EFFECTIVE MESONIC AND BARYONIC DEGREES OF FREEDOM IN NEUTRON STARS

2004 ◽  
Vol 13 (07) ◽  
pp. 1365-1373 ◽  
Author(s):  
MANFRED DILLIG ◽  
MATHIAS SCHOTT ◽  
EDUARDO F. LÜTZ ◽  
ALEXANDRE MESQUITA ◽  
CÉSAR A. Z. VASCONCELLOS
Keyword(s):  
Neutron Stars ◽  
Quark Gluon Plasma ◽  
Degrees Of Freedom ◽  
Gluon Plasma ◽  
Hadronic Matter

We present a sketchy survey on the role of effective mesonic and baryonic degrees of freedom in dense hadronic matter and briefly mention still very crude attempts to include constituent quarks degrees of freedom for a transition to a quark gluon plasma.

scholarly journals Astrophysical Aspects of Neutrino Dynamics in Ultradegenerate Quark Gluon Plasma

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Souvik Priyam Adhya
Keyword(s):  
Neutron Stars ◽  
Quark Gluon Plasma ◽  
Fermi Liquid ◽  
Mean Free Path ◽  
Gluon Plasma ◽  
Collective Excitations ◽  
Liquid Behavior ◽  
Astrophysical Scenario ◽  
Physical Quantities

The cardinal focus of the present review is to explore the role of neutrinos originating from the ultradense core of neutron stars composed of quark gluon plasma in the astrophysical scenario. The collective excitations of the quarks involving the neutrinos through the different kinematical processes have been studied. The cooling of the neutron stars as well as pulsar kicks due to asymmetric neutrino emission has been discussed in detail. Results involving calculation of relevant physical quantities like neutrino mean free path and emissivity have been presented in the framework of non-Fermi liquid behavior as applicable to ultradegenerate plasma.

scholarly journals Quark Cluster Expansion Model for Interpreting Finite-T Lattice QCD Thermodynamics

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 514
Author(s):  
David Blaschke ◽  
Kirill A. Devyatyarov ◽  
Olaf Kaczmarek
Keyword(s):  
Lattice Qcd ◽  
Cluster Expansion ◽  
Quark Gluon Plasma ◽  
Degrees Of Freedom ◽  
Gluon Plasma ◽  
Polyakov Loop ◽  
Unified Approach ◽  
Narrow Temperature Interval ◽  
Levinson Theorem ◽  
Expansion Model

In this work, we present a unified approach to the thermodynamics of hadron–quark–gluon matter at finite temperatures on the basis of a quark cluster expansion in the form of a generalized Beth–Uhlenbeck approach with a generic ansatz for the hadronic phase shifts that fulfills the Levinson theorem. The change in the composition of the system from a hadron resonance gas to a quark–gluon plasma takes place in the narrow temperature interval of 150–190 MeV, where the Mott dissociation of hadrons is triggered by the dropping quark mass as a result of the restoration of chiral symmetry. The deconfinement of quark and gluon degrees of freedom is regulated by the Polyakov loop variable that signals the breaking of the Z(3) center symmetry of the color SU(3) group of QCD. We suggest a Polyakov-loop quark–gluon plasma model with O(αs) virial correction and solve the stationarity condition of the thermodynamic potential (gap equation) for the Polyakov loop. The resulting pressure is in excellent agreement with lattice QCD simulations up to high temperatures.

scholarly journals QUARK–DIQUARK EQUATIONS OF STATE MODELS: THE ROLE OF INTERACTIONS

2003 ◽  
Vol 12 (03) ◽  
pp. 519-526 ◽  
Author(s):  
J. E. HORVATH ◽  
G. LUGONES ◽  
J. A. DE FREITAS PACHECO
Keyword(s):  
Equation Of State ◽  
Boundary Conditions ◽  
Neutron Stars ◽  
Hard Sphere ◽  
Degrees Of Freedom ◽  
Equations Of State ◽  
Compact Star ◽  
Star Models ◽  
State Models

Recent observational data suggests a high compacticity (the quotient M/R) of some "neutron" stars. Motivated by these works we revisit models based on quark–diquark degrees of freedom and address the question of whether that matter is stable against diquark disassembling and hadronization within the different models. We find that equations of state modeled as effective λϕ4 theories do not generally produce stable self-bound matter and are not suitable for constructing very compact star models, that is the matter would decay into neutron matter. We also discuss some insights obtained by including hard sphere terms in the equation of state to model repulsive interactions. We finally compare the resulting equations of state with previous models and emphasize the role of the boundary conditions at the surface of compact self-bound stars, features of a possible normal crust of the latter and related topics.

scholarly journals Holographic Multiquarks in the Quark-Gluon Plasma: A Review

2011 ◽  
Vol 2011 ◽  
pp. 1-40 ◽  
Author(s):  
Piyabut Burikham ◽  
Ekapong Hirunsirisawat
Keyword(s):  
Magnetic Field ◽  
Phase Diagram ◽  
Magnetic Properties ◽  
Quark Gluon Plasma ◽  
Bound States ◽  
Degrees Of Freedom ◽  
Gluon Plasma ◽  
Screening Length ◽  
Holographic Approach ◽  
Multiquark States

We review the holographic multiquark states in the deconfined quark-gluon plasma. Nuclear matter can become deconfined by extremely high temperature and/or density. In the deconfined nuclear medium, bound states with colour degrees of freedom are allowed to exist. Using holographic approach, the binding energy and the screening length of the multiquarks can be calculated. Using the deconfined Sakai-Sugimoto model, the phase diagram of the multiquark phase, the vacuum phase, and the chiral-symmetric quark-gluon plasma can be obtained. Then we review the magnetic properties of the multiquarks and their phase diagrams. The multiquark phase is compared with the pure pion gradient, the magnetized vacuum, and the chiral-symmetric quark-gluon plasma phases. For moderate temperature and sufficiently large density at a fixed magnetic field, the mixed phase of multiquark and pion gradient is the most energetically preferred phase.

scholarly journals Nonextensive statistical effects in the quark-gluon plasma formation at relativistic heavy-ion collisions energies

Open Physics ◽  
2012 ◽  
Vol 10 (3) ◽  
Author(s):  
Gianpiero Gervino ◽  
Andrea Lavagno ◽  
Daniele Pigato
Keyword(s):  
Quark Gluon Plasma ◽  
Mean Field ◽  
Relativistic Equation ◽  
Baryon Number ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Baryon Density ◽  
Hadronic Matter ◽  
Relativistic Heavy Ion Collisions ◽  
Relativistic Mean Field

AbstractWe investigate the relativistic equation of state of hadronic matter and quark-gluon plasma at finite temperature and baryon density in the framework of the non-extensive statistical mechanics, characterized by power-law quantum distributions. We impose the Gibbs conditions on the global conservation of baryon number, electric charge and strangeness number. For the hadronic phase, we study an extended relativistic mean-field theoretical model with the inclusion of strange particles (hyperons and mesons). For the quark sector, we employ an extended MIT-Bag model. In this context we focus on the relevance of non-extensive effects in the presence of strange matter.

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