Examination of an isospin-dependent single-nucleon momentum distribution for isospin-asymmetric nuclear matter in heavy-ion collisions

Within a transport model using nucleon momentum profiles as the input from a parameterized isospin-dependent single-nucleon momentum distribution,with a high momentum tail induced by short-range correlations,we employ197 Au+197 Au collisions at 400 MeV/nucleon to examine the effects of the short-range correlations on the pion and flow observables in probing the nuclear symmetry energy.We investigate how reliable this isospin-dependent single-nucleon momentum distribution is and determine the corresponding parameter settings.Apart from the significant effects of the short-range correlations on the pion and flow observables that are observed,we also find that the theoretical simulations of the197 Au+197 Au collisions with this momentum distribution using two sets of parameters,extracted from the experimental analysis and the self-consistent Green’s function prediction,can reproduce the neutron ellipticflows of the FOPI-LAND experiment and the pà=ptratios of the FOPI experiment,respectively,under the symmetry energy setting in a particular range.Therefore,we conclude that this parameterized isospin-dependent single-nucleon momentum distribution is reliable for isospin-asymmetric nuclear matter.Correspondingly,two sets of parameters extracted from both the experimental analysis and the selfconsistent Green’s function prediction cannot be excluded according to the available experimental information at present.

Exact solution of the (1+2)-dimensional generalized Kemmer oscillator in the cosmic string background with the magnetic field

We study a two-dimensional generalized Kemmer oscillator in the cosmic string spacetime with the magnetic field to better understand the contribution from gravitational field caused by topology defects,and present the exact solutions to the generalized Kemmer equation in the cosmic string with the Morse potential and Coulomb-liked potential through using the Nikiforov-Uvarov(NU)method and biconfluent Heun equation method,respectively.Our results give the topological defect’s correction for the wave function,energy spectrum and motion equation,and show that the energy levels of the generalized Kemmer oscillator rely on the angular deficitαconnected with the linear mass density m of the cosmic string and characterized the metric’s structure in the cosmic string spacetime.

Critical behavior and Joule-Thomson expansion of charged AdS black holes surrounded by exotic fluid with modified Chaplygin equation of state

By considering the concept of a unified single fluid model,referred to as modified Chaplygin gas(MCG),which amalgamates dark energy and dark matter,we explore the thermodynamic characteristics of charged anti-de Sitter(AdS)black holes existing in an unconventional fluid accompanied by MCG.To accomplish this objective,we derive the equations of state by regarding the charge Q2as a thermodynamic variable.The effects of MCG parameters on the critical thermodynamic quantities(ψc,Tc,Qc2)are examined,followed by a detailed analysis of the Q2-ψdiagram.To provide a clearer explanation of the phase transition,we present an analysis of the Gibbs free energy.It is important to note that if the Hawking temperature exceeds the critical temperature,a distinct pattern is observed known as swallowtail behavior.This indicates that the system undergoes a first-order phase transition from a smaller black hole to a larger one.The critical exponent of the system is found to be in complete agreement with that of the van der Waals fluid system.Furthermore,we investigate the impact of MCG parameters and black hole charge on Joule-Thomson(J-T)expansion in the extended phase space.The J-T coefficient is examined to pinpoint the exact region experiencing cooling or heating,and the observation reveals that the presence of negative heat capacity results in the occurrence of a cooling process.The impact of MCG on the inversion curve of charged black holes exhibits a striking resemblance to that observed in most multi-dimensional black hole systems.In addition,it is worth noting that certain parameters exert a significant influence on the ratio Tmin/Tc.For specific values of the MCG parameters,the ratio is consistent with the charged AdS black hole.The parametersγandβhave a non-negligible effect on the isenthalpic curve.

Black hole evaporation and its remnants with the generalized uncertainty principle including a linear term

In recent years,researchers have investigated the evaporation of Schwarzschild black holes using various forms of the generalized uncertainty principle(GUP),metric quantum correction,and noncommutative geometry,respectively.However,there are differences between the GUP correction and the other two methods in terms of describing the later stages of black hole evaporation.Furthermore,some studies argue that the GUP with a negative parameter cannot effectively correct black hole evaporation,while others contend that the positivity or negativity of the GUP parameters should not affect the correction results.Taking the above into consideration,we reconsider black hole evaporation with the generalized uncertainty principle including a linear term(LGUP),and examine the case of negative parameters.The results indicate that the evaporation behavior of both Schwarzschild black holes and Reissner–Nordstr?m black holes,under LGUP correction,is consistent with the results of metric quantum correction and non-commutative geometry.Additionally,the negative parameter LGUP can also effectively correct for black hole evaporation.

Joule-Thomson expansion of charged dilatonic black holes

Based on the Einstein-Maxwell theory,the Joule-Thomson(J-T)expansion of charged dilatonic black holes(the solutions are neither flat nor AdS)in(n+1)-dimensional spacetime is studied herein.To this end,we analyze the effects of the dimension n and dilaton fieldαon J-T expansion.An explicit expression for the J-T coefficient is derived,and consequently,a negative heat capacity is found to lead to a cooling process.In contrast to its effect on the dimension,the inversion curve decreases with charge Q at low pressures,whereas the opposite effect is observed at high pressures.We can observe that with an increase in the dimension n or parameter a,both the pressure cut-off point and the minimum inversion temperature T_(min)change.Moreover,we analyze the ratio T_(min)/T_(c)numerically and discover that the ratio is independent of charge;however,it depends on the dilaton field and dimension:for n=3 andα=0,the ratio is 1/2.The dilaton field is found to enhance the ratio.In addition,we identify the cooling-heating regions by investigating the inversion and isenthalpic curves,and the behavior of the minimum inversion mass M_(min)indicates that this cooling-heating transition may not occur under certain special conditions.

The effect of different generalized uncertainty principles on Jeans mass modification

Jeans mass is regarded as a crucial factor in the study of nebula collapse.Astronomical data shows that Jeans mass is larger in theory than it is in observation.Someone mentioned that Jeans mass can be modified by using the generalized uncertainty principle(GUP).However,different physical backgrounds lead to different forms of GUP expression.In order to make the theoretical values of Jeans mass and its observed values match better,we use three distinct types of GUPs to correct Jeans mass in this paper.We find that the corrected Jeans masses are smaller than the uncorrected ones,where the Pedram corrected Jeans mass is the minimum and is close to the observed value.In addition,we consider the impact of temperature T and the GUP parameters(η,βandγ)for the corrected Jeans mass.

Solution of the Dipoles in Noncommutative Space with Minimal Length

The single neutral spin-half particle with electric dipole moment and magnetic dipole moment moving in an external electromagnetic field is studied. The Aharonov-Casher effect and He-McKellar-Wilkens effect are emphatically discussed in noncommutative(NC) space with minimal length. The energy eigenvalues of the systems are obtained exactly in terms of the Jacobi polynomials. Additionally, a special case is discussed and the related energy spectra are plotted.

Fractional Angular Momentum of an Atom on a Noncommutative Plane

The mechanism of obtaining the fractional angular momentum by employing a trapped atom which possesses a permanent magnetic dipole moment in the background of two electric fields is reconsidered by using an alternative method. Then, we generalize this model to a noncommutative plane. We show that there are two different mechanisms,which include cooling down the atom to the negligibly small kinetic energy and modulating the density of electric charges to the critical value to get the fractional angular momentum theoretically.

The ringing of quantum corrected Schwarzschild black hole with GUP

Schwarzschild black holes with quantum corrections are studied under scalar field perturbations and electromagnetic field perturbations to analyze the effect of the correction term on the potential function and quasinormal mode(QNM).In classical general relativity,spacetime is continuous and there is no existence of the so-called minimal length.The introduction of the correction items of the generalized uncertainty principle,the parameterβ,can change the singularity structure of the black hole gauge and may lead to discretization in time and space.We apply the sixth-order WKB method to approximate the QNM of Schwarzschild black holes with quantum corrections and perform numerical analysis to derive the results of the method.Also,we find that the effective potential and QNM in scalar fields are larger than those in electromagnetic fields.