10490272
Strangeness conservation constraints in hadron gas models.
We examine the implications of the constraints arising due to strangeness conservation on the strangeness production in various existing thermal hadron-gas models. The dependence of strangeness chemical potential {mu}{sub {ital S}} on the baryon chemical potential {mu}{sub {ital B}} and temperature {ital T} is investigated. The incorporation of finite-size, hard-core, repulsive interactions in the thermodynamically consistent description of hot and dense hadron gas alters the results obtained for pointlike particles. We compare results in two extreme alternative cases: (1) {ital K} and {ital K}{sup {asterisk}} mesons are treated as point particles and they can penetrate all volumes occupied by baryons and antibaryons and (2) the volume occupied by the baryons and antibaryons is not accessible to them. We find that the results indeed depend on the assumptions made. Moreover, the anomalous results obtained for the ratios {bar {Xi}}/{Xi} and {bar {Lambda}}/{Lambda} rule out the second possibility. {copyright} {ital 1996 The American Physical Society.}
120612824
On the Singh-Uddin-Kamal relation in the negative binomial distribution
Abstract The empirical relation between the parameters k and n of the negative binomial distribution (NBD) as proposed by Singh, Uddin and Kamal is shown to emerge from the concept of the stationary branching process. Further consequences of this relation are derived and compared with the experimental data.
119366615
Anisotropic Bianchi Type-II Cosmological Models in Self-Creation Cosmology
Totally anisotropic Bianchi type-II cosmological solutions are presented in Barber's second self-creation theory of gravitation both in vacuum and in the presence of stiff-matter. The corresponding cosmological models have no finite singularity. The stiff-matter model gives essentially an empty universe for large time. Some physical and kinematical properties of the models are discussed.
115391521
QUARK GLUON PLASMA : CURRENT STATUS OF PROPERTIES AND SIGNALS
120005715
Signals of quark-gluon plasma
Abstract Production and observation of a quark-gluon plasma (QGP) is one of the most ambitious goals of the ultrarelativistic heavy ion experiments being carried out at CERN's super proton synchrotron (SPS) and at Brookhaven's Alternating Gradient Synchrotron (AGS). Future experiments at Brookhaven's Relativistic Heavy Ion Collider (RHIC) and at CERN's Large Hadron Collider (LHC) will give a new dimension to this search. In this review, the physics of QGP is presented with particular emphasis on its promising signatures existing in the literature. We hope that the present survey will lead us to identify some unambiguous signatures of QGP before the advent of RHIC and LHC experiments.
120728280
Rescattering effects in three-particle final-state reactions
The phenomenological aspect of single-pion production in ..pi../sup -/p interaction is explored by considering the final-state interactions in a rescattering box-diagram approach. We predict the qualitative and the quantitative features expected from our model in angular and momentum distributions of final pions. The preliminary data available so far appear to support our theoretical predictions.
42506674
Neutrino magnetic moment effects in neutrino nucleus reactions.
Some low energy neutrino nucleus reactions induced by neutrinos (antineutrinos) having a magnetic moment of the order of 10{sup {minus}9}{minus}10{sup {minus}10} Bohr magneton are studied. It is found that in the case of {sup 4}He, {sup 12}C, and {sup 16}O, the detection of very low energy scalar and isoscalar elastic and inelastic reactions induced by the isoscalar vector currents can provide a better limit on the neutrino magnetic moment.
35249306
Quantum violation of stochastic noncontextual hidden-variable theories.
We formulate stochastic noncontextual hidden-variable theories. In such theories the hidden state λ specifies not definite values, but expectation values A − (λ), ... of observables A, ... and noncontextuality means that A − (λ) is independent of which other commuting observables commuting with A are measured together with A. We show via Bell inequalities that such theories conflict with quantum theory and propose a two-photon experimental test. We also show that for a single particle of spin (2 n −1)/2, quantum violation of classical noncontextuality grows exponentially with n.
18313253
Distribution of the color fields around static quarks: Flux tube profiles.
We report detailed calculations of the profiles of energy and action densities in the quark-antiquark string in SU(2) lattice gauge theory. We conclude that at a {ital q}-{ital q}{vert_bar} separation {ital R}{approx_equal}1.0 fm we are beginning to see the asymptotic flux tube. By employing the Michael sum rules we further conclude that the peak energy density approaches a constant in {ital R}. {copyright} {ital 1995 The American Physical Society.}
37575993
Coulomb excitation studies in antimony isotopes.
Various low-lying energy levels up to 1.145 MeV in {sup 121,123}Sb have been Coulomb excited using 3.0--4.0 MeV proton-beam energies. The reduced transition probabilities of the excited levels have been newly deduced from the measured yields of the deexcitation gamma rays. The values of mixing ratios for a few transitions and the removal of ambiguities in the spin values of some levels have been presented from the angular distribution analysis.
32129688
Systematics of preequilibrium contributions in (n,p) reactions at 14 MeV.
The existing up to data global data on angle integrated energy spectra (AIES) and energy integrated angular distributions (EIAD) of protons from ([ital n],[ital p]) reactions at 14 MeV nominal neutron energy have been analyzed to develop systematics in relative preequilibrium contributions (RPC). The experimental estimates of RPC were obtained either from asymmetric components of the extrapolated EIAD or from the analysis of AIES, by comparison with equilibrium contributions obtained from the Hauser-Feshbach model. The experimentally obtained RPC have been compared with those expected from recent Feschbach-Kerman-Koonin theory as extended by Kalbach [ital et] [ital al]. as well as with theoretical predictions by Brown and Muirhead. The mass number systematics of RPC manifest shell and even-odd effects. The fraction of the precompound nucleus decays obtained from RPC, using the Blann-Griffin model, is constant and small for [ital A][ge]72, and increases to about 1 for small [ital A]'s. The analysis with the Kalbach model yields the dependence of the level density parameters [ital a][sub 1] and [ital a][sub 2] on [ital A]; also values of [ital a][sub 1] and [ital a][sub 2] manifest prominent structures near closed shell nuclei. The values of [ital a][sub 1] for compound nucleus are systematically highermore » than [ital a][sub 2], for the residual nuclei by an amount much larger than expected by usual [ital A] dependence, indicating excitation energy dependence of the single particle level density [ital g]. The excitation energy dependence of [ital g] when explored in the light of Rosenzweig's positive power law, with parameters [ital n] and [ital k], reveals that for most cases 1.2[le][ital n][le]1.5, with no systematic dependence of [ital n] on [ital A], compared to reported theoretical values of [ital n][congruent]1.6 by Rosenzweig, and 0.8[le][ital k][le]3.8 with a trend of slow increase of [ital k] with [ital A].« less