We derive an equation of state for magnetized charge neutral nuclear matter relevant for neutron ... more We derive an equation of state for magnetized charge neutral nuclear matter relevant for neutron star structure. The calculations are performed within an effective chiral model based on generalization of sigma model with nonlinear self interactions of the sigma mesons along with vector mesons and a $\rho-\sigma$ cross-coupling term. The effective chiral model is extended by introducing the contributions of strong magnetic field on the charged particles of the model. The contributions arising from the effects of magnetic field on the Dirac sea of charged baryons are also included. The resulting equation of state for the magnetized dense matter is used to investigate the neutron star properties, like, mass-radius relation and tidal deformability. The dimensionless tidal deformability of $1.4~{M}_\odot$ NS is found to be $\Lambda_{1.4}=526$, which is consistent with recent observation of GW170817. The maximum mass of neutron star in presence of strong magnetic field is consistent with ...
We estimate the electrical conductivity and the Hall conductivity of hot and dense hadron gas usi... more We estimate the electrical conductivity and the Hall conductivity of hot and dense hadron gas using the relaxation time approximation of the Boltzmann transport equation in the presence of electromagnetic field. We have investigated the temperature and the baryon chemical potential dependence of these transport coefficients in presence of magnetic field. The explicit calculation is performed within the ambit of the hadron resonance gas model. We find that the electrical conductivity decreases in the presence of magnetic field. The Hall conductivity on the other hand shows a non monotonic behavior with respect to the dependence on magnetic field. We argue that for a pair plasma (particle-anti particle plasma) where μB = 0, Hall conductivity vanishes. Only for non vanishing baryon chemical potential Hall conductivity has non zero value. We also estimate the electrical conductivity and the Hall conductivity as a function of the center of mass energy along the freeze out curve as may be...
... field by the Euler-Lagrange equation, we get F= ZAS( Then by choosing [ 8 ] s( =- with mz >... more ... field by the Euler-Lagrange equation, we get F= ZAS( Then by choosing [ 8 ] s( =- with mz > 0, the lagrangian density becomes Y-2((auz+iVy,ua~Vz ... Volume 251, number 4 References [ 1 ] J. Wess and J. Bagger, Supersymmetry and supergravity (Princeton UP, Princeton, 1983). ...
We consider here quark matter equation of state in a relativistic harmonic confinement model at z... more We consider here quark matter equation of state in a relativistic harmonic confinement model at zero temperature. The same is considered to study phase transition of neutron matter to quark matter at high densities. This, along with a phenomenological equation of state in the neutron matter sector is used to study hybrid stars. Using Tolman-Oppenheimer-Volkoff equations, stable solutions for hybrid stars are obtained with a maximum mass of 1.98 Mʘ and radii around 10 km with a quark core of about 1 to 2 km.
We have attempted to review on microscopic calculation of transport coefficients like shear and b... more We have attempted to review on microscopic calculation of transport coefficients like shear and bulk viscosities in the framework of hadron resonance gas (HRG) model, where a special attention is explored on the effect of finite system size. The standard expressions of transport coefficients, obtained from relaxation time approximation of kinetic theory or diagrammatic Kubo-type formalism, carry mainly two temperature-dependent components — thermodynamical phase space and relaxation time of medium constituent. Owing to the quantum effect of finite system size, thermodynamical phase space can be reduced as its momentum distribution will be started from some finite lower momentum cut-off instead of zero momentum. On the other hand, relaxation time of hadrons can also face finite size effect by considering only those relaxation scales, which are lower than the system size. Owing to these phenomenological issues, we have proposed a system size-dependent upper bound of transport coeffici...
The European Physical Journal Special Topics, 2022
We discuss the vacuum structure of dense quark matter in strong magnetic fields at finite tempera... more We discuss the vacuum structure of dense quark matter in strong magnetic fields at finite temperature and densities in a three-flavor Nambu Jona Lasinio (NJL) model using a variational method. The method uses an explicit structure for the ‘ground’ state in terms of quark–antiquark condensates related to chiral symmetry breaking as well as diquark condensates related to color superconductivity. The mass gap equations and the superconducting gap equations are solved self-consistently and are used to compute the thermodynamic potential along with charge neutrality conditions. We also derive the equation of state for charge neutral strange quark matter in the presence of strong magnetic fields which could be relevant for neutron stars.
In this article, there are 18 sections discussing various current topics in the field of relativi... more In this article, there are 18 sections discussing various current topics in the field of relativistic heavy-ion collisions and related phenomena, which will serve as a snapshot of the current state of the art. Section 1 reviews experimental results of some recent light-flavored particle production data from ALICE collaboration. Other sections are mostly theoretical in nature. Very strong but transient magnetic field created in relativistic heavy-ion collisions could have important observational consequences. This has generated a lot of theoretical activity in the last decade. Sections 2, 7, 9, 10 and 11 deal with the effects of the magnetic field on the properties of the QCD matter. More specifically, Sec. 2 discusses mass of [Formula: see text] in the linear sigma model coupled to quarks at zero temperature. In Sec. 7, one-loop calculation of the anisotropic pressure are discussed in the presence of strong magnetic field. In Sec. 9, chiral transition and chiral susceptibility in th...
ABSTRACT We investigate the phase diagram of strange quark matter in beta equllibrium where the l... more ABSTRACT We investigate the phase diagram of strange quark matter in beta equllibrium where the lighter up and down quarks form the two flavor superconducting matter whereas the strange quark remains unpaired. This is studied wihin a Nambu-Jona-Lasinio model. The variational method as used here allows us to investigate simultaneous formation of condensates in quark-antiquark as well as in diquark channels. Color and electric charge neutrality conditions are imposed in the calculation of the thermodynamic potential. Medium dependance of strange quark mass plays a sensitive role in maintaining charge neutrality conditions. At zero temperature the system goes from the gapless phase to the usual BCS phase through an intermediate normal phase as density is increased. However, at higher temperature the gapless to BCS transition becomes a smooth transition. The gapless modes show a smooth behaviour with respect to temperature vanishing above a critical temperature which is larger than the BCS transition temperature.
We discuss here some nonperturbative techniques of field theory, where we dress nuclear matter as... more We discuss here some nonperturbative techniques of field theory, where we dress nuclear matter as a whole with off-mass-shell pions. Here s-wave pion pairs simulate the effect of σ-meson of the mean field approach of Walecka. The signatures are in agreement with earlier results along with new physical insight.
We derive an equation of state for magnetized charge neutral nuclear matter relevant for neutron ... more We derive an equation of state for magnetized charge neutral nuclear matter relevant for neutron star structure. The calculations are performed within an effective chiral model based on generalization of sigma model with nonlinear self interactions of the sigma mesons along with vector mesons and a $\rho-\sigma$ cross-coupling term. The effective chiral model is extended by introducing the contributions of strong magnetic field on the charged particles of the model. The contributions arising from the effects of magnetic field on the Dirac sea of charged baryons are also included. The resulting equation of state for the magnetized dense matter is used to investigate the neutron star properties, like, mass-radius relation and tidal deformability. The dimensionless tidal deformability of $1.4~{M}_\odot$ NS is found to be $\Lambda_{1.4}=526$, which is consistent with recent observation of GW170817. The maximum mass of neutron star in presence of strong magnetic field is consistent with ...
We estimate the electrical conductivity and the Hall conductivity of hot and dense hadron gas usi... more We estimate the electrical conductivity and the Hall conductivity of hot and dense hadron gas using the relaxation time approximation of the Boltzmann transport equation in the presence of electromagnetic field. We have investigated the temperature and the baryon chemical potential dependence of these transport coefficients in presence of magnetic field. The explicit calculation is performed within the ambit of the hadron resonance gas model. We find that the electrical conductivity decreases in the presence of magnetic field. The Hall conductivity on the other hand shows a non monotonic behavior with respect to the dependence on magnetic field. We argue that for a pair plasma (particle-anti particle plasma) where μB = 0, Hall conductivity vanishes. Only for non vanishing baryon chemical potential Hall conductivity has non zero value. We also estimate the electrical conductivity and the Hall conductivity as a function of the center of mass energy along the freeze out curve as may be...
... field by the Euler-Lagrange equation, we get F= ZAS( Then by choosing [ 8 ] s( =- with mz >... more ... field by the Euler-Lagrange equation, we get F= ZAS( Then by choosing [ 8 ] s( =- with mz > 0, the lagrangian density becomes Y-2((auz+iVy,ua~Vz ... Volume 251, number 4 References [ 1 ] J. Wess and J. Bagger, Supersymmetry and supergravity (Princeton UP, Princeton, 1983). ...
We consider here quark matter equation of state in a relativistic harmonic confinement model at z... more We consider here quark matter equation of state in a relativistic harmonic confinement model at zero temperature. The same is considered to study phase transition of neutron matter to quark matter at high densities. This, along with a phenomenological equation of state in the neutron matter sector is used to study hybrid stars. Using Tolman-Oppenheimer-Volkoff equations, stable solutions for hybrid stars are obtained with a maximum mass of 1.98 Mʘ and radii around 10 km with a quark core of about 1 to 2 km.
We have attempted to review on microscopic calculation of transport coefficients like shear and b... more We have attempted to review on microscopic calculation of transport coefficients like shear and bulk viscosities in the framework of hadron resonance gas (HRG) model, where a special attention is explored on the effect of finite system size. The standard expressions of transport coefficients, obtained from relaxation time approximation of kinetic theory or diagrammatic Kubo-type formalism, carry mainly two temperature-dependent components — thermodynamical phase space and relaxation time of medium constituent. Owing to the quantum effect of finite system size, thermodynamical phase space can be reduced as its momentum distribution will be started from some finite lower momentum cut-off instead of zero momentum. On the other hand, relaxation time of hadrons can also face finite size effect by considering only those relaxation scales, which are lower than the system size. Owing to these phenomenological issues, we have proposed a system size-dependent upper bound of transport coeffici...
The European Physical Journal Special Topics, 2022
We discuss the vacuum structure of dense quark matter in strong magnetic fields at finite tempera... more We discuss the vacuum structure of dense quark matter in strong magnetic fields at finite temperature and densities in a three-flavor Nambu Jona Lasinio (NJL) model using a variational method. The method uses an explicit structure for the ‘ground’ state in terms of quark–antiquark condensates related to chiral symmetry breaking as well as diquark condensates related to color superconductivity. The mass gap equations and the superconducting gap equations are solved self-consistently and are used to compute the thermodynamic potential along with charge neutrality conditions. We also derive the equation of state for charge neutral strange quark matter in the presence of strong magnetic fields which could be relevant for neutron stars.
In this article, there are 18 sections discussing various current topics in the field of relativi... more In this article, there are 18 sections discussing various current topics in the field of relativistic heavy-ion collisions and related phenomena, which will serve as a snapshot of the current state of the art. Section 1 reviews experimental results of some recent light-flavored particle production data from ALICE collaboration. Other sections are mostly theoretical in nature. Very strong but transient magnetic field created in relativistic heavy-ion collisions could have important observational consequences. This has generated a lot of theoretical activity in the last decade. Sections 2, 7, 9, 10 and 11 deal with the effects of the magnetic field on the properties of the QCD matter. More specifically, Sec. 2 discusses mass of [Formula: see text] in the linear sigma model coupled to quarks at zero temperature. In Sec. 7, one-loop calculation of the anisotropic pressure are discussed in the presence of strong magnetic field. In Sec. 9, chiral transition and chiral susceptibility in th...
ABSTRACT We investigate the phase diagram of strange quark matter in beta equllibrium where the l... more ABSTRACT We investigate the phase diagram of strange quark matter in beta equllibrium where the lighter up and down quarks form the two flavor superconducting matter whereas the strange quark remains unpaired. This is studied wihin a Nambu-Jona-Lasinio model. The variational method as used here allows us to investigate simultaneous formation of condensates in quark-antiquark as well as in diquark channels. Color and electric charge neutrality conditions are imposed in the calculation of the thermodynamic potential. Medium dependance of strange quark mass plays a sensitive role in maintaining charge neutrality conditions. At zero temperature the system goes from the gapless phase to the usual BCS phase through an intermediate normal phase as density is increased. However, at higher temperature the gapless to BCS transition becomes a smooth transition. The gapless modes show a smooth behaviour with respect to temperature vanishing above a critical temperature which is larger than the BCS transition temperature.
We discuss here some nonperturbative techniques of field theory, where we dress nuclear matter as... more We discuss here some nonperturbative techniques of field theory, where we dress nuclear matter as a whole with off-mass-shell pions. Here s-wave pion pairs simulate the effect of σ-meson of the mean field approach of Walecka. The signatures are in agreement with earlier results along with new physical insight.
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