121441857
Centrality dependence of nonstatistical fluctuation in single particle density distribution in S-32-Ag/Br interaction at 200A-GeV/c
Nonstatistical fluctuations in the density distribution of shower tracks coming out of 32S–Ag/Br interaction at an incident momentum of 200A GeV/c, have been characterized by using the intermittency and multifractality techniques. A sample of 32S–Ag/Br nuclear emulsion events has been partitioned into three subsamples with respect to the shower track multiplicity in such a way that one can roughly estimate the average centrality for each subsample. Thereby, the centrality dependence of a set of relevant intermittency and multifractal issues has been investigated.
123842721
Multifractal study of singly charged particles produced in S-32 induced Ag/Br interactions at CERN
In this contribution, we describe an investigation of the fractal nature of non-statistical fluctuations in the density distribution of singly charged secondary particles produced in 32S-Ag/Br interactions in emulsion target at incident energy of 200A GeV. The experimental results have been compared with those obtained from an event sample simulated by the Lund Monte Carlo code FRITIOF. Besides obtaining the fractal dimensions and a smooth multifractal spectrum, show that the results can be used to determine universal parameters such as the Levy index, and the multifractal specific heat.
120176685
Intermittency and multiplicity moments of charged particles produced in 32S–Ag/Br interaction at 200 A GeV/c
The nature of nonstatistical fluctuations in the density distribution of singly charged particles produced in 32S–Ag/Br interactions at an incident momentum of 200 A GeV/c has been investigated. With the help of the nuclear photographic emulsion technique, the data were collected, and using different statistical methods of multiplicity moments these data have been analysed in terms of intermittency and fractal properties of one- and two-dimensional phase space distributions. Wherever possible, experimental results have been compared with the results obtained in other similar heavy-ion-induced experiments, as well as with those obtained from simulated events of the Lund Monte Carlo code FRITIOF. In some cases events simulated by generating (pseudo)random numbers have also been used for the purpose of comparison. The investigation shows the presence of weak intermittency in one dimension (1D) that is consistent with self-similarity in the density distribution. In two dimensions (2D), anisotropy in the distributions along longitudinal and transverse phase space variables indicates that self-affinity, rather than self-similarity in the distributions, is responsible for the observed behaviour. From the analysis of factorial correlators and oscillatory multiplicity moments, the presence of a few-particle short-range correlation has also been established. In almost all cases, the simulated interactions fail to replicate the experimental results.
120167461
Anomalous behavior of the level density parameter in neutron and charged particle evaporation
The compound nucleus $^{76}\mathrm{Kr}*$ was populated at the excitation energy of $75\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$ and angular momentum of $39\ensuremath{\hbar}$ in fusion reactions with two complementary, mass-symmetric $(^{31}\mathrm{P}+^{45}\mathrm{Sc})$ and mass-asymmetric $(^{12}\mathrm{C}+^{64}\mathrm{Zn})$ entrance channels. The neutron evaporation spectra were measured and compared with the predictions of statistical model calculations using the transmission coefficients for the spherical nuclei in the inverse absorption channel, the rotating liquid drop model moment of inertia, and the normal systematic value of $A∕8$ for the level density parameter $a$. The results for the mass-asymmetric reaction are found to be consistent with the predictions of the statistical model calculations. However, for the mass-symmetric reaction $(^{31}\mathrm{P}+^{45}\mathrm{Sc})$, the experimental spectra are found to be harder than the theoretical neutron spectra and the statistical model calculations require a lower value of $A∕10$ for the parameter $a$ to reproduce the shape of the experimental spectra, indicating the neutron to be evaporated at higher temperature for the same excitation energy and angular momentum in symmetric system. According to the dynamical model, the formation time $(37\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}22}\phantom{\rule{0.3em}{0ex}}\mathrm{sec})$ of the compound nucleus for the symmetric $^{31}\mathrm{P}+^{45}\mathrm{Sc}$ system is significantly higher than that $(29\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}22}\phantom{\rule{0.3em}{0ex}}\mathrm{sec})$ for the asymmetric $^{12}\mathrm{C}+^{64}\mathrm{Zn}$ system. This may probably lead to the formation of a temperature-equilibrated dinuclear complex that may be responsible for neutron emission at higher temperature in the case of the symmetric system.
118474507
INTERIOR REISSNER-NORDSTR ¨ OM METRIC ON SPHEROIDAL SPACE-TIMES
The collapse of a spherically symmetric distribution of matter to a point singularity can be avoided when the matter is accompanied by the presence of some charge, the gravitational attraction then being counterbalanced by the repulsive Coulombian force field in addition to the pressure gradient. The problem of determining analytic interior solutions to the coupled Einstein-Maxwell equations corresponding to charged perfect fluid spheres in equilibrium has therefore received considerable attention [1–8]. Vaidya and Tikekar [9] and Tikekar [10] have shown that spheriodal space-times (i.e. space-times whose t = const sections have the geometry of a 3-spheroid immersed in a 4-dimensional Euclidean space) admit solutions to the Einstein field equations describing the interior space-times of spherical superdense stars in equilibrium. This approach has also been extensively examined by Maharaj and Leach [11] and Mukherjee, et al. [12]. These studies indicate an intimate relationship between the spheroidal geometry of the physical space and the distribution of matter in equilibrium of astrophysical significance. Since the gravitational collapse of spherical distributions of matter can be averted by the presence of electric charge, there arises a pertinent question of whether space-times endowed with spheroidal geometry can accommodate the presence of an electric charge. In this paper it is shown that the ansatz prescribing the spheroidal geometry to the 3-space associated with
120875055
Charged fluid distribution in higher dimensional spheroidal space-time
A general solution of Einstein field equations corresponding to a charged fluid distribution on the background of higher dimensional spheroidal space-time is obtained. The solution generates several known solutions for superdense star having spheroidal space-time geometry.
119010434
Energy conservation laws in general relativity with reference to the expanding universe
122026076
Role of nuclear dissipation and entrance channel mass asymmetry in pre-scission neutron multiplicity enhancement in fusion-fission reactions
Pre-scission neutron multiplicities are measured for ${}^{12}\mathrm{C} + {}^{204}\mathrm{Pb}$ and ${}^{19}\mathrm{F} + {}^{197}\mathrm{Au}$ reactions at laboratory energies of 75\char21{}95 MeV for the $^{12}\mathrm{C}$ beam and 98\char21{}118 MeV for the $^{19}\mathrm{F}$ beam. The chosen projectile-target combinations in the present study lie on either side of the Businaro-Gallone mass asymmetry (${\ensuremath{\alpha}}_{\mathrm{BG}}$) and populate the $^{216}\mathrm{Ra}$ compound nucleus. The dissipation strength is deduced after comparing the experimentally measured neutron yield with the statistical model predictions which contains the nuclear viscosity as a free parameter. Present results demonstrate the combined effects of entrance channel mass asymmetry and the dissipative property of nuclear matter on the pre-scission neutron multiplicity in fusion-fission reactions.