scholarly journals Instantons and the chiral phase transition at nonzero baryon density

1998 ◽  
Vol 57 (7) ◽  
pp. 3950-3961 ◽  
Author(s):  
T. Schäfer
Universe ◽  
2019 ◽  
Vol 5 (8) ◽  
pp. 180 ◽  
Author(s):  
Michał Marczenko ◽  
David Blaschke ◽  
Krzysztof Redlich ◽  
Chihiro Sasaki

We extend the recently developed hybrid quark–meson–nucleon model by augmenting a six-point scalar interaction and investigate the consequences for neutron-star sequences in the mass–radius diagram. One of the characteristic features of the model is that the chiral symmetry is restored within the hadronic phase by lifting the mass splitting between chiral partner states, before quark deconfinement takes place. At low temperature and finite baryon density, the model predicts a first- or second-order chiral phase transition, or a crossover, depending on the expectation value of a scalar field, and a first-order deconfinement phase transition. We discuss two sets of free parameters, which result in compact-star mass–radius relations that are at tension with the combined constraints for maximum-mass ( 2 M ⊙ ) and the compactness (GW170817). We find that the most preferable mass–radius relations result in isospin-symmetric phase diagram with rather low temperature for the critical point of the chiral phase transition.


2020 ◽  
Vol 102 (11) ◽  
Author(s):  
Paolo Castorina ◽  
Daniele Lanteri ◽  
Marco Ruggieri

1994 ◽  
Vol 34 ◽  
pp. 289-291
Author(s):  
G. Boyd ◽  
S. Gupta ◽  
F. Karsch ◽  
E. Laermann

1994 ◽  
Vol 34 ◽  
pp. 292-294 ◽  
Author(s):  
E. Laermann ◽  
G. Boyd ◽  
S. Gupta ◽  
F. Karsch ◽  
B. Petersson ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Abdel Nasser Tawfik ◽  
Niseem Magdy

Sensitivity of Polyakov Nambu-Jona-Lasinio (PNJL) model and Polyakov linear sigma-model (PLSM) has been utilized in studying QCD phase-diagram. From quasi-particle model (QPM) a gluonic sector is integrated into LSM. The hadron resonance gas (HRG) model is used in calculating the thermal and dense dependence of quark-antiquark condensate. We review these four models with respect to their descriptions for the chiral phase transition. We analyze the chiral order parameter, normalized net-strange condensate, and chiral phase-diagram and compare the results with recent lattice calculations. We find that PLSM chiral boundary is located in upper band of the lattice QCD calculations and agree well with the freeze-out results deduced from various high-energy experiments and thermal models. Also, we find that the chiral temperature calculated from HRG is larger than that from PLSM. This is also larger than the freeze-out temperatures calculated in lattice QCD and deduced from experiments and thermal models. The corresponding temperature and chemical potential are very similar to that of PLSM. Although the results from PNJL and QLSM keep the same behavior, their chiral temperature is higher than that of PLSM and HRG. This might be interpreted due the very heavy quark masses implemented in both models.


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