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Vishnu M. Bannur

Publications and source records attributed to Vishnu M. Bannur.

At least 19 recordsLinked to original sources
arXiv2020

Thermodynamic Behaviour of Magnetized QGP within the Self-Consistent Quasiparticle Model

The self-consistent quasiparticle model has been successful in studying QCD thermodynamics. In this model, the medium effects are taken into account by considering quarks and gluons as quasiparticles with temperature-dependent masses which are proportional to the plasma frequency. The present work involves the extension of this model in the presence of magnetic fields. We have included the effect of the magnetic field by considering relativistic Landau Levels. The quasiparticle masses are then found to be dependent on both temperature and magnetic field. The thermomagnetic mass thus defined allows obtaining the thermodynamics of magnetized quark matter within the self-consistent quasiparticle model. The model then has been applied to the case of 2-flavor Quark-Gluon Plasma and the equation of state obtained in the presence of magnetic fields.

nucl-th↗
arXiv2020

Thermomagnetic properties and Debye Screening for magnetized quark-gluon Plasma using the extended self-consistent quasiparticle model

The thermomagnetic behavior of quark-gluon plasma has recently received a lot of attention. In this work, we make use of the extended self-consistent quasiparticle model to study the thermodynamic properties of magnetized (2+1) flavor quark-gluon plasma. The system is considered as a non-interacting system of quasiparticles with masses depending on both temperature and magnetic field. This allows obtaining the equation of state of the system and the other thermodynamic properties such as the speed of sound. We use the extended self-consistent model to obtain the magnetization and show that QGP has a paramagnetic nature. In addition, we study the pressure anisotropy and calculate the transverse pressure. The obtained anisotropic pressure may be used in hydrodynamic studies of magnetized QGP produced in heavy-ion collisions. Finally, we examine the screening properties of magnetized QGP in the longitudinal direction by calculating the Debye screening mass.

hep-ph↗
arXiv2015

General and Stronger Uncertainty Relation

Recently, Maccone and Pati [Phys. Rev. Lett. {\bf 113}, 260401 (2014)] derived few inequalities among variances of incompatible operators which they called stronger uncertainty relations, stronger than Heisenberg-Robertson or Schrodinger uncertainty relations. Here we generalize their study to get infinite number of such inequalities and propose that only one of them may be the correct uncertainty relation between incompatible operators. We get back well known uncertainty relations of Heisenberg-Robertson and Schrodinger under certain limits. We also reexamine the conclusions of Maccone and Pati and comment on their work.

quant-ph↗
arXiv2014

Virial expansion and condensation with a new generating function

Mayer's convergence method for virial expansion and condensation is studied using a new generating function for canonical partition function, which directly depends on irreducible cluster integral, $β_k$, unlike Mayer's work where it depends on reducible cluster integral, $b_l$. The virial expansion, criteria for it's validity and criteria for condensation, etc. are derived from our generating function. All earlier Mayer's results are obtained from this new generating function.

cond-mat.stat-mech↗
arXiv2013

Landau's statistical mechanics for quasiparticle models

Landau's formalism of statistical mechanics \cite{la.1} is applied to the quasiparticle model of quark gluon plasma. It is a general formalism and consistent with our earlier studies \cite{ba.1} based on Pathria's formalism \cite{pa.1}. Both the formalism are consistent with thermodynamics and statistical mechanics. Under certain conditions, which are wrongly called thermodynamic consistent relation, we recover other formalism of quasiparticle system \cite{go.1}, widely studied in quark gluon plasma.

hep-ph↗
arXiv2012

Thermodynamic inconsistency in quasiparticle model - a revisit

Widely studied quasiparticle models for quark gluon plasma is revisited here to understand the statistical mechanics and thermodynamics of the system. We investigate the statistical mechanics and thermodynamics inconsistencies involved in these models and their consequences in the observables. Quasiparticle model is a phenomenological model with few parameters and by adjusting them all models fit the results of lattice gauge simulation of gluon plasma \cite{bo.1}. However, after fixing 2 of the 3 parameters of the model by physical arguments, only one quasiparticle model, which is consistent with both statistical mechanics and thermodynamics, fits the Bielefeld lattice data \cite{bo.1}. The same model also fits the recent lattice results of Wuppertal-Budapest group \cite{fo.1}, which deals with precision SU(3) thermodynamics for a large temperature range, reasonably well.

hep-ph↗
arXiv2011

Thermodynamics of (2+1) flavor QGP in quasiparticle model

Using our recently developed one parameter quasiparticle model, we analyze more recent (refined) results of (2+1) flavor QGP in lattice simulation of QCD by various groups \cite{f.1,k.1,u.1,d.1}. We got a remarkable good fit to lattice thermodynamics of Ref. Szabolcs Borsanyi {\it et al.}, [hep-lat/1007.2580v2] and reasonable good fit to Ref. A. Bazavov {\it it al.}, Phys. Rev. {\bf D80}, 014504 (2009) by adjusting single parameter of the model which may be related QCD scale parameter. Further we extend our model for above system with zero chemical potential to non-zero chemical potential and predict quark density without any new parameters which may be compared with future lattice data.

hep-ph↗
arXiv2009

Is QGP really a liquid ?

Here we address the question regarding the nature of quark gluon plasma (QGP), whether it is a liquid or strongly coupled plasma (SCP), using two different phenomenological models, namely quasi-particle model (qQGP) and strongly coupled quark gluon plasma (SCQGP). First we compare these two models, both of which explains the results of lattice simulation of quantum chromodynamics, as a function of plasma parameter and conclude that the QGP is largely ($T > 1.5 T_c$) SCQGP and only for $T < 1.5 T_c$ it may be a liquid.

hep-ph↗
arXiv2008

Relativistic harmonic oscillator model for quark stars

The relativistic harmonic oscillator (RHO) model of hadrons is used to study quark stars. The mass-radius relationship is obtained and compared with bag model of quark star, using Tolman-Oppenheimer-Volkoff equation. In this model, the outward degenerate pressure due to discrete Landau levels and Landau degeneracy balances the inward gravitational pressure. Where as in bag model the degenerate pressure is due to the standard continuum levels which balances the combined inward pressure due to gravitation and bag pressure. So in RHO model, the confinement effect is included in the degenerate pressure. We found a qualitative similarity, but quantitative differences in mass-radius relationship of quark stars in these two models. Masses and radii are relatively larger and the central energy densities, required for stable quark stars, are lower in RHO model than that of bag model.

hep-ph↗
arXiv2007

Self-consistent quasiparticle model for 2, 3 and (2+1) flavor QGP

Quasi-particle model of quark gluon plasma is the statistical mechanics of particles with medium dependent mass, related to plasma frequency, which was proposed to describe the thermodynamics of the medium itself. At relativistic limit the plasma frequency depends on number density and temperature. The number density is a thermodynamic quantity of the medium which in turn depends on plasma frequency. Hence, one need to solve this problem self-consistently, instead of using perturbative expressions for plasma frequency. Here we carry out such a self-consistent calculations using our, recently developed, a new formulations of quasiparticle model. By adjusting a single parameter for each system, a remarkably good fit to lattice QCD results are obtained for 2, 3 and (2+1) flavor quark gluon plasma systems, first, with zero chemical potential. Then, it is extended to systems with finite chemical potential and fits very well the lattice results without any new parameter.

hep-ph↗
arXiv2007

Fully nonlinear excitations of non-Abelian plasma

We investigate fully nonlinear, non-Abelian excitations of quark-antiquark plasma, using relativistic fluid theory in cold plasma approximation. There are mainly three important nonlinearities, coming from various sources such as non-Abelian interactions of Yang-Mills (YM) fields, Wong's color dynamics and plasma nonlinearity, in our model. By neglecting nonlinearities due to plasma and color dynamics we get back the earlier results of Blaizot {\it et. al.}, Phys. Rev. Lett. 72, 3317 (1994). Similarly, by neglecting YM fields nonlinearity and plasma nonlinearity, it reduces to the model of Gupta {\it et. al.}, Phys. Lett. B498, 223 (2005). Thus we have the most general non-Abelian mode of quark-gluon plasma (QGP). Further, our model resembles the problem of propagation of laser beam through relativistic plasma, Physica 9D, 96 (1983). in the absence of all non-Abelian interactions.

hep-ph↗
arXiv2007

Comments on quasiparticle models of quark-gluon plasma

Here we comment on the thermodynamic inconsistency problem and the reformulation of statistical mechanics of widely studied quasiparticle models of quark-gluon plasma. Their starting relation, the expression for pressure itself is a wrong choice and lead to thermodynamic inconsistency and the requirements of the reformulation of statistical mechanics. Hence we revise the model using the standard statistical mechanics and is thermodynamically consistent. We also show that the other quasiparticle models may be obtained from our general formalism as a special case under certain restrictive condition. Further, as an example, we applied our model to explain the nonideal behaviour of gluon plasma and obtained a remarkable good fit to the lattice results by adjusting just a single parameter.

hep-ph↗
arXiv2006

Self-consistent quasiparticle model for quark-gluon plasma

Here we present a self-consistent quasi-particle model for quark-gluon plasma and apply it to explain the non-ideal behaviour seen in lattice simulations. The basic idea, borrowed from electrodynamic plasma, is that the gluons acquire mass as it propagates through plasma due to collective effects and is approximately equal to the plasma frequency. The statistical mechanics and thermodynamics of such a system is studied by treating it as an ideal gas of massive gluons. Since mass or plasma frequency depends on density, which itself is a thermodynamic quantity, the whole problem need to be solved self-consistently.

hep-ph↗
arXiv2006

Single parameter quasi-particle model for QGP

We discuss a new single parameter quasi-particle model and study the thermodynamics of (2+1)-flavor quark gluon plasma (QGP). Our model with a single parameter explains remarkably well the lattice simulation results of Fodor et. al. Phys. Lett. B568, 73 (2003).

hep-ph↗
arXiv2006

Self-consistent quasi-particle model for relativistic plasma

Relativistic plasma with radiation at thermodynamic equilibrium is ageneral system of interest in astrophysics and high energy physics. We develop a new self-consistent quasi-particle model for such a system to take account of collective behaviour of plasma andthermodynamic properties are derived. It is applied to electrodynamic plasma and quark gluon plasma and compared with existing results.

hep-ph↗
arXiv2006

Statistical mechanics of confined quantum particles

We develop statistical mechanics and thermodynamics of Bose and Fermi systems in relativistic harmonic oscillator (RHO) confining potential, which may be applicable in quark gluon plasma (QGP), astrophysics, Bose-Einstein condensation (BEC), condensed matter physics etc. Detailed study of QGP system is carried out and compared with lattice results. Further, as an application, our equation of state (EoS) of QGP is used to study compact stars like quark star.

hep-ph↗