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1.
The models of translationally invariant infinite nuclear matter in the relativistic mean field models are very interesting and simple, since the nucleon can connect only to a constant vector and scalar meson field. Can one connect these to the complicated phase transitions of QCD? For an affirmative answer to this question, one must consider models where the coupling contstants to the scalar and vector fields depend on density in a nonlinear way, since as such the models are not explicitly chirally invariant. Once this is ensured, indeed one can derive a quark condensate indirectly from the energy density of nuclear matter which goes to zero at large density and temperature. The change to zero condensate indicates a smooth phase transition.  相似文献   

2.
The models of translationally invariant infinite nuclear matter in the relativistic mean field models are very interesting and simple, since the nucleon can connect only to a constant vector and scalar meson field. Can one connect these to the complicated phase transitions of QCD? For an affirmative answer to this question, one must consider models where the coupling contstants to the scalar and vector fields depend on density in a nonlinear way, since as such the models are not explicitly chirally invariant. Once this is ensured, indeed one can derive a quark condensate indirectly from the energy density of nuclear matter which goes to zero at large density and temperature. The change to zero condensate indicates a smooth phase transition.  相似文献   

3.
The shear (η) and bulk (ζ) viscosities are calculated in a quasiparticle relaxation-time approximation for a hadron matter described within the relativistic mean-field-based model with scaled hadron masses and couplings. Comparison with results of other models is presented. We demonstrate that a small value of the shear viscosity to entropy density ratio required for explaining a large elliptic flow observed at RHIC may be reached in the hadron phase. Relatively large values of the bulk viscosity are noted in the case of a baryon-enriched matter.  相似文献   

4.
5.
Various phenomenological models of particle multiplicity distributions are discussed using a general form of a unified model which is based on the grand canonical partition function and Feynman's path integral approach to statistical processes. These models can be written as special cases of a more general distribution which has three control parameters which are a,x,z. The relation to these parameters to various physical quantities are discussed. A connection of the parameter a with Fisher's critical exponent τ is developed. Using this grand canonical approach, moments, cumulants and combinants are discussed and a physical interpretation of the combinants are given and their behavior connected to the critical exponent τ. Various physical phenomena such as hierarchical structure, void scaling relations, Koba–Nielson–Olesen or KNO scaling features, clan variables, and branching laws are shown in terms of this general approach. Several of these features which were previously developed in terms of the negative binomial distribution are found to be more general. Both hierarchical structure and void scaling relations depend on the Fisher exponent τ. Applications of our approach to the charged particle multiplicity distribution in jets of L3 and H1 data are given.  相似文献   

6.
The frequency redistribution function r(νi, νf) for scattering by relativistic electrons is derived, when this scattering is isotropic in the electron rest frame and recoil effects are neglected. Unlike previous derivations, we obtain for r(νi, νf) an expression which reduces exactly to its classical value for a non-relativistic gas.  相似文献   

7.
P. K. Sahu  N. Otuka  M. Isse  Y. Nara  A. Ohnishi 《Pramana》2006,66(5):809-816
We analyze the spectra of pions and protons in heavy-ion collisions at relativistic energies from 2 A GeV to 65+65 A GeV by using a jet-implemented hadron-string cascade model. In this energy region, hadron transverse mass spectra first show softening until SPS energies, and re-hardening may emerge at RHIC energies. Since hadronic matter is expected to show only softening at higher energy densities, this re-hardening of spectra can be interpreted as a good signature of the quark-gluon plasma formation  相似文献   

8.
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10.
The kinetic theory of dilute gases to first order in the gradients yields linear relations between forces and fluxes. The heat flux for the relativistic gas has been shown to be related not only to the temperature gradient but also to the density gradient in the representation where number density, temperature and hydrodynamic velocity are the independent state variables. In this work we show the calculation of the corresponding transport coefficients from the full Boltzmann equation and compare the magnitude of the relativistic correction.  相似文献   

11.
12.
The stability of the canonical partition function of a two-dimensional classical plasma with respect to condensation phenomena is discussed.  相似文献   

13.
The partition function of a degenerate quadratic functional is defined and studied. It is shown that Ray-Singer invariants can be interpreted as partition functions of quadratic functionals. In the case of a degenerate non-quadratic functional the semiclassical approximation to the partition function is considered.  相似文献   

14.
The distributions of zeros of the partition function of lattice gas models of Fisher (at some temperature) and of Temperley are obtained. The former is a closed loop crossing the real axis and the latter is a part of the negative real axis.  相似文献   

15.
《Physics letters. A》1968,28(2):166-167
An elementary derivation of the exact equation of state of a two-dimensional classical plasma exhibits a condensation phenomenon at T = Tc = e2/4K. We show that the partition function does no longer exists even if T < 2Tc.  相似文献   

16.
It is shown that the time operatorQ 0 appearing in the realization of the RCCR's [Q,Pv]=–jhgv, on Minkowski quantum spacetime is a self adjoint operator on Hilbert space of square integrable functions over m =×v m , where is a timelike hyperplane. This result leads to time-energy uncertainty relations that match their space-momentum counterparts. The operators Q appearing in Born's metric operator in quantum spacetime emerge as internal spacetime operators for exciton states, and the condition that the metric operator should possess a ground exciton state assumes the significance of achieving minimal spacetime4-momentum uncertainty in fundamental standards for spacetime measurements.Supported in part by NSERC research grant No. A5206.  相似文献   

17.
Hui Zhao  Qi-Wen Ran  Jing Ma 《Optik》2011,122(6):540-543
A new phase-space distribution, linear canonical ambiguity function (LCAF), is proposed based on the linear canonical transform (LCT). The properties and physical meaning of the LCAF are given. The LCT moments are introduced and the relationships between the LCAF and the LCT moments are also derived. As an application, simple expressions for the center of gravity of the LCT power spectra and the effective width of the first-order optical system diffracted beam are derived. Compared with the conventional ambiguity function, the LCAF has three additional freedoms, i.e., the parameters characterizing a LCT, which make the LCAF more attractive for the analysis of optical signals.  相似文献   

18.
The equation of state for gases of point particles with logarithmic interaction is derived. The system exhibits a phase transition at a critical temperature Tc. The critical temperature is a function of the dimension of the system. A hard core must be added below Tc to prevent the system from collapsing. The specific heat diverges on both sides as |Tc - T|-2 in any dimension.For TTc there are no zeros of the grand partition function in the complex fugacity plane, for T >Tc all zeros occupy the whole negative real axis. The density of zeros will be calculated.  相似文献   

19.
Abstract: In this comprehensive study the multiplicity characteristics of the backward emitted relativistic hadron (shower particle) through hadron-nucleus and nucleus-nucleus are overviewed in three dimensions. These dimensions are the projectile size, target size, and energy. To confirm the universality in this production system, wide ranges of system size and energy (Elab~2.1 A up to 200 A GeV) are used. The multiplicity characteristics of this hadron imply a limiting behavior with respect to the projectile size and energy. The target size is the main effective parameter in this production system. The exponential decay shapes is a characteristic feature of the backward shower particle multiplicity distributions. The decay constant changes with the target size to be nearly 2.02, 1.41, and 1.12 for the interactions with CNO, Era, and AgBr nuclei, respectively, irrespective of the projectile size and energy. While the backward production probability and average multiplicity are constants at different projectile sizes and energies, they can be correlated with the target size in power law relations.  相似文献   

20.
In this comprehensive study the multiplicity characteristics of the backward emitted relativistic hadron(shower particle) through hadron-nucleus and nucleus-nucleus are overviewed in three dimensions. These dimensions are the projectile size, target size, and energy. To confirm the universality in this production system, wide ranges of system size and energy(Elab ~2.1 A up to 200 A GeV) are used. The multiplicity characteristics of this hadron imply a limiting behavior with respect to the projectile size and energy. The target size is the main effective parameter in this production system. The exponential decay shapes is a characteristic feature of the backward shower particle multiplicity distributions. The decay constant changes with the target size to be nearly 2.02, 1.41, and 1.12 for the interactions with CNO, Em, and Ag Br nuclei, respectively, irrespective of the projectile size and energy. While the backward production probability and average multiplicity are constants at different projectile sizes and energies, they can be correlated with the target size in power law relations.  相似文献   

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