indicate that the correlation volume does not scale exactly with Npart in contradiction to previous assumptions by thermal models.

  8. Role of strangeness in hybrid stars and possible observables

    NASA Astrophysics Data System (ADS)

    Dexheimer, V.; Negreiros, R.; Schramm, S.

    2015-05-01

    We study the effects of strangeness on the quark sector of a hybrid-star equation of state. Since the model we use to describe quarks is the same as the one we use to describe hadrons, we can also study the effects of strangeness on the chiral symmetry restoration and deconfinement phase transitions (first order or crossover). Finally, we analyze the combined effects of hyperons and quarks on global properties of hybrid stars such as mass, radius, and cooling profiles. It is found that a large amount of strangeness in the core is related to the generation of twin-star solutions, which can have the same mass as the lower or zero strangeness counterpart, but with smaller radii.

  9. Intriguing aspects of strangeness production at CERN energies

    SciTech Connect

    Odyniec, G.

    1996-07-01

    Strange particle production in pp, pA and AA collisions at CERN SPS energies is reviewed. First results from Pb beam experiments are briefly presented. The emerging picture (still incomplete) is discussed.

  10. Strange form factors of octet and decuplet baryons

    SciTech Connect

    Hong, Soon-Tae

    1999-11-22

    The strange form factors of baryon octet are evaluated, in the chiral models with the general chiral SU(3) group structure, to yield the theoretical predictions comparable to the recent experimental data of SAMPLE Collaboration and to study the spin symmetries. Other model predictions are also briefly reviewed to compare with our results and then the strange form factors of baryon octet and decuplet are predicted.

  11. Overview of Issues Surrounding Strangeness in the Nucleon

    SciTech Connect

    Thomas, Anthony W.

    2009-12-17

    The calculation of the strangeness content of the nucleon and its experimental verification is a fundamental step in establishing non-perturbative QCD as the correct theory describing the structure of hadrons. It holds a role in QCD analogous to the correct calculation of the Lamb shift in QED. We review the latest developments in the vector and scalar matrix elements of the strange quarks in the proton, where there has recently been considerable progress.

  12. Overview of Issues Surrounding Strangeness in the Nucleon

    SciTech Connect

    A. W. Thomas

    2009-12-01

    The calculation of the strangeness content of the nucleon and its experimental verification is a fundamental step in establishing non-perturbative QCD as the correct theory describing the structure of hadrons. It holds a role in QCD analogous to the correct calculation of the Lamb shift in QED. We review the latest developments in the vector and scalar matrix elements of the strange quarks in the proton, where there has recently been considerable progress.

  13. RX J1856.5-3754: A Strange Star with Solid Quark Surface?

    NASA Technical Reports Server (NTRS)

    Zhang, Xiaoling; Xu, Renxin; Zhang, Shuangnan

    2003-01-01

    The featureless spectra of isolated 'neutron stars' may indicate that they are actually bare strange stars but a definitive conclusion on the nature of the compact objects cannot be reached until accurate and theoretically calculated spectra of the bare quark surface are known. However due to the complex nonlinearity of quantum chromodynamics it is almost impossible to present a definitive and accurate calculation of the density-dominated quark-gluon plasma from the first principles. Nevertheless it was suggested that cold quark matter with extremely high baryon density could be in a solid state. Within the realms of this possibility we have fitted the 500ks Chandra LETG/HRC data for the brightest isolated neutron star RX 51856.5-3754 with a phenomenological spectral model and found that electric conductivity of quark matter on the stellar surface is about 1.5 x 10(exp 16)/s.

  14. Strange meson-baryon interaction in hot and dense medium: recent progress for a road to GSI/FAIR

    NASA Astrophysics Data System (ADS)

    Cabrera, D.; Tolos, L.; Aichelin, J.; Bratkovskaya, E.

    2016-01-01

    We report recent results on the dynamics of strange hadrons in two-body reactions relevant for near-threshold production in heavy-ion collisions at GSI/FAIR and NICA-Dubna. In particular, K¯N scattering in hot and dense nuclear matter is studied within a chiral unitary framework in coupled channels, setting up the starting point for implementations in microscopic off-shell transport approaches. We focus on the calculation of transition rates with special attention to the excitation of hyperon resonances and isospin effects. Additionally, we explore “unconventional” strangeness generation by meson-meson and meson-baryon interactions in connection with recent HADES observations of deep sub-threshold Φ and Ξ production.

  15. Spin-Orbit Effects in Closed-Shell Heavy and Superheavy Element Monohydrides and Monofluorides with Coupled-Cluster Theory.

    PubMed

    Gao, Dong-Dong; Cao, Zhanli; Wang, Fan

    2016-03-03

    Bond lengths and force constants of a set of closed-shell sixth-row and superheavy element monohydrides and monofluorides are calculated in this work. Kramers restricted coupled-cluster approaches (KR-CC) with spin-orbit coupling (SOC) included at the self-consistent field (SCF) level as well as CC approaches with SOC included in post-SCF treatment (SOC-CC) are employed in calculations. Recently published relativistic effective core potentials are employed, and highly accurate results for superheavy element molecules are achieved with KR-CCSD(T). SOC effects on bond lengths and force constants of these molecules are investigated. Effects of electron correlation are shown to be affected by SOC to a large extent for some superheavy element molecules. Bond lengths and force constants with SOC-CC agree very well with those of KR-CC for most of the sixth-row element molecules. As for superheavy element molecules, SOC-CCSD is able to afford results that are in good agreement with those of KR-CCSD except for 111F, while the error of SOC-CCSD(T) is more pronounced. Large error would be encountered with SOC-CC approaches for molecules when both SOC and electron correlation effects are sizable.

  16. Role of the "window" component of the friction tensor in the formation of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Liang, Yu-Jie; Zhu, Min; Liu, Zu-Hua; Wang, Wen-Zhong

    2014-03-01

    Formation of superheavy nuclei is greatly hindered by the inner barrier and strong dissipation on the way from the contact point of two colliding nuclei to the compound nucleus configuration. One of the dissipation mechanisms is related to the exchange of particles across the window between two nuclei in relative motion, which is the "window" term in the "wall-plus-window" formula. By means of the dynamic analysis for the symmetric systems Xe132 + Xe132 and Xe136 + Xe136, we have shown that the window component of friction tensor retards the elongation of the fusing composite nucleus, decreases the height of the inner barrier, and hence increases the fusion probability. Therefore, the friction associated with "window" term enhances the formation cross sections of superheavy nuclei. Besides, we have shown the mass difference (in units of the temperature) of the fission and neutron emission saddle points as a function of mass number of the hassium isotopes, which may provide a useful reference for synthesis and study of the nuclei adjacent to the doubly magic nucleus Hs270.

  17. Average charge states of heavy and superheavy ions passing through a rarified gas: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Khuyagbaatar, J.; Shevelko, V. P.; Borschevsky, A.; Düllmann, Ch. E.; Tolstikhina, I. Yu.; Yakushev, A.

    2013-10-01

    The average charge states q¯ of heavy and superheavy ions (atomic numbers Z=80-114) passing through He gas are studied experimentally and theoretically. Experimental data were measured at the gas-filled recoil separator, i.e., the TransActinide Separator and Chemistry Apparatus (TASCA) at GSI Darmstadt, for ion energies of a few hundred keV/u at gas pressures of 0.2 to 2.0 mbar. An attempt is made to describe experimental q¯ values by means of atomic calculations of the binding energies and electron-loss and electron-capture cross sections. The influence of the gas-density effect is included in the calculations. The calculated q¯ reproduce the experimental values for elements with Z=80-114 within 20%. A comparison with different semiempirical models is presented as well, including a local fit of high accuracy, which is often used in superheavy-element experiments to estimate the average charge states of heavy ions, e.g., at the gas-filled recoil separator TASCA. The q¯ values for elements with Z=115, 117, 119, and 120 at He-gas pressure of 0.8 mbar are predicted.

  18. Charge-exchange resonances and restoration of Wigner's supersymmetry in heavy and superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Lutostansky, Yu. S.; Tikhonov, V. N.

    2016-11-01

    Various facets of the question of whether Wigner's supersymmetry [ SU(4) symmetry] may be restored in heavy and superheavy nuclei are analyzed on the basis of a comparison of the results of calculations with experimental data. The energy difference between the giant Gamow-Teller resonance and the analog resonance (the difference of E G and E A) according to calculations based on the theory of finite Fermi systems is presented for the case of 33 nuclei for which experimental data are available. The calculated difference Δ E G-A of E G and E A tends to zero in heavier nuclei, showing evidence of the restoration of Wigner's SU(4) symmetry. Also, the isotopic dependence of the Coulomb energy difference between neighboring isobaric nuclei is analyzed within the SU(4) approach for more than 400 nuclei in the mass-number range of A = 5-244. The restoration of Wigner's SU(4) symmetry in heavy nuclei is confirmed. It is shown that the restoration of SU(4) symmetry is compatible with the possible existence of the stability island in the region of superheavy nuclei.

  19. Global properties of even-even superheavy nuclei in macroscopic-microscopic models

    SciTech Connect

    Baran, Andrzej; Lojewski, Zdzislaw; Sieja, Kamila; Kowal, Michal

    2005-10-01

    A systematic study of global properties of superheavy nuclei in the framework of macroscopic-microscopic method is performed. Equilibrium deformations, masses, quadrupole moments, radii, shell energies, fission barriers and half-lives are calculated using the following macroscopic models: Myers-Swiatecki liquid drop, droplet, Yukawa-plus-exponential, and Lublin-Strasbourg drop. Shell and pairing energies are calculated in Woods-Saxon potential with a universal set of parameters. The analysis covers a wide range of even-even superheavy nuclei from Z=100 to 122. Magic and semimagic numbers occurring in this region are indicated and their influence on the observables is discussed. The strongest shell effects appear at proton number Z=114 and at neutron number N=184. Deformed shell closures are found at N=152 and 162. Spontaneous fission half-lives are calculated in a dynamical approach where the full minimization of the action integral in a three-dimensional deformation space of {beta} deformations is performed. The fission half-lives obtained this way are two orders of magnitude smaller than the ones resulting from static calculations. The agreement of theoretical results and experimental data is satisfying.

  20. Synthesis of superheavy elements: Uncertainty analysis to improve the predictive power of reaction models

    NASA Astrophysics Data System (ADS)

    Lü, Hongliang; Boilley, David; Abe, Yasuhisa; Shen, Caiwan

    2016-09-01

    Background: Synthesis of superheavy elements is performed by heavy-ion fusion-evaporation reactions. However, fusion is known to be hindered with respect to what can be observed with lighter ions. Thus some delicate ambiguities remain on the fusion mechanism that eventually lead to severe discrepancies in the calculated formation probabilities coming from different fusion models. Purpose: In the present work, we propose a general framework based upon uncertainty analysis in the hope of constraining fusion models. Method: To quantify uncertainty associated with the formation probability, we propose to propagate uncertainties in data and parameters using the Monte Carlo method in combination with a cascade code called kewpie2, with the aim of determining the associated uncertainty, namely the 95 % confidence interval. We also investigate the impact of different models or options, which cannot be modeled by continuous probability distributions, on the final results. An illustrative example is presented in detail and then a systematic study is carried out for a selected set of cold-fusion reactions. Results: It is rigorously shown that, at the 95 % confidence level, the total uncertainty of the empirical formation probability appears comparable to the discrepancy between calculated values. Conclusions: The results obtained from the present study provide direct evidence for predictive limitations of the existing fusion-evaporation models. It is thus necessary to find other ways to assess such models for the purpose of establishing a more reliable reaction theory, which is expected to guide future experiments on the production of superheavy elements.

  1. Heavy and Superheavy Elements Production in High Intensive Neutron Fluxes of Explosive Process

    NASA Astrophysics Data System (ADS)

    Lutostansky, Yu. S.; Lyashuk, V. I.; Panov, I. V.

    2015-06-01

    Mathematical model of heavy and superheavy nuclei production in intensive pulsed neutron fluxes of explosive process is developed. The pulse character of the process allows dividing it in time into two stages: very short rapid process of multiple neutron captures with higher temperature and very intensive neutron fluxes, and relatively slower process with lesser temperature and neutron fluxes. The model was also extended for calculation of the transuranium yields in nuclear explosions takes into account the adiabatic character of the process, the probabilities of delayed fission, and the emission of delayed neutrons. Also the binary starting target isotopes compositions were included. Calculations of heavy transuranium and transfermium nuclei production were made for "Mike", "Par" and "Barbel" experiments, performed in USA. It is shown that the production of transfermium neutron-rich nuclei and superheavy elements with A ~ 295 is only possible when using binary mixture of starting isotopes with the significant addition of heavy components, such as long-lived isotopes of curium, or californium.

  2. Superconducting quark matter in the Chromodielectric Model

    SciTech Connect

    Linares, L.; Malheiro, M.; Fiolhais, M.; Taurines, A.R.

    2004-12-02

    In this work we study the strange quark matter in an extended version of the Chromodielectric Model (CDM) with a BCS quark pairing implemented, and analyze the superconducting color flavor locked (CFL) phase. We compare the equation of state and the stability of the strange quark matter from QCD in the CFL phase with the superconducting version of the CDM. In the CDM there is a confining potential which originates a dynamical bag constant in the sense that its value depends on the density. Our results indicate that the inclusion in the energy density of the pairing quark interaction allows for an absolutely stable quark matter state even for large potential energies, preventing the metastability of quark matter found in the CDM at high densities.

  3. 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.

  4. New results on mesons containing strange quarks

    SciTech Connect

    Aston, D.; Awaji, N.; Bienz, T.; Bird, F.; D'Amore, J.; Dunwoodie, W.; Endorf, R.; Fujii, K.; Hayashii, H.; Iwata, S.

    1987-01-01

    Recent results of strange and strangeonium mesons are presented. The data come from a high sensitivity study (4.1 ev/nb) of K/sup -/p interactions at 11 GeV/c using the LASS spectrometer at SLAC. The complete leading orbitally-excited K* series up through J/sup P/ = 5/sup -/ and a substantial number of the expected underlying states are observed decaying into K/sup -/..pi../sup +/, anti K/sub 3//sup 0/..pi../sup +/..pi../sup -/, and K eta final states, and new measurements are made of their masses, widths, and branching ratios. Production of strangeonium states via hypercharge exchange is observed into K/sub 3//sup 0/K/sub 3//sup 0/, K/sup -/K/sup +/, and K/sub 3//sup 0/K/sup + -/..pi../sup - +/ final states. The leading orbitally-excited phi series through J/sup P/ = 3/sup -/ is clearly seen and evidence is presented for additional high spin structure in the 2.2 GeV/c/sup 2/ region. No f/sub 2/(1720) is observed. The K/sub 3//sup 0/K/sup + -/..pi../sup - +/ spectrum is dominated by 1/sup +/(K* anti K + anti K* K) production in the region below 1.6 GeV/c/sup 2/. These results are compared with data on the same systems produced by different production mechanisms. 12 refs., 28 figs.

  5. Atmospheric neutrinos can make beauty strange

    NASA Astrophysics Data System (ADS)

    Harnik, Roni; Larson, Daniel T.; Murayama, Hitoshi; Pierce, Aaron

    2004-05-01

    The large observed mixing angle in atmospheric neutrinos, coupled with grand unification, motivates the search for large mixing between right-handed strange and bottom squarks. Such mixing does not appear in the standard Cabibbo-Kobayashi-Maskawa phenomenology, but may induce significant b→s transitions through gluino diagrams. Working in the mass eigenbasis, we show quantitatively that an O(1) effect on CP violation in B0d→φKS is possible due to a large mixing between sR and bR, while still satisfying constraints from b→sγ. We also include the effect of bL-bR mixing proportional to mbμ tan β. In the case where mbμ tan β≪M2SUSY there may be a large effect in Bs mixing correlated with a large effect in B0d→φKS, typically yielding an unambiguous signal of new physics at Tevatron run II.

  6. Atmospheric neutrinos can make beauty strange

    SciTech Connect

    Harnik, Roni; Larson, Daniel T.; Murayama, Hitoshi; Pierce, Aaron

    2002-12-01

    The large observed mixing angle in atmospheric neutrinos, coupled with Grand Unification, motivates the search for a large mixing between right-handed strange and bottom squarks. Such mixing does not appear in the standard CKM phenomenology, but may induce significant b {yields} s transitions through gluino diagrams. Working in the mass eigenbasis, we show quantitatively that an order one effect on CP violation in B{sub d}{sup 0} {yields} {pi}K{sub S} is possible due to a large mixing between right-handed b and s squarks, while still satisfying constraints from b {yields} s {gamma}. We also include the effect of right- and left-handed bottom squark mixing proportional to m{sub b}{mu} tan{beta}. For small {mu}tan{beta} there may also be a large effect in B{sub s} mixing correlated with a large effect in B{sub d}{sup 0} {yields} {phi}K{sub S}, typically yielding an unambiguous signal of new physics at Tevatron Run II.

  7. Slowly rotating neutron and strange stars in R{sup 2} gravity

    SciTech Connect

    Staykov, Kalin V.; Yazadjiev, Stoytcho S.; Doneva, Daniela D.; Kokkotas, Kostas D. E-mail: daniela.doneva@uni-tuebingen.de E-mail: kostas.kokkotas@uni-tuebingen.de

    2014-10-01

    In the present paper we investigate self-consistently slowly rotating neutron and strange stars in R-squared gravity with Lagrangian f(R) = R + aR{sup 2}, where a is a parameter. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in f(R)-gravity and then simultaneously solve numerically the exterior and the interior problem. The structure of the slowly rotating neutron stars is studied for two different hadronic equations of state and a strange matter equation of state. The moment of inertia and its dependence on the stellar mass and the R-squared gravity parameter a is also examined in details. The numerical results show that the neutron star moment of inertia can be up to 30% larger compared to the corresponding general relativistic models. This is much higher than the change in the maximum mass induced by R-squared gravity and is beyond the EOS uncertainty. In this way the future observations of the moment of inertia of compact stars could allow us to distinguish between general relativity and f(R) gravity, and more generally to test the strong field regime of gravity.

  8. Super Heavy Dark Matter in light of BICEP2, Planck and Ultra High Energy Cosmic Rays Observations

    SciTech Connect

    Aloisio, R.; Matarrese, S.; Olinto, A.V. E-mail: sabino.matarrese@pd.infn.it

    2015-08-01

    The announcement by BICEP2 of the detection of B-mode polarization consistent with primordial gravitational waves with a tensor-to-scalar ratio, r=0.2{sup +0.07}{sub −0.05}, challenged predictions from most inflationary models of a lower value for r. More recent results by Planck on polarized dust emission show that the observed tensor modes signal is compatible with pure foreground emission. A more significant constraint on r was then obtained by a joint analysis of Planck, BICEP2 and Keck Array data showing an upper limit to the tensor to scalar ratio r≤ 0.12, excluding the case 0r= with low statistical significance. Forthcoming measurements by BICEP3, the Keck Array, and other CMB polarization experiments, open the possibility for making the fundamental measurement of r. Here we discuss how r sets the scale for models where the dark matter is created at the inflationary epoch, the generically called super-heavy dark matter models. We also consider the constraints on such scenarios given by recent data from ultrahigh energy cosmic ray observatories which set the limit on super-heavy dark matter particles lifetime. We discuss how super-heavy dark matter can be discovered by a precise measurement of r combined with future observations of ultra high energy cosmic rays.

  9. A statistical approach to describe highly excited heavy and superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Chen, Peng-Hui; Feng, Zhao-Qing; Li, Jun-Qing; Zhang, Hong-Fei

    2016-09-01

    A statistical approach based on the Weisskopf evaporation theory has been developed to describe the de-excitation process of highly excited heavy and superheavy nuclei, in particular for the proton-rich nuclei. The excited nucleus is cooled by evaporating γ-rays, light particles (neutrons, protons, α etc) in competition with binary fission, in which the structure effects (shell correction, fission barrier, particle separation energy) contribute to the processes. The formation of residual nuclei is evaluated via sequential emission of possible particles above the separation energies. The available data of fusion-evaporation excitation functions in the 28Si+198Pt reaction can be reproduced nicely within the approach. Supported by Major State Basic Research Development Program in China (2015CB856903), National Natural Science Foundation of China Projects (11175218, U1332207, 11475050, 11175074), and Youth Innovation Promotion Association of Chinese Academy of Sciences

  10. Towards Superheavies: Spectroscopy of 94 < Z < 98, 150 < N < 154 Nuclei

    NASA Astrophysics Data System (ADS)

    Chowdhury, P.; Hota, S. S.; Qiu, Y.; Ahmad, I.; Carpenter, M. P.; Greene, J. P.; Janssens, R. V. F.; Khoo, T. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; Seweryniak, D.; Zhu, S.

    2016-09-01

    The heaviest nuclei where excitations above the ground state can be studied lie near Z ~ 100. These nuclear structure studies are important testing grounds for theoretical models that aim to describe superheavy nuclei. To study the highest neutron orbitals (150 ≤ N ≤ 154), we have populated high angular momentum states in a series of Pu (Z = 94), Cm (Z = 96) and Cf (Z = 98) nuclei, via inelastic and transfer reactions, with heavy beams on long-lived radioactive actinide targets. Multiple collective excitation modes and structures were identified, and their configurations deduced. Quasiparticle alignments are mapped, with odd-A band structures helping identify specific orbital contributions via blocking arguments. Higher-order multipole shapes are observed to play a significant role in disentangling competing neutron and proton alignments. The N > 152 data provide new perspectives on physics beyond the N = 152 sub-shell gap.

  11. Influence of proton shell closure on the evaporation residue cross sections of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Bao, X. J.; Guo, S. Q.; Zhang, H. F.; Li, J. Q.

    2017-04-01

    Within the dinuclear system model we systematically calculate the evaporation residue cross sections (ERCSs) of superheavy nuclei (SHN) for the 48Ca-induced hot fusion reactions. Different calculations of the fission barriers of the SHN are used. The difference is as large as two orders of magnitude of ERCSs by applying the various fission barriers for the reaction 48Ca+249Cf. The dependence of the calculated ERCSs on the predicted shell structure and magic numbers of the heavier SHN is discussed. It is found that the structure of SHN crucially influences the ERCSs. Measurement of ERCSs for at least one isotope of the Z > 118 nucleus would help us to set a proper shell model for the SHN with Z > 118.

  12. Superheavy Nuclei: Which Regions of Nuclear Map are Accessible for the Nearest Studies

    NASA Astrophysics Data System (ADS)

    Karpov, A. V.; Zagrebaev, V. I.; Greiner, W.

    2015-11-01

    Use of fusion reactions for synthesis and studying new superheavy nuclei is considered in the paper. Perspectives of synthesis of new elements with Z > 118 are discussed. The gap of unknown SH nuclei, located between the isotopes which were produced earlier in the cold and hot fusion reactions, can be filled in fusion reactions of 48Ca with available lighter isotopes of Pu, Am, and Cm. Cross sections for the production of these nuclei are predicted to be rather large. The found area of β+-decaying SH nuclei with 111 ≤ Z ≤ 115 located to the "right" (more neutron-rich) to those synthesized recently in Dubna in 48Ca-induced fusion reactions gives a unique chance to synthesize in fusion reactions the most stable SH nuclei located at the center of the island of stability.

  13. Possibilities for synthesis of new isotopes of superheavy nuclei in cold fusion reactions

    NASA Astrophysics Data System (ADS)

    Bao, X. J.; Gao, Y.; Li, J. Q.; Zhang, H. F.

    2016-04-01

    In order to find a way to produce superheavy nuclei (SHN), which appear in the gap between the SHN synthesized by cold fusion and those by hot fusion, or those so far not yet been produced in the laboratory, we tried to make use of a set of projectile isotopic chains, to use a radioactive beam projectile, and to test symmetric fusion reactions for gaining more neutrons to synthesize neutron-richer SHN based on the dinuclear system (DNS) model via cold fusion reactions. It is found that the nuclei 265Mt,Ds,272268,273Rg, and 274,275,276Cn may be produced with the detectable evaporation residual cross sections. The intensities of radioactive beams are significantly less than those of the stable beams, therefore using a stable beam is predicted to be the most favorable method for producing SHN. From the symmetric reaction system 136Xe+136Xe , no fusion event was found.

  14. Observation of Superheavy Nuclei Produced in the Reaction of 86Kr with 208Pb

    NASA Astrophysics Data System (ADS)

    Ninov, V.; Gregorich, K. E.; Loveland, W.; Ghiorso, A.; Hoffman, D. C.; Lee, D. M.; Nitsche, H.; Swiatecki, W. J.; Kirbach, U. W.; Laue, C. A.; Adams, J. L.; Patin, J. B.; Shaughnessy, D. A.; Strellis, D. A.; Wilk, P. A.

    1999-08-01

    Following a prediction by Smolan´czuk [Phys. Rev. C 59, 2634 (1999)], we searched for superheavy element formation in the bombardment of 208Pb with 449-MeV 86Kr ions. We have observed three decay chains, each consisting of an implanted heavy atom and six subsequent α decays, correlated in time and position. In these decay chains, a rapid (ms) sequence of high energy α particles ( Eα>=10 MeV) indicates the decay of a new high- Z element. The observed chains are consistent with the formation of 293118 and its decay by sequential α-particle emission to 289116, 285114, 281112, 277110, 273Hs ( Z = 108) and 269Sg ( Z = 106). The production cross section is 2.2+2.6-0.8 pb.

  15. Alpha Decay Potential Barriers and Half-Lives and Analytical Formula Predictions for Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Royer, Guy; Zhang, Hongfei

    The α decay potential barriers are determined in the cluster-like shape path within a generalized liquid drop model including the proximity effects between the α particle and the daughter nucleus and adjusted to reproduce the experimental Qα. The α emission half-lives are determined within the WKB penetration probability. Calculations using previously proposed formulae depending only on the mass and charge of the alpha emitter and Qα are also compared with new experimental alpha-decay half-lives. The agreement allows to provide predictions for the α decay half-lives of other still unknown superheavy nuclei using the Qα determined from the 2003 atomic mass evaluation of Audi, Wapstra and Thibault.

  16. New approach for alpha decay half-lives of superheavy nuclei and applicability of WKB approximation

    NASA Astrophysics Data System (ADS)

    Dong, Jianmin; Zuo, Wei; Scheid, Werner

    2011-07-01

    The α decay half-lives of recently synthesized superheavy nuclei (SHN) are calculated by applying a new approach which estimates them with the help of their neighbors based on some simple formulas. The estimated half-life values are in very good agreement with the experimental ones, indicating the reliability of the experimental observations and measurements to a large extent as well as the predictive power of our approach. The second part of this work is to test the applicability of the Wentzel-Kramers-Brillouin (WKB) approximation for the quantum mechanical tunneling probability. We calculated the accurate barrier penetrability for alpha decay along with proton and cluster radioactivity by numerically solving Schrödinger equation. The calculated results are compared with those of the WKB method to find that WKB approximation works well for the three physically analogical decay modes.

  17. Fusion-Fission Dynamics of Super-Heavy Element Formation and Decay

    SciTech Connect

    Zagrebaev, V.I.

    2004-04-12

    The paper is focused on reaction dynamics of super-heavy nucleus formation and decay at beam energies near the Coulomb barrier. The aim is to review the things we have learned from recent experiments on fusion-fission reactions leading to the formation of compound nuclei with Z {>=} 102 and from their extensive theoretical analysis. Main attention is paid to the dynamics of formation of very heavy compound nuclei taking place in strong competition with the process of fast fission (quasi-fission). The choice of collective degrees of freedom playing a principal role, finding the multi-dimensional driving potential and the corresponding dynamic equation regulating the whole process are discussed. Theoretical predictions are made for synthesis of SH nuclei up to Z=120 in the asymmetric 'hot' fusion reactions basing on use of the heavy transactinide targets.

  18. On the way to unveiling the atomic structure of superheavy elements

    NASA Astrophysics Data System (ADS)

    Laatiaoui, Mustapha

    2016-12-01

    Optical spectroscopy of the transfermium elements (atomic number Z > 100) is nowadays one of the most fascinating and simultaneously challenging tasks in atomic physics. On the one hand, key atomic and even nuclear ground-state properties may be obtained by studying the spectral lines of these heaviest elements. On the other hand, these elements have to be produced "online" by heavy-ion induced fusion-evaporation reactions yielding rates on the order of a few atoms per second at most, which renders their optical spectroscopy extremely difficult. Only recently, a first foray of laser spectroscopy into this heaviest element region was reported. Several atomic transitions in the element nobelium (Z = 102) were observed and characterized, using an ultra-sensitive and highly efficient resonance ionization technique. The findings confirm the predictions and additionally provide a benchmark for theoretical modelling. The work represents an important stepping stone towards experimental studies of the atomic structure of superheavy elements.

  19. Shell Effects in Fusion-Fission of Heavy and Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Itkis, M. G.; Bogatchev, A. A.; Itkis, I. M.; Jandel, M.; Kliman, J.; Kniajeva, G. N.; Kondratiev, N. A.; Korzyukov, I. V.; Kozulin, E. M.; Krupa, L.; Oganessian, Yu. Ts.; Pokrovsky, I. V.; Prokhorova, E. V.; Voskresenski, V. M.; Zagrebaev, V. I.; Rusanov, A. Ya.; Corradi, L.; Gadea, A.; Latina, L.; Stefanini, A. M.; Szilner, S.; Trotta, M.; Vinodkumar, A. M.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Äystö, J.; Khlebnikov, S. V.; Rubchenya, V. A.; Trzaska, W. H.; Vakhtin, D. N.; Goverdovski, A. A.; Hanappe, F.; Materna, T.; Dorvaux, O.; Rowley, N.; Stuttge, L.; Giardina, G.

    2003-07-01

    The process of fusion-fission of heavy and superheavy nuclei with Z=82-122 formed in the reactions with 48Ca, 58Fe and 64Ni ions at energies near and below the Coulomb barrier has been studied. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Russia), the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy ) and the Accelerator of the Laboratory of University of Jyväskylä (JYFL, Finland) using the time-of-flight spectrometer of fission fragments CORSET[1] and the neutron multi-detector DEMON[2,3]. As a result of the experiments, mass and energy distributions (MED) of fission fragments, cross-sections of fission, quasi-fission and evaporation residues, multiplicities of neutrons and γ-quanta and their dependence on the mechanism of formation and decay of compound systems have been studied.

  20. Validation of new superheavy elements and IUPAC-IUPAP joint working group

    NASA Astrophysics Data System (ADS)

    Jarlskog, Cecilia

    2016-12-01

    The great chemist Glenn Seaborg has written a delightful little book "Man-made Transuranium Elements", published in 1963, in which he points out that: "The former basic criterion for the discovery of a new element - namely, chemical identification and separation from all previously-known elements - had to be changed in the case of lawrencium (element 103). This also may be true for elements beyond lawrencium." Indeed this is what has happened. The elements with Z ≥ 103 are produced in nuclear reactions and are detected by counters. The detectors have undergone substantial refinement. For example one uses multiwire proportional chambers [for which George Charpak received the 1992 Nobel Prize in Physics] as well as solid state micro-strip detectors. In spite of this remarkable shift from chemistry to physics, the managerial staff of the International Union of Pure and Applied Chemistry (IUPAC) does not seem to be aware of what has been going on. The validation of superheavy elements should be done by physicists as the chemists lack the relevant competence as I will discuss here below. This article is about a collaboration between International Union of Pure and Applied Chemistry (IUPAC) and its sister organization International Union of Pure and Applied Physics (IUPAP), to deal with discovery of superheavy elements beyond Z = 112. I spent a great deal of time on this issue. In my opinion, the collaboration turned out to be a failure. For the sake of science, which should be our most important concern (and not politics), the rules for the future collaborations, if any, should be accurately defined and respected. The validation of new elements should be done by people who have the relevant competence - the physicists.

  1. Strangeness production in Si + Au interactions at 14. 6 GeV/c per nucleon

    SciTech Connect

    Hansen, O.

    1989-01-01

    Production of strange particles in proton-proton interactions is systematically suppressed relative to the production of non-strange particles. A first order goal of experiments on strangeness production in nucleus-nucleus collisions is to find out if strangeness is suppressed in a way similar to the p-p interactions or whether the nuclear environment changes the behaviour. This paper investigates this possibility. 13 refs., 1 tab.

  2. The strange flight behaviour of slowly spinning soccer balls

    NASA Astrophysics Data System (ADS)

    Mizota, Taketo; Kurogi, Kouhei; Ohya, Yuji; Okajima, Atsushi; Naruo, Takeshi; Kawamura, Yoshiyuki

    2013-05-01

    The strange three-dimensional flight behaviour of slowly spinning soccer balls is one of the most interesting and unknown phenomenon associated with the trajectories of sports balls. Many spectators have experienced numerous exciting and emotional instances while observing the curious flight behaviour of these balls. We examine the aerodynamic mechanisms of erratic ball behaviours through real flight observations, unsteady force measurements and flow pattern visualisations. The strange behaviour is elucidated by the relationship between the unsteady forces on the ball and the wake flow. The irregular changes in position for twin longitudinal vortices have already been discovered in the supercritical Reynolds number region of a sphere with a smooth surface. This finding is applicable to the strange behaviour of the flight of soccer balls with this supercritical flow. The players, spectators, and television viewers will gain greater insight into the effects of soccer ball flights.

  3. Studies of the Strange Sea-Quarks Spin with Kaons

    NASA Astrophysics Data System (ADS)

    Benmokhtar, Fatiha; Voloshin, Andrew; Goodwill, Justin; Lendacky, Andrew

    2017-01-01

    It is well known that quarks and gluons give the substructure to the nucleons. and understanding of the spin structure of the nucleon in terms of quarks and gluons has been the goal of intense investigations during the last decades. The determination of strangeness is challenging and the only way of determining the strange distribution accurately from data is to improve the semi-inclusive information. This talk is focused on the determination of the strange sea contribution to the nucleon spin through the pseudo-scalar method using semi-inclusive Kaon detection technique with CLAS12 at Jefferson Lab. A Ring Imaging CHerenkov (RICH) detector is under construction and will be used for pion-kaon-proton separation. National Science Foundation #1615067.

  4. A meson cloud model of strangeness asymmetry in the proton

    NASA Astrophysics Data System (ADS)

    Netzel, Greg; Raschko, David; Hansen, Chase

    2013-10-01

    We use a meson cloud model to describe strangeness in the proton. In this model the proton can fluctuate into meson-baryon pairs, as allowed by the Heisenberg uncertainty principle. The leading contributions to strangeness are from the meson-baryon pairs K Λ or K Σ. In this model, the probability of finding strange quark pairs depends on both the splitting functions, which represent the probability of splitting into a given meson-baryon state, and the phenomenological vertex form factors. Because the s and {s} quarks reside in different hadrons, their momentum distributions will differ, as suggested by the NuTeV anomaly and recent global parton distribution fits. We compare our results to other theoretical calculations and to experimental data from HERMES and ATLAS, and to global parton distribution fits. Supported in part by NSF Grants No. 0855656 and 1205686.

  5. Statistical properties of chaotic dynamical systems which exhibit strange attractors

    SciTech Connect

    Jensen, R.V.; Oberman, C.R.

    1981-07-01

    A path integral method is developed for the calculation of the statistical properties of turbulent dynamical systems. The method is applicable to conservative systems which exhibit a transition to stochasticity as well as dissipative systems which exhibit strange attractors. A specific dissipative mapping is considered in detail which models the dynamics of a Brownian particle in a wave field with a broad frequency spectrum. Results are presented for the low order statistical moments for three turbulent regimes which exhibit strange attractors corresponding to strong, intermediate, and weak collisional damping.

  6. A strange horn between Paolo Mantegazza and Charles Darwin.

    PubMed

    Garbarino, Carla; Mazzarello, Paolo

    2013-09-01

    During the preparation of an exhibition in Pavia dedicated to the centennial anniversary of the death of the Italian Pathologist Paolo Mantegazza, a strange cheratinic horn was found at the Museum for the History of the University of Pavia labelled as 'spur of a cock transplanted into an ear of a cow.' After some historical investigation, we found this strange object was at the centre of a scientific correspondence between Mantegazza and Charles Darwin, who made reference to it in his book The Variation of Animals and Plants under Domestication.

  7. Chiral extrapolations on the lattice with strange sea quarks

    NASA Astrophysics Data System (ADS)

    Descotes-Genon, Sébastien

    2005-06-01

    The (light but not-so-light) strange quark may play a special role in the low-energy dynamics of QCD. Strange sea-quark pairs may induce significant differences in the pattern of chiral symmetry breaking in the chiral limits of two and three massless flavours, in relation with the violation of the Zweig rule in the scalar sector. This effect could affect chiral extrapolations of unquenched lattice simulations with three dynamical flavours, and it could be detected through the quark-mass dependence of hadron observables [S. Descotes-Genon, hep-ph/0410233].

  8. Prolapse-free relativistic Gaussian basis sets for the superheavy elements up to Uuo (Z = 118) and Lr (Z = 103)

    SciTech Connect

    Macedo, Luiz Guilherme M de Borin, Antonio Carlos; Silva, Alberico B.F. da

    2007-11-15

    Prolapse-free basis sets suitable for four-component relativistic quantum chemical calculations are presented for the superheavy elements up to {sub 118}Uuo ({sub 104}Rf, {sub 105}Db, {sub 106}Sg, {sub 107}Bh, {sub 108}Hs, {sub 109}Mt, {sub 110}Ds, {sub 111}Rg, {sub 112}Uub, {sub 113}Uut, {sub 114}Uuq, {sub 115}Uup, {sub 116}Uuh, {sub 117}Uus, {sub 118}Uuo) and {sub 103}Lr. These basis sets were optimized by minimizing the absolute values of the energy difference between the Dirac-Fock-Roothaan total energy and the corresponding numerical value at a milli-Hartree order of magnitude, resulting in a good balance between cost and accuracy. Parameters for generating exponents and new numerical data for some superheavy elements are also presented.

  9. Color-flavor locked phase of high density QCD at nonzero strange quark mass

    SciTech Connect

    Kryjevski, Andrei; Yamada, Daisuke

    2005-01-01

    We compute free energy of quark matter at asymptotically high baryon number density in the presence of nonzero strange quark mass including dynamics of pseudo Nambu-Goldstone bosons due to chiral symmetry breaking, extending previously existing analysis based on perturbative expansion in m{sub s}{sup 2}/4{mu}{delta}. We demonstrate that the CFLK{sup 0} state has lower free energy than the symmetric CFL state for 0

  10. 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.

  11. 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.

  12. Some measurements for determining strangeness matrix elements in the nucleon

    SciTech Connect

    Henley, E.M.; Pollock, S.J.; Ying, S.; Frederico, T.; Krein,; Williams, A.G.

    1991-12-31

    Some experiments to measure strangeness matrix elements of the proton are proposed. Two of these suggestions are described in some detail, namely electro-production of phi mesons and the difference between neutrino and antineutrino scattering for isospin zero targets such as deuterium.

  13. Some measurements for determining strangeness matrix elements in the nucleon

    SciTech Connect

    Henley, E.M.; Pollock, S.J.; Ying, S. ); Frederico, T. , Sao Jose dos Campos, SP . Inst. de Estudos Avancados); Krein, . Inst. de Fisica Teorica); Williams, A.G. )

    1991-01-01

    Some experiments to measure strangeness matrix elements of the proton are proposed. Two of these suggestions are described in some detail, namely electro-production of phi mesons and the difference between neutrino and antineutrino scattering for isospin zero targets such as deuterium.

  14. Probing the strange nature of the nucleon with phi photoproduction

    SciTech Connect

    Lowry, M.M.

    1997-03-06

    The presence inside the nucleon of a significant component of strange-antistrange quark pairs has been invoked to explain a number of current puzzles in the low energy realm of QCD. The {sigma} term in {pi}N scattering is a venerable conundrum which can be explained with a 10%--20% admixture. The spin crisis brought on by the EMC result and follow on experiments was first interpreted as requiring a large strange content of s quarks whose spin helped cancel the contribution of the u and d quarks to the nucleon spin, again of order 10%. Excess phi meson production in p{anti p} annihilation at LEAR has also been explained in terms of up to a 19% admixture of s{anti s} pairs. Charm production in deep-inelastic neutrino scattering would appear to provide evidence for a 3% strange sea. It is clear that a definite probe of the strange quark content would be an invaluable tool in unraveling a number of mysteries. The longitudinal beam target asymmetry in {psi} photoproduction is a particularly sensitive probe of that content. It is explored here.

  15. Measuring Infant-Mother Attachment: Is the Strange Situation Enough?

    ERIC Educational Resources Information Center

    Clarke-Stewart, K. Alison; Goossens, Frits A.; Allhusen, Virginia D.

    2001-01-01

    Examined validity of the California Attachment Procedure (CAP), which does not involve mother-child separations. Overall, toddlers were more likely to be classified as secure in the CAP than in the Strange Situation (SS) test. The CAP yielded higher rates of security, particularly for children in day care, and security in the CAP correlated more…

  16. Oral osteomyelitis: pre-AIDS manifestation or strange coincidence?

    PubMed

    Harel-Raviv, M; Gorsky, M; Lust, I; Raviv, E

    1996-01-01

    A bizarre and unexplained localized osteomyelitis was discovered in the mandible of an otherwise apparently healthy 36-year-old man. This strange oral manifestation was followed 2 years later by a diagnosis of Pneumocystis carinii pneumonia, which indicated full-blown AIDS. Could osteomyelitis of the mandible be an alarming oral manifestation of AIDS before the disease is manifested in other ways?

  17. Strangeness -2 and -3 Baryons in a Constituent Quark Model

    SciTech Connect

    Muslema Pervin; Winston Roberts

    2007-09-19

    We apply a quark model developed in earlier work to the spectrum of baryons with strangeness -2 and -3. The model describes a number of well-established baryons successfully, and application to cascade baryons allows the quantum numbers of some known states to be deduced.

  18. Strange vector form factors from parity-violating electron scattering

    SciTech Connect

    Kent Paschke, Anthony Thomas, Robert Michaels, David Armstrong

    2011-06-01

    The simplest models might describe the nucleon as 3 light quarks, but this description would be incomplete without inclusion of the sea of glue and qbar q pairs which binds it. Early indications of a particularly large contribution from strange quarks in this sea to the spin and mass of the nucleon motivated an experimental program examining the role of these strange quarks in the nucleon vector form factors. The strangeness form factors can be extracted from the well-studied electromagnetic structure of the nucleon using parity-violation in electron-nuclear scattering to isolate the effect of the weak interaction. With high luminosity and polarization, and a very stable beam due to its superconducting RF cavities, CEBAF at Jefferson Lab is a precision instrument uniquely well suited to the challenge of measurements of the small parity-violating asymmetries. The techniques and results of the two major Jefferson Lab experimental efforts in parity-violation studies, HAPPEX and G0, as well as efforts to describe the strange form factors in QCD, will be reviewed.

  19. Exploring Strange Nonchaotic Attractors through Jacobian Elliptic Functions

    ERIC Educational Resources Information Center

    Garcia-Hoz, A. Martinez; Chacon, R.

    2011-01-01

    We demonstrate the effectiveness of Jacobian elliptic functions (JEFs) for inquiring into the reshaping effect of quasiperiodic forces in nonlinear nonautonomous systems exhibiting strange nonchaotic attractors (SNAs). Specifically, we characterize analytically and numerically some reshaping-induced transitions starting from SNAs in the context of…

  20. Study of doubly strange systems using stored antiprotons

    NASA Astrophysics Data System (ADS)

    Singh, B.; Erni, W.; Krusche, B.; Steinacher, M.; Walford, N.; Liu, B.; Liu, H.; Liu, Z.; Shen, X.; Wang, C.; Zhao, J.; Albrecht, M.; Erlen, T.; Fink, M.; Heinsius, F.; Held, T.; Holtmann, T.; Jasper, S.; Keshk, I.; Koch, H.; Kopf, B.; Kuhlmann, M.; Kümmel, M.; Leiber, S.; Mikirtychyants, M.; Musiol, P.; Mustafa, A.; Pelizäus, M.; Pychy, J.; Richter, M.; Schnier, C.; Schröder, T.; Sowa, C.; Steinke, M.; Triffterer, T.; Wiedner, U.; Ball, M.; Beck, R.; Hammann, C.; Ketzer, B.; Kube, M.; Mahlberg, P.; Rossbach, M.; Schmidt, C.; Schmitz, R.; Thoma, U.; Urban, M.; Walther, D.; Wendel, C.; Wilson, A.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Patel, B.; Czyzycki, W.; Domagala, M.; Filo, G.; Jaworowski, J.; Krawczyk, M.; Lisowski, E.; Lisowski, F.; Michałek, M.; Poznański, P.; Płażek, J.; Korcyl, K.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Biernat, J.; Kamys, B.; Kistryn, S.; Korcyl, G.; Krzemien, W.; Magiera, A.; Moskal, P.; Psyzniak, A.; Rudy, Z.; Salabura, P.; Smyrski, J.; Strzempek, P.; Wronska, A.; Augustin, I.; Böhm, R.; Lehmann, I.; Nicmorus Marinescu, D.; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Ehret, A.; Flemming, H.; Gerhardt, A.; Götzen, K.; Gromliuk, A.; Gruber, L.; Karabowicz, R.; Kliemt, R.; Krebs, M.; Kurilla, U.; Lehmann, D.; Löchner, S.; Lühning, J.; Lynen, U.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Ugur, C.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V. M.; Alexeev, G.; Arefiev, A.; Astakhov, V. I.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Yu. I.; Dodokhov, V. Kh.; Efremov, A. A.; Fechtchenko, A.; Fedunov, A. G.; Galoyan, A.; Grigoryan, S.; Koshurnikov, E. K.; Lobanov, V. I.; Lobanov, Y. Yu.; Makarov, A. F.; Malinina, L. V.; Malyshev, V. L.; Olshevskiy, A.; Perevalova, E.; Piskun, A. A.; Pocheptsov, T.; Pontecorvo, G.; Rodionov, V.; Rogov, Y.; Salmin, R.; Samartsev, A.; Sapozhnikov, M. G.; Shabratova, G.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Suleimanov, M.; Teshev, R.; Tokmenin, V.; Uzhinsky, V.; Vodopyanov, A.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Böhm, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Dobbs, S.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savriè, M.; Akishina, V.; Kisel, I.; Kozlov, G.; Pugach, M.; Zyzak, M.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Biguenko, K.; Brinkmann, K.; Di Pietro, V.; Diehl, S.; Dormenev, V.; Drexler, P.; Düren, M.; Etzelmüller, E.; Galuska, M.; Gutz, E.; Hahn, C.; Hayrapetyan, A.; Kesselkaul, M.; Kühn, W.; Kuske, T.; Lange, J. S.; Liang, Y.; Metag, V.; Nanova, M.; Nazarenko, S.; Novotny, R.; Quagli, T.; Reiter, S.; Rieke, J.; Rosenbaum, C.; Schmidt, M.; Schnell, R.; Stenzel, H.; Thöring, U.; Ullrich, M.; Wagner, M. N.; Wasem, T.; Wohlfarth, B.; Zaunick, H.; Ireland, D.; Rosner, G.; Seitz, B.; Deepak, P. N.; Kulkarni, A.; Apostolou, A.; Babai, M.; Kavatsyuk, M.; Lemmens, P.; Lindemulder, M.; Loehner, H.; Messchendorp, J.; Schakel, P.; Smit, H.; Tiemens, M.; van der Weele, J. C.; Veenstra, R.; Vejdani, S.; Dutta, K.; Kalita, K.; Kumar, A.; Roy, A.; Sohlbach, H.; Bai, M.; Bianchi, L.; Büscher, M.; Cao, L.; Cebulla, A.; Dosdall, R.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Lehrach, A.; Nellen, R.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Prencipe, E.; Pütz, J.; Ritman, J.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Zambanini, A.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Isaksson, L.; Achenbach, P.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Karavdina, A.; Lauth, W.; Liu, Z.; Merkel, H.; Müller, U.; Pochodzalla, J.; Schlimme, S.; Sfienti, C.; Thiel, M.; Ahmadi, H.; Ahmed, S.; Bleser, S.; Capozza, L.; Cardinali, M.; Dbeyssi, A.; Deiseroth, M.; Feldbauer, F.; Fritsch, M.; Fröhlich, B.; Jasinski, P.; Kang, D.; Khaneft, D.; Klasen, R.; Leithoff, H. H.; Lin, D.; Maas, F.; Maldaner, S.; Martìnez Rojo, M.; Marta, M.; Michel, M.; Mora Espì, M. C.; Morales Morales, C.; Motzko, C.; Nerling, F.; Noll, O.; Pflüger, S.; Pitka, A.; Rodríguez Piñeiro, D.; Sanchez Lorente, A.; Steinen, M.; Valente, R.; Weber, T.; Zambrana, M.; Zimmermann, I.; Fedorov, A.; Korjik, M.; Missevitch, O.; Boukharov, A.; Malyshev, O.; Marishev, I.; Balanutsa, P.; Balanutsa, V.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Chandratre, V.; Datar, V.; Dutta, D.; Jha, V.; Kumawat, H.; Mohanty, A. K.; Parmar, A.; Roy, B.; Sonika, G.; Fritzsch, C.; Grieser, S.; Hergemöller, A. K.; Hetz, B.; Hüsken, N.; Khoukaz, A.; Wessels, J. P.; Khosonthongkee, K.; Kobdaj, C.; Limphirat, A.; Srisawad, P.; Yan, Y.; Barnyakov, M.; Barnyakov, A. Yu.; Beloborodov, K.; Blinov, A. E.; Blinov, V. E.; Bobrovnikov, V. S.; Kononov, S.; Kravchenko, E. A.; Kuyanov, I. A.; Martin, K.; Onuchin, A. P.; Serednyakov, S.; Sokolov, A.; Tikhonov, Y.; Atomssa, E.; Kunne, R.; Marchand, D.; Ramstein, B.; Van de Wiele, J.; Wang, Y.; Boca, G.; Costanza, S.; Genova, P.; Montagna, P.; Rotondi, A.; Abramov, V.; Belikov, N.; Bukreeva, S.; Davidenko, A.; Derevschikov, A.; Goncharenko, Y.; Grishin, V.; Kachanov, V.; Kormilitsin, V.; Levin, A.; Melnik, Y.; Minaev, N.; Mochalov, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Tomasi-Gustafsson, E.; Roy, U.; Yabsley, B.; Belostotski, S.; Gavrilov, G.; Izotov, A.; Manaenkov, S.; Miklukho, O.; Veretennikov, D.; Zhdanov, A.; Makonyi, K.; Preston, M.; Tegner, P.; Wölbing, D.; Bäck, T.; Cederwall, B.; Rai, A. K.; Godre, S.; Calvo, D.; Coli, S.; De Remigis, P.; Filippi, A.; Giraudo, G.; Lusso, S.; Mazza, G.; Mignone, M.; Rivetti, A.; Wheadon, R.; Balestra, F.; Iazzi, F.; Introzzi, R.; Lavagno, A.; Olave, J.; Amoroso, A.; Bussa, M. P.; Busso, L.; De Mori, F.; Destefanis, M.; Fava, L.; Ferrero, L.; Greco, M.; Hu, J.; Lavezzi, L.; Maggiora, M.; Maniscalco, G.; Marcello, S.; Sosio, S.; Spataro, S.; Birsa, R.; Bradamante, F.; Bressan, A.; Martin, A.; Calen, H.; Ikegami Andersson, W.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Papenbrock, M.; Pettersson, J.; Schönning, K.; Wolke, M.; Galnander, B.; Diaz, J.; Pothodi Chackara, V.; Chlopik, A.; Kesik, G.; Melnychuk, D.; Slowinski, B.; Trzcinski, A.; Wojciechowski, M.; Wronka, S.; Zwieglinski, B.; Bühler, P.; Marton, J.; Steinschaden, D.; Suzuki, K.; Widmann, E.; Zmeskal, J.; Gerl, Jürgen; Kojouharov, Ivan; Kojouharova, Jasmina

    2016-10-01

    Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P ‾ ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ--atoms will be feasible and even the production of Ω--atoms will be within reach. The latter might open the door to the | S | = 3 world in strangeness nuclear physics, by the study of the hadronic Ω--nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions.

  1. Familiar-Strange: Teaching the Scripture as John Would Teach

    ERIC Educational Resources Information Center

    Ha, Tung-Chiew

    2014-01-01

    The Gospel of John teaches through telling the story of Jesus in light of the familiar Hebrew faith stories. It is an interpretive task that presents Jesus to his audience and teaches them adequate faith. John the Teacher skillfully uses narrative skills to create the familiar-strange effect in his storytelling. Each story is followed by a…

  2. 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

  3. Density-Dependent Relations among Properties of Hadronic Matter and Applications to Hadron-Quark Stars

    SciTech Connect

    Uechi, Hiroshi; Uechi, Schun T.

    2011-05-06

    Density-dependent relations among the saturation properties of symmetric nuclear matter and hyperonic matter, and properties of hadron-(strange) quark stars are shown by applying the conserving nonlinear {sigma}-{omega}-{rho} hadronic mean-field theory. Nonlinear interactions are renormalized self-consistently as effective coupling constants, effective masses, and sources of equations of motion by maintaining thermodynamic consistency to the mean-field approximation. Effective masses and coupling constants at the saturation point of symmetric nuclear matter simultaneously determine the binding energy and saturation properties of hyperonic matter. The coupling constants expected from the hadronic mean-field model and SU(6) quark model for the vector coupling constants are compared by calculating masses of hadron-quark neutron stars. The nonlinear {sigma}-{omega}-{rho} mean-field approximation with vacuum fluctuation corrections and strange quark matter defined by the MIT-bag model were employed to examine properties of hadron-(strange) quark stars. We found that hadron-(strange) quark stars become more stable at high densities compared to pure hadronic and strange quark stars.

  4. Hades experiment probing baryonic matter at SIS18 overview of results

    NASA Astrophysics Data System (ADS)

    Salabura, Piotr

    2017-03-01

    HADES experiment at GSI is the only high precision experiment probing nuclear matter in the beam energy range of a few AGeV. Pion, proton and ion beams are used to study rare dielectron and strangeness probes to diagnose properties of strongly interacting matter in this energy regime. Selected results from p + A and A + A collisions are presented and discussed.

  5. Calculation of evaporation residue cross sections for the synthesis of superheavy nuclei in hot fusion reactions

    NASA Astrophysics Data System (ADS)

    Zhang, Jinjuan; Wang, Chengbin; Ren, Zhongzhou

    2013-07-01

    A systematic calculation of the production cross sections of superheavy elements (SHEs) in hot fusion reactions is performed. First, we analyze the reactions of 48Ca + 238U, 244Pu, and 248Cm, from which the parameter values in the model for each process are determined by comparing the calculated capture, fusion, and evaporation residue (ER) cross sections, respectively, with the measured data. Then, we calculate the ER cross sections of other hot fusion reactions with the derived parameter values. The calculated results are in good agreement with the available data. Furthermore, the possible isotope production cross sections of elements 118 and 117 in the reactions of 48Ca + ACf and ABk are computed. We find that with the increase of the neutron number of the target, the production cross sections of the SHEs increase, primarily caused by the smaller neutron separation energies of the corresponding neutron-rich compound nucleus (CN). Finally, the production cross sections of elements 120 and 119 are evaluated in fusion-evaporation reactions with 50Ti as a projectile.

  6. Alpha-decay of deformed superheavy nuclei as a probe of shell closures

    NASA Astrophysics Data System (ADS)

    Ismail, M.; Seif, W. M.; Adel, A.; Abdurrahman, A.

    2017-02-01

    A systematic study on α-decay half-life time, Tα, of α-particle emission from a large number of deformed heavy and superheavy nuclei is presented. The calculations are employed in the framework of the density-dependent cluster model. The microscopic α-daughter nuclear interaction potential is calculated in the framework of the double-folding model with the realistic effective Michigan-three-Yukawa Reid nucleon-nucleon interaction. We study the neutron number variation of log Tα and arranged different isotones at each neutron magic number according to their stability, in the sense that the more stable isotone corresponds to the lowest value of log Tα. We found that the half-life time becomes minimum when the neutron or proton numbers of the corresponding daughter nucleus are magic. Moreover, the half-life time is maximum for parent nucleus with magicity. The nuclear stability is assumed to be proportional with the depth of the minimum value in log Tα for the daughter nucleus or the height of its maximum value for the parent one. The neutron magic numbers predicted and confirmed from the present study are 126, 152, 162, 172, 184, 196, 202 and 212, most of them were deduced by other authors based on different methods.

  7. Charge Spectrum of Heavy and Superheavy Components of Galactic Cosmic Rays: Results of the Olimpiya Experiment

    NASA Astrophysics Data System (ADS)

    Alexeev, Victor; Bagulya, Alexander; Chernyavsky, Mikhail; Gippius, Alexei; Goncharova, Lyudmila; Gorbunov, Sergei; Gorshenkov, Mikhail; Kalinina, Galina; Konovalova, Nina; Liu, Jie; Zhai, Pengfei; Okatyeva, Natalia; Pavlova, Tatyana; Polukhina, Natalia; Starkov, Nikolai; Naing Soe, Than; Trautmann, Christina; Savchenko, Elena; Shchedrina, Tatyana; Vasiliev, Alexander; Volkov, Alexander

    2016-10-01

    The aim of the OLIMPIYA experiment is to search for and identify traces of heavy and superheavy nuclei of galactic cosmic rays (GCR) in olivine crystals from stony-iron meteorites serving as nuclear track detectors. The method is based on layer-by-layer grinding and etching of particle tracks in these crystals. Unlike the techniques of other authors, this annealing-free method uses two parameters: the etching rate along the track (V etch) and the total track length (L), to identify charge Z of a projectile. A series of irradiations with different swift heavy ions at the accelerator facilities of GSI (Darmstadt) and IMP (Lanzhou) were performed in order to determine and calibrate the dependence of projectile charge on V etch and L. To date, one of the most essential results of the experiment is the obtained charge spectrum of GCR nuclei within the range of Z > 40, based on about 11.6 thousand processed tracks. As the result of data processing, 384 nuclei with charges Z ≥ 75 have been identified, including 10 nuclei identified as actinides (90 < Z < 103). Three tracks were identified to be produced by nuclei with charges 113 < Z < 129. Such nuclei may be part of the Island of Stability of transfermium elements.

  8. Production of heavy and superheavy neutron-rich nuclei in neutron capture processes

    NASA Astrophysics Data System (ADS)

    Zagrebaev, V. I.; Karpov, A. V.; Mishustin, I. N.; Greiner, Walter

    2011-10-01

    The neutron capture process is considered as an alternative method for production of superheavy (SH) nuclei. Strong neutron fluxes might be provided by nuclear reactors and nuclear explosions in the laboratory frame and by supernova explosions in nature. All these cases are discussed in the paper. There are two gaps of short-lived nuclei (one is the well-known fermium gap and the other one is located in the region of Z=106-108 and N˜170) which impede the formation of SH nuclei by rather weak neutron fluxes realized at available nuclear reactors. We find that in the course of multiple (rather “soft”) nuclear explosions these gaps may be easily bypassed, and thus, a measurable amount of the neutron-rich long-living SH nuclei located at the island of stability may be synthesized. Existing pulsed reactors do not allow one to bypass these gaps. We formulate requirements for the pulsed reactors of the next generation that could be used for production of long-living SH nuclei. Natural formation of SH nuclei (in supernova explosions) is also discussed. The yield of SH nuclei relative to lead is estimated to be about 10-12, which is not beyond the experimental sensitivity for a search of SH elements in cosmic rays.

  9. Superheavy Element Chemistry by Relativistic Density Functional Theory Electronic Structure Modeling

    NASA Astrophysics Data System (ADS)

    Zaitsevskii, A. V.; Polyaev, A. V.; Demidov, Yu. A.; Mosyagin, N. S.; Lomachuk, Yu. V.; Titov, A. V.

    2015-06-01

    Two-component density functional theory in its non-collinear formulation combined with the accurate relativistic electronic structure model defined by shape-consistent small-core pseudopotentials (PP/RDFT) provides a robust basis of efficient computational schemes for predicting energetic and structural properties of complex polyatomic systems including superheavy elements (SHEs). Because of the exceptional role of thermochromatography in the experiments on the "chemical" identification of SHEs with atomic numbers Z ≥ 112, we focus on the description of the adsorption of single SHE atoms on the surfaces of solids through cluster modeling of adsorption complexes. In some cases our results differ significantly from those of previous theoretical studies. The results of systematic comparative studies on chemical bonding in simple molecules of binary compounds of SHEs and their nearest homologs with most common light elements, obtained at the PP/RDFT level and visualized through the "chemical graphs", provide the understanding of the general chemistry of SHEs which at present cannot be derived from the experimental data. These results are used to discuss the main trends in changing chemical properties of the elements in the given group of the periodic table and demonstrate the specificity of SHEs.

  10. Heavy particle radioactivity from superheavy nuclei leading to 298114 daughter nuclei

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Priyanka, B.

    2014-09-01

    The feasibility for the alpha decay and the heavy particle decay from the even-even superheavy (SH) nuclei with Z = 116- 124 has been studied within the Coulomb and proximity potential model (CPPM). Our predicted half lives agree well with the values evaluated using the Universal formula for cluster decay (UNIV) of Poenaru et al., the Universal Decay Law (UDL) of Qi et al., and the Scaling Law of Horoi et al. The spontaneous fission half lives of the corresponding parents have also been evaluated using the semi-empirical formula of Santhosh et al. Within our fission model, we have studied the cluster formation probability for various clusters and the maximum cluster formation probability is found for the decay accompanying 298114. In the plots for log10 (T1/2) against the neutron number of the daughter in the corresponding decay, the half life is found to be the minimum for the decay leading to 298114 (Z = 114, N = 184). Most of the predicted half lives are well within the present upper limit for measurements (T1/2 <1030 s) and the computed alpha half lives for 290,292Lv agree well with the experimental data.

  11. Multi-strangeness production in hadron induced reactions

    NASA Astrophysics Data System (ADS)

    Gaitanos, T.; Moustakidis, Ch.; Lalazissis, G. A.; Lenske, H.

    2016-10-01

    We discuss in detail the formation and propagation of multi-strangeness particles in reactions induced by hadron beams relevant for the forthcoming experiments at FAIR. We focus the discussion on the production of the decuplet-particle Ω and study for the first time the production and propagation mechanism of this heavy hyperon inside hadronic environments. The transport calculations show the possibility of Ω-production in the forthcoming P ‾ANDA-experiment, which can be achieved with measurable probabilities using high-energy secondary Ξ-beams. We predict cross sections for Ω-production. The theoretical results are important in understanding the hyperon-nucleon and, in particular, the hyperon-hyperon interactions also in the high-strangeness sector. We emphasize the importance of our studies for the research plans at FAIR.

  12. Parity Violating Electron Scattering and Strangeness in the Nucleon

    SciTech Connect

    Maas, Frank E.

    2008-10-13

    A measurement of the weak form factor of the proton allows a flavor separation of the strangeness contribution to the electromagnetic form factors. The weak form factor is accessed experimentally by the measurement of a parity violating (PV) asymmetry in the scattering of polarized electrons on unpolarized protons. An extended experimental program to measure these parity violating asymmetries has been performed and is going on at different accelerators. After the first round of experiments allowing a separation of the strangeness form factors G{sub E}{sup s} and G{sub M}{sup s} at a Q{sup 2}-value of 0.1 (GeV/c){sup 2}, new, preliminary results have been achieved at 0.23 (GeV/c){sup 2}.

  13. Strange quintessence star in Krori-Barua spacetime

    NASA Astrophysics Data System (ADS)

    Bhar, Piyali

    2015-04-01

    In the present paper a new model of a compact star is obtained by utilizing the Krori-Barua (KB) ansatz [Krori and Barua in J. Phys. A, Math. Gen. 8:508, 1975] in the presence of a quintessence field characterized by a parameter ω q with . The obtained model of strange stars is singularity free and satisfies all the physical requirements. Our model is stable as well as it is in static equilibrium. The numerical values of the mass of the strange stars 4U1820-30 (radius=10 km), SAX J1808.4-3658(SS1) (radius=7.07 km) and Her X-1 (radius=7.7 km) calculated from our model are very close to the standard data. The interior solution is matched to the exterior Schwarzschild spacetime in the presence of a thin shell where a negative surface pressure is needed to keep the thin shell from collapsing.

  14. Strange attractors in weakly turbulent Couette-Taylor flow

    NASA Technical Reports Server (NTRS)

    Brandstater, A.; Swinney, Harry L.

    1987-01-01

    An experiment is conducted on the transition from quasi-periodic to weakly turbulent flow of a fluid contained between concentric cylinders with the inner cylinder rotating and the outer cylinder at rest. Power spectra, phase-space portraits, and circle maps obtained from velocity time-series data indicate that the nonperiodic behavior observed is deterministic, that is, it is described by strange attractors. Various problems that arise in computing the dimension of strange attractors constructed from experimental data are discussed and it is shown that these problems impose severe requirements on the quantity and accuracy of data necessary for determining dimensions greater than about 5. In the present experiment the attractor dimension increases from 2 at the onset of turbulence to about 4 at a Reynolds number 50-percent above the onset of turbulence.

  15. Strangeness-conserving hadronic parity violation at low energies

    NASA Astrophysics Data System (ADS)

    Liu, C.-P.

    2007-05-01

    The parity-violating nucleaon interacton is the key to understanding the strangeness-conserving hadronic weak interaction at low energies. In this brief talk, I review the past accomplishement in and current status of this subject, and outline a new joint effort between experiment and theory that that tries to address the potential problems in the past by focusing on parity violation in few-nucleon systems and using the language of effective field theory.

  16. A useful approximate isospin equality for charmless strange B decays.

    SciTech Connect

    Lipkin, H. J.; High Energy Physics; Weizmann Inst. of Science; Aviv Univ.

    1999-01-01

    A useful inequality is obtained if charmless strange B decays are assumed to be dominated by a {Delta}l=0 transition like that from the gluonic penguin diagram and the contributions of all other diagrams including the tree, electroweak penguin and annihilation diagrams are small but not negligible. The interference contributions which are linear in these other amplitudes are included but the direct contributions which are quadratic are neglected.

  17. Competition between alpha-decay and spontaneous fission at isotopes of superheavy elements Rf, Db, and Sg

    SciTech Connect

    Anghel, Claudia Ioana; Silisteanu, Andrei Octavian

    2015-12-07

    The most important decay modes for heavy and superheavy nuclei are their α-decay and spontaneous fission. This work investigates the evolution and the competition of these decay modes in long isotopic sequences. The partial half-lives are given by minimal sets of parameters extracted from the fit of experimental data and theoretical results. A summary of the experimental and calculated α-decay and spontaneous fission half-lives of the isotopes of elements Rf, Db, and Sg is presented. Some half-life extrapolations for nuclides not yet known are also obtained.

  18. Mean-field studies of time reversal breaking states in super-heavy nuclei with the Gogny force

    SciTech Connect

    Robledo, L. M.

    2015-10-15

    Recent progress on the description of time reversal breaking (odd mass and multi-quasiparticle excitation) states in super-heavy nuclei within a mean field framework and using several flavors of the Gogny interaction is reported. The study includes ground and excited states in selected odd mass isotopes of nobelium and mendelevium as well as high K isomeric states in {sup 254}No. These are two and four-quasiparticle excitations that are treated in the same self-consistent HFB plus blocking framework as the odd mass states.

  19. Mean-field studies of time reversal breaking states in super-heavy nuclei with the Gogny force

    NASA Astrophysics Data System (ADS)

    Robledo, L. M.

    2015-10-01

    Recent progress on the description of time reversal breaking (odd mass and multi-quasiparticle excitation) states in super-heavy nuclei within a mean field framework and using several flavors of the Gogny interaction is reported. The study includes ground and excited states in selected odd mass isotopes of nobelium and mendelevium as well as high K isomeric states in 254No. These are two and four-quasiparticle excitations that are treated in the same self-consistent HFB plus blocking framework as the odd mass states.

  20. Thermodynamic instabilities in hot and dense nuclear matter

    NASA Astrophysics Data System (ADS)

    Lavagno, A.

    2016-11-01

    We study the presence of thermodynamic instabilities in a hot and dense nuclear medium where a nuclear phase transition can take place. Similarly to the low density nuclear liquid-gas phase transition, we show that such a phase transition is characterized by pure hadronic matter with both mechanical instability (fluctuations on the baryon density) that by chemical-diffusive instability (fluctuations on the strangeness concentration). The analysis is performed by requiring the global conservation of baryon number and zero net strangeness in the framework of an effective relativistic mean field theory with the inclusion of the Δ(1232)-isobars, hyperons and the lightest pseudoscalar and vector meson degrees of freedom. It turns out that in this situation hadronic phases with different values of strangeness content may coexist, altering significantly meson-antimeson ratios.

  1. Quark matter symmetry energy and quark stars

    SciTech Connect

    Chu, Peng-Cheng; Chen, Lie-Wen

    2014-01-10

    We extend the confined-density-dependent-mass (CDDM) model to include isospin dependence of the equivalent quark mass. Within the confined-isospin-density-dependent-mass (CIDDM) model, we study the quark matter symmetry energy, the stability of strange quark matter, and the properties of quark stars. We find that including isospin dependence of the equivalent quark mass can significantly influence the quark matter symmetry energy as well as the properties of strange quark matter and quark stars. While the recently discovered large mass pulsars PSR J1614–2230 and PSR J0348+0432 with masses around 2 M {sub ☉} cannot be quark stars within the CDDM model, they can be well described by quark stars in the CIDDM model. In particular, our results indicate that the two-flavor u-d quark matter symmetry energy should be at least about twice that of a free quark gas or normal quark matter within the conventional Nambu-Jona-Lasinio model in order to describe PSR J1614–2230 and PSR J0348+0432 as quark stars.

  2. Hyperon-Nucleon Interactions and the Composition of Dense Matter from Quantum Chromodynamics

    SciTech Connect

    Konstantinos Orginos, Silas Beane, Emmanuel Chang, Saul Cohen, Huey-Wen Lin, Tom Luu, Assumpta Parreno, Martin Savage, Andre Walker-Loud, William Detmold

    2012-10-01

    The low-energy n{Sigma}{sup -} interactions determine, in part, the role of the strange quark in dense matter, such as that found in astrophysical environments. The scattering phase-shifts for this system are determined from a numerical evaluation of the QCD path integral using the technique of Lattice QCD. Our results, performed at a pion mass of m{sub {pi}} ~ 389 MeV in two large lattice volumes, and at one lattice spacing, are extrapolated to the physical pion mass using effective field theory. The calculated interactions indicate that the strange quark plays an important role in dense matter.

  3. Applications of Skyrme energy-density functional to fusion reactions for synthesis of superheavy nuclei

    SciTech Connect

    Wang Ning; Scheid, Werner; Wu Xizhen; Liu Min; Li Zhuxia

    2006-10-15

    The Skyrme energy-density functional approach has been extended to study massive heavy-ion fusion reactions. Based on the potential barrier obtained and the parametrized barrier distribution the fusion (capture) excitation functions of a lot of heavy-ion fusion reactions are studied systematically. The average deviations of fusion cross sections at energies near and above the barriers from experimental data are less than 0.05 for 92% of 76 fusion reactions with Z{sub 1}Z{sub 2}<1200. For the massive fusion reactions, for example, the {sup 238}U-induced reactions and {sup 48}Ca+{sup 208}Pb, the capture excitation functions have been reproduced remarkably well. The influence of structure effects in the reaction partners on the capture cross sections is studied with our parametrized barrier distribution. By comparing the reactions induced by double-magic nucleus {sup 48}Ca and by {sup 32}S and {sup 35}Cl, the ''threshold-like'' behavior in the capture excitation function for {sup 48}Ca-induced reactions is explored and an optimal balance between the capture cross section and the excitation energy of the compound nucleus is studied. Finally, the fusion reactions with {sup 36}S, {sup 37}Cl, {sup 48}Ca, and {sup 50}Ti bombarding {sup 248}Cm, {sup 247,249}Bk, {sup 250,252,254}Cf, and {sup 252,254}Es, as well as the reactions leading to the same compound nucleus with Z=120 and N=182, are studied further. The calculation results for these reactions are useful for searching for the optimal fusion configuration and suitable incident energy in the synthesis of superheavy nuclei.

  4. COMMITTEES: SQM2009 - 14th International Conference on Strangeness in Quark Matter SQM2009 - 14th International Conference on Strangeness in Quark Matter

    NASA Astrophysics Data System (ADS)

    2008-04-01

    Local Organizing Committee Takeshi Kodama Chair, UFRJ Jun Takahashi Co-chair, UNICAMP Ignácio Bediaga e Hickman CBPF Eduardo Fraga UFRJ Frederique Grassi USP Yogiro Hama USP Gastão Krein IFT Erasmo Madureira Ferreira UFRJ Marcelo G. Munhoz USP Fernando Navarra USP Sandra Padula IFT Alejandro Szanto de Toledo USP César Augusto Zen Vasconcellos UFRGS International Advisory Committee Jörg Aichelin Nantes Federico Antinori Padova Tamás Biró Budapest Peter Braun-Munzinger GSI Jean Cleymans Cape Town Láaszló Csernai Bergen Timothy Hallman BNL Huan Zhong Huang UCLA Takeshi Kodama Rio de Janeiro Yu-Gang Ma Shanghai Jes Madsen Aarhus Ágnes Mócsy Pratt University Berndt Müller Duke University Grazyna Odyniec LBNL Helmut Oeschler Darmstadt Johann Rafelski Arizona Hans Georg Ritter LBNL Gunther Rolland MIT Karel Šafařík CERN Ladislav Sandor Kosice University Jack Sandweiss Yale University George S F Stephans MIT Horst Stöcker Frankfurt Larry McLerranBNL Helmut Satz Universitä Bielefeld Nu Xu LBNL Fuqiang Wang Purdue University William A. Zajc Columbia University Pengfei Zhuang Tsinghua University

  5. Search for long-lived superheavy eka-tungsten with radiopure ZnWO4 crystal scintillator

    NASA Astrophysics Data System (ADS)

    Belli, P.; Bernabei, R.; Cappella, F.; Cerulli, R.; Danevich, F. A.; Denisov, V. Yu; d'Angelo, A.; Incicchitti, A.; Kobychev, V. V.; Poda, D. V.; Polischuk, O. G.; Tretyak, V. I.

    2015-08-01

    The data collected with a radioactively pure ZnWO4 crystal scintillator (699 g) in low background measurements during 2130 h at the underground (3600 m w.e.) Laboratori Nazionali del Gran Sasso (INFN, Italy) were used to set a limit on possible concentration of superheavy eka-W (seaborgium Sg, Z = 106) in the crystal. Assuming that one of the daughters in a chain of decays of the initial Sg nucleus decays with emission of high energy α particle ({{Q}α }\\gt 8 MeV) and analyzing the high energy part of the measured α spectrum, the limit N(Sg)/N(W) \\lt 5.5× {{10}-14} atoms/atom at 90% C.L. was obtained (for Sg half-life of 109 yr). In addition, a limit on the concentration of eka-Bi was set by analysing the data collected with a large BGO scintillation bolometer in an experiment performed by another group (Cardani et al 2012 JINST 7 P10022): N(eka-Bi)/N(Bi) \\lt 1.1× {{10}-13} atoms/atom with 90% C.L. Both the limits are comparable with those obtained in recent experiments which instead look for spontaneous fission of superheavy elements or use the accelerator mass spectrometry.

  6. Prospects for laser spectroscopy, ion chemistry and mobility measurements of superheavy elements in buffer-gas traps

    NASA Astrophysics Data System (ADS)

    Backe, H.; Lauth, W.; Block, M.; Laatiaoui, M.

    2015-12-01

    Laser spectroscopic methods are reviewed which are of potential interest for the investigation of atomic and ionic level structures of superheavy elements. The latter are defined here as the trans-fermium elements with Z > 100 for which no experimental atomic or ionic level structure information is known so far, and which cannot be bred in high flux nuclear power reactors via successive neutron capture. The principles of suitable laser spectroscopic methods are described, and illustrated by examples of real experiments. The addressed methods include single-ion spectroscopy in Paul traps, laser-induced fluorescence spectroscopy (LIF), radiation-detected optical pumping (RADOP), radioactive decay-detected resonance ionization spectroscopy (RADRIS), and ion-guide-detected resonance ionization spectroscopy (IGRIS). With the exception of the first all take advantage of a storage of the ions or atoms in so-called buffer-gas traps. The developed experimental methods can, in principle, also be employed for studying ion-chemical reactions with gas admixtures like O2 as well as for performing ion mobility measurements. Both provide complementary information on the electronic structure of superheavy ions. First attempts on this road of research are reviewed as well.

  7. Theoretical predictions on the decay properties of superheavy nuclei Z = 123 in the region 297 ≤ A ≤ 307

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Nithya, C.

    2016-12-01

    Decay modes of isotopes of the superheavy element Z = 123 within the range 297 ≤ A ≤ 307 have been studied by comparing the alpha decay half-lives with the spontaneous fission half-lives. Three different mass tables were used for the calculation of the alpha decay energy. A close study of alpha decay half-lives within the range 297 ≤ A ≤ 307 has been performed using the Coulomb and proximity potential model for deformed nuclei (CPPMDN). The alpha half-lives calculated using CPPMDN are in harmony with the values obtained by the Viola-Seaborg systematic, the universal curve of Poenaru et al., and the analytical formula of Royer. Spontaneous fission half-lives are evaluated using the new shell-effect-dependent formula proposed by Santhosh et al., and the semi-empirical formula of Xu et al. Through our study it is seen that the isotopes 300-303123 exhibit 8α chains and the isotopes 304-307123 exhibit 5α chains with half-lives in a measurable range. Clearly the isotopes of Z = 123 within the range 300 ≤ A ≤ 307 will decay through alpha emission followed by spontaneous fission and thus can be predicted as synthesized and detected in laboratory via alpha decay. Since the predictions on decay modes of isotopes of the superheavy element Z = 123 is done for the first time it is hoped that the study will open up new areas in experimental investigations.

  8. Asymmetries between strange and antistrange particle production inpion-proton interactions

    SciTech Connect

    Gutierrez, T.D.; Vogt, R.

    2002-01-29

    Recent measurements of the asymmetries between Feynman x-distributions of strange and antistrange hadrons in {pi}{sup -}A interactions show a strong effect as a function of x{sub F}. We calculate strange hadron production in the context of the intrinsic model and make predictions for particle/antiparticle asymmetries in these interactions.

  9. Aspects of strangeness production with 15 -- 30 GeV proton beams

    SciTech Connect

    Dover, C.B.

    1992-04-01

    We discuss the spectrum of physics questions related to strangeness which could be addressed with a 15--30 GeV proton storage ring. We focus on various aspects of strangeness production, including hyperon production in pp collisions, studies of hyperon-nucleon scattering, production of hyper-fragments in p-nucleus collisions, and hyperon spin observables in inclusive production.

  10. Universal strangeness production in hadronic and nuclear collisions

    NASA Astrophysics Data System (ADS)

    Castorina, P.; Plumari, S.; Satz, H.

    2016-07-01

    We show that strangeness suppression in hadronic and nuclear collisions is fully determined by the initial energy density of the collision. The suppression factor γs(s), with s denoting the collision energy, can be expressed as a universal function of the initial energy density ɛ0(s), and the resulting pattern is in excellent agreement with data from p-p, p-Pb, Cu-Cu, Au-Au and Pb-Pb data over a wide range of energies and for different centralities.

  11. Extracting nucleon strange and anapole form factors from data

    SciTech Connect

    R.D. Young; J. Roche; R.D. Carlini; A.W. Thomas

    2006-04-14

    Using the complete world set of parity violating electron scattering data up to Q{sup 2} {approx} 0.3 GeV{sup 2}, we extract the current best determination of the strange electric and magnetic form factors of the proton, as well as the weak axial form factors of the proton and neutron at Q{sup 2} = 0.1 GeV{sup 2}. The results are consistent with state of the art calculations of all four form factors, with the latter including the anapole contribution.

  12. Connected, disconnected and strange quark contributions to HVP

    NASA Astrophysics Data System (ADS)

    Bijnens, Johan; Relefors, Johan

    2016-11-01

    We calculate all neutral vector two-point functions in Chiral Perturbation Theory (ChPT) to two-loop order and use these to estimate the ratio of disconnected to connected contributions as well as contributions involving the strange quark. We extend the ratio of -1/10 derived earlier in two flavour ChPT at one-loop order to a large part of the higher order contributions and discuss corrections to it. Our final estimate of the ratio disconnected to connected is negative and a few % in magnitude.

  13. Neutrino-driven Explosion of a 20 Solar-mass Star in Three Dimensions Enabled by Strange-quark Contributions to Neutrino-Nucleon Scattering

    NASA Astrophysics Data System (ADS)

    Melson, Tobias; Janka, Hans-Thomas; Bollig, Robert; Hanke, Florian; Marek, Andreas; Müller, Bernhard

    2015-08-01

    Interactions with neutrons and protons play a crucial role for the neutrino opacity of matter in the supernova core. Their current implementation in many simulation codes, however, is rather schematic and ignores not only modifications for the correlated nuclear medium of the nascent neutron star, but also free-space corrections from nucleon recoil, weak magnetism, or strange quarks, which can easily add up to changes of several 10% for neutrino energies in the spectral peak. In the Garching supernova simulations with the Prometheus-Vertex code, such sophistications have been included for a long time except for the strange-quark contributions to the nucleon spin, which affect neutral-current neutrino scattering. We demonstrate on the basis of a 20 {M}⊙ progenitor star that a moderate strangeness-dependent contribution of {g}{{a}}{{s}}=-0.2 to the axial-vector coupling constant {g}{{a}}≈ 1.26 can turn an unsuccessful three-dimensional (3D) model into a successful explosion. Such a modification is in the direction of current experimental results and reduces the neutral-current scattering opacity of neutrons, which dominate in the medium around and above the neutrinosphere. This leads to increased luminosities and mean energies of all neutrino species and strengthens the neutrino-energy deposition in the heating layer. Higher nonradial kinetic energy in the gain layer signals enhanced buoyancy activity that enables the onset of the explosion at ˜300 ms after bounce, in contrast to the model with vanishing strangeness contributions to neutrino-nucleon scattering. Our results demonstrate the close proximity to explosion of the previously published, unsuccessful 3D models of the Garching group.

  14. Soft CP violation and the global matter-antimatter symmetry of the universe

    NASA Technical Reports Server (NTRS)

    Senjanovic, G.; Stecker, F. W.

    1980-01-01

    Scenarios for baryon production are considered within the context of SU(5) and SO(10) grand unified theories where CP violation arises spontaneously. The spontaneous CP symmetry breaking then results in a matter-antimatter domain structure in the universe. Two possible, distinct types of theories of soft CP violation are defined. In the first type the CP nonconservation originates only from the breaking of SU(2) sub L X U(1) symmetry, and in the second type, even at the unification temperature scale, CP violation can emerge as a result of symmetry breaking by the vacuum expectation values of the superheavy Higgs sector scalars.

  15. Spontaneous Fission Modes and Lifetimes of Superheavy Elements in the Nuclear Density Functional Theory

    SciTech Connect

    Staszczak, A,

    2013-01-01

    Background: The reactions with the neutron-rich 48Ca beam and actinide targets resulted in the detection of new superheavy (SH) nuclides with Z=104 118. The unambiguous identification of the new isotopes, however, still poses a problem because their -decay chains terminate by spontaneous fission (SF) before reaching the known region of the nuclear chart. The understanding of the competition between -decay and SF channels in SH nuclei is, therefore, of crucial importance for our ability to map the SH region and to assess its extent.

    Purpose: We perform self-consistent calculations of the competing decay modes of even-even SH isotopes with 108 Z 126 and 148 N 188.

    Methods: We use the state-of-the-art computational framework based on self-consistent symmetry-unrestricted nuclear density functional theory capable of describing the competition between nuclear attraction and electrostatic repulsion. We apply the SkM* Skyrme energy density functional. The collective mass tensor of the fissioning superfluid nucleus is computed by means of the cranking approximation to the adiabatic time-dependent Hartree-Fock-Bogoliubov (HFB) approach. This paper constitutes a systematic self-consistent study of spontaneous fission in the SH region, carried out at a full HFB level, that simultaneously takes into account both triaxiality and reflection asymmetry.

    Results: Breaking axial symmetry and parity turns out to be crucial for a realistic estimate of collective action; it results in lowering SF lifetimes by more than 7 orders of magnitude in some cases. We predict two competing SF modes: reflection symmetric modes and reflection asymmetric modes.

    Conclusions: The shortest-lived SH isotopes decay by SF; they are expected to lie in a narrow corridor formed by 280Hs, 284Fl, and 118284Uuo that separates the regions of SH nuclei synthesized in cold-fusion and hot-fusion reactions. The region of long-lived SH nuclei is expected to be centered on 294Ds with a total half-life of

  16. Spontaneous superfluid current generation in the kaon condensed color flavor locked phase at nonzero strange quark mass

    SciTech Connect

    Kryjevski, Andrei

    2008-01-01

    We find that for a large enough strange quark mass, m{sub s}{sup 2}/4{mu}{delta}>2/3(1-0.023) ({mu} is the quark number chemical potential, {delta} is the superconducting gap), the kaon condensed color flavor locked (CFL) phase of asymptotically dense strongly interacting 3 flavor quark matter is unstable with respect to spontaneous generation of currents of Nambu Goldstone bosons due to spontaneous breaking of baryon number symmetry and hypercharge symmetry in the CFLK{sup 0} ground state. The total baryon and hypercharge currents vanish in the ground state. We find that CFLK{sup 0} and the new state are separated by a first order phase transition. The result is derived in the mean field approximation of high density effective theory with electromagnetic interactions turned off.

  17. Comparing Two Attachment Classification Methods Applied to Preschool Strange Situations

    PubMed Central

    Spieker, Susan; Crittenden, Patricia Mckinsey

    2013-01-01

    This study compared two methods for classifying preschool-age children's behavior in the Strange Situation procedure, the MacArthur (MAC) and the Preschool Assessment of Attachment (PAA), to determine whether they operationalized converging or diverging approaches to attachment theory. Strange Situations of 306 randomly selected 3-year-old children and their mothers in the NICHD Study of Early Child Care and Youth Development were classified with the MAC and PAA. The methods showed 50% agreement. A block of seven demographic, child and family predictors was unrelated to MAC classifications, but accounted for 19% of the variance in PAA classifications. The MAC and PAA each had associations with some child outcomes in grades 1-5 (ages 6-10) totalling 5% and 12% of the variance respectively, but some of the MAC associations were counter to the hypothesis. The MAC and PAA were sufficiently different to reflect both different classificatory methods and different theoretical understandings of attachment. Results are discussed in terms of limitations of the sample and measures available to compare the two methods, and clinical implications. PMID:19914941

  18. Electroproduction of baryon-meson states and strangeness suppression

    NASA Astrophysics Data System (ADS)

    Santopinto, E.; García-Tecocoatzi, H.; Bijker, R.

    2016-08-01

    We describe the electroproduction ratios of baryon-meson states from nucleon, inferring from the sea quarks in the nucleon using an extension of the quark model that takes into account the sea. As a result we provide, with no adjustable parameters, the predictions of ratios of exclusive meson-baryon final states: ΛK+, Σ* K, ΣK, pπ0, and nπ+. These predictions are in agreement with the new JLab experimental data showing that sea quarks play an important role in the electroproduction. We also predicted further ratios of exclusive reactions that can be measured and tested in future experiments. In particular, we suggested new experiments on deuterium and tritium. Such measurements can provide crucial tests of different predictions concerning the structure of nucleon and its sea quarks helping to solve an outstanding problem. Finally, we compute the so called strangeness suppression factor, λs, that is the suppression of strange quark-antiquark pairs compared to nonstrange pairs, and we found that our finding with this simple extension of the quark model is in good agreement with the results of JLab and CERN experiments.

  19. "Making strange": a role for the humanities in medical education.

    PubMed

    Kumagai, Arno K; Wear, Delese

    2014-07-01

    Stories, film, drama, and art have been used in medical education to enhance empathy, perspective-taking, and openness to "otherness," and to stimulate reflection on self, others, and the world. Yet another, equally important function of the humanities and arts in the education of physicians is that of "making strange"-that is, portraying daily events, habits, practices, and people through literature and the arts in a way that disturbs and disrupts one's assumptions, perspectives, and ways of acting so that one sees the self, others, and the world anew. Tracing the development of this concept from Viktor Shklovsky's "enstrangement" (ostranenie) through Bertolt Brecht's "alienation effect," this essay describes the use of this technique to disrupt the "automaticity of thinking" in order to discover new ways of perceiving and being in the world.Enstrangement may be used in medical education in order to stimulate critical reflection and dialogue on assumptions, biases, and taken-for-granted societal conditions that may hinder the realization of a truly humanistic clinical practice. In addition to its ability to enhance one's critical understanding of medicine, the technique of "making strange" does something else: By disrupting fixed beliefs, this approach may allow a reexamination of patient-physician relationships in terms of human interactions and provide health care professionals an opportunity-an "open space"-to bear witness and engage with other individuals during challenging times.

  20. An almost symmetric Strang splitting scheme for nonlinear evolution equations.

    PubMed

    Einkemmer, Lukas; Ostermann, Alexander

    2014-07-01

    In this paper we consider splitting methods for the time integration of parabolic and certain classes of hyperbolic partial differential equations, where one partial flow cannot be computed exactly. Instead, we use a numerical approximation based on the linearization of the vector field. This is of interest in applications as it allows us to apply splitting methods to a wider class of problems from the sciences. However, in the situation described, the classic Strang splitting scheme, while still being a method of second order, is not longer symmetric. This, in turn, implies that the construction of higher order methods by composition is limited to order three only. To remedy this situation, based on previous work in the context of ordinary differential equations, we construct a class of Strang splitting schemes that are symmetric up to a desired order. We show rigorously that, under suitable assumptions on the nonlinearity, these methods are of second order and can then be used to construct higher order methods by composition. In addition, we illustrate the theoretical results by conducting numerical experiments for the Brusselator system and the KdV equation.

  1. An almost symmetric Strang splitting scheme for nonlinear evolution equations☆

    PubMed Central

    Einkemmer, Lukas; Ostermann, Alexander

    2014-01-01

    In this paper we consider splitting methods for the time integration of parabolic and certain classes of hyperbolic partial differential equations, where one partial flow cannot be computed exactly. Instead, we use a numerical approximation based on the linearization of the vector field. This is of interest in applications as it allows us to apply splitting methods to a wider class of problems from the sciences. However, in the situation described, the classic Strang splitting scheme, while still being a method of second order, is not longer symmetric. This, in turn, implies that the construction of higher order methods by composition is limited to order three only. To remedy this situation, based on previous work in the context of ordinary differential equations, we construct a class of Strang splitting schemes that are symmetric up to a desired order. We show rigorously that, under suitable assumptions on the nonlinearity, these methods are of second order and can then be used to construct higher order methods by composition. In addition, we illustrate the theoretical results by conducting numerical experiments for the Brusselator system and the KdV equation. PMID:25844017

  2. Hadronic matter and rapidly rotating compact stars

    SciTech Connect

    Weber, F.; Kettner, C.; Glendenning, N.K.

    1994-03-01

    In part one of this paper the authors review the present status of neutron star matter calculations, and introduce a representative collection of realistic nuclear equations of state which are derived for different assumptions about the physical behavior of dense matter (baryon populations, pion condensation, possible transition of baryon matter to quark matter). Part two deals with the theoretical determination of the minimum possible rotational periods of neutron stars, performed in the framework of general relativity, whose knowledge serves to distinguish between pulsars that can be understood as rotating neutron stars and those that cannot. Likely candidates for the latter are hypothetical strange stars. Their properties are discussed in the third part of this contribution.

  3. Warm stellar matter within the quark-meson-coupling model

    NASA Astrophysics Data System (ADS)

    Panda, P. K.; Providência, C.; Menezes, D. P.

    2010-10-01

    In the present article, we investigate stellar matter obtained within the quark-meson-coupling (QMC) model for fixed temperature and with the entropy of the order of 1 or 2 Boltzmann units per baryon for neutrino-free matter and matter with trapped neutrinos. A new prescription for the calculation of the baryon effective masses in terms of the free energy is used. Comparing the results of the present work with those obtained from the nonlinear Walecka model, smaller strangeness and neutrino fractions are predicted within QMC. As a consequence, QMC has a smaller window of metastability for conversion into a low-mass blackhole during cooling.

  4. Warm stellar matter within the quark-meson-coupling model

    SciTech Connect

    Panda, P. K.; Providencia, C.; Menezes, D. P.

    2010-10-15

    In the present article, we investigate stellar matter obtained within the quark-meson-coupling (QMC) model for fixed temperature and with the entropy of the order of 1 or 2 Boltzmann units per baryon for neutrino-free matter and matter with trapped neutrinos. A new prescription for the calculation of the baryon effective masses in terms of the free energy is used. Comparing the results of the present work with those obtained from the nonlinear Walecka model, smaller strangeness and neutrino fractions are predicted within QMC. As a consequence, QMC has a smaller window of metastability for conversion into a low-mass blackhole during cooling.

  5. Exotic Archaeology:. Searching for Superheavy Elements in Nature and Dating Human DNA with the 14C Bomb Peak

    NASA Astrophysics Data System (ADS)

    Kutschera, Walter; Dellinger, Franz; Liebl, Jakob; Steier, Peter

    2011-03-01

    This contribution conveys the power of accelerator mass spectrometry (AMS) to measure ultra-low traces of long-lived radionuclides in two highly divers fields: Astrophysics and molecular biology. Our search for nuclides of superheavy elements (SHE) in several natural materials did not confirm the claims of positive evidence for SHEs reported by the group of Amnon Marinov from Jerusalem, even though the sensitivity of our AMS measurements were several orders of magnitude higher. We also report on the investigation by the group of Kirsty Spalding from Stockholm to date human DNA with the 14C bomb peak. This allows one to determine retrospectively the birth date of cells in sections of the human body. Ongoing efforts to miniaturize carbon samples down to the level of 10 μg C for AMS measurements will allow one to venture into ever smaller subsections of the human brain.

  6. Synthesis of superheavy element 120 via {sup 50}Ti+{sup A}Cf hot fusion reactions

    SciTech Connect

    Liu, Z. H.; Bao Jingdong

    2009-11-15

    Synthesis of superheavy element 120 in terms of the {sup 50}Ti+{sup 249-252}Cf fusion-evaporation reactions is evaluated and discussed. It is found that the reactions of {sup 250,251}Cf({sup 50}Ti,3n){sup 297,298}120 and {sup 251,252}Cf({sup 50}Ti,4n){sup 297,298}120 are relatively favorable with the maximum evaporation-residue cross sections of 0.12, 0.09, 0.11, and 0.25 pb, respectively. However, {sup 252}Cf may be difficult to be target because its spontaneous fission will bring about serious background in the experiment. Fusion probabilities for different target-projectile combinations leading to the formation of surperheavy nucleus {sup 302}120 are estimated with the ''fusion-by-diffusion'' model and presented as a function of the Coulomb parameter Z{sub 1}Z{sub 2}/(A{sub 1}{sup 1/3}+A{sub 2}{sup 1/3}). Among the reactions {sup 50}Ti+{sup 252}Cf, {sup 54}Cr+{sup 248}Cm, {sup 58}Fe+{sup 244}Pu, and {sup 64}Ni+{sup 238}U, the reaction {sup 50}Ti+{sup 252}Cf has the largest fusion probability. Synthesis of superheavy element 120 is of essential importance for determining whether the magic proton shell should be at Z=114 or at higher proton numbers Z=120-126. Therefore, the experiment to produce isotopes with Z=120 in the fusion reactions {sup 50}Ti+{sup 250,251}Cf is of great interest.

  7. Generation and Distribution of a Magnetic Field in Superconducting Strange Stars

    NASA Astrophysics Data System (ADS)

    Sedrakian, D. M.; Hayrapetyan, M. V.; Baghdasaryan, D. S.

    2015-12-01

    Generation of a magnetic field and its distribution are considered within a rotating strange quark star with a crust. It is shown how, over time, a differential rotation is established between the superfluid and superconducting quark core and normal electron plasma, which leads to the generation of magnetic field. The magnetic field at the surface of a strange star may attain values of 1011-1015 G, depending on the star model. It is suggested that magnetars may be manifestations of strange stars, the cores of which rotate much faster than the observable part, i.e., the crust.

  8. Comment on "Reevaluation of the parton distribution of strange quarks in the nucleon"

    NASA Astrophysics Data System (ADS)

    Stolarski, M.

    2015-11-01

    The HERMES collaboration in Phys. Rev. D 89, 097101 (2014) extracted information about the strange quark density in the nucleon. One of the main results is an observation that the shape of the extracted density is very different from the shapes of the strange quark density from global QCD fits and also from that of the light antiquarks. In this paper systematic studies on the HERMES published multiplicity of pion and kaon data are presented. It is shown that the conclusions concerning the strange quark distribution in the nucleon reached in Phys. Rev. D 89, 097101 (2014) are at the moment premature.

  9. NEUTRINO-PRODUCTION OF CHARM AND THE STRANGENESS ASYMMETRY OF THE NUCLEON.

    SciTech Connect

    KRETZER,S.

    2004-04-14

    Interest in the strange nucleon sea has been renewed when it was realized that the strangeness asymmetry s{sup -} = s - {bar s} plays a prominent role in the interpretation of the NuTeV weak mixing angle anomaly. The author reviews the NLO QCD calculation of the neutrino-production of opposite-sign dimuons as the experimental signature of the strange quark parton density. Results from a recent CTEQ fit are presented and discussed with respect to their stability under NLO corrections and their impact on the NuTeV measurement.

  10. The strange little animals of Antony van Leeuwenhoek surgical revolution.

    PubMed

    Toledo-Pereyra, Luis H

    2009-01-01

    Antony van Leeuwenhoek (1632-1723) created a surgical revolution by demonstrating, through a series of extraordinary discoveries, the presence of "strange little animals" under the microscope. His outstanding advances were directly related to his ability to grind better glasses, which enhanced magnification many times over previously manufactured glasses. His meticulous and dedicated observational skills were unmatched by anyone dealing with magnification at the time. The surgical revolution did not occur during Leeuwenhoek's time but more than a century later when the value of his findings was evidently recognized. Today Leeuwenhoek is considered the father of microscopy as well. It is particularly enlightening that for not being a scientist himself, he demonstrated all the good virtues of method and technique for which professional scientists are admired.

  11. Role of the strange quark in the ρ(770) meson

    NASA Astrophysics Data System (ADS)

    Molina, R.; Guo, D.; Hu, B.; Alexandru, A.; Doering, M.

    2017-03-01

    Recently, the GWU lattice group has evaluated high-precision phase-shift data for ππ scattering in the I = 1, J = 1 channel. Unitary Chiral Perturbation Theory describes these data well around the resonance region and for different pion masses. Moreover, it allows to extrapolate to the physical point and estimate the effect of the missing KK¯ channel in the two-flavor lattice calculation. The absence of the strange quark in the lattice data leads to a lower ρ mass, and the analysis with UχPT shows that the KK¯ channel indeed pushes the ππ-scattering phase shift upward, having a surprisingly large effect on the ρ-mass. The inelasticity is shown to be compatible with the experimental data. The analysis is then extended to all available two-flavor lattice simulations and similar mass shifts are observed. Chiral extrapolations of Nf = 2 + 1 lattice simulations for the ρ(770) are also reported.

  12. Strangeness enhancement - a potential signature for QGP phase

    NASA Astrophysics Data System (ADS)

    Tiwari, V. K.; Singh, C. P.

    1997-09-01

    Strangeness enhancement has always been considered as a potential signature for deconfining as well as chiral symmetry restoring quark-hadron phase transition. We obtain the ratios Λ¯/Λ, Ξ¯/Ξ and K+/K- from a quark-gluon plasma (QGP) using a modified equation of state (EOS). Similarly these ratios are also obtained from a hadron gas (HG) by using a thermodynamically consistent equation of state (EOS) which incorporates the finite size, hard-core repulsive interactions among baryons as an excluded volume effect. We then suggest that the variations of these ratios either with the energy density or with baryon density can serve as a potential signature for detecting a QGP formation in the ultra-relativistic heavy-ion collisions.

  13. Probing Proton Strangeness with Time-Like Virtual Compton Scattering

    SciTech Connect

    Stephen R. Cotanch; Robert A. Williams

    2002-05-01

    We document that p(gamma,e+e-)p measurements will yield new, important information about the off-shell time-like nucleon form factors, especially in the phi meson region (q{sup 2} = M{sup 2}{sub {phi}}) governing the phi N couplings g{sup V,T}{sub {phi}NN}. Calculations for p(gamma,e+e-)p, utilizing vector meson dominance, predict measurable phi enhancements at high |t| compared to the expected phi background production from pi, eta and Pomeron exchange. The phi form factor contribution generates a novel experimental signature for OZI violation and the proton strangeness content. The phi N couplings are determined independently from a combined analysis of the neutron electric form factor and recent high |t| phi photoproduction. The pi, eta and Pomeron transition form factors are also predicted and the observed pi and eta transition moments are reproduced.

  14. Observation of the doubly strange b baryon Omegab-.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Andrieu, B; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Avila, C; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Carrera, E; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cuplov, V; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; DeVaughan, K; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dorland, T; Dubey, A; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Kalk, J M; Karmanov, D; Kasper, P A; Katsanos, I; Kau, D; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Komissarov, E V; Konrath, J-P; Kozelov, A V; Kraus, J; Kuhl, T; Kumar, A; Kupco, A; Kurca, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lellouch, J; Li, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna, R; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendoza, L; Mercadante, P G; Merekov, Y P; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Mitrevski, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Orduna, J; Oshima, N; Osman, N; Osta, J; Otec, R; Otero y Garzón, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Rich, P; Rieger, J; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Rominsky, M; Royon, C; Rozhdestvenski, A; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, E; Strauss, M; Ströhmer, R; Strom, D; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Tamburello, P; Tanasijczuk, A; Taylor, W; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Torchiani, I; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; van den Berg, P J; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Vertogradova, Y; Verzocchi, M; Vilanova, D; Villeneuve-Seguier, F; Vint, P; Vokac, P; Voutilainen, M; Wagner, R; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Welty-Rieger, L; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Williams, M; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zeitnitz, C; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G

    2008-12-05

    We report the observation of the doubly strange b baryon Omegab- in the decay channel Omegab(-)-->J/psiOmega-, with J/psi-->mu+mu(-) and Omega(-)-->LambdaK(-)-->(ppi-)K-, in pp collisions at sqrt[s]=1.96 TeV. Using approximately 1.3 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider, we observe 17.8+/-4.9(stat)+/-0.8(syst) Omegab- signal events at a mass of 6.165+/-0.010(stat)+/-0.013(syst) GeV. The significance of the observed signal is 5.4sigma, corresponding to a probability of 6.7 x 10(-8) of it arising from a background fluctuation.

  15. (Anti-)strangeness in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Moreau, P.; Cassing, W.; Palmese, A.; Bratkovskaya, E. L.

    2016-08-01

    We study the production of hadrons in nucleus-nucleus collisions within the Parton-Hadron-String Dynamics (PHSD) transport approach that is extended to incorporate essentials aspects of chiral symmetry restoration (CSR) in the hadronic sector (via the Schwinger mechanism) on top of the deconfinement phase transition as implemented in PHSD before. The essential impact of CSR is found in the Schwinger mechanism (for string decay) which fixes the ratio of strange to light quark production in the hadronic medium. Our studies suggest a microscopic explanation for the maximum in the K + /π + and (Ʌ + Σ0)/π - ratios at about 30 A GeV which only shows up if in addition to CSR a deconfinement transition to partonic degrees-of-freedom is incorporated in the reaction dynamics.

  16. Strange quarks in the nucleon sea: Results from HAPPEX II

    SciTech Connect

    K.A. Aniol; HAPPEX Collaboration

    2007-03-01

    The HAPPEX Collaboration measured parity-violating electron scattering from 4He(e, e) and H(e, e) in 2004 and 2005 for Q2 ≤ 0.11 GeV2. Results for the strange-quark contributions to the electromagnetic form factors of the nucleon from the 2004 data will be reviewed. Preliminary results from the 2005 data, which have significantly greater statistical precision, are GsE = 0.004 0.014stat 0.013syst for Q2 = 0.0772 GeV2 from the helium data and GsE + 0.088 GsM = 0.004 0.011stat 0.005syst 0.004FF for Q2 = 0.1089 GeV2 from the hydrogen data.

  17. Entropy & equation of state (EOS) for hot bare strange stars

    NASA Astrophysics Data System (ADS)

    Ray, S.; Dey, J.; Dey, M.; Ray, K.; Samanta, B. C.

    2000-12-01

    Compactness of some stars is explained if they are strange stars (SS) as shown by Dey et al. (1998) (D98) and Li et al. (1999a). One of these compact star candidates is the SAX J1808.4-3658 (SAX in short) believed to be an important link in the genesis of radio pulsars. SS have also been suggested for bursting X-ray pulsars (GRO J1744-28, Cheng et al. 1998), from quasi-periodic oscillations (QPO) of X-ray binaries (4U 1728-34, Li et al. 1999b) and from peculiarity of properties of radio pulsars (PSR 0943+10, Xu et al.1999; Kapoor et al. 2000). We now extend doall(logger,onlynew=('-a','') not in opt.

  18. Ionization potentials and electron affinities of the superheavy elements 115-117 and their sixth-row homologues Bi, Po, and At

    NASA Astrophysics Data System (ADS)

    Borschevsky, A.; Pašteka, L. F.; Pershina, V.; Eliav, E.; Kaldor, U.

    2015-02-01

    Calculations of the first and second ionization potentials and electron affinities of superheavy elements 115-117 are presented. The calculations are performed in the framework of the Dirac-Coulomb Hamiltonian, and the results are corrected for the Breit and QED contributions. Correlation is treated by the relativistic coupled cluster approach with single, double, and perturbative triple excitations [CCSD(T)]. The same approach is used to calculate the ionization potentials and electron affinities of the lighter homologues, Bi, Po, and At. Comparison of the available experimental values for these atoms, namely, the first ionization potentials (IPs) of Bi, Po, and At and the second IP and EA of Bi, with our results shows excellent agreement, within a few hundredths of an eV, lending credence to our predictions for their superheavy homologues. High-accuracy predictions are also made for the second ionization potentials and electron affinities of Po and At, where no experiment is available.

  19. Possibilities of synthesis of unknown isotopes of superheavy nuclei with charge numbers Z > 108 in asymmetric actinide-based complete fusion reactions

    NASA Astrophysics Data System (ADS)

    Hong, Juhee; Adamian, G. G.; Antonenko, N. V.

    2016-10-01

    The possibilities of production of new isotopes of superheavy nuclei with charge numbers Z = 109-114 in various asymmetric hot fusion reactions are studied for the first time. The excitation functions of the formation of these isotopes in the xn evaporation channels are predicted and the optimal conditions for the synthesis are proposed. The products of the suggested reactions can fill a gap of unknown isotopes between the isotopes of the heaviest nuclei obtained in cold and hot complete fusion reactions.

  20. Hot and dense hadronic matter in an effective mean-field approach

    SciTech Connect

    Lavagno, A.

    2010-04-15

    We investigate the equation of state of hadronic matter at finite values of baryon density and temperature reachable in high-energy heavy-ion collisions. The analysis is performed by requiring the Gibbs conditions on the global conservation of baryon number, electric charge fraction, and zero net strangeness. We consider an effective relativistic mean-field model with the inclusion of DELTA isobars, hyperons, and the lightest pseudoscalar and vector meson degrees of freedom. In this context, we study the influence of the DELTA-isobar degrees of freedom in the hadronic equation of state and, in connection, the behavior of different particle-antiparticle ratios and strangeness production.

  1. (Multi-)strange hadron and light (anti-)nuclei production with ALICE at the LHC

    SciTech Connect

    Lea, Ramona

    2016-01-22

    Thanks to its excellent tracking performance and particle identification capabilities, the ALICE detector allows for the identification of light (anti-)(hyper)nuclei and for the measurement of (multi-)strange particles over a wide range of transverse momentum. Deuterons, {sup 3}He and {sup 4}He and their corresponding anti-nuclei are identified via their specific energy loss in the Time Projection Chamber and the velocity measurement provided by the Time-Of-Flight detector. Strange and multi-strange baryons and mesons as well as (anti-)hypertritons are reconstructed via their topological decays. Detailed measurements of (multi-)strange hadron production in pp, p–Pb and Pb–Pb collision and of light (anti-)nuclei and (anti-)hypertritons in Pb–Pb collisions with ALICE at the LHC are presented. The experimental results will be compared with the predictions of both statistical hadronization and coalescence models.

  2. Strangeness S = -3 and -4 baryon-baryon interactions in chiral EFT

    SciTech Connect

    Haidenbauer, Johann

    2011-10-24

    I report on recent progress in the description of baryon-baryon systems within chiral effective field theory. In particular, I discuss results for the strangeness S = -3 to -4 baryon-baryon systems, obtained to leading order.

  3. Strangeness S = -3 and -4 baryon-baryon interactions in chiral EFT

    NASA Astrophysics Data System (ADS)

    Haidenbauer, Johann

    2011-10-01

    I report on recent progress in the description of baryon-baryon systems within chiral effective field theory. In particular, I discuss results for the strangeness S = -3 to -4 baryon-baryon systems, obtained to leading order.

  4. Flavour Oscillations in Dense Baryonic Matter

    NASA Astrophysics Data System (ADS)

    Filip, Peter

    2017-01-01

    We suggest that fast neutral meson oscillations may occur in a dense baryonic matter, which can influence the balance of s/¯s quarks in the nucleus-nucleus and proton-nucleus interactions, if primordial multiplicities of neutral K 0, mesons are sufficiently asymmetrical. The phenomenon can occur even if CP symmetry is fully conserved, and it may be responsible for the enhanced sub-threshold production of multi-strange hyperons observed in the low-energy A+A and p+A interactions.

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

    SciTech Connect

    Edwards, Adam J.; /SLAC

    2007-10-15

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

  6. Strange quark suppression and strange hadron production in pp collisions at energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider

    SciTech Connect

    Long Haiyan; Feng Shengqin; Zhou Daimei; Yan Yuliang; Ma Hailiang; Sa Benhao

    2011-09-15

    The parton and hadron cascade model PACIAE based on PYTHIA is utilized to systematically investigate strange particle production in pp collisions at energies available at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). Globally speaking, the PACIAE results of the strange particle rapidity density at midrapidity and the transverse momentum distribution are better than those of PYTHIA (default) in comparison with STAR and ALICE experimental data. This may represent the importance of the parton and hadron rescatterings, as well as the reduction mechanism of strange quark suppression, added in the PACIAE model. The K/{pi} ratios as a function of reaction energy in pp collisions from CERN Super Proton Synchrotron (SPS) to LHC energies are also analyzed in this paper.

  7. Ground state of high-density matter

    NASA Technical Reports Server (NTRS)

    Copeland, ED; Kolb, Edward W.; Lee, Kimyeong

    1988-01-01

    It is shown that if an upper bound to the false vacuum energy of the electroweak Higgs potential is satisfied, the true ground state of high-density matter is not nuclear matter, or even strange-quark matter, but rather a non-topological soliton where the electroweak symmetry is exact and the fermions are massless. This possibility is examined in the standard SU(3) sub C tensor product SU(2) sub L tensor product U(1) sub Y model. The bound to the false vacuum energy is satisfied only for a narrow range of the Higgs boson masses in the minimal electroweak model (within about 10 eV of its minimum allowed value of 6.6 GeV) and a somewhat wider range for electroweak models with a non-minimal Higgs sector.

  8. Strange Quark Magnetic Moment of the Nucleon at the Physical Point.

    PubMed

    Sufian, Raza Sabbir; Yang, Yi-Bo; Alexandru, Andrei; Draper, Terrence; Liang, Jian; Liu, Keh-Fei

    2017-01-27

    We report a lattice QCD calculation of the strange quark contribution to the nucleon's magnetic moment and charge radius. This analysis presents the first direct determination of strange electromagnetic form factors including at the physical pion mass. We perform a model-independent extraction of the strange magnetic moment and the strange charge radius from the electromagnetic form factors in the momentum transfer range of 0.051  GeV^{2}≲Q^{2}≲1.31  GeV^{2}. The finite lattice spacing and finite volume corrections are included in a global fit with 24 valence quark masses on four lattices with different lattice spacings, different volumes, and four sea quark masses including one at the physical pion mass. We obtain the strange magnetic moment G_{M}^{s}(0)=-0.064(14)(09)μ_{N}. The four-sigma precision in statistics is achieved partly due to low-mode averaging of the quark loop and low-mode substitution to improve the statistics of the nucleon propagator. We also obtain the strange charge radius ⟨r_{s}^{2}⟩_{E}=-0.0043(16)(14)  fm^{2}.

  9. Strange Quark Magnetic Moment of the Nucleon at the Physical Point

    NASA Astrophysics Data System (ADS)

    Sufian, Raza Sabbir; Yang, Yi-Bo; Alexandru, Andrei; Draper, Terrence; Liang, Jian; Liu, Keh-Fei; χ QCD Collaboration

    2017-01-01

    We report a lattice QCD calculation of the strange quark contribution to the nucleon's magnetic moment and charge radius. This analysis presents the first direct determination of strange electromagnetic form factors including at the physical pion mass. We perform a model-independent extraction of the strange magnetic moment and the strange charge radius from the electromagnetic form factors in the momentum transfer range of 0.051 GeV2≲Q2≲1.31 GeV2 . The finite lattice spacing and finite volume corrections are included in a global fit with 24 valence quark masses on four lattices with different lattice spacings, different volumes, and four sea quark masses including one at the physical pion mass. We obtain the strange magnetic moment GMs(0 )=-0.064 (14 )(09 )μN. The four-sigma precision in statistics is achieved partly due to low-mode averaging of the quark loop and low-mode substitution to improve the statistics of the nucleon propagator. We also obtain the strange charge radius ⟨rs2⟩E=-0.0043 (16 )(14 ) fm2 .

  10. Intrinsic strange distributions in the nucleon from the light-cone models

    NASA Astrophysics Data System (ADS)

    Salajegheh, Maral

    2015-10-01

    Precise knowledge of the strange and antistrange quark distributions of the nucleon is a major step toward better understanding of the strong interaction and the nucleon structure. Moreover, the s -s ¯ asymmetry in the nucleon plays an important role in some physical processes involving hadrons. The goal of this paper is the study of intrinsic strange contribution to the strange sea of the nucleon. To this aim, we calculate the intrinsic strange distributions from the various light-cone models, including Brodsky, Hoyer, Peterson, and Sakai (BHPS); scalar five-quark; and meson-baryon models and then compare their results. These models can lead to the rather different distributions for the intrinsic strange that are dominated in different values of x . Furthermore, the meson-baryon model leads to the s -s ¯ asymmetry that can be comparable in some situations to the result obtained from the global analysis of PDFs. We also present a simple parametrization for each model prediction of intrinsic strange distribution.

  11. Perturbative and nonperturbative contributions to the strange quark asymmetry in the nucleon

    NASA Astrophysics Data System (ADS)

    Feng, Guan-Qiu; Cao, Fu-Guang; Guo, Xin-Heng; Signal, A. I.

    2012-12-01

    There are two mechanisms for the generation of an asymmetry between the strange and anti-strange quark distributions in the nucleon: nonperturbative contributions originating from nucleons fluctuating into virtual baryon-meson pairs such as ΛK and ΣK, and perturbative contributions arising from gluons splitting into strange and anti-strange quark pairs. While the nonperturbative contributions are dominant in the large- x region, the perturbative contributions are more significant in the small- x region. We calculate this asymmetry taking into account both nonperturbative and perturbative contributions, thus giving a more accurate evaluation of this asymmetry over the whole domain of x. We find that the perturbative contributions are generally a few times larger in magnitude than the nonperturbative contributions, which suggests that the best region to detect this asymmetry experimentally is in the region 0.02< x<0.03. We find that the asymmetry may have more than one node, which is an effect that should be taken into account, e.g. for parameterizations of the strange and anti-strange quark distributions used in global analysis of parton distributions.

  12. 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.

  13. The familiar and the strange: the dynamics of change.

    PubMed

    Lazar, R

    1995-01-01

    This article relates to curative factors in the therapeutic process, or, to be more precise, to the various modes of the therapist's presence as presumed factors of change. It points to factors of change that have been discussed at length in the various streams of the analytical literature, which emphasized passive attention, absorption, processing and interpretation on the analyst's part, in an atmosphere of restraint and understanding (factors such as "free floating attention," "empathy," etc.). It stresses the importance of another psychic function different in nature--"defamiliarization"--as a condition that facilitates and accompanies processes of understanding and changes in perspective in relation to a reality aesthetically mediated by every human work of art, in general, and in relation to the personal-inner reality as it is expressed in the therapeutic work of art, in particular. This term sheds light on an active, mobile, breaking away--distancing--and rebinding aspect in the psychic functioning of the therapist (and in parallel of the patient), which allows them to "see the new" in a (supposedly) very familiar emotional given. In my view, this term joins others such as "act of freedom" and "constructive listening" in deepening our understanding of the therapeutic factor. There is reference to the term "defamiliarization," or "making strange," in its natural context--its birthplace--in literary criticism, and in a different historical context--in two key articles of the thirties that related to the causes of change in therapy in a very different way.

  14. Strange eigenmodes of chaotic granular flow in a tumbler

    NASA Astrophysics Data System (ADS)

    Christov, Ivan C.; Ottino, Julio M.; Lueptow, Richard M.

    2011-11-01

    Through a combined computational-experimental study of monodisperse granular flow in a slowly-rotating quasi-two-dimensional container we show the presence of naturally-persistent mixing patterns, i.e., ``strange'' eigenmodes of the advection- diffusion operator governing the mixing process in the Eulerian frame. A comparative analysis of the structure of eigenmodes and the corresponding Poincaré section and finite-time Lyapunov exponent field of the flow highlights the relationship between the Eulerian and Lagrangian descriptions of mixing. In addition, we show how the mapping method for scalar transport can be modified to include diffusive effects, which are more significant in a granular flow (in laboratory size equipment) than in a similar fluid flow. This allow us to examine (for the first time in a granular flow) the change in shape, lifespan, and eventual decay of eigenmodes due to diffusive effects at larger numbers of revolutions. Finally, it is shown that segregation patterns in bidisperse mixtures correspond to permanently-excited eigenmodes. This work was supported, in part, by NSF Grant CMMI-1000469.

  15. Narcolepsy with Cataplexy Mimicry: The Strange Case of Two Sisters

    PubMed Central

    Pizza, Fabio; Vandi, Stefano; Poli, Francesca; Moghadam, Keivan Kaveh; Franceschini, Christian; Bellucci, Claudia; Cipolli, Carlo; Ingravallo, Francesca; Natalini, Giuliana; Mignot, Emmanuel; Plazzi, Giuseppe

    2013-01-01

    We report on two sisters, 17 and 12 years of age, with clinical features suggesting narcolepsy with cataplexy (NC): daytime sleepiness, spontaneous and emotionally triggered sudden falls to the ground, and overweight/obesity. MSLT showed borderline sleep latency, with 1 and 0 sleep onset REM periods. HLA typing disclosed the DQB1*0602 allele. Video-polygraphy of the spells ruled out NC diagnosis by demonstrating their easy elicitation by suggestion, with wake EEG, electromyo-graphic persistence of muscle tone, and stable presence of tendon reflexes (i.e., pseudo-cataplexy), together with normal cerebrospinal hypocretin-1 levels. Our cases emphasize the need of a clear depiction of cataplexy pattern at the different ages, the usefulness of examining ictal neurophysiology, and collecting all available disease markers in ambiguous cases. Citation: Pizza F; Vandi S; Poli F; Moghadam KK; Fran-ceschini C; Bellucci C; Cipolli C; Ingravallo F; Natalini G; Mignot E; Plazzi G. Narcolepsy with cataplexy mimicry: the strange case of two sisters. J Clin Sleep Med 2013;9(6):611-612. PMID:23772196

  16. Threshold effects in P -wave bottom-strange mesons

    NASA Astrophysics Data System (ADS)

    Ortega, Pablo G.; Segovia, Jorge; Entem, David R.; Fernández, Francisco

    2017-02-01

    Using a nonrelativistic constituent quark model in which the degrees of freedom are quark-antiquark and meson-meson components, we have recently shown that the D(*)K thresholds play an important role in lowering the mass of the c s ¯ states associated with the physical Ds0 *(2317 ) and Ds 1(2460 ) mesons. This observation is also supported by other theoretical approaches such as lattice-regularized QCD or chiral unitary theory in coupled channels. Herein, we extend our computation to the lowest P -wave Bs mesons, taking into account the corresponding JP=0+, 1+ and 2+ bottom-strange states predicted by the naive quark model and the B K and B*K thresholds. We assume that mixing with Bs(*)η and isospin-violating decays to Bs(*)π are negligible. This computation is important because there is no experimental data in the b s ¯ sector for the equivalent jqP=1 /2+ (Ds0 *(2317 ), Ds 1(2460 )) heavy-quark multiplet and, as it has been seen in the c s ¯ sector, the naive theoretical result can be wrong by more than 100 MeV. Our calculation allows us to introduce the coupling with the D -wave B*K channel and to compute the probabilities associated with the different Fock components of the physical state.

  17. Direct observation of the strange b baryon Xib-.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Banerjee, P; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chan, K; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clément, C; Clément, B; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, S J; de Jong, P; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, J; Guo, F; Gutierrez, P; Gutierrez, G; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J R; Kalk, J M; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kopal, M; Korablev, V M; Kothari, B; Kozelov, A V; Krop, D; Kryemadhi, A; Kuhl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lazoflores, J; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Lesne, V; Leveque, J; Lewis, P; Li, J; Li, Q Z; Li, L; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merekov, Y P; Merkin, M; Merritt, K W; Meyer, J; Meyer, A; Michaut, M; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Otero y Garzón, G J; Owen, M; Padley, P; Pangilinan, M; Panov, G; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perea, P M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Pompos, A; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Rani, K J; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Royon, C; Rozhdestvenski, A; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schliephake, T; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Shpakov, D; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, R P; Snow, J; Snow, G R; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, M; Strauss, E; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Talby, M; Tamburello, P; Tanasijczuk, A; Taylor, W; Telford, P; Temple, J; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Trefzger, T; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, S; Uvarov, L; Uzunyan, S; Vachon, B; van den Berg, P J; van Eijk, B; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Vertogradova, Y; Verzocchi, M; Villeneuve-Seguier, F; Vint, P; Vokac, P; Von Toerne, E; Voutilainen, M; Vreeswijk, M; Wagner, R; Wahl, H D; Wang, L; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Weber, G; Weerts, H; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, J; Yu, C; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G

    2007-08-03

    We report the first direct observation of the strange b baryon Xi(b)- (Xi(b)+). We reconstruct the decay Xi(b)- -->J/psiXi-, with J/psi-->mu+mu-, and Xi--->Lambdapi--->ppi-pi- in pp collisions at square root of s =1.96 TeV. Using 1.3 fb(-1) of data collected by the D0 detector, we observe 15.2 +/- 4.4(stat)(-0.4)(+1.9)(syst) Xi(b)- candidates at a mass of 5.774 +/- 0.011(stat) +/- 0.015(syst) GeV. The significance of the observed signal is 5.5 sigma, equivalent to a probability of 3.3 x 10(-8) of it arising from a background fluctuation. Normalizing to the decay Lambda(b)-->J/psiLambda, we measure the relative rate sigma(Xi(b-) x B(Xi)b})- -->J/psiXi-)/sigma(Lambda(b)) x B(Lambda(b)-->J/psiLambda) = 0.28+/-0.09(stat)(-0.08)(+0.09)(syst).

  18. The Art of Reflection: Turning the Strange into the Familiar.

    PubMed

    Weingarten, Kaethe

    2016-06-01

    There are a great many useful articles on the dynamics and pragmatics of reflecting teams but few articles address what constitutes a good or inept reflection and why. I provide a conceptual model for thinking about what a good reflection does, distinguishing it from a nice reflection. With some further refinements in place, I then illustrate how reflections can be part of any relationship, not just clinical ones. We have opportunities to make them and to recognize when others make them to us. By using examples from my personal life-as a grandmother, daughter, radio listener, cancer survivor, and client-I attempt to ease the personal/professional binary, a project of mine for the last 35 years. In the second part of the article, I address how writing can serve reflection. Although best offered at the moment one is called for, it is never too late for a reflection. Writing allows people to offer reflections after the fact to those who have shared their stories. Sometimes, it is to ourselves we offer those reflections, when the reflector has long since dropped the thread of obligation or interest. I provide an example of working with iconic imagery to unpack meaning so that reflection can eventually take place, allowing integration to proceed, facilitating the strange becoming the familiar.

  19. Strong decays of 2+ charm and charm-strange mesons

    NASA Astrophysics Data System (ADS)

    Zhang, Si-Cheng; Wang, Tianhong; Jiang, Yue; Li, Qiang; Wang, Guo-Li

    2017-02-01

    In this paper, we calculate the strong decays of 2+ heavy-light states, namely, the charmed D2∗(2460)0 meson and the charm-strange Ds2∗(2573)+ meson. The method we adopt is the reduction formula, PCAC relation and low energy theorem, following which, the transition amplitudes are calculated. The wave functions of the heavy mesons involved are achieved by solving the instantaneous Bethe-Salpeter equation. As the OZI-allowed two-body strong decays give the dominant contribution, they can be used to estimate the total widths of mesons. Our results are: Γ[D2∗(2460)0] = 51.3MeV and Γ[Ds2∗(2573)+] = 19.6MeV. The ratios of branching ratios of two main channels are Br[D2∗(2460)0 → D+π‑]/Br[D 2∗(2460)0 → D∗+π‑] = 2.13 and Br[Ds2∗(2573)+ → D∗0K+]/Br[D s2∗(2573)+ → D0K+] = 0.08, respectively.

  20. Dynamics of nuclear single-particle structure in covariant theory of particle-vibration coupling: From light to superheavy nuclei

    SciTech Connect

    Litvinova, E. V.; Afanasjev, A. V.

    2011-07-15

    The impact of particle-vibration coupling and polarization effects due to deformation and time-odd mean fields on single-particle spectra is studied systematically in doubly magic nuclei from low-mass {sup 56}Ni up to superheavy ones. Particle-vibration coupling is treated fully self-consistently within the framework of the relativistic particle-vibration coupling model. Polarization effects due to deformation and time-odd mean field induced by odd particle are computed within covariant density functional theory. It has been found that among these contributions the coupling to vibrations makes a major impact on the single-particle structure. The impact of particle-vibration coupling and polarization effects on calculated single-particle spectra, the size of the shell gaps, the spin-orbit splittings and the energy splittings in pseudospin doublets is discussed in detail; these physical observables are compared with experiment. Particle-vibration coupling has to be taken into account when model calculations are compared with experiment since this coupling is responsible for observed fragmentation of experimental levels; experimental spectroscopic factors are reasonably well described in model calculations.

  1. Silas Weir Mitchell and "The Strange Case of George Dedlow".

    PubMed

    Kline, David G

    2016-07-01

    It has been said of Silas Weir Mitchell (1829-1914) that as a young man he was first among the physiologists of his day, in middle age first among physicians, and as an older man, one of the most noted novelists of his country. Mitchell's novels were written in his later life as a means to avoid boredom during lengthy summer vacations that were the norm for that time among the affluent members of Philadelphia society. These novels were criticized by some because of poor plots, which in some instances failed to move along, or for text that offered a stereotyped depiction of genteel society and the effects that war or personal disaster had on the characters' behavior The criticism came despite the fact that all critics agreed that Mitchell's portrayals of psychopathology in his fictional characters was unique and accurate. However, in his 30s, Mitchell had written and by chance had published a fictional short story that not only transcended such criticisms but became immensely popular. "The Strange Case of George Dedlow" portrays a union officer who was not a physician but who had some medical background and who sustained a series of war wounds leading to severe nerve pain, the author's first description of causalgia, multiple amputations, and the psychological as well as physical symptoms of phantom limb syndrome. The protagonist tells of his torments in the first person in a very engaging fashion. Thus, long before he began writing his, at that time, acclaimed novels in the 1880s, Mitchell wrote a piece of fiction that combines accurate and very important medical observations with fiction of great historical interest. The following rendering of this now classic short story includes selected quotes and some interpretation and is perhaps appropriate for this year, 2 years after the centenary year of his death in 1914.

  2. Strange history: the fall of Rome explained in Hereditas.

    PubMed

    Bengtsson, Bengt O

    2014-12-01

    In 1921 Hereditas published an article on the fall of Rome written by the famous classical scholar Martin P:son Nilsson. Why was a paper on this unexpected topic printed in the newly founded journal? To Nilsson, the demise of the Roman Empire was explained by the "bastardization" occurring between "races" from different parts of the realm. Offspring from mixed couples were of a less stable "type" than their parents, due to the breaking up by recombination of the original hereditary dispositions, which led to a general loss of competence to rule and govern. Thus, the "hardness" of human genes, together with their recombination, was - according to Nilsson - the main cause of the fall of Rome. Nilsson's argument is not particularly convincingly presented. Human "races" are taken to have the same genetic structure as inbred crop strains, and Nilsson believes in a metaphysical unity between the individual and the race to which it belongs. However, in my view, Martin P:son Nilsson and his friend Herman Nilsson-Ehle had wider aims with the article than to explain a historical event. The article can be read as indicating strong support from the classical human sciences to the ambitious new science of genetics. Support is also transferred from genetics to the conservative worldview, where the immutability and inflexibility of the Mendelian genes are used to strengthen the wish for greater stability in politics and life. The strange article in Hereditas can, thus, be read as an early instance in the - still ongoing - tug-of-war between the conservative and the liberal ideological poles over how genetic results best are socially interpreted.

  3. [The first ambulatory clinic for the prevention of women's cancer: the Strang clinic of New York].

    PubMed

    Alonso de Ruiz, Patricia; Ruiz Moreno, José Antonio

    2013-01-01

    The first ambulatory clinic for the prevention of women's cancers was the Strang clinic of New York City, founded by L'Esperance in 1932. Careful and complete clinical examination and some additional tests were the basis for the initial diagnosis of early cancers. In 1945, the Papanicolaou test was added as a new examination tool. Some years later, the Strang clinic proved that detection and treatment of cervical cancers in their preinvasive phase were an important factor for the control of this frequent and mortal neoplasia. The Strang clinic demonstrated that the preventive medicine principles can be applied on the discovery and diagnosis of initial cancer cases and that the treatment applied in such cases offers the best results. Additionally, according with these results, the early diagnosis and treatment of cancers should be the work's philosophy applied in all the health systems.

  4. A New Strangeness Fit to World Parity-Violating Electron Scattering Data

    NASA Astrophysics Data System (ADS)

    Gilbert, Benjamin

    2017-01-01

    A global experimental effort to determine the strangeness content of nuclei, including experiments such as G0, SAMPLE, HAPPEx, and A4, have presented results on the precision frontier for parity-violating electron scattering. In particular, the kinematics of these experiments are in the low momentum-transfer region (Q2 < 1), to allow more robust extrapolation to the static (Q2 = 0) properties of the nucleon. The combination of these results into a global fit presents a new opportunity to comment on the globally observed strangeness content in nuclei. The process for constructing this fit faces certain challenges, with electromagnetic form factor model dependence standing out in particular. A novel fit including the most recent data for 1H, 2H, and 4He target parity-violating electron scattering experiments will also be presented, suggesting small but non-zero electromagnetic strangeness contributions. U.S. Department of Energy grant #DE-FG02-07ER41522

  5. An Examination of Changes in Emotion Co-Regulation among Mother and Child Dyads during the Strange Situation

    ERIC Educational Resources Information Center

    Guo, Yuqing; Leu, Szu-Yun; Barnard, Kathryn E.; Thompson, Elaine A.; Spieker, Susan J.

    2015-01-01

    The present study applied state-space grid analysis to describe how preschooler-mother dyads co-regulate emotion in the Strange Situation. Second-to-second mother and child affect during pre-separation play (baseline) and the final reunion (post perturbation) episodes of the Strange Situation were coded for 80 dyads. Change in emotion…

  6. Rank One Strange Attractors in Periodically Kicked Predator-Prey System with Time-Delay

    NASA Astrophysics Data System (ADS)

    Yang, Wenjie; Lin, Yiping; Dai, Yunxian; Zhao, Huitao

    2016-06-01

    This paper is devoted to the study of the problem of rank one strange attractor in a periodically kicked predator-prey system with time-delay. Our discussion is based on the theory of rank one maps formulated by Wang and Young. Firstly, we develop the rank one chaotic theory to delayed systems. It is shown that strange attractors occur when the delayed system undergoes a Hopf bifurcation and encounters an external periodic force. Then we use the theory to the periodically kicked predator-prey system with delay, deriving the conditions for Hopf bifurcation and rank one chaos along with the results of numerical simulations.

  7. Parity-Violating Electron Scattering and the Electric and Magnetic Strange Form Factors of the Nucleon

    SciTech Connect

    Armstrong, David S.; McKeown, Robert

    2012-11-01

    Measurement of the neutral weak vector form factors of the nucleon provides unique access to the strange quark content of the nucleon. These form factors can be studied using parity-violating electron scattering. A comprehensive program of experiments has been performed at three accelerator laboratories to determine the role of strange quarks in the electromagnetic form factors of the nucleon. This article reviews the remarkable technical progress associated with this program, describes the various methods used in the different experiments, and summarizes the physics results along with recent theoretical calculations.

  8. Disorder-driven electron delocalization in strange metals: The case of tetragonal FeTe

    NASA Astrophysics Data System (ADS)

    Craco, Luis

    2017-03-01

    We investigate the dual roles of electron-electron interactions and site-diagonal disorder in a strange bad-metal. Saturating- and insulating-like resistivity observed in the non-magnetically ordered phase of tetragonal FeTe are shown to be driven by the interplay between multiband effects and iron-d shell band-filling. Incorporation of site-diagonal disorder promotes weak electronic delocalization and metallicity in tetragonal FeTe. The correlated electronic structure we derive is promising in the sense that it leads to results that might explain why moderate disorder can generate nearly linear resistivity dependence in strange metals.

  9. Evidence for two JP = 2 - strange meson states in the K2 (1770) region

    NASA Astrophysics Data System (ADS)

    Aston, D.; Bienz, T.; Bird, F.; Dunwoodie, W.; Johnson, W.; Kunz, P.; Kwon, Y.; Leith, D. W. G. S.; Levinson, L.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Sinervo, P.; Tarnopolsky, G.; Toge, N.; Waite, A.; Williams, S.; Awaji, N.; Fujii, K.; Hayashii, H.; Iwata, S.; Kajikawa, R.; Matsui, T.; Miyamoto, A.; Ozaki, H.; Pak, C.; Shimomura, T.; Sugiyama, A.; Suzuki, S.; Tauchi, T.; D'Amore, J.; Endorf, R.; Martinez, J.; Meadows, B.; Nussbaum, M.; Ukai, K.

    1993-06-01

    Evidence is presented for two JP=2 - strange mesons; one at ∼ 1.77 GeV/ c2 and the other at ∼ 1.82 GeV/ c2. These states have been observed in a partial wave analysis of the Kω system in the reaction K-p→ K-π+π-π0p where the strange mesons decay into K-ω and the ω then decays to π+π-π0. The data set contains ∼ 10 5Kωp events at 11 GeV/ c taken by the LASS spectrometer at SLAC.

  10. Improved Light Cone Model calculation of strangeness asymmetry in the proton

    NASA Astrophysics Data System (ADS)

    Budnik, Garrett; Fox, Jordan; Tuppan, Sam

    2014-09-01

    We expect strangeness in the proton from the Heisenberg uncertainty principle, which allows for the proton to split into a meson and a baryon, such as a K and a Λ. Our goal is to accurately model the momentum distributions of the strange quarks and anti-strange quarks in the proton. We choose the Light Cone Model because it is a natural explanation for strangeness and for s (x) ≠ s (x) . In the Light Cone Model of Cao and Signal, α is a single parameter in the meson-baryon fluctuation functions f (y) and in the s and s distributions of the mesons and baryons. These functions are exponentials in which α is related to the spatial extent of the particles. Because the s and s are in different environments, we explore an array of values for α which reflect the sizes of the particles and study this effect on our model. We compare our results to global pdfs and experimental data from NuTeV, HERMES and ATLAS. We expect strangeness in the proton from the Heisenberg uncertainty principle, which allows for the proton to split into a meson and a baryon, such as a K and a Λ. Our goal is to accurately model the momentum distributions of the strange quarks and anti-strange quarks in the proton. We choose the Light Cone Model because it is a natural explanation for strangeness and for s (x) ≠ s (x) . In the Light Cone Model of Cao and Signal, α is a single parameter in the meson-baryon fluctuation functions f (y) and in the s and s distributions of the mesons and baryons. These functions are exponentials in which α is related to the spatial extent of the particles. Because the s and s are in different environments, we explore an array of values for α which reflect the sizes of the particles and study this effect on our model. We compare our results to global pdfs and experimental data from NuTeV, HERMES and ATLAS. This research has been supported in part by the Research in Undergraduate Institutions program of the National Science Foundation, Grant No. 1205686.

  11. The dark side of cosmology: dark matter and dark energy.

    PubMed

    Spergel, David N

    2015-03-06

    A simple model with only six parameters (the age of the universe, the density of atoms, the density of matter, the amplitude of the initial fluctuations, the scale dependence of this amplitude, and the epoch of first star formation) fits all of our cosmological data . Although simple, this standard model is strange. The model implies that most of the matter in our Galaxy is in the form of "dark matter," a new type of particle not yet detected in the laboratory, and most of the energy in the universe is in the form of "dark energy," energy associated with empty space. Both dark matter and dark energy require extensions to our current understanding of particle physics or point toward a breakdown of general relativity on cosmological scales.

  12. Experiments on the synthesis of superheavy nuclei 284Fl and 285Fl in the Pu,240239+48Ca reactions

    NASA Astrophysics Data System (ADS)

    Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu. Ts.; Rykaczewski, K. P.; Abdullin, F. Sh.; Dmitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu. S.; Voinov, A. A.; Subbotin, V. G.; Sukhov, A. M.; Sabel'nikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2015-09-01

    Irradiations of 239Pu and 240Pu targets with 48Ca beams aimed at the synthesis of Z =114 flerovium isotopes were performed at the Dubna Gas Filled Recoil Separator. A new spontaneously fissioning (SF) isotope 284Fl was produced for the first time in the 240Pu+48Ca (250 MeV) and 239Pu+48Ca (245 MeV) reactions. The cross section of the 239Pu(48Ca,3 n )284Fl reaction channel was about 20 times lower than predicted by theoretical models and about 50 times lower than the maximum fusion-evaporation cross section for the 3 n and 4 n channels measured in the 244Pu+48Ca reaction. In the 240Pu+48Ca experiment, performed at 245 MeV in order to maximize the 3 n -evaporation channel, three decay chains of 285Fl were detected. The α -decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined with higher accuracy. The assignment of SF events observed during the irradiation of the 240Pu target with a 250 MeV 48Ca beam to 284Fl decay is presented and discussed. The cross sections at both 48Ca energies are similar and exceed that observed in the reaction with the lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate a rapid decrease of stability of superheavy nuclei as the neutron number decreases from the predicted magic neutron number N =184 .

  13. Whose body is it anyway? Human cells and the strange effects of property and intellectual property law.

    PubMed

    Feldman, Robin

    2011-06-01

    Whatever else I might own in this world, it would seem intuitively obvious that I own the cells of my body. Where else could the notion of ownership begin, other than with the components of the tangible corpus that all would recognize as "me"? The law, however, does not view the issue so neatly and clearly, particularly when cells are no longer in my body. As so often happens in law, we have reached this point, not by design, but by the piecemeal development of disparate notions that, when gathered together, form a strange and disconcerting picture. This Article examines both property and intellectual property doctrines in relation to human cells that are no longer within the body. In particular, the Article discusses the Bilski decision, in the context of life science process patents, and the Molecular Pathology case, in the context of gene patents. For patent law, the Article concludes that the problem lies not with the fact that genes constitute patentable subject matter, but rather with the extent of the rights that are granted. For both property and intellectual property law, the Article concludes that a more careful application of basic legal principles would better reflect the interests of society as a whole and the interests of individual human subjects, as well as the interests of those who innovate.

  14. Bulk viscosity due to kaons in color-flavor-locked quark matter

    SciTech Connect

    Alford, Mark G.; Braby, Matt; Reddy, Sanjay; Schaefer, Thomas

    2007-05-15

    We calculate the bulk viscosity of color-superconducting quark matter in the color-flavor-locked (CFL) phase. We assume that the lightest bosons are the superfluid mode H and the kaons K{sup 0} and K{sup +}, and that there is no kaon condensate. We calculate the rate of strangeness-equilibrating processes that convert kaons into superfluid modes, and the resultant bulk viscosity. We find that for oscillations with a timescale of milliseconds, at temperatures T<1 MeV, the CFL bulk viscosity is much less than that of unpaired quark matter, but at higher temperatures the bulk viscosity of CFL matter can become larger.

  15. Prospects of heavy and superheavy element production via inelastic nucleus-nucleus collisions - from 238U+238U to18O+254Es

    NASA Astrophysics Data System (ADS)

    Schädel, Matthias

    2016-12-01

    Multi-nucleon transfer reactions, frequently termed deep-inelastic, between heavy-ion projectiles and actinide targets provide prospects to synthesize unknown isotopes of heavy actinides and superheavy elements with neutron numbers beyond present limits. The 238U on 238U reaction, which revealed essential aspects of those nuclear reactions leading to surviving heavy nuclides, mainly produced in 3n and 4n evaporation channels, is discussed in detail. Positions and widths of isotope distributions are compared. It is shown, as a general rule, that cross sections peak at irradiation energies about 10% above the Coulomb barrier. Heavy target nuclei are essential for maximizing cross sections. Experimental results from the 238U on 248Cm reaction, including empirical extrapolations, are compared with theoretical model calculations predicting relatively high cross sections for neutron-rich nuclei. Experiments to test the validity of such predictions are proposed. Comparisons between rather symmetric heavy-ion reactions like 238U on 248Cm (or heavier targets up to 254Es) with very asymmetric ones like 18O on 254Es reveal that the ones with 238U as a projectile have the highest potential in the superheavy element region while the latter ones can be advantageous for the synthesis of heavy actinide isotopes. Concepts for highly efficient recoil separators designed for transfer products are presented.

  16. Strange baryons in a chiral quark-meson model (II). broken SU(3)

    NASA Astrophysics Data System (ADS)

    McGovern, Judith A.; Birse, Michael C.

    1990-01-01

    The chiral-quark meson model is used to study baryon properties with realistic breaking of SU(3). The symmetry breaking is assumed to be strong, so that a random phase approximation (RPA) can be used. In this the strange baryons are described as excitations built on the hedgehog soliton and have an excitation energy of 315 MeV. Other properties of strange baryons are obtained by an approximate spin-isospin projection from the RPA wave function. The magnetic moments agree reasonably well with experiment, but the deviations from the experimental values suggest that the method is valid for the case of rather stronger symmetry breaking than is realistic. The dependence of the RPA energy on the magnitude of the symmetry breaking is examined, and found to be strongly nonlinear for realistic values. This supports the idea that a large πN sigma commutator need not imply a large strange-quark content in the proton. For reasonable values of the scalar meson masses the strange-quark condensate is found to be less than 5% of the total, at the mean-field level. We also estimate the contribution to the condensate from RPA correlations. Within a one-mode approximation we find these to be very small, ˜2%.

  17. Search for doubly charmed baryons and study of charmed strange baryons at Belle

    SciTech Connect

    Kato, Y.; Iijima, T.; Adachi, I.; Aihara, H.; Asner, D. M.; Aushev, T.; Bakich, A. M.; Bala, A.; Ban, Y.; Bhardwaj, V.; Bhuyan, B.; Bobrov, A.; Bonvicini, G.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, K.; Chobanova, V.; Choi, Y.; Cinabro, D.; Dalseno, J.; Danilov, M.; Doležal, Z.; Drásal, Z.; Drutskoy, A.; Dutta, D.; Dutta, K.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Gaur, V.; Gabyshev, N.; Ganguly, S.; Garmash, A.; Gillard, R.; Goh, Y. M.; Golob, B.; Haba, J.; Hayasaka, K.; Hayashii, H.; He, X. H.; Horii, Y.; Hoshi, Y.; Hou, W. -S.; Hsiung, Y. B.; Inami, K.; Ishikawa, A.; Iwasaki, Y.; Iwashita, T.; Jaegle, I.; Julius, T.; Kang, J. H.; Kato, E.; Kawasaki, T.; Kiesling, C.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, J. H.; Kim, M. J.; Kim, Y. J.; Klucar, J.; Ko, B. R.; Kodyš, P.; Korpar, S.; Krokovny, P.; Kuhr, T.; Kuzmin, A.; Kwon, Y. -J.; Lee, S. -H.; Li, J.; Li, Y.; Li Gioi, L.; Libby, J.; Liu, Y.; Liventsev, D.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Moll, A.; Muramatsu, N.; Mussa, R.; Nagasaka, Y.; Nakano, E.; Nakao, M.; Nakazawa, H.; Nayak, M.; Nedelkovska, E.; Ng, C.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Nitoh, O.; Ogawa, S.; Okuno, S.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Park, H.; Park, H. K.; Pedlar, T. K.; Peng, T.; Pestotnik, R.; Petrič, M.; Piilonen, L. E.; Ritter, M.; Röhrken, M.; Rostomyan, A.; Sahoo, H.; Saito, T.; Sakai, Y.; Sandilya, S.; Santelj, L.; Sanuki, T.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Semmler, D.; Senyo, K.; Seon, O.; Shapkin, M.; Shen, C. P.; Shibata, T. -A.; Shiu, J. -G.; Shwartz, B.; Sibidanov, A.; Sohn, Y. -S.; Sokolov, A.; Solovieva, E.; Stanič, S.; Starič, M.; Steder, M.; Sumihama, M.; Sumiyoshi, T.; Tamponi, U.; Tanida, K.; Tatishvili, G.; Teramoto, Y.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Van Hulse, C.; Vanhoefer, P.; Varner, G.; Vinokurova, A.; Vorobyev, V.; Wagner, M. N.; Wang, C. H.; Wang, M. -Z.; Wang, P.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yamashita, Y.; Yashchenko, S.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.

    2014-03-17

    We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider.

  18. Evidence of a strange nonchaotic attractor in the El Niño dynamics

    NASA Astrophysics Data System (ADS)

    Serykh, Ilya; Sonechkin, Dmitry

    2015-04-01

    Basing on a mathematical idea about the so-called strange nonchaotic attractor in the quasi-periodically forced dynamical systems, re-analyses data are considered. It is found that the El Niño - Southern Oscillation (ENSO) is driven not only by the annual Sun-induced periodic heating, but also by two more external periodicities (incommensurate to the annual period) associated with the ~18.6-year lunar-solar nutation of the Earth rotation axis, and the ~14-month Chandler wobble in the Earth's pole motion. Because of the incommensurability of their periods all three forces affect the system in inappropriate time moments. As a result, the ENSO time series look to be very complex (strange in mathematical terms). The power spectra of these series reveal numerous peaks located at the periods that are multiples of the above periodicities as well as at their sub- and super-harmonic. In spite of this strangeness, a mutual order seems to be inherent to these time series and their spectra. This order reveals itself in the existence of a scaling of the power spectrum peaks and respective rhythms in the ENSO dynamics that look like the power spectrum and dynamics of the strange nonchaotic attractor. It means there are no limits to forecast ENSO, in principle. In practice, it opens a possibility to forecast ENSO for several years ahead.

  19. Latest Results on Orbitally Excited Strange Bottom Mesons with the CDF II Detector

    SciTech Connect

    Gorelov, Igor V.; /New Mexico U.

    2006-10-01

    The authors present the latest results on the spectroscopy of orbitally excited strange bottom mesons from {approx} 1 fb{sup -1} of CDF data. The measurements are performed with fully reconstructed B decays collected by the CDF II detector at {radical}s = 1.96 TeV in both the di-muon and the fully hadronic trigger paths.

  20. New indication on scaling properties of strangeness production in pp collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Tokarev, M. V.; Zborovský, I.

    2017-02-01

    Experimental data on transverse momentum spectra of strange particles (KS0,K‑,K∗0,ϕ, Λ, Λ∗, Σ∗, Ξ‑, Ω) produced in pp collisions at s = 200GeV obtained by the STAR and PHENIX collaborations at RHIC are analyzed in the framework of z-scaling approach. The concept of the z-scaling is based on fundamental principles of self-similarity, locality, and fractality of hadron interactions at high energies. General properties of the data z-presentation are studied. Self-similarity of fractal structure of protons and fragmentation processes with strange particles is discussed. A microscopic scenario of constituent interactions developed within the z-scaling scheme is used to study the dependence of momentum fractions and recoil mass on the collision energy, transverse momentum and mass of produced inclusive particle, and to estimate the constituent energy loss. We consider that obtained results can be useful in study of strangeness origin, in searching for new physics with strange probes, and can serve for better understanding of fractality of hadron interactions at small scales.

  1. Silent Films and Strange Stories: Theory of Mind, Gender, and Social Experiences in Middle Childhood

    ERIC Educational Resources Information Center

    Devine, Rory T.; Hughes, Claire

    2013-01-01

    In this study of two hundred and thirty 8- to 13-year-olds, a new "Silent Films" task is introduced, designed to address the dearth of research on theory of mind in older children by providing a film-based analogue of F. G. E. Happe's (1994) Strange Stories task. Confirmatory factor analysis showed that all items from both tasks loaded…

  2. Polarisation observables for strangeness photoproduction on a frozen spin target with CLAS at Jefferson Lab

    SciTech Connect

    Stuart Fegan

    2012-04-01

    The FROST experiment at Jefferson Lab used the CLAS detector in Hall B with the intention of performing a complete measurement of polarization observables associated with strangeness photoproduction, in combination with data from previous JLab experiments. This was achieved by utilizing the FROST polarized target in conjunction with polarized photon beams, allowing direct measurement of beam-target double polarization observables. By studying strangeness reactions, such as {gamma}p {yields} K{sup +}{Lambda}{sup 0}, it may be possible to find 'missing' baryon resonances, predicted by symmetric quark models but not observed in previous experiments, whose results are consistent with the di-quark model. It is thought these 'missing' resonances remain undiscovered because they have different coupling strengths for different reaction channels, such as the strangeness reactions, whereas the current data is dominated by studies of pN reactions. Observing these resonances therefore has important implications for our knowledge of the excited states of nucleons, and the models predicting the quark interactions within them. The G polarization observable is one of the beam-target double polarization observables, associated with a longitudinally polarized target and a linearly polarized photon beam, and its measurement for the strangeness reaction {gamma}p {yields} K{sup +}{Lambda}{sup 0} is the focus of the work presented.

  3. On Mature Reflection: "Strange Objects" and the Cultivation of Reflective Reading.

    ERIC Educational Resources Information Center

    Heyde, Emma

    2000-01-01

    Examines Gary Crew's novel written for a young adult audience, called "Strange Objects," a story containing verifiable historical fact interwoven with elements of fiction and the supernatural. Shows how the numerous genres and viewpoints in the book challenge and contradict one another, forcing young readers to perform resistant readings…

  4. The impact of s-bar{s} asymmetry on the strange electromagnetic form factor

    NASA Astrophysics Data System (ADS)

    Ghasempour Nesheli, Ali

    2016-09-01

    The existence of the strange quark asymmetry in the nucleon sea has been indicated by both the experimental and theoretical analyses. Although it is well known that the s-bar{{s}} asymmetry is important for some processes in high-energy hadron collisions, it has also been indicated that it can be related to the strange Dirac form factor F 1 s. In this work, we have studied the impact of s- bar{{s}} asymmetry and its uncertainty from various modern parton distribution functions (PDFs) on F 1 s and compared the obtained results with the available experimental information. As a result, we found that the uncertainty in F 1 s( t) due to the s( x) - bar{s}( x) distribution is rather large so that it dominates the model uncertainty at all values of the squared momentum transfer t. However, taking into account the uncertainties, the theoretical predictions of F 1 s( t) are fully compatible with the estimate extracted from experiment. We concluded that the future accurate experimental data of the strange Dirac form factor might be used to put direct constraints on the strange content of the proton and reduce its uncertainty that has always been a challenge.

  5. Beyond Capital High: On Dual Citizenship and the Strange Career of "Acting White"

    ERIC Educational Resources Information Center

    Fordham, Signithia

    2008-01-01

    In this article, I reflect on the strange career of the "burden of "acting White"" since it attracted widespread popular and academic attention over 20 years ago. I begin by noting that my original definition of "the burden of "acting White"" should not be confused with a prominent misconception of the problem as the "fear" of "acting White." I…

  6. Probing parton dynamics of QCD matter with Ω and Φ production

    DOE PAGES

    Adamczyk, L.

    2016-02-24

    In this paper, we present measurements of Ω and Φ production at midrapidity from Au+Au collisions at nucleon-nucleon center-of-mass energies √sNN = 7.7, 11.5, 19.6 , 27, and 39 GeV by the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). Motivated by the coalescence formation mechanism for these strange hadrons, we study the ratios of N(Ω- +more » $$\\overline{Ω}$$+) / [2N (Φ)] . These ratios as a function of transverse momentum pT fall on a consistent trend at high collision energies, but start to show deviations in peripheral collisions at √sNN = 19.6, 27, and 39 GeV, and in central collisions at 11.5 GeV in the intermediate pT region of 2.4 - 3.6 GeV/ . We further evaluate empirically the strange quark pT distributions at hadronization by studying the Ω/Φ ratios scaled by the number of constituent quarks (NCQ). The NCQ-scaled Ω/Φ ratios show a suppression of strange quark production in central collisions at 11.5 GeV compared to √sNN ≥ 19.6 GeV. The shapes of the presumably thermal strange quark distributions in 0–60% most central collisions at 7.7 GeV show significant deviations from those in 0–10% most central collisions at higher energies. Lastly, these features suggest that there is likely a change of the underlying strange quark dynamics in the transition from quark matter to hadronic matter at collision energies below 19.6 GeV.« less

  7. Probing parton dynamics of QCD matter with Ω and ϕ production

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A. I.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, X.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jentsch, A.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, X.; Li, Y.; Li, W.; Lin, T.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, R.; Ma, G. L.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Matis, H. S.; McDonald, D.; McKinzie, S.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Z.; Sun, X. M.; Sun, Y.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, G.; Wang, J. S.; Wang, H.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Xu, H.; Xu, Z.; Xu, J.; Yang, S.; Yang, Y.; Yang, Y.; Yang, C.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Y.; Zhang, J.; Zhang, J.; Zhang, S.; Zhang, S.; Zhang, Z.; Zhang, J. B.; Zhao, F.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-02-01

    We present measurements of Ω and ϕ production at midrapidity from Au+Au collisions at nucleon-nucleon center-of-mass energies √{sN N}=7.7 , 11.5 , 19.6 , 27, and 39 GeV by the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). Motivated by the coalescence formation mechanism for these strange hadrons, we study the ratios of N (Ω-+Ω¯+) /[2 N (ϕ ) ] . These ratios as a function of transverse momentum pT fall on a consistent trend at high collision energies, but start to show deviations in peripheral collisions at √{sN N}=19.6 , 27, and 39 GeV, and in central collisions at 11.5 GeV in the intermediate pT region of 2.4 -3.6 GeV/c . We further evaluate empirically the strange quark pT distributions at hadronization by studying the Ω /ϕ ratios scaled by the number of constituent quarks (NCQ). The NCQ-scaled Ω /ϕ ratios show a suppression of strange quark production in central collisions at 11.5 GeV compared to √{sN N}≥19.6 GeV. The shapes of the presumably thermal strange quark distributions in 0-60% most central collisions at 7.7 GeV show significant deviations from those in 0-10% most central collisions at higher energies. These features suggest that there is likely a change of the underlying strange quark dynamics in the transition from quark matter to hadronic matter at collision energies below 19.6 GeV.

  8. 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.

  9. 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.

  10. A Strange Supernova with a Gamma-Ray Burst

    NASA Astrophysics Data System (ADS)

    1998-10-01

    Important Observations with La Silla Telescopes Several articles appear today in the scientific journal Nature about the strange supernova SN 1998bw that exploded earlier this year in the spiral galaxy ESO184-G82 . These studies indicate that this event was linked to a Gamma-Ray Burst and may thus provide new insights into this elusive phenomenon. Important observations of SN 1998bw have been made with several astronomical telescopes at the ESO La Silla Observatory by some of the co-authors of the Nature articles [1]. The measurements at ESO will continue during the next years. The early observations On April 25, the BeppoSAX satellite detected a Gamma-Ray Burst from the direction of the constellation Telescopium, deep in the southern sky. Although there is now general consensus that they originate in very distant galaxies, the underlying physical causes of these events that release great amounts of energy within seconds are still puzzling astronomers. Immediately after reports about the April 25 Burst had been received, astronomers at La Silla took some images of the sky region where the gamma-rays were observed as a "Target of Opportunity" (ToO) programme. The aim was to check if the visual light of one of the objects in the field had perhaps brightened when compared to exposures made earlier. This would then provide a strong indication of the location of the Gamma-Ray Burst. The digital exposures were transferred to the Italian/Dutch group around BeppoSax that had requested these ToO observations. Astronomers of this group quickly noticed a new, comparatively bright star, right on the arm of a small spiral galaxy. This galaxy was first catalogued in the 1970's during the ESO/Uppsala Survey of the Southern Sky and received the designation ESO184-G82 . It is located at a distance of about 140 million light-years. SN 1998bw ESO PR Photo 39a/98 ESO PR Photo 39a/98 [Preview - JPEG: 800 x 963 pix - 592k] [High-Res - JPEG: 3000 x 3612 pix - 4.1Mb] ESO PR Photo 39b/98

  11. Strange hadrons and their resonances: A diagnostic tool of quark-gluon plasma freeze-out dynamics

    NASA Astrophysics Data System (ADS)

    Rafelski, Johann; Letessier, Jean; Torrieri, Giorgio

    2001-11-01

    We update our chemical analysis of (strange) hadrons produced at the SPS in Pb-Pb collisions at 158A GeV and discuss chemical analysis of RHIC results. We report that the shape of (anti)hyperon m⊥ spectra in a thermal freeze-out analysis leads to freeze-out conditions found in chemical analysis, implying sudden strange-hyperon production. We discuss how a combined analysis of several strange-hadron resonances of differing lifespan can be used to understand the dynamical process present during chemical and thermal freeze-outs. In medium resonance quenching is considered.

  12. 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)

  13. Strangeness Physics at CLAS in the 6 GeV Era

    SciTech Connect

    Schumacher, Reinhard A.

    2016-04-01

    A very brief overview is presented of varied strangeness-physics studies that have been conducted with the CLAS system in the era of 6 GeV beam at Jefferson Lab. A full bibliography of articles related to open strangeness production is given, together with some physics context for each work. One natural place where these studies could be continued, using a K L beam and the GlueX detector, is in the further investigation of the Λ(1405) baryon. The line shapes and cross sections of this state were found, using photoproduction at CLAS, to differ markedly in the three possible Σπ final states. The analogous strong-interaction reactions using a K L beam could further bring this phenomenon into focus. 1. The CLAS program ran from 1998 to 2012, during the time when the maximum Jefferson Lab beam energy was 6 GeV. An important thrust of this program was to investigate the spectrum of N * and Δ * (non-strange) baryon resonances using photo-and electro-production reactions. To this end, final states containing strange particles (K mesons and low-mass hyperons) played a significant role. The reason for this is partly due to favorable kinemat-ics. When the total invariant energy W (= √ s) of a baryonic system exceeds 1.6 GeV it becomes possible to create the lightest strangeness-containing final state, K + Λ. This is a two-body final state that is straightforward to reconstruct in the CLAS detector system [1], and theoretically it is easier to deal with two-body reaction amplitudes than with three-and higher-body reaction amplitudes. In the mass range W > 1.6 GeV the decay modes of excited nucleons tend to not to favor two-body π-nucleon final states but rather multi-pion states. As input to partial-wave decompositions and resonance-extraction models, therefore, the strangeness-containing final states of high-mass nucleon excitations have had importance. Excited baryons decay through all possible channels simultaneously, constrained by unitarity of course

  14. Strangeness production in heavy ion collisions: What have we learned with the energy increase from SPS to RHIC

    SciTech Connect

    Odyniec, Grazyna

    2002-08-23

    A review of strange particle production in heavy ion collisions at ultrarelativistic energies is presented. The particle yields and ratios from SPS and RHIC are discussed in view of the newest developments in understanding collision dynamics, and in view of their role in the search for a quark gluon plasma. A strangeness enhancement, most notably observed in CERN Pb-beam results, shows a remarkable two fold global enhancement with a much larger effect seen in the case of multistrange baryons. Hadronic models did fail to explain this pattern. At RHIC energy strangeness assumes a different role, since temperatures are higher and the central rapidity region almost baryon-free. An intriguing question: ''Did RHIC change the way we understand strangeness production in heavy ion collisions ?'' is discussed.

  15. High-School Student Discovers Strange Astronomical Object

    NASA Astrophysics Data System (ADS)

    2009-09-01

    A West Virginia high-school student analyzing data from a giant radio telescope has discovered a new astronomical object -- a strange type of neutron star called a rotating radio transient. Lucas Bolyard, a sophomore at South Harrison High School in Clarksburg, WV, made the discovery while participating in a project in which students are trained to scrutinize data from the National Science Foundation's giant Robert C. Byrd Green The project, called the Pulsar Search Collaboratory (PSC), is a joint project of the National Radio Astronomy Observatory (NRAO) and West Virginia University (WVU), funded by a grant from the National Science Foundation. Bolyard made the discovery in March, after he already had studied more than 2,000 data plots from the GBT and found nothing. "I was home on a weekend and had nothing to do, so I decided to look at some more plots from the GBT," he said. "I saw a plot with a pulse, but there was a lot of radio interference, too. The pulse almost got dismissed as interference," he added. Nonetheless, he reported it, and it went on a list of candidates for West Virginia University astronomers Maura McLaughlin and Duncan Lorimer to re-examine, scheduling new observations of the region of sky from which the pulse came. Disappointingly, the follow-up observations showed nothing, indicating that the object was not a normal pulsar. However, the astronomers explained to Bolyard that his pulse still might have come from a rotating radio transient. Confirmation didn't come until July. Bolyard was at the NRAO's Green Bank Observatory with fellow PSC students. The night before, the group had been observing with the GBT in the wee hours, and all were very tired. Then Lorimer showed Bolyard a new plot of his pulse, reprocessed from raw data, indicating that it is real, not interference, and that Bolyard is likely the discoverer of one of only about 30 rotating radio transients known. Suddenly, Bolyard said, he wasn't tired anymore. "That news made me full

  16. Strangeness in Au+Au collisions at √sNN = 130 GeV observed with the STAR detector

    NASA Astrophysics Data System (ADS)

    Barnby, Lee S.; STAR Collaboration; Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B. D.; Anderson, M.; Averichev, G. S.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Berger, J.; Bichsel, H.; Bland, L. C.; Blyth, C. O.; Bonner, B. E.; Boucham, A.; Brandin, A.; Cadman, R. V.; Caines, H.; Calderón de la Barca Sánchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chattopadhyay, S.; Chen, M. L.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Deng, W. S.; Derevschikov, A. A.; Didenko, L.; Draper, J. E.; Dunin, V. B.; Dunlop, J. C.; Eckardt, V.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Filimonov, K.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K. J.; Fu, J.; Gagliardi, C. A.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Grabski, J.; Grachov, O.; Grigoriev, V.; Guedon, M.; Gushin, E.; Hallman, T. J.; Hardtke, D.; Harris, J. W.; Heffner, M.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Huang, H. Z.; Humanic, T. J.; Hümmler, H.; Igo, G.; Ishihara, A.; Ivanshin, Yu. I.; Jacobs, P.; Jacobs, W. W.; Janik, M.; Johnson, I.; Jones, P. G.; Judd, E. G.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Konstantinov, A. S.; Kotchenda, L.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lakehal-Ayat, L.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lebedev, A.; Lednický, R.; Leontiev, V. M.; LeVine, M. J.; Li, Q.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, L.; Liu, Z.; Liu, Q. J.; Ljubicic, T.; Llope, W. J.; Curto, G. Lo; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Lynn, D.; Majka, R.; Margetis, S.; Markert, C.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meissner, F.; Melnick, Yu.; Meschanin, A.; Messer, M.; Miller, M. L.; Milosevich, Z.; Minaev, N. G.; Mitchell, J.; Moiseenko, V. A.; Moore, C. F.; Morozov, V.; de Moura, M. M.; Munhoz, M. G.; Nelson, J. M.; Nevski, P.; Nikitin, V. A.; Nogach, L. V.; Norman, B.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Paic, G.; Pandey, S. U.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Perevoztchikov, V.; Peryt, W.; Petrov, V. A.; Pluta, J.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potrebenikova, E.; Prindle, D.; Pruneau, C.; Radomski, S.; Rai, G.; Ravel, O.; Ray, R. L.; Razin, S. V.; Reichhold, D.; Reid, J. G.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevski, O. V.; Romero, J. L.; Roy, C.; Rykov, V.; Sakrejda, I.; Sandweiss, J.; Saulys, A. C.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schroeder, L. S.; Schüttauf, A.; Schweda, K.; Seger, J.; Seliverstov, D.; Seyboth, P.; Shahaliev, E.; Shestermanov, K. E.; Shimanskii, S. S.; Shvetcov, V. S.; Skoro, G.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stephenson, E. J.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Struck, C.; Suaide, A. A. P.; Sugarbaker, E.; Suire, C.; umbera, M.; Symons, T. J. M.; Szanto de Toledo, A.; Szarwas, P.; Tai, A.; Takahashi, J.; Tang, A. H.; Thomas, J. H.; Thompson, M.; Tikhomirov, V.; Tokarev, M.; Tonjes, M. B.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Trofimov, V.; Tsai, O.; Turner, K.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; Vander Molen, A. M.; Vasilevski, I. M.; Vasiliev, A. N.; Vigdor, S. E.; Voloshin, S. A.; Wang, F.; Ward, H.; Watson, J. W.; Wells, R.; Wenaus, T.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Willson, R.; Wissink, S. W.; Witt, R.; Wood, J.; Xu, N.; Xu, Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yurevich, V. I.; Zanevski, Y. V.; Zborovský, I.; Zhang, H.; Zhang, W. M.; Zoulkarneev, R.; Zubarev, A. N.

    2002-07-01

    The STAR detector has made a variety of measurements of strange and other hadronic species in Au+Au collisions at √sNN = 130 GeV. A comparison of kaon and pion production enables an examination of the systematics of strangeness production with energy by comparing them to lower energy collisions. Anti-baryon to baryon ratios indicate a much reduced net-baryon density and transverse momentum spectra show that a picture of transverse expansion seems appropriate.

  17. Strangeness production in S + Pb and p + Pb collisions at 200 GeV/c per nucleon

    SciTech Connect

    Sakrejda, I.

    1992-09-01

    Results from CERN experiment NA36 are reported. Cross sections for the production of singly strange particles in the S+Pb and p+Pb reactions have been measured in the rapidity range 1.250.2 GeV. A significant difference in the rapidity distributions of the lambda particles originating from these reactions suggests a fundamental difference in the strangeness production mechanism.

  18. Strangeness production in S + Pb and p + Pb collisions at 200 GeV/c per nucleon

    SciTech Connect

    Sakrejda, I.; NA 36 Collaboration

    1992-09-01

    Results from CERN experiment NA36 are reported. Cross sections for the production of singly strange particles in the S+Pb and p+Pb reactions have been measured in the rapidity range 1.250.2 GeV. A significant difference in the rapidity distributions of the lambda particles originating from these reactions suggests a fundamental difference in the strangeness production mechanism.

  19. Calculation of the evaporation residue cross sections for the synthesis of the superheavy element Z=119 via the {sup 50}Ti+{sup 249}Bk hot fusion reaction

    SciTech Connect

    Liu Zuhua; Bao, Jing-Dong

    2011-09-15

    The evaporation residue (ER) cross sections for 3n and 4n evaporation channels in the {sup 50}Ti + {sup 249}Bk reaction leading the formation of {sup 296}119 and {sup 295}119 isotopes are evaluated by means of a modified fusion-by-diffusion model. In the model, the dynamic evolution from dinucleus to mononucleus is taken into account with the two-dimensional coupled Langenvin equations. The calculated maximum ER cross sections in 3n and 4n evaporation channels of the {sup 50}Ti + {sup 249}Bk reaction are 0.17 and 0.57 pb, respectively. The cross section of 0.57 pb is close to the present experimental limit for the registration of the evaporation residual nuclei. Therefore, superheavy element 119 may be the most hopeful new element with Z>118 to be synthesized under somehow improved experimental conditions in the near future.

  20. First online multireflection time-of-flight mass measurements of isobar chains produced by fusion-evaporation reactions: Toward identification of superheavy elements via mass spectroscopy

    NASA Astrophysics Data System (ADS)

    Schury, P.; Wada, M.; Ito, Y.; Kaji, D.; Arai, F.; MacCormick, M.; Murray, I.; Haba, H.; Jeong, S.; Kimura, S.; Koura, H.; Miyatake, H.; Morimoto, K.; Morita, K.; Ozawa, A.; Rosenbusch, M.; Reponen, M.; Söderström, P.-A.; Takamine, A.; Tanaka, T.; Wollnik, H.

    2017-01-01

    Using a multireflection time-of-flight mass spectrograph located after a gas cell coupled with the gas-filled recoil ion separator GARIS-II, the masses of several α -decaying heavy nuclei were directly and precisely measured. The nuclei were produced via fusion-evaporation reactions and separated from projectilelike and targetlike particles using GARIS-II before being stopped in a helium-filled gas cell. Time-of-flight spectra for three isobar chains, 204Fr-204Rn-204At-204Po , 205Fr-205Rn-205At-205Po-205Bi , and 206Fr-206Rn-206At , were observed. Precision atomic mass values were determined for Fr-206204, Rn,205204, and At,205204. Identifications of 205Bi, Po,205204, 206Rn, and 206At were made with N ≲10 detected ions, representing the next step toward use of mass spectrometry to identify exceedingly low-yield species such as superheavy element ions.

  1. Violation of mass ordering for multi-strange hadrons at RHIC and LHC

    NASA Astrophysics Data System (ADS)

    Takeuchi, Shiori; Murase, Koichi; Hirano, Tetsufumi; Huovinen, Pasi; Nara, Yasushi

    2016-12-01

    We study effects of the hadronic rescattering on final observables especially for multi-strange hadrons such as ϕ, Ξ and Ω in high-energy heavy-ion collisions within an integrated dynamical approach. In this approach, (3+1)-dimensional ideal hydrodynamics is combined with a microscopic transport model, JAM. We simulate the collisions with or without hadronic rescatterings and compare observables between these two options so that we quantify the effects of the hadronic rescattering. We find that the mean transverse momentum and the elliptic flow parameter of multi-strange hadrons are less affected by hadronic rescattering and, as a result, the mass ordering of the pT-differential elliptic flow parameter v2 (pT) is violated: At the RHIC and the LHC energies the v2 (pT) for ϕ-mesons is larger than that for protons in the low-pT regions.

  2. Strange beta: an assistance system for indoor rock climbing route setting.

    PubMed

    Phillips, C; Becker, L; Bradley, E

    2012-03-01

    This paper applies the mathematics of chaos to the task of designing indoor rock-climbing routes. Chaotic variation has been used to great advantage on music and dance, but the challenges here are quite different, beginning with the representation. We present a formalized system for transcribing rock climbing problems and then describe a variation generator that is designed to support human route-setters in designing new and interesting climbing problems. This variation generator, termed strange beta, uses chaos to introduce novelty. We validated this approach with a large blinded study in a commercial climbing gym, in cooperation with experienced climbers and expert route setters. The results show that strange beta can help a human setter produce routes that are at least as good as, and in some cases better than, those produced in the traditional manner.

  3. Predicting the τ strange branching ratios and implications for V us

    NASA Astrophysics Data System (ADS)

    Antonelli, Mario; Cirigliano, Vincenzo; Lusiani, Alberto; Passemar, Emilie

    2013-10-01

    Hadronic τ decays provide several ways to extract the Cabbibo-Kobashi-Maskawa (CKM) matrix element V us . The most precise determination involves using inclusive τ decays and requires as input the total branching ratio into strange final states. Recent results from B-factories have led to a discrepancy of about 3.4 σ from the value of V us implied by CKM unitarity and direct determination from Kaon semi-leptonic modes. In this paper we predict the three leading strange τ branching ratios, using dispersive parameterizations of the hadronic form factors and taking as experimental input the measured Kaon decay rates and the τ → Kπν τ decay spectrum. We then use our results to reevaluate V us , for which we find | V us | = 0.2207 ± 0.0027, in better agreement with CKM unitarity.

  4. strange beta: An assistance system for indoor rock climbing route setting

    NASA Astrophysics Data System (ADS)

    Phillips, C.; Becker, L.; Bradley, E.

    2012-03-01

    This paper applies the mathematics of chaos to the task of designing indoor rock-climbing routes. Chaotic variation has been used to great advantage on music and dance, but the challenges here are quite different, beginning with the representation. We present a formalized system for transcribing rock climbing problems and then describe a variation generator that is designed to support human route-setters in designing new and interesting climbing problems. This variation generator, termed strange beta, uses chaos to introduce novelty. We validated this approach with a large blinded study in a commercial climbing gym, in cooperation with experienced climbers and expert route setters. The results show that strange beta can help a human setter produce routes that are at least as good as, and in some cases better than, those produced in the traditional manner.

  5. Production of multi-strangeness hypernuclei and the YN-interaction

    NASA Astrophysics Data System (ADS)

    Gaitanos, T.; Lenske, H.

    2014-10-01

    We investigate for the first time the influence of hyperon-nucleon (YN) interaction models on the strangeness dynamics of antiproton-nucleus and Ξ-nucleus interactions. Of particular interest is the formation of bound multi-strangeness hypermatter in reactions relevant for Pbar ANDA . The main features of two well-established microscopic approaches for YN-scattering are first discussed and their results are then analyzed such that they can be applied in transport-theoretical simulations. The transport calculations for reactions induced by antiproton beams on a primary target including also the secondary cascade beams on a secondary target show a strong sensitivity on the underlying YN-interaction. In particular, we predict the formation of Ξ-hypernuclei with an observable sensitivity on the underlying ΞN-interaction. We conclude the importance of our studies for the forthcoming research plans at FAIR.

  6. Strange scaling and relaxation of finite-size fluctuation in thermal equilibrium

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Yoshiyuki Y.

    2016-07-01

    We numerically exhibit two strange phenomena of finite-size fluctuation in thermal equilibrium of a paradigmatic long-range interacting system having a second-order phase transition. One is a nonclassical finite-size scaling at the critical point, which differs from the prediction by statistical mechanics. With the aid of this strange scaling, the scaling theory for infinite-range models conjectures the nonclassical values of critical exponents for the correlation length. The other is relaxation of the fluctuation strength from one level to another in spite of being in thermal equilibrium. A scenario is proposed to explain these phenomena from the viewpoint of the Casimir invariants and their nonexactness in finite-size systems, where the Casimir invariants are conserved in the Vlasov dynamics describing the long-range interacting systems in the limit of large population. This scenario suggests appearance of the reported phenomena in a wide class of isolated long-range interacting systems.

  7. The Strange Stories test--a replication study of children and adolescents with Asperger syndrome.

    PubMed

    Kaland, Nils; Møller-Nielsen, Annette; Smith, Lars; Mortensen, Erik Lykke; Callesen, Kirsten; Gottlieb, Dorte

    2005-03-01

    The aim of the present study was to assess the ability of 21 children and adolescents with Asperger syndrome (AS) of normal intelligence to infer mental states in a story context using Happe's Strange Stories test. The participants in the AS group were compared with an age-matched control group (N=20) of normally developing children and adolescents on a test of social understanding. The test material comprised social communication such as Pretence, Joke, Lie, White Lie, Figure of Speech, Misunderstanding, Persuasion, Irony, Double Bluff and Contrary Emotions, Appearance/Reality and Forgetting. As compared to the controls, the participants in the AS group performed less well on these tasks, and answered fewer correct mental state inferences, but performed well on a physical state control task. This study supports the main finding of earlier studies, showing that even individuals with AS of normal intelligence have problems in using mental state terms context-appropriately when tested on the Strange Stories test.

  8. RX J1856.5-3754 as a possible strange star candidate

    NASA Astrophysics Data System (ADS)

    Henderson, Jillian Anne; Page, Dany

    2007-04-01

    RX J1856.5-3754 has been proposed as a strange star candidate due to its very small apparent radius measured from its X-ray thermal spectrum. However, its optical emission requires a much larger radius and thus most of the stellar surface must be cold and undetectable in X-rays. In the case the star is a neutron star such a surface temperature distribution can be explained by the presence of a strong toroidal field in the crust (Pérez-Azorín et al.: Astron. Astrophys. 451, 1009 (2006); Geppert et al.: Astron. Astrophys. 457, 937 (2006)) We consider a similar scenario for a strange star with a thin baryonic crust to determine if such a magnetic field induced effect is still possible.

  9. Using low-energy neutrinos from pion decay at rest to probe the proton strangeness.

    PubMed

    Pagliaroli, G; Lujan-Peschard, C; Mitra, M; Vissani, F

    2013-07-12

    The study of the neutral current elastic scattering of neutrinos on protons at lower energies can be used as a compelling probe to improve our knowledge of the strangeness of the proton. We consider a neutrino beam generated from pion decay at rest, as provided by a cyclotron or a spallation neutron source and a 1 kton scintillating detector with a potential similar to the Borexino detector. Despite several backgrounds from solar and radioactive sources, it is possible to estimate two optimal energy windows for the analysis, one between 0.65 and 1.1 MeV and another between 1.73 and 2.2 MeV. The expected number of neutral current events in these two regions, for an exposure of 1 yr, is enough to obtain an error on the strange axial charge 10 times smaller than available at present.

  10. Metaphorical mapping between raw-cooked food and strangeness-familiarity in Chinese culture.

    PubMed

    Deng, Xiaohong; Qu, Yuan; Zheng, Huihui; Lu, Yang; Zhong, Xin; Ward, Anne; Li, Zijun

    2017-02-01

    Previous research has demonstrated metaphorical mappings between physical coldness-warmth and social distance-closeness. Since the concepts of interpersonal warmth are frequently expressed in terms of food-related words in Chinese, the present study sought to explore whether the concept of raw-cooked food could be unconsciously and automatically mapped onto strangeness-familiarity. After rating the nutritive value of raw or cooked foods, participants were presented with morphing movies in which their acquaintances gradually transformed into strangers or strangers gradually morphed into acquaintances, and were asked to stop the movies when the combined images became predominantly target faces. The results demonstrated that unconscious and automatic metaphorical mappings between raw-cooked food and strangeness-familiarity exist. This study provides a foundation for testing whether Chinese people can think about interpersonal familiarity using mental representations of raw-cooked food and supports cognitive metaphor theory from a crosslinguistic perspective.

  11. Variety of strange pseudohyperbolic attractors in three-dimensional generalized Hénon maps

    NASA Astrophysics Data System (ADS)

    Gonchenko, A. S.; Gonchenko, S. V.

    2016-12-01

    In the present paper we focus on the problem of the existence of strange pseudohyperbolic attractors for three-dimensional diffeomorphisms. Such attractors are genuine strange attractors in that sense that each orbit in the attractor has positive maximal Lyapunov exponent and this property is robust, i.e., it holds for all close systems. We restrict attention to the study of pseudohyperbolic attractors that contain only one fixed point. Then we show that three-dimensional maps may have only 5 different types of such attractors, which we call the discrete Lorenz, figure-8, double-figure-8, super-figure-8, and super-Lorenz attractors. We find the first four types of attractors in three-dimensional generalized Hénon maps of form x ¯ = y, y ¯ = z, z ¯ = Bx + Az + Cy + g(y , z) , where A , B and C are parameters (B is the Jacobian) and g(0 , 0) =g‧(0 , 0) = 0.

  12. High-precision calculation of the strange nucleon electromagnetic form factors

    SciTech Connect

    Green, Jeremy; Meinel, Stefan; Engelhardt, Michael G.; Krieg, Stefan; Laeuchli, Jesse; Negele, John W.; Orginos, Kostas; Pochinsky, Andrew; Syritsyn, Sergey

    2015-08-26

    We report a direct lattice QCD calculation of the strange nucleon electromagnetic form factors GsE and GsM in the kinematic range 0 ≤ Q2 ≤ 1.2GeV2. For the first time, both GsE and GsM are shown to be nonzero with high significance. This work uses closer-to-physical lattice parameters than previous calculations, and achieves an unprecented statistical precision by implementing a recently proposed variance reduction technique called hierarchical probing. We perform model-independent fits of the form factor shapes using the z-expansion and determine the strange electric and magnetic radii and magnetic moment. As a result, we compare our results to parity-violating electron-proton scattering data and to other theoretical studies.

  13. Towards an understanding of the new charm and charm-strange mesons

    NASA Astrophysics Data System (ADS)

    Godfrey, Stephen

    2005-01-01

    The observation of the DsJ*(2317), DsJ(2460), and SELEX DsJ*(2632) states with properties differing considerably from what was expected has led to a renewed interest in hadron spectroscopy. In addition to these states, non-strange partners of the DsJ states have also been observed. Understanding the D0* and D1' states can provide important insights into the DsJ states. In this contribution I examine quark model predictions for the D0* and D1' states and discuss experimental measurements that can shed light on them. I find that these states are well described as the broad, j = 1/2 non-strange charmed P-wave mesons. In the latter part of this writeup I discuss the cbar s possibilities for the SELEX DsJ*(2632) and measurements that can shed light on it.

  14. The (. gamma. ,K) program: A new CEBAF initiative for the study of nuclear strangeness

    SciTech Connect

    Chrien, R.E.; Hungerford, E.V.

    1987-06-01

    This paper is a summary of the CEBAF working group discussions on electromagnetic production of strangeness in nuclear systems. A review of the recent BNL results in (..pi..,K) is presented as representative of the physics questions that could be addressed with the CEBAF facility. Recommendations of the working group concerning the necessary experimental apparatus for a (e,e',K) program are presented. 13 figs., 2 tabs.

  15. Regarding the charmed-strange member of the 2³S₁ meson state.

    PubMed

    Feng, Xue-Chao; Chen, Jing

    2013-01-01

    By employing the mass relations derived from the mass matrix and Regge trajectory, we investigate the masses of charmed and charmed-strange members of the 2³S₁ meson. The masses are compared with the values predicted by other theoretical approaches and experimental data. The results may be useful for the discovery of the unobserved meson and the determination of the quantum number of the newly discovered states.

  16. Regarding the Charmed-Strange Member of the 23S1 Meson State

    PubMed Central

    Feng, Xue-Chao; Chen, Jing

    2013-01-01

    By employing the mass relations derived from the mass matrix and Regge trajectory, we investigate the masses of charmed and charmed-strange members of the 23S1 meson. The masses are compared with the values predicted by other theoretical approaches and experimental data. The results may be useful for the discovery of the unobserved meson and the determination of the quantum number of the newly discovered states. PMID:24250272

  17. Measurement of the strange quark contribution to the vector structure of the proton

    SciTech Connect

    Phillips, Sarah

    2007-11-30

    The goal of the G0 experiment is to determine the contribution of the strange quarks in the quark-antiquark sea to the structure of the nucleon. To this end, the experiment measured parityviolating asymmetries from elastic electron-proton scattering from 0.12 ≤ Q2 ≤ 1.0 (GeV/c)2 at Thomas Jefferson National Accelerator Facility. These asymmetries come from the interference of the electromagnetic and neutral weak interactions, and are sensitive to the strange quark contributions in the proton. The results from the forward-angle measurement, the linear combination of the strange electric and magnetic form factors GsE +ηGsM, suggest possible non-zero, Q2 dependent, strange quark contributions and provide new information to understand the magnitude of the contributions. This dissertation presents the analysis and results of the forward-angle measurement. In addition, the G0 experiment measured the beam-normal single-spin asymmetry in the elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q2 = 0.15, 0.25 (GeV/c)2 as part of the forward-angle measurement. The transverse asymmetry provides a direct probe of the imaginary component of the two-photon exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments. The results of the measurement indicate that calculations using solely the elastic nucleon intermediate state are insufficient and generally agree with calculations that include significant inelastic hadronic intermediate state contributions. This dissertation presents the analysis and results of this measurement.

  18. A study in dualism: The strange case of Dr. Jekyll and Mr. Hyde

    PubMed Central

    Singh, Shubh M.; Chakrabarti, Subho

    2008-01-01

    R. L. Stevenson's novel, The Strange Case of Dr. Jekyll and Mr. Hyde is a prominent example of Victorian fiction. The names Jekyll and Hyde have become synonymous with multiple personality disorder. This article seeks to examine the novel from the view point of dualism as a system of philosophy and as a religious framework and also from the view point of Freud's structural theory of the mind. PMID:19742237

  19. A study in dualism: The strange case of Dr. Jekyll and Mr. Hyde.

    PubMed

    Singh, Shubh M; Chakrabarti, Subho

    2008-07-01

    R. L. Stevenson's novel, The Strange Case of Dr. Jekyll and Mr. Hyde is a prominent example of Victorian fiction. The names Jekyll and Hyde have become synonymous with multiple personality disorder. This article seeks to examine the novel from the view point of dualism as a system of philosophy and as a religious framework and also from the view point of Freud's structural theory of the mind.

  20. Newly observed B(5970) and the predictions of its spin and strange partners

    NASA Astrophysics Data System (ADS)

    Xu, Hao; Liu, Xiang; Matsuki, Takayuki

    2014-05-01

    Using the effective Lagrangian approach, we study the decay behavior of the newly observed B(5970) meson, which is assigned as the 2S13 state in the B meson family. A more important prediction is the detailed information of the partial and total decay widths of B(2S01), Bs(2S01), and Bs(2S13) as the spin and strange partners of B(5970), which can be tested in future experimental searches for these missing states.

  1. [About international adoption: the double strangeness of the child from abroad].

    PubMed

    Golse, B

    2011-06-01

    The foster child through an intercountry adoption is a "foreigner" in two ways: as a support for parental unconscious projections (as any child, including biological children) on the one hand, and because of the strangeness ethnic often involved in this framework in the other hand. After recalling the main parental representations concerning the unborn child, the author then proposes to think the approval procedure as a kind of imaginary and symbolic equivalent of the usual psychic pregnancy.

  2. Strangeness production in Au+Au collisions at the AGS: recent results from E917.

    SciTech Connect

    Chang, W.-C.; Back, B. B.; Betts, R. R.; Britt, H. C.; Chang, W. C.; Gillitzer, A.; Henning, W. F.; Hofman, D. J.; Holzman, B.; Nanal, V.; Wuosmaa, A. H.

    1999-03-30

    Strangeness production in Au+Au collisions has been measured via the yields of K{sup +} , K{sup {minus}} at 6, 8 AGeV and of {bar {Lambda}} at 10.8 AGeV beam kinetic energy in experiment E917. By varying the collision centrally and beam energy, a systematic search for indications of new phenomena and in-medium effects under high baryon density is undertaken.

  3. Learning science in an era of globalization: a phenomenology of the foreign/strange

    NASA Astrophysics Data System (ADS)

    Hwang, Sungwon; Roth, Wolff-Michael

    2008-12-01

    In this study, we propose a set of concepts for conceptualizing issues of learning science related to globalization, the encounter with the (radically) foreign/strange—as this occurs as part of migration and even as part of the encounter of a learner with the unknown content that science lessons are to impart—from the perspective of the experiencing person and the experience. We take an approach to the question of the foreign/strange that is grounded in philosophies of difference, which have emerged in continental Europe, and which make use of advances in phenomenology, dialectics, and materialism. We draw on ethnographic work in one undergraduate physics course at a Canadian university, where we followed in particular one female Japanese student, who had come to this country for the purpose of getting a degree. As an entry point and as source of empirical materials, we draw on our own auto/ethnographic experience that brings particular advantages to ally pathos to the experience of the foreign/strange, something is happening to (affecting) us that is beyond all experience, understanding, and anticipation. We articulate three phenomenological aspects that pathos (empathy) allows us to understand concerning the experience of the foreign/strange and then provide an exemplary and exemplifying analysis.

  4. Collectivity of (non-)strange hadrons in high-multiplicity pp with CMS

    NASA Astrophysics Data System (ADS)

    Stephans, George S. F.; CMS collaboration

    2017-01-01

    Observation of an enhanced long-range, near-side, two-particle correlation (known as the “Ridge”) in high-multiplicity pp and pPb collisions opened up new opportunities of exploring QCD dynamics in small collision systems. The CMS detector at the LHC has excellent capabilities of reconstructing weakly decaying strange hadrons such as , Λ and Ξ. Studies of strange hadron production and correlations in small colliding systems provide additional insights into the physical origin of the observed collective phenomena. New results for pT spectra and long-range two-particle correlations for charged particles and identified strange hadrons in high-multiplicity pp and pPb collisions are presented. The data at various collision energies for pp and pPb collisions are compared to those obtained for PbPb at similar multiplicities. Multi-particle cumulants for pp and pPb events are studied in order to more fully explore the collective nature of the long-range correlations.

  5. An almost symmetric Strang splitting scheme for the construction of high order composition methods☆

    PubMed Central

    Einkemmer, Lukas; Ostermann, Alexander

    2014-01-01

    In this paper we consider splitting methods for nonlinear ordinary differential equations in which one of the (partial) flows that results from the splitting procedure cannot be computed exactly. Instead, we insert a well-chosen state y⋆ into the corresponding nonlinearity B(y)y, which results in a linear term B(y⋆)y whose exact flow can be determined efficiently. Therefore, in the spirit of splitting methods, it is still possible for the numerical simulation to satisfy certain properties of the exact flow. However, Strang splitting is no longer symmetric (even though it is still a second order method) and thus high order composition methods are not easily attainable. We will show that an iterated Strang splitting scheme can be constructed which yields a method that is symmetric up to a given order. This method can then be used to attain high order composition schemes. We will illustrate our theoretical results, up to order six, by conducting numerical experiments for a charged particle in an inhomogeneous electric field, a post-Newtonian computation in celestial mechanics, and a nonlinear population model and show that the methods constructed yield superior efficiency as compared to Strang splitting. For the first example we also perform a comparison with the standard fourth order Runge–Kutta methods and find significant gains in efficiency as well better conservation properties. PMID:25473146

  6. An almost symmetric Strang splitting scheme for the construction of high order composition methods.

    PubMed

    Einkemmer, Lukas; Ostermann, Alexander

    2014-12-01

    In this paper we consider splitting methods for nonlinear ordinary differential equations in which one of the (partial) flows that results from the splitting procedure cannot be computed exactly. Instead, we insert a well-chosen state [Formula: see text] into the corresponding nonlinearity [Formula: see text], which results in a linear term [Formula: see text] whose exact flow can be determined efficiently. Therefore, in the spirit of splitting methods, it is still possible for the numerical simulation to satisfy certain properties of the exact flow. However, Strang splitting is no longer symmetric (even though it is still a second order method) and thus high order composition methods are not easily attainable. We will show that an iterated Strang splitting scheme can be constructed which yields a method that is symmetric up to a given order. This method can then be used to attain high order composition schemes. We will illustrate our theoretical results, up to order six, by conducting numerical experiments for a charged particle in an inhomogeneous electric field, a post-Newtonian computation in celestial mechanics, and a nonlinear population model and show that the methods constructed yield superior efficiency as compared to Strang splitting. For the first example we also perform a comparison with the standard fourth order Runge-Kutta methods and find significant gains in efficiency as well better conservation properties.

  7. Strange Quark Contribution to the Proton Spin, from Elastic $\\vecep$ and $\

    SciTech Connect

    Stephen Pate

    2006-10-02

    The strangeness contribution to the vector and axial form factors of the proton is presented for momentum transfers in the range 0.45 < Q{sup 2} < 1.0 GeV{sup 2}. The results are obtained via a combined analysis of forward-scattering parity-violating elastic {rvec e}p asymmetry data from the G0 and HAPPEx experiments at Jefferson Lab, and elastic {nu}p and {bar {nu}}p scattering data from Experiment 734 at Brookhaven National Laboratory. The combination of the two data sets allows for the simultaneous extraction of G{sub E}{sup s}, G{sub M}{sup s}, and G{sub A}{sup s} over a significant range of Q{sup 2} for the very first time. Determination of the strange axial form factor G{sub A}{sup s} is vital to an understanding of the strange quark contribution to the proton spin.

  8. Strange Floods: The Upper Tail of Flood Peaks in the Conterminous US

    NASA Astrophysics Data System (ADS)

    Smith, J. A.; Baeck, M. L.

    2015-12-01

    The strangest flood in US history is arguably the 14 June 1903 flood that devastated Heppner, Oregon. The notion of strange floods is based on the assumption that there are flood agents that dominate the upper tail of flood distributions for a region (severe thunderstorms in complex terrain in the case of the Heppner flood) and are exceedingly poorly characterized by conventional flood records. The orographic thunderstorm systems in the central Appalachians that dominate envelope curves of flood peaks in the eastern US for basin areas less than 1,000 sq. km. and control portions of the global envelope curve of rainfall accumulations at time scales shorter than 6 hours) provide a well-documented example of strange floods. Despite extensive evidence of their occurrence, principally from field-based case studies, they are poorly represented in conventional USGS flood records. We develop methods for examining strange floods based on analyses of the complete record of USGS annual peak observations and on hydrometeorological analyses of the most extreme floods in the US flood record. The methods we present are grounded in extreme value theory and designed to enhance our understanding of extreme floods and improve methods for estimating extreme flood magnitudes.

  9. Sizes of the Smallest Particles at the Outer B Ring Edge, Huygens Ringlet, and Strange Ringlet

    NASA Astrophysics Data System (ADS)

    Eckert, Stephanie; Colwell, Josh E.; Becker, Tracy M.; Esposito, Larry W.

    2016-10-01

    The Cassini Ultraviolet Imaging Spectrograph (UVIS)'s High Speed Photometer (HSP) has observed stellar occultations of Saturn's rings that reveal ring structure at high resolution. We observe diffraction spikes at the sharp edges of some rings and ringlets where the observed signal exceeds the unocculted star signal, indicating that small particles are diffracting light into the detector. Becker et al. (2015 Icarus doi:10.1016/j.icarus.2015.11.001) analyzed data at the A ring edge and edges of the Encke gap. The smallest particle sizes were a few mm. We use the same technique to analyze the diffraction signal at the outer edge of the B ring and the edges of the so-called Strange ringlet near the outer edge of the Huygens Gap. While we see diffraction from sub-cm particles in the Strange Ringlet, detections from the wider Huygens Ringlet which resides in between the Strange Ringlet and the outer edge of the B ring are weaker and narrower, indicating a cutoff of the size distribution above 1 cm. At the outer edge of the B ring we find strong diffraction signals in 7 of 19 occultations for which the signal and geometry make the detection possible. The typical value of the smallest particle size (amin) is 4 mm and the derived slope of the power-law size distribution (q) is 2.9. The average amin is similar to the 4.5 mm average observed at the A ring outer edge while the q value is lower than the A ring outer edge value of 3.2. In the Strange Ringlet we find strong diffraction signals in 2 of 19 possible occultations for the outer edge and 1 of 17 possible occultations for the inner edge. The smallest particle size is ~5 mm and the derived slope of the power-law size distribution is 3.3. These values are similar to the average values at the A ring outer edge. The absence of a broad diffraction signal at the Huygens Ringlet suggests a different size distribution for that ring than for the Strange Ringlet and the outer several km of the B ring or perhaps less vigorous

  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. Nonstandard Yukawa couplings and Higgs portal dark matter

    SciTech Connect

    Bishara, Fady; Brod, Joachim; Uttayarat, Patipan; Zupan, Jure

    2016-01-04

    We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model, the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. In conclusion, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.

  13. Nonstandard Yukawa couplings and Higgs portal dark matter

    DOE PAGES

    Bishara, Fady; Brod, Joachim; Uttayarat, Patipan; ...

    2016-01-04

    We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model,more » the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. In conclusion, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.« less

  14. Measurement of the strange - antistrange asymmetry at NLO in QCD from NuTeV dimuon data

    SciTech Connect

    Mason, David Alexander

    2006-03-01

    A measurement of the asymmetry between the strange and antistrange quark distributions, from a next to leading order QCD analysis of dimuon events measured by the NuTeV experiment at Fermilab is presented. Neutrino charged current events with two muons in the final state provide a direct means for studying charm production and measuring the strange sea. NuTeV's sign selected beam allows independent measurement of the strange and antistrange seas. An improved measurement of the neutrino and antineutrino forward dimuon cross section tables, using the complete charged current event sample for normalization is performed. These tables are then analyzed at NLO to measure the strange and antistrange seas. Detector acceptance is modeled using an NLO charm cross section differential in all variables required. The strange quark distribution is found to have an integrated momentum weighted asymmetry of +0.00196 ± 0.00046(stat) ± 0.00045(syst) ± 0.00182(external). The charm mass is found to be 1.41 ± 0.10(stat) ± 0.08(syst) ± 0.12(external) GeV.

  15. Inclusive Production of Strange Particles at the CERN Proton-Antiproton Collider

    NASA Astrophysics Data System (ADS)

    Tan, Ching-Hua

    1994-01-01

    During the 1987 run of the CERN Proton-Antiproton Collider, at sqrt{s} = 630 GeV, the UA1 experiment collected about 2.4 times 10^6 (65 murm b^{-1}) events with a minimum bias trigger. An extensive study of the strange particle productions in this data set was performed. The measured masses of the strange particles are in very good agreement with the particle data group values and demonstrate the superb quality of the data. The production cross sections of K_sp{S}{0}, K^+/- , Lambda and |{Lambda} are measured. K_sp{S}{0 }, K^+/- production cross section measurements are in agreement with an available new NLO QCD prediction. The K_sp{S }{0} to the charged hadrons production ratio and that of Lambda + |{Lambda} to the charged hadrons as a function of multiplicity are measured. They are well explained by the quark model. We have also compared these features with those in heavy ion experiments. The strangeness suppression factor lambda is measured to be exactly the world average value. The average p_{t} of K _sp{S}{0}, K/ pi ratio and lambda are found to increase with sqrt{s}. The predictions for K/pi and lambda are made at the LHC energy 15 TeV pp collisions. The initial energy density that UA1 reached is given and the expectations at the LHC 6300 GeV/A Pb-Pb and RHIC Au-Au 200 GeV/A collisions are illustrated. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.).

  16. Strange-face-in-the-mirror illusion and schizotypy during adolescence.

    PubMed

    Fonseca-Pedrero, Eduardo; Badoud, Deborah; Antico, Lia; Caputo, Giovanni B; Eliez, Stephan; Schwartz, Sophie; Debbané, Martin

    2015-03-01

    Patients with schizophrenia can sometimes report strange face illusions when staring at themselves in the mirror; such experiences have been conceptualized as anomalous self-experiences that can be experienced with a varying degree of depersonalization. During adolescence, anomalous self-experiences can also be indicative of increased risk to develop schizophrenia-spectrum disorders. To date however, the Mirror-Gazing test (MGT), an experimentally validated experiment to evaluate the propensity of strange face illusions in nonclinical and clinical adults, has yet to be investigated in an adolescent sample. The first goal of the present study was to examine experimentally induced self-face illusions in a nonclinical sample of adolescents, using the MGT. The second goal was to investigate whether dimensions of adolescent trait schizotypy were differentially related to phenomena arising during the MGT. One hundred and ten community adolescents (59 male) aged from 12 to 19 years (mean age = 16.31, SD age = 1.77) completed the MGT and Schizotypal Personality Questionnaire. The results yielded 4 types of strange face illusions; 2 types of illusions (slight change of light/color [20%] and own face deformation [45.5%]) lacked depersonalization-like phenomena (no identity change), while 2 other types (vision of other identity [27.3%], and vision of non-human identity [7.3%]) contained clear depersonalization-like phenomena. Furthermore, the disorganization dimension of schizotypy associated negatively with time of first illusion (first press), and positively with frequency of illusions during the MGT. Statistically significant differences on positive and disorganized schizotypy were found when comparing groups on the basis of degree of depersonalization-like phenomena (from slight color changes to non-human visions). Similarly to experimentally induced self-face illusions in patients with schizophrenia, such illusions in a group of nonclinical adolescents present

  17. Strange-Face-in-the-Mirror Illusion and Schizotypy During Adolescence

    PubMed Central

    Fonseca-Pedrero, Eduardo; Badoud, Deborah; Antico, Lia; Caputo, Giovanni B.; Eliez, Stephan; Schwartz, Sophie; Debbané, Martin

    2015-01-01

    Patients with schizophrenia can sometimes report strange face illusions when staring at themselves in the mirror; such experiences have been conceptualized as anomalous self-experiences that can be experienced with a varying degree of depersonalization. During adolescence, anomalous self-experiences can also be indicative of increased risk to develop schizophrenia-spectrum disorders. To date however, the Mirror-Gazing test (MGT), an experimentally validated experiment to evaluate the propensity of strange face illusions in nonclinical and clinical adults, has yet to be investigated in an adolescent sample. The first goal of the present study was to examine experimentally induced self-face illusions in a nonclinical sample of adolescents, using the MGT. The second goal was to investigate whether dimensions of adolescent trait schizotypy were differentially related to phenomena arising during the MGT. One hundred and ten community adolescents (59 male) aged from 12 to 19 years (mean age = 16.31, SD age = 1.77) completed the MGT and Schizotypal Personality Questionnaire. The results yielded 4 types of strange face illusions; 2 types of illusions (slight change of light/color [20%] and own face deformation [45.5%]) lacked depersonalization-like phenomena (no identity change), while 2 other types (vision of other identity [27.3%], and vision of non-human identity [7.3%]) contained clear depersonalization-like phenomena. Furthermore, the disorganization dimension of schizotypy associated negatively with time of first illusion (first press), and positively with frequency of illusions during the MGT. Statistically significant differences on positive and disorganized schizotypy were found when comparing groups on the basis of degree of depersonalization-like phenomena (from slight color changes to non-human visions). Similarly to experimentally induced self-face illusions in patients with schizophrenia, such illusions in a group of nonclinical adolescents present

  18. 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

  19. Actinide collisions for QED and superheavy elements with the time-dependent Hartree-Fock theory and the Balian-Vénéroni variational principle

    NASA Astrophysics Data System (ADS)

    Simenel, Cédric; Golabek, Cédric; Kedziora, David J.

    2011-10-01

    Collisions of actinide nuclei form, during very short times of few zs (10-21 s), the heaviest ensembles of interacting nucleons available on Earth. Such collisions are used to produce super-strong electric fields by the huge number of interacting protons to test spontaneous positron-electron pair emission (vacuum decay) predicted by the quantum electrodynamics (QED) theory. Multi-nucleon transfer in actinide collisions could also be used as an alternative way to fusion in order to produce neutron-rich heavy and superheavy elements thanks to inverse quasifission mechanisms. Actinide collisions are studied in a dynamical quantum microscopic approach. The three-dimensional time-dependent Hartree-Fock (TDHF) code tdhf3d is used with a full Skyrme energy density functional to investigate the time evolution of expectation values of one-body operators, such as fragment position and particle number. This code is also used to compute the dispersion of the particle numbers (e.g., widths of fragment mass and charge distributions) from TDHF transfer probabilities, on the one hand, and using the BalianVeneroni variational principle, on the other hand. A first application to test QED is discussed. Collision times in 238U+238U are computed to determine the optimum energy for the observation of the vacuum decay. It is shown that the initial orientation strongly affects the collision times and reaction mechanism. The highest collision times predicted by TDHF in this reaction are of the order of ~ 4 zs at a center of mass energy of 1200 MeV. According to modern calculations based on the Dirac equation, the collision times at Ecm > 1 GeV are sufficient to allow spontaneous electron-positron pair emission from QED vacuum decay, in case of bare uranium ion collision. A second application of actinide collisions to produce neutron-rich transfermiums is discussed. A new inverse quasifission mechanism associated to a specific orientation of the nuclei is proposed to produce transfermium

  20. 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.

  1. Strangeness suppression of qq¯ creation observed in exclusive reactions

    DOE PAGES

    Mestayer, M. D.; Park, K.; Adhikari, K. P.; ...

    2014-10-10

    In this study, we measured the ratios of electroproduction cross sections from a proton target for three exclusive meson-baryon final states: ΛK+, pπ0, and nπ+, with the CLAS detector at Jefferson Lab. Using a simple model of quark hadronization, we extract qq¯ creation probabilities for the first time in exclusive two-body production, in which only a single qq¯ pair is created. We observe a sizable suppression of strange quark-antiquark pairs compared to nonstrange pairs, similar to that seen in high-energy production.

  2. Distinguishing Newly Born Strange Stars from Neutron Stars with g-Mode Oscillations

    SciTech Connect

    Fu Weijie; Wei Haiqing; Liu Yuxin

    2008-10-31

    The gravity-mode (g-mode) eigenfrequencies of newly born strange quark stars (SQSs) and neutron stars (NSs) are studied. It is found that the eigenfrequencies in SQSs are much lower than those in NSs by almost 1 order of magnitude, since the components of a SQS are all extremely relativistic particles while nucleons in a NS are nonrelativistic. We therefore propose that newly born SQSs can be distinguished from the NSs by detecting the eigenfrequencies of the g-mode pulsations of supernovae cores through gravitational radiation by LIGO-class detectors.

  3. Distinguishing newly born strange stars from neutron stars with g-mode oscillations.

    PubMed

    Fu, Wei-Jie; Wei, Hai-Qing; Liu, Yu-Xin

    2008-10-31

    The gravity-mode (g-mode) eigenfrequencies of newly born strange quark stars (SQSs) and neutron stars (NSs) are studied. It is found that the eigenfrequencies in SQSs are much lower than those in NSs by almost 1 order of magnitude, since the components of a SQS are all extremely relativistic particles while nucleons in a NS are nonrelativistic. We therefore propose that newly born SQSs can be distinguished from the NSs by detecting the eigenfrequencies of the g-mode pulsations of supernovae cores through gravitational radiation by LIGO-class detectors.

  4. High-pT azimuthal correlations of neutral strange baryons and mesons in STAR at RHIC

    SciTech Connect

    Bielcikova, Jana

    2006-07-11

    We present results on two-particle azimuthal correlations of high-pT neutral strange baryons ({lambda},{lambda}-bar) and mesons (K{sub S}{sup 0}) associated with non-identified charged particles in d+Au and Au+Au collisions at {radical}(s{sub NN}) = 200 GeV. In particular, we discuss properties of the near-side yield of associated charged particles as a function of centrality, transverse momentum and zT, as well as possible baryon/meson and particle/antiparticle differences. The results are compared to the proton and pion triggered correlations and to fragmentation and recombination models.

  5. Accretion disks around neutron and strange stars in R+aR2 gravity

    NASA Astrophysics Data System (ADS)

    Staykov, Kalin V.; Doneva, Daniela D.; Yazadjiev, Stoytcho S.

    2016-08-01

    We study the electromagnetic spectrum of accretion disks around neutron and strange stars in R+aR2 gravity. Both static and rapidly rotating models are investigated. The results are compared with the General Relativistic results. We found difference between the results in both theories of about 50% for the electromagnetic flux and about 20% in the luminosity for models with equal mass and angular velocity in both theories. The observed differences are much lower for models rotating with Keplerian velocity and with equal masses.

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  7. Radiative transitions in charm-strange meson from Nf = 2 twisted mass lattice QCD

    NASA Astrophysics Data System (ADS)

    Li, Ning; Wu, Ya-Jie

    2016-07-01

    We present an exploratory study on the radiative transition for the charm-strange meson: Ds∗→ D sγ using Nf = 2 twisted mass lattice quantum chromodynamics gauge configurations. The form factor for Ds meson is also determined. The simulation is performed on lattices with lattice spacings a = 0.067 fm and lattice size 323 × 64, and a = 0.085 fm and lattice size 243 × 48, respectively. Our numerical results for radiative decay width and the experimental data overlap within the margin of error.

  8. Quasi-equilibrium sequences of binary strange quark stars in general relativity

    NASA Astrophysics Data System (ADS)

    Limousin, Francois; Gondek-Rosińska, Dorota; Gourgoulhon, Eric

    2004-12-01

    Inspiraling compact binaries are expected to be the strongest sources of gravitational waves for VIRGO, LIGO and other laser interferometers. We present the first computations of quasi-equilibrium sequences of compact binaries containing two strange quark stars (which are currently considered as a possible alternative to neutron stars). We study a precoalescing stage in the conformal flatness approximation of general relativity using a multidomain spectral method. A hydrodynamical treatment is performed under the assumption that the flow is either rigidly rotating or irrotational. In each of those cases, we show the differences in the gravitational waves signal from neutron stars described by polytropic equation of state.

  9. Non-smooth saddle-node bifurcations III: Strange attractors in continuous time

    NASA Astrophysics Data System (ADS)

    Fuhrmann, G.

    2016-08-01

    Non-smooth saddle-node bifurcations give rise to minimal sets of interesting geometry built of so-called strange non-chaotic attractors. We show that certain families of quasiperiodically driven logistic differential equations undergo a non-smooth bifurcation. By a previous result on the occurrence of non-smooth bifurcations in forced discrete time dynamical systems, this yields that within the class of families of quasiperiodically driven differential equations, non-smooth saddle-node bifurcations occur in a set with non-empty C2-interior.

  10. V0 Reconstruction of Strange Hadrons in Au+Au Collisions at 1.23 AGeV with HADES

    NASA Astrophysics Data System (ADS)

    Scheib, T.; HADES Collaboration

    2015-04-01

    Preliminary results on the production of weakly decaying strange hadrons are reported for collisions of Au+Au at 1.23 AGeV beam energy studied with the HADES detector at GSI in Darmstadt. At this collision energy all strange particles are created below their elementary threshold. The reconstruction of the investigated particles (i.e. Λ and K0s) via the topology of their charged decay products (V0 reconstruction) is presented in detail. From the corrected yields of Λ and K0s the ratio K0S/Λ can be calculated and included into a statistical model fit.

  11. Strange Quark Contributions to Parity-Violating Asymmetries in the Forward G0 Electron-Proton Scattering Experiment

    SciTech Connect

    David Armstrong; Francois Arvieux; Razmik Asaturyan; Todd Averett; Stephanie Bailey; Guillaume Batigne; Douglas Beck; Elizabeth Beise; Jay Benesch; Louis Bimbot; James Birchall; Angela Biselli; Peter Bosted; Elodie Boukobza; Herbert Breuer; Roger Carlini; R. Carr; Nicholas Chant; Yu-Chiu Chao; Swapan Chattopadhyay; Russell Clark; Silviu Covrig; Anthony Cowley; Daniel Dale; C. Davis; Willie Falk; John Finn; Tony Forest; Gregg Franklin; Christophe Furget; David Gaskell; Joseph Grames; Keith Griffioen; Klaus Grimm; Benoit Guillon; Hayko Guler; Lars Hannelius; R. Hasty; A. Hawthorne Allen; Tanja Horn; Kathleen Johnston; Mark Jones; Peter Kammel; Reza Kazimi; Paul King; Ameya Kolarkar; Elie Korkmaz; Wolfgang Korsch; Serge Kox; Joachim Kuhn; Jeff Lachniet; Lawrence Lee; Jason Lenoble; Eric Liatard; J. Liu; Berenice Loupias; A. Lung; Glen MacLachlan; Dominique Marchand; J.W. Martin; Kenneth McFarlane; Daniella Mckee; Robert McKeown; Fernand Merchez; Hamlet Mkrtchyan; Bryan Moffit; M. Morlet; Itaru Nakagawa; Kazutaka Nakahara; Melissa Nakos; Retief Neveling; Silvia Niccolai; S. Ong; Shelley Page; Vassilios Papavassiliou; Stephen Pate; Sarah Phillips; Mark Pitt; Benard Poelker; Tracy Porcelli; Gilles Quemener; Brian Quinn; William Ramsay; Aamer Rauf; Jean-Sebastien Real; Julie Roche; Philip Roos; Gary Rutledge; Jeffery Secrest; Neven Simicevic; G.R. Smith; Damon Spayde; Samuel Stepanyan; Marcy Stutzman; Vincent Sulkosky; Vardan Tadevosyan; Raphael Tieulent; Jacques Van de Wiele; Willem van Oers; Eric Voutier; William Vulcan; G. Warren; S.P. Wells; Steven Williamson; S.A. Wood; Chen Yan; Junho Yun; Valdis Zeps

    2005-06-01

    We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < Q{sup 2} < 1.0 GeV{sup 2}. These asymmetries, arising from interference of the electromagnetic and neutral weak interactions, are sensitive to strange quark contributions to the currents of the proton. The measurements were made at JLab using a toroidal spectrometer to detect the recoiling protons from a liquid hydrogen target. The results indicate non-zero, Q{sup 2} dependent, strange quark contributions and provide new information beyond that obtained in previous experiments.

  12. Confirming the Potential of Systems Containing Strangeness for 3D Structure Studies of the Proton

    NASA Astrophysics Data System (ADS)

    Ali, Salina; Horn, Tanja; Carmignotto, Marco

    2017-01-01

    The additional flavor degree of freedom in kaon electroproduction provides a unique opportunity to study the mechanism underlying strangeness production and the transition from hadronic to partonic degrees of freedom in exclusive processes. At sufficiently high energies, where soft non-perturbative and hard physics have been shown to factorize, the Generalized Parton Distributions provide a spatial tomography of the nucleon. The applicability of this formalism can be experimentally verified. The E12-09-011 experiment at the 12 GeV Jefferson Lab aims to test the expected approach of the hard scattering regime through precision measurements of the fully separated exclusive kaon production cross section, and in particular the relative contributions and kinematic dependencies of the longitudinal and transverse cross sections. The longitudinal cross section also allows one to test the kaon pole dominance and could allow for kaon form factor extractions. In this talk, I will present the current status and discuss the outlook on future studies of strange quarks with kaon production as well as the particle identification requirements, and possible kaon form factor extractions at a 12-GeV Jefferson Lab. Supported in part by NSF grants PHY-1306227 and PHY-1306418.

  13. Strong decays of excited 1D charmed(-strange) mesons in the covariant oscillator quark model

    NASA Astrophysics Data System (ADS)

    Maeda, Tomohito; Yoshida, Kento; Yamada, Kenji; Ishida, Shin; Oda, Masuho

    2016-05-01

    Recently observed charmed mesons, D1* (2760), D3* (2760) and charmed-strange mesons, Ds1 * (2860), Ds3 * (2860), by BaBar and LHCb collaborations are considered to be plausible candidates for c q ¯ 13 DJ (q = u, d, s) states. We calculate the strong decays with one pion (kaon) emission of these states including well-established 1S and 1P charmed(-strange) mesons within the framework of the covariant oscillator quark model. The results obtained are compared with the experimental data and the typical nonrelativistic quark-model calculations. Concerning the results for 1S and 1P states, we find that, thanks to the relativistic effects of decay form factors, our model parameters take reasonable values, though our relativistic approach and the nonrelativistic quark model give similar decay widths in agreement with experiment. While the results obtained for 13 DJ=1,3 states are roughly consistent with the present data, they should be checked by the future precise measurement.

  14. Measurement of the bottom-strange meson mixing phase in the full CDF data set.

    PubMed

    Aaltonen, T; Álvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Bae, T; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Bisello, D; Bizjak, I; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brigliadori, L; Bromberg, C; Brucken, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Calamba, A; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chung, W H; Chung, Y S; Ciocci, M A; Clark, A; Clarke, C; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuevas, J; Culbertson, R; Dagenhart, D; d'Ascenzo, N; Datta, M; de Barbaro, P; Dell'Orso, M; Demortier, L; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, M; Dorigo, T; Ebina, K; Elagin, A; Eppig, A; Erbacher, R; Errede, S; Ershaidat, N; Eusebi, R; Farrington, S; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Funakoshi, Y; Furic, I; Gallinaro, M; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Grillo, L; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Hahn, S R; Halkiadakis, E; Hamaguchi, A; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Hewamanage, S; Hocker, A; Hopkins, W; Horn, D; Hou, S; Hughes, R E; Hurwitz, M; Husemann, U; Hussain, N; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Karchin, P E; Kasmi, A; Kato, Y; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kim, Y J; Kimura, N; Kirby, M; Klimenko, S; Knoepfel, K; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Kruse, M; Krutelyov, V; Kuhr, T; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; LeCompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leo, S; Leone, S; Lewis, J D; Limosani, A; Lin, C-J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, H; Liu, Q; Liu, T; Lockwitz, S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maeshima, K; Maestro, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Martínez, M; Mastrandrea, P; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Noh, S Y; Norniella, O; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Poprocki, S; Potamianos, K; Prokoshin, F; Pranko, A; Ptohos, F; Punzi, G; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Rescigno, M; Riddick, T; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shochet, M; Shreyber-Tecker, I; Simonenko, A; Sinervo, P; Sliwa, K; Smith, J R; Snider, F D; Soha, A; Sorin, V; Song, H; Squillacioti, P; Stancari, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Ukegawa, F; Uozumi, S; Varganov, A; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wagner, R L; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Wester, W C; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Wick, F; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamato, D; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zhou, C; Zucchelli, S

    2012-10-26

    We report a measurement of the bottom-strange meson mixing phase β(s) using the time evolution of B(s)(0)→J/ψ(→μ(+)μ(-))φ(→K(+)K(-)) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at √s=1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb(-1) of integrated luminosity. We report confidence regions in the two-dimensional space of β(s) and the B(s)(0) decay-width difference ΔΓ(s) and measure β(s)∈[-π/2,-1.51]∪[-0.06,0.30]∪[1.26,π/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of β(s), we also determine ΔΓ(s)=0.068±0.026(stat)±0.009(syst) ps(-1) and the mean B(s)(0) lifetime τ(s)=1.528±0.019(stat)±0.009(syst) ps, which are consistent and competitive with determinations by other experiments.

  15. Simple estimates of the masses of pentaquarks with hidden beauty or strangeness

    NASA Astrophysics Data System (ADS)

    Kopeliovich, Vladimir; Potashnikova, Irina

    2016-04-01

    The masses of cryptoexotic pentaquarks with hidden beauty are estimated phenomenologically using the results by the LHCb Collaboration which discovered recently the cryptoexotic pentaquarks with hidden charm. The expected masses of the hidden beauty pentaquarks are about 10.8 GeV and 10.7 GeV in the limit of some kind of heavy quark symmetry. The states with hidden strangeness considered in a similar way have masses of about 2.37 GeV and 2.30 GeV, several hundred MeV higher than states discussed previously in connection with the relatively light positive strangeness pentaquark θ+. Empirical data on the spectra of pentaquarks can be used to get information about quarkonia interaction with nucleons. The results obtained for the case of heavy flavors are in fair agreement with the model of isospin (pion) exchange between flavored baryons and antiflavored vector mesons proposed by Karliner and Rosner, and in qualitative agreement with the bound-state version of the chiral soliton model.

  16. Compositeness of the strange, charm, and beauty odd parity Λ states

    NASA Astrophysics Data System (ADS)

    Garcia-Recio, C.; Hidalgo-Duque, C.; Nieves, J.; Salcedo, L. L.; Tolos, L.

    2015-08-01

    We study the dependence on the quark mass of the compositeness of the lowest-lying odd parity hyperon states. Thus, we pay attention to Λ -like states in the strange, charm, and beauty sectors which are dynamically generated using a unitarized meson-baryon model. In the strange sector we use a SU(6) extension of the Weinberg-Tomozawa meson-baryon interaction, and we further implement the heavy-quark spin symmetry to construct the meson-baryon interaction when charmed or beauty hadrons are involved. In the three examined flavor sectors, we obtain two JP=1 /2- and one JP=3 /2- Λ states. We find that the Λ states which are bound states (the three Λb) or narrow resonances [one Λ (1405 ) and one Λc(2595 )] are well described as molecular states composed of s -wave meson-baryon pairs. The 1/2- wide Λ (1405 ) and Λc(2595 ) as well as the 3/2- Λ (1520 ) and Λc(2625 ) states display smaller compositeness so they would require new mechanisms, such as d -wave interactions.

  17. Strange-quark asymmetry in the proton in chiral effective theory

    DOE PAGES

    Wang, X. G.; Ji, Chueng -Ryong; Melnitchouk, W.; ...

    2016-11-29

    We perform a comprehensive analysis of the strange-antistrange parton distribution function (PDF) asymmetry in the proton in the framework of chiral effective theory, including the full set of lowest-order kaon loop diagrams with off-shell and contact interactions, in addition to the usual on-shell contributions previously discussed in the literature. We identify the presence of δ-function contributions to the s¯ PDF at x = 0, with a corresponding valencelike component of the s-quark PDF at larger x, which allows greater flexibility for the shape of s–s¯. Expanding the moments of the PDFs in terms of the pseudoscalar kaon mass, we computemore » the leading nonanalytic behavior of the number and momentum integrals of the s and s¯ distributions, consistent with the chiral symmetry of QCD. Lastly, we discuss the implications of our results for the understanding of the NuTeV anomaly and for the phenomenology of strange-quark PDFs in global QCD analysis.« less

  18. Strange-quark asymmetry in the proton in chiral effective theory

    SciTech Connect

    Wang, X. G.; Ji, Chueng -Ryong; Melnitchouk, W.; Salamu, Y.; Thomas, A. W.; Wang, P.

    2016-11-29

    We perform a comprehensive analysis of the strange-antistrange parton distribution function (PDF) asymmetry in the proton in the framework of chiral effective theory, including the full set of lowest-order kaon loop diagrams with off-shell and contact interactions, in addition to the usual on-shell contributions previously discussed in the literature. We identify the presence of δ-function contributions to the s¯ PDF at x = 0, with a corresponding valencelike component of the s-quark PDF at larger x, which allows greater flexibility for the shape of s–s¯. Expanding the moments of the PDFs in terms of the pseudoscalar kaon mass, we compute the leading nonanalytic behavior of the number and momentum integrals of the s and s¯ distributions, consistent with the chiral symmetry of QCD. Lastly, we discuss the implications of our results for the understanding of the NuTeV anomaly and for the phenomenology of strange-quark PDFs in global QCD analysis.

  19. New Precision Limit on the Strange Vector Form Factors of the Proton

    SciTech Connect

    Ahmed, Z.; Allada, K.; Aniol, K. A.; Armstrong, D. S.; Arrington, J.; Baturin, P.; Bellini, V.; Benesch, J.; Beminiwattha, R.; Benmokhtar, F.; Canan, M.; Camsonne, A.; Cates, G. D.; Chen, J. -P.; Chudakov, E.; Cisbani, E.; Dalton, M. M.; de Jager, C. W.; De Leo, R.; Deconinck, W.; Decowski, P.; Deng, X.; Deur, A.; Dutta, C.; Franklin, G. B.; Friend, M.; Frullani, S.; Garibaldi, F.; Giusa, A.; Glamazdin, A.; Golge, S.; Grimm, K.; Hansen, O.; Higinbotham, D. W.; Holmes, R.; Holmstrom, T.; Huang, J.; Huang, M.; Hyde, C. E.; Jen, C. M.; Jin, G.; Jones, D.; Kang, H.; King, P.; Kowalski, S.; Kumar, K. S.; Lee, J. H.; LeRose, J. J.; Liyanage, N.; Long, E.; McNulty, D.; Margaziotis, D.; Meddi, F.; Meekins, D. G.; Mercado, L.; Meziani, Z. -E.; Michaels, R.; Muñoz-Camacho, C.; Mihovilovic, M.; Muangma, N.; Myers, K. E.; Nanda, S.; Narayan, A.; Nelyubin, V.; Nuruzzaman, None; Oh, Y.; Pan, K.; Parno, D.; Paschke, K. D.; Phillips, S. K.; Qian, X.; Qiang, Y.; Quinn, B.; Rakhman, A.; Reimer, P. E.; Rider, K.; Riordan, S.; Roche, J.; Rubin, J.; Russo, G.; Saenboonruang, K.; Saha, A.; Sawatzky, B.; Silwal, R.; Sirca, S.; Souder, P. A.; Sperduto, M.; Subedi, R.; Suleiman, R.; Sulkosky, V.; Sutera, C. M.; Tobias, W. A.; Urciuoli, G. M.; Waidyawansa, B.; Wang, D.; Wexler, J.; Wilson, R.; Wojtsekhowski, B.; Zhan, X.; Yan, X.; Yao, H.; Ye, L.; Zhao, B.; Zheng, X.

    2012-03-01

    The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624 GeV2 and beam energy Eb = 3.48 GeV to be APV = -23.80 ± 0.78 (stat) ± 0.36 (syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors GEs + 0.517 GMs = 0.003 ± 0.010 (stat) ± 0.004 (syst) ± 0.009 (ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.

  20. Strangeness Vector and Axial-Vector Form Factors of the Nucleon

    NASA Astrophysics Data System (ADS)

    Pate, Stephen; Trujillo, Dennis

    2014-03-01

    A revised global fit of electroweak ep and vp elastic scattering data has been performed, with the goal of determining the strange quark contribution to the vector and axial-vector form factors of the nucleon in the momentum-transfer range 0 < Q2 < 1 GeV2. The two vector (electric and magnetic) form factors GsE(Q2) and GsM(Q2) are strongly constrained by ep elastic scattering data, while the major source of information on the axial-vector form factor GsA(Q2) is vp scattering data. Combining the two kinds of data into a single global fit makes possible additional precision in the determination of these form factors, and provides a unique way to determine the strange quark contribution to the nucleon spin, ΔS , independently of leptonic deep-inelastic scattering. The fit makes use of data from the BNL-E734, SAMPLE, HAPPEx, G0, and PVA4 experiments; we will also compare the result of the fit with recent data from MiniBooNE, and anticipate how this fit can be improved when new data from MicroBooNE become available.

  1. New Precision Limit on the Strange Vector Form Factors of the Proton

    DOE PAGES

    Ahmed, Z.; Allada, K.; Aniol, K. A.; ...

    2012-03-01

    The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624 GeV2 and beam energy Eb = 3.48 GeV to be APV = -23.80 ± 0.78 (stat) ± 0.36 (syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors GEs + 0.517 GMs = 0.003 ± 0.010 (stat) ± 0.004 (syst) ± 0.009 (ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections.more » With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.« less

  2. Strange-quark asymmetry in the proton in chiral effective theory

    NASA Astrophysics Data System (ADS)

    Wang, X. G.; Ji, Chueng-Ryong; Melnitchouk, W.; Salamu, Y.; Thomas, A. W.; Wang, P.

    2016-11-01

    We perform a comprehensive analysis of the strange-antistrange parton distribution function (PDF) asymmetry in the proton in the framework of chiral effective theory, including the full set of lowest-order kaon loop diagrams with off-shell and contact interactions, in addition to the usual on-shell contributions previously discussed in the literature. We identify the presence of δ -function contributions to the s ¯ PDF at x =0 , with a corresponding valencelike component of the s -quark PDF at larger x , which allows greater flexibility for the shape of s -s ¯. Expanding the moments of the PDFs in terms of the pseudoscalar kaon mass, we compute the leading nonanalytic behavior of the number and momentum integrals of the s and s ¯ distributions, consistent with the chiral symmetry of QCD. We discuss the implications of our results for the understanding of the NuTeV anomaly and for the phenomenology of strange-quark PDFs in global QCD analysis.

  3. Predictions on the alpha decay half lives of superheavy nuclei with Z = 113 in the range 255 ≤ A ≤ 314

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Augustine, A.; Nithya, C.; Priyanka, B.

    2016-07-01

    An intense study of the alpha decay properties of the isotopes on superheavy element with Z = 113 has been performed within the Coulomb and proximity potential model for deformed nuclei (CPPMDN) within the wide range 255 ≤ A ≤ 314. The predicted alpha decay half lives of 278113 and 282113 and the alpha half lives of their decay products are in good agreement with the experimental data. 6α chains and 4α chains predicted respectively for 278113 and 282113 are in agreement with the experimental observation. Our study shows that the isotopes in the mass range 278 ≤ A ≤ 286 will survive fission and can be synthesized and detected in the laboratory via alpha decay. In our study, we have predicted 6α chains from 279113, 4α chains from 286113, 3α chains from 280,281,283113, 2α chains from 284113 and 1α chain from 285113. We hope that these predictions will be a guideline for future experimental investigations.

  4. Analytical expression for the α-decay half-life and understanding the data including very long life-times and superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Sahu, Basudeb

    2008-10-01

    An analytically solvable composite potential that can closely reproduce the combined potential of an α+nucleus system consisting of attractive nuclear and repulsive electrostatic potentials is developed. The exact s-wave solution of the Schrödinger equation with this potential in the interior region and the outside Coulomb wave function are used to give a heuristic expression for the width or half-life of the quasibound state at the accurately determined resonance energy, called the Q value of the decaying system. By using the fact that for a relatively low resonance energy, the quasibound state wave function is quite similar to the bound state wave function where the amplitude of the wave function in the interaction region is very large as compared to the amplitude outside, the resonance energy could easily be calculated from the variation of relative probability densities of inside and outside waves as a function of energy. By considering recent α-decay systems, the applicability of the model is demonstrated with excellent explanations being found for the experimental data of Q values and half-lives of a vast range of masses including superheavy nuclei and nuclei with very long lifetimes (of order 1022 s). Throughout the application, by simply varying the value of a single potential parameter describing the flatness of the barrier, we obtain successful results in cases with as many as 70 pairs of α+daughter nucleus systems.

  5. The influence of the enhanced vector meson sector on the properties of the matter of neutron stars.

    PubMed

    Bednarek, Ilona; Manka, Ryszard; Pienkos, Monika

    2014-01-01

    This paper gives an overview of the model of a neutron star with non-zero strangeness constructed within the framework of the nonlinear realization of the chiral SU(3)L x SU(3)R symmetry. The emphasis is put on the physical properties of the matter of a neutron star as well as on its internal structure. The obtained solution is particularly aimed at the problem of the construction of a theoretical model of a neutron star matter with hyperons that will give high value of the maximum mass.

  6. The Influence of the Enhanced Vector Meson Sector on the Properties of the Matter of Neutron Stars

    PubMed Central

    Bednarek, Ilona; Manka, Ryszard; Pienkos, Monika

    2014-01-01

    This paper gives an overview of the model of a neutron star with non-zero strangeness constructed within the framework of the nonlinear realization of the chiral symmetry. The emphasis is put on the physical properties of the matter of a neutron star as well as on its internal structure. The obtained solution is particularly aimed at the problem of the construction of a theoretical model of a neutron star matter with hyperons that will give high value of the maximum mass. PMID:25188304

  7. String cloud and domain walls with quark matter for a higher dimensional FRW universe in self creation cosmology

    NASA Astrophysics Data System (ADS)

    Halife, Caǧlar; Sezgin, Aygün

    2016-04-01

    In this study, we research a higher dimensional flat Friedmann-Robertson-Walker (FRW) universe in Barber-s second theory when strange quark matter (SQM) and normal matter (NM) are attached to the string cloud and domain walls. We obtain zero string tension density for this model. We obtain dust quark matter solutions. This result agrees with Kiran and Reddy, Krori et al, Sahoo and Mishra and Reddy. In our solutions the quark matter transforms to other particles over time. We also obtain two different solutions for domain walls with quark and normal matters by using a deceleration parameter. Also, the features of the obtained solutions are discussed and some physical and kinematical quantities are generalized and discussed. Our results are consistent with Yılmaz, Adcox et al and Back et al in four and five dimensions.

  8. Sum rules and photon emission in hadronic matter

    NASA Astrophysics Data System (ADS)

    Holt, Nathan Prescott Montgomery

    In this work, we examine properties of quantum chromodynamics (QCD) at moderate temperatures and density. These conditions are reached in the later stages of ultra-relativistic heavy-ion collisions after the matter has cooled sufficiently to re-hadronize from a quark-gluon plasma. The properties of matter in this stage are expected to change smoothly with temperature. We explore this behavior in two ways. First, we use finite-temperature sum rules to analyze the properties of vector and axial-vector spectral functions at low temperatures. Previous models used in sum rule analyses frequently led to ambiguous applications. Here we avoid such ambiguities by using an improved vacuum spectral function model together with a strict leading-order-in-temperature expansion. This results in well-defined finite temperature spectral functions. Additionally, we incorporate a finite pion mass, which we show induces an analytical violation of the sum rules. We then proceed to numerically measure that violation. Second, we calculate thermal photon emissivities of QCD matter from interactions involving both mesons and baryons. We identify a novel source of thermal photons from a system composed of pi, rho, and o mesons, then calculate photon emission rates from this system using both relativistic kinetic theory and thermal field theory. These rates are compared to existing calculations and found to be significant. We then calculate thermal photon emission rates from baryon interactions, using an exhaustive set of both strange and non-strange particles. We again find novel sources of photons from this system, compare the total rates to calculations of current state-of-the-art photon emission rates, and find them to be comparable.

  9. Probing parton dynamics of QCD matter with Ω and Φ production

    SciTech Connect

    Adamczyk, L.

    2016-02-24

    In this paper, we present measurements of Ω and Φ production at midrapidity from Au+Au collisions at nucleon-nucleon center-of-mass energies √sNN = 7.7, 11.5, 19.6 , 27, and 39 GeV by the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). Motivated by the coalescence formation mechanism for these strange hadrons, we study the ratios of N(Ω- + $\\overline{Ω}$+) / [2N (Φ)] . These ratios as a function of transverse momentum pT fall on a consistent trend at high collision energies, but start to show deviations in peripheral collisions at √sNN = 19.6, 27, and 39 GeV, and in central collisions at 11.5 GeV in the intermediate pT region of 2.4 - 3.6 GeV/ . We further evaluate empirically the strange quark pT distributions at hadronization by studying the Ω/Φ ratios scaled by the number of constituent quarks (NCQ). The NCQ-scaled Ω/Φ ratios show a suppression of strange quark production in central collisions at 11.5 GeV compared to √sNN ≥ 19.6 GeV. The shapes of the presumably thermal strange quark distributions in 0–60% most central collisions at 7.7 GeV show significant deviations from those in 0–10% most central collisions at higher energies. Lastly, these features suggest that there is likely a change of the underlying strange quark dynamics in the transition from quark matter to hadronic matter at collision energies below 19.6 GeV.

  10. What (if anything) can few-body strange systems teach us about quark-gluon hadronic substructure

    SciTech Connect

    Maltman, K. . Dept. of Physics Los Alamos National Lab., NM )

    1990-01-01

    We discuss expectation, relevant to the proposed ({pi},K) program at PILAC, for the effects of hadronic quark-gluon substructure on the physics of few-body strangeness {minus}1 systems, in the context of QCD-inspired models used previously to describe the hadron spectrum and short distance nucleon-nucleon scattering. 50 refs., 2 tabs.

  11. Beautifully strange

    NASA Astrophysics Data System (ADS)

    2009-04-01

    The list of famous Bristolians is an illustrious one. The Victorian engineer Isambard Kingdom Brunel, for example, is recognized everywhere in Bristol for his many iconic structures, even though he was not born, bred or even resident in the city. Another well-known son of the city is the Hollywood legend Cary Grant, born as Archie Leach in the suburb of Horfield and now commemorated with a striking bronze statue outside Bristol's hands-on science museum. The physicist Paul Dirac actually went to the same elementary school as Grant/Leach, and the abstract sculpture dedicated to him stands just a stone's throw away from Grant's bronze likeness. Dirac also has a building named after him: Dirac House, the headquarters of IOP Publishing (which publishes Physics World).

  12. Strange Brew.

    ERIC Educational Resources Information Center

    Osterer, Irv

    2003-01-01

    Describes an art project in which juniors and seniors in graphic design created their own label designs for a one liter plastic bottle of soft drinks. Discusses in detail how the students created their labels. States that the seniors also created a box. (CMK)

  13. 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.

  14. Strangeness production in high-energy collisions and Hawking-Unruh radiation

    NASA Astrophysics Data System (ADS)

    Tawfik, Abdel Nasser; Yassin, Hayam; Abo Elyazeed, Eman R.

    The assumption that the production of quark-antiquark pairs and their sequential string-breaking takes place, likely as a tunneling process, through the event horizon of the color confinement determines the freezeout temperature and gives a plausible interpretation for the thermal pattern of elementary and nucleus-nucleus collisions. When relating the black-hole electric charges to the baryon-chemical potentials, it was found that the phenomenologically deduced parameters from the ratios of various particle species and the higher-order moments of net-proton multiplicity in the statistical thermal models and Polyakov linear-sigma model agree well with the ones determined from the thermal radiation from charged black hole. Accordingly, the resulting freezeout conditions, such as normalized entropy density s/T3 = 7 and average energy per particle /≃ 1GeV, are confirmed at finite chemical potentials as well. Furthermore, the problem of strangeness production in elementary collisions can be interpreted by thermal particle production from the Hawking-Unruh radiation. Consequently, the freezeout temperature depends on the quark masses. This leads to a deviation from full equilibrium and thus a suppression of the strangeness production in the elementary collisions. But in nucleus-nucleus collisions, an average temperature should be introduced in order to dilute the quark masses. This nearly removes the strangeness suppression. An extension to finite chemical potentials is introduced. The particle ratios of kaon-to-pion (K+/π+), phi-to-kaon (ϕ/K‑) and antilambda-to-pion (Λ¯/π‑) are determined from Hawking-Unruh radiation and compared with the thermal calculations and the measurements in different experiments. We conclude that these particle ratios can be reproduced, at least qualitatively, as Hawking-Unruh radiation at finite chemical potential. With increasing energy, both K+/π+ and ϕ/K‑ keep their maximum values at low SPS energies. But the further

  15. Nature of charmed strange baryons Ξc(3055 ) and Ξc(3080 )

    NASA Astrophysics Data System (ADS)

    Zhao, Ze; Ye, Dan-Dan; Zhang, Ailin

    2016-12-01

    The hadronic decay widths and some ratios of branching fractions of the newly observed charmed strange baryons, Ξc(3055 )0 , Ξc(3055 )+, and Ξc(3080 )+ are calculated in a 3P0 model. In the calculation, they are considered as 34 kinds of D-wave charmed strange baryons. Among these assignments, Ξc(3055 )+ is very possibly a JP=5/2+ Ξ^c3' (5/2+) or Ξˇc32(5/2+). In these two assignments, Ξc(3055 )+ has the total decay width Γ =10.1 MeV and Γ =7.6 MeV , respectively. The predicted ratios Γ (Ξc(3055)+→Λ D+)/Γ(Ξc(3055)+→ Σc++K-)=3.39. Ξc(3055)+ is also very possibly a JP=7/2+ Ξ^c3 '(7/2+) or Ξˇc3 2(7/2+). In these two assignments, Ξc(3055 )+ has the total decay width Γ =9.7 MeV and Γ =6.3 MeV , respectively. The predicted ratios Γ (Ξc(3055 )+→Λ D+)/Γ (Ξc(3055 )+→Σc++K-)=5.91 or 6.04. As an isospin partner of Ξc(3055 )+, Ξc(3055 )0is also very possibly a JP=5/2+ Ξ^c3 '(5/2+) or Ξˇc3 2(5/2+). In these assignments, Ξc(3055 )0 has the total decay width Γ =10.9 MeV and Γ =7.0 MeV . The predicted ratios Γ (Ξc(3055 )0→Λ D0)/Γ (Ξc(3055 )0→Σc+K-)=4.24 or 4.20. Ξc(3055 )0 is also very possibly a JP=7/2+ Ξ^c3 '(7/2+) or Ξˇc3 2(7/2+). In these assignments, Ξc(3055 )0 has the total decay width Γ =10.3 MeV and Γ =7.1 MeV . The predicted ratios Γ (Ξc(3055 )0→Λ D0)/Γ (Ξc(3055 )0→Σc+K-)=7.47 or 7.56. The results agree well with recent experimental data from Belle. Ξc(3080)+ seems impossible to identify with a D-wave charmed strange baryon.

  16. A Friend Acting Strangely: an Exhibition on Climate Change in the Arctic

    NASA Astrophysics Data System (ADS)

    Stauffer, B. W.; Fitzhugh, W. W.; Krupnik, I.; Mannes, J.; Rusk, K.

    2003-12-01

    The Arctic: A Friend Acting Strangely is a new exhibit being developed at the Smithsonian Institution's National Museum of Natural History (NMNH) as a part of the museum's Forces of Change exhibit series on global change issues. The exhibit will open to the public in Summer 2004 and is the third component of the series. The other two components are about El Niño (El Niño's Powerful Reach) and atmospheric chemistry (Change is in the Air). The Arctic exhibit's underlying theme is that current global change is causing such rapid shifts in Arctic weather and the polar environment that it has become `strange,' - or unpredictable - to its residents. The speed of change in Arctic ice and climate patterns, ocean and terrestrial ecosystems, and wildlife creates a great challenge for polar scientists; but it also advances beyond the experience and memory of northern indigenous people, who know it so well. The key issues the NMNH team faces in preparing the new exhibit are: how to document and display the forces and consequences of rapid change; how to make complex scientific processes and research comprehensible to visitors; and how to engage the general public in the on-going discussion. Because current shifts in the Arctic environment have been observed and recorded in much detail by scientists and Native residents alike, this topic offers unique opportunities beyond the museum presentation, including outreach through public programs and the Internet. The exhibit is being developed jointly by the NMNH Arctic Studies Center and Office of the Exhibits, and in close collaboration with NOAA' Office of Arctic Research, NSF' new Study of Environmental Arctic Change (SEARCH) initiative, and NASA's Earth Science Enterprise. Exhibit components will include objects, text, graphic panels, video, and a computer interactive. Special efforts will be made to present the voices and opinions of Arctic indigenous people who experience new challenges to their traditional subsistence

  17. Development of Exhibit on Arctic Climate Change Called The Arctic: A Friend Acting Strangely Exhibition

    SciTech Connect

    Stauffer, Barbara W.

    2006-04-01

    The exhibition, The Arctic: A Friend Acting Strangely, was developed at the Smithsonian Institution’s National Museum of Natural History (NMNH) as a part of the museum’s Forces of Change exhibit series on global change. It opened to the public in Spring 2006, in conjunction with another Forces of Change exhibit on the Earth’s atmosphere called Change Is in the Air. The exhibit was a 2000 square-foot presentation that explored the forces and consequences of the changing Arctic as documented by scientists and native residents alike. Native peoples of the Arctic have always lived with year-to-year fluctuations in weather and ice conditions. In recent decades, they have witnessed that the climate has become unpredictable, the land and sea unfamiliar. An elder in Arctic Canada recently described the weather as uggianaqtuq —an Inuit word that can suggest strange, unexpected behavior, sometimes described as that of “a friend acting strangely.” Scientists too have been documenting dramatic changes in the Arctic. Air temperatures have warmed over most—though not all—of the Arctic since the 1950s; Arctic precipitation may have increased by as much as 8%; seasonal melting of the Greenland Ice Sheet has increased on average by 16% since 1979; polar-orbiting satellites have measured a 15¬–20% decline in sea ice extent since the 1970s; aircraft reconnaissance and ship observations show a steady decrease in sea ice since the 1950s. In response to this warming, plant distributions have begun to shift and animals are changing their migration routes. Some of these changes may have beneficial effects while others may bring hardship or have costly implications. And, many scientists consider arctic change to be a ‘bell-weather’ for large-scale changes in other regions of the world. The exhibition included text, photos artifacts, hands-on interactives and other exhibitry that illustrated the changes being documented by indigenous people and scientists alike.

  18. Hadronic matter at finite temperature and density within an effective relativistic mean-field model

    NASA Astrophysics Data System (ADS)

    Lavagno, A.

    2012-10-01

    We study hot and dense hadronic matter by means of an effective relativistic mean-field model with the inclusion of the full octet of baryons, the Δ-isobar degrees of freedom and the lightest pseudoscalar and vector mesons. These last particles are considered by taking into account an effective chemical potential and an effective mass depending on the self-consistent interaction between baryons. The analysis is performed by requiring the Gibbs conditions on the global conservation of baryon number, electric charge fraction and zero net strangeness.

  19. Signatures of Flux Tube Fragmentation and Strangeness Correlations in pp Collisions

    NASA Astrophysics Data System (ADS)

    Wong, Cheuk-Yin

    2017-01-01

    In the fragmentation of a color flux tube in high-energy pp collisions or e +-e‑ annihilations, the production of pairs along a color flux tube precedes the fragmentation of the tube. The local conservation laws in the production of these pairs will lead to the correlations of adjacently produced hadrons. As a consequence, the fragmentation of a flux tube will yield a many-hadron correlation in the form of a chain of hadrons ordered in rapidity, with adjacent hadrons correlated in charges, flavor contents, and azimuthal angles. It will also lead to a two-hadron angular correlation between two hadrons with opposite charges or strangeness that is suppressed at Δϕ ~ 0 but enhanced at Δϕ ~ π, within a rapidity window Δy~1/(dN/dy).

  20. THE MOST LUMINOUS SUPERNOVA ASASSN-15LH: SIGNATURE OF A NEWBORN RAPIDLY ROTATING STRANGE QUARK STAR

    SciTech Connect

    Dai, Z. G.; Wang, S. Q.; Wang, J. S.; Wang, L. J.; Yu, Y. W.

    2016-02-01

    In this paper we show that the most luminous supernova discovered very recently, ASASSN-15lh, could have been powered by a newborn ultra-strongly magnetized pulsar, which initially rotates near the Kepler limit. We find that if this pulsar is a neutron star, its rotational energy could be quickly lost as a result of gravitational-radiation-driven r-mode instability; if it is a strange quark star (SQS), however, this instability is highly suppressed due to a large bulk viscosity associated with the nonleptonic weak interaction among quarks and thus most of its rotational energy could be extracted to drive ASASSN-15lh. Therefore, we conclude that such an ultra-energetic supernova provides a possible signature for the birth of an SQS.