123622657
Many-particle density of states in a finite-dimensional vector space
Abstract We demonstrate that the statistical mechanics methods for obtaining the density of states, when applied to a finite dimensional vector space, leads to a Gaussian distribution in the lowest order. Successive approximations lead naturally to the Gram-Charlier series.
121836312
Excluded volume in nuclear fragmentation
16308546
First Order Phase Transition in Intermediate-Energy Heavy Ion Collisions
We model the disassembly of an excited nuclear system formed as a result of a heavy ion collision. We find that, as the beam energy in central collisions in varied, the dissociating system crosses a liquid-gas coexistence curve, resulting in a first-order phase transition. Accessible experimental signatures are identified: a peak in specific heat, a power-law yield for composites, and a maximum in the second moment of the yield distribution.
2820708
Transverse momenta, nuclear equation of state, and momentum-dependent interactions in heavy-ion collisions.
We investigate the generation of transverse momentum in high-energy heavy-ion collisions and its relation to the nuclear equation of state. We find that streamer chamber data can be fitted by Boltzmann-Uehling-Uhlenbeck calculations with a momentum-dependent potential that closely models realistic nuclear matter interactions and yields an equation of state with {ital K}=215 MeV.
14927510
A Transport Model for Nuclear Reactions Induced by Radioactive Beams
Major ingredients of an isospin and momentum dependent transport model for nuclear reactions induced by radioactive beams are outlined. Within the IBUU04 version of this model we study several experimental probes of the equation of state of neutron‐rich matter, especially the density dependence of the nuclear symmetry energy. Comparing with the recent experimental data from NSCL/MSU on isospin diffusion, we found a nuclear symmetry energy of Esym(ρ) ≈ 31.6(ρ/ρ0)1.05 at subnormal densities. Predictions on several observables sensitive to the density dependence of the symmetry energy at supranormal densities accessible at GSI and the planned Rare Isotope Accelerator (RIA) are also made.
119186084
Bimodality and Coulomb effects with a canonical thermodynamic model
Abstract The effect of the Coulomb interaction on the phase diagram of finite nuclei is studied within the Canonical Thermodynamic Model. If Coulomb effects are artificially switched off, this model shows a phenomenology consistent with the liquid–gas phase transition. The inclusion of Coulomb does not significantly affect the phase diagram but it drastically modifies the nature and order parameter of the transition. A clear understanding of the phenomenon can be achieved looking at the distribution of the largest fragment produced in each fragmentation event. Possible connections with experimental observations are outlined.
122963652
Intrinsic density and energy dependence: Exchange effects in alpha-nucleus scattering
The exchange effect for the alpha-nucleus potential has been computed by folding in the density matrices with a finite range effective interaction. The ''effective'' exchange interaction is both density and energy dependent. The potential agrees closely with phenomenology.
119482928
The electrical conductivity and soft photon emissivity of the QCD plasma
Abstract The electrical conductivity in the hot phase of the QCD plasma is extracted from a quenched lattice measurement of the Euclidean time vector correlator for 1.5 ⩽ T / T c ⩽ 3 . The spectral density in the vicinity of the origin is examined using a method specially adapted to this region, and a peak at small energies is seen. The continuum limit of the electrical conductivity, and the closely related soft photon emissivity of the QCD plasma, are then extracted from a fit to the Fourier transform of the temporal vector correlator.
119393927
Spin-Orbit Interaction in Two-Pion Exchange Nuclear Potential
123623965
Observations on muon multiplicity distribution with the GRAPES-2 experiment at Ooty for studies on the mass composition of cosmic rays at PeV energies
Precise knowledge of the mass composition of the primary cosmic ray flux below and above the knee in the primary energy spectrum at E∼3×10 15 eV is essential for understanding the acceleration and propagation of high energy cosmic rays. Simulations have shown that the correlations between the electron and muon components of showers are very sensitive to the mass of the primary nuclei. In particular, different regions of the muon multiplicity distribution observed with a large area muon detector, for well-defined selection on the electron component of showers, have a high sensitivity to different nuclear groups present in the primary flux. The GRAPES-2 experiment at Ooty seeks to exploit this sensitivity using a 200m 2 area muon detector to study the mass composition of the primary flux in the energy range 10 14 -10 16 eV. The details of the experiment are presented and early observations are discussed in relation to the expectations from simulations.
119328029
Hadron Properties just before Deconfinement
Abstract We have investigated hadron screening masses, the chiral condensate, and the pion decay constant close to the deconfinement phase transition in the confined phase of QCD. The simulations were done in the quenched approximation, on a lattice of size 32 3 × 8. We examined temperatures ranging from 0.75 T c up to 0.92 T c . We see no sign of a temperature dependence in the chiral condensate or the meson properties, but some temperature dependence for the nucleon screening mass is not excluded.