Conversion of neutron stars to 2 + 1 flavor Nambu–Jona-Lasinio quark stars as a mechanism for gamma-ray bursts

2017 ◽  
Vol 32 (37) ◽  
pp. 1750209
Author(s):  
Xiao-Yu Shu ◽  
Yong-Feng Huang ◽  
Hong-Shi Zong
Keyword(s):  
Phase Transition ◽  
Gamma Ray ◽  
Chemical Potential ◽  
Proper Time ◽  
Mean Field ◽  
Gamma Ray Bursts ◽  
Compact Stars ◽  
Relativistic Mean Field ◽  
Quark Stars ◽  
Njl Model

The phase transition from a neutron star to a quark star and its relation to gamma-ray bursts are investigated. A new model: the 2 + 1 flavor Nambu–Jona-Lasinio (NJL) model with the method of proper-time regularization (PTR) is utilized for the quark phase; while the Relativistic Mean Field (RMF) theory is used for the hadronic phase. The process of phase transition is studied by considering the chemical potential, paying special attention to the phase transition point and the emergence of strange quark matter. Characteristics of compact stars are illustrated, and the energy release during the phase transition is found to be [Formula: see text] erg.

Gamma-ray bursts generated from phase transition of neutron stars to quark stars

2017 ◽  
Vol 32 (04) ◽  
pp. 1750027 ◽  
Author(s):  
Xiao-Yu Shu ◽  
Yong-Feng Huang ◽  
Hong-Shi Zong
Keyword(s):  
Phase Transition ◽  
Neutron Stars ◽  
Gamma Ray ◽  
Mean Field ◽  
Gamma Ray Bursts ◽  
Compact Stars ◽  
Particle Model ◽  
Relativistic Mean Field ◽  
Quark Stars ◽  
Quark Phase

The evolution of compact stars is believed to be able to produce various violent phenomena in our universe. In this paper, we discuss the possibility that gamma-ray bursts (GRBs) might result from the phase transition of a neutron star to a quark star and calculate the energy released from the conversion. In our study, we utilize the relativistic mean field (RMF) theory to describe the hadronic phase of neutron stars, while an improved quasi-particle model is adopted to describe the quark phase of quark stars. With quark matter equation-of-state (EOS) more reliable than models used before, it is found that the energy released is of the order of 10[Formula: see text] erg, which confirms the validity of the phase transition model.

Studies on proper time regularization and the QCD chiral phase transition

2019 ◽  
Vol 34 (01) ◽  
pp. 1950003
Author(s):  
Yu-Qiang Cui ◽  
Zhong-Liang Pan
Keyword(s):  
Phase Transition ◽  
Small Parameter ◽  
Effective Mass ◽  
Finite Temperature ◽  
Chemical Potential ◽  
Proper Time ◽  
Chiral Phase ◽  
Chiral Phase Transition ◽  
Njl Model ◽  
The Difference

We investigate the finite-temperature and zero quark chemical potential QCD chiral phase transition of strongly interacting matter within the two-flavor Nambu–Jona-Lasinio (NJL) model as well as the proper time regularization. We use two different regularization processes, as discussed in Refs. 36 and 37, separately, to discuss how the effective mass M varies with the temperature T. Based on the calculation, we find that the M of both regularization schemes decreases when T increases. However, for three different parameter sets, quite different behaviors will show up. The results obtained by the method in Ref. 36 are very close to each other, but those in Ref. 37 are getting farther and farther from each other. This means that although the method in Ref. 37 seems physically more reasonable, it loses the advantage in Ref. 36 of a small parameter dependence. In addition, we also, find that two regularization schemes provide similar results when T [Formula: see text] 100 MeV, while when T is larger than 100 MeV, the difference becomes obvious: the M calculated by the method in Ref. 36 decreases more rapidly than that in Ref. 37.

Proper time regularization at finite quark chemical potential

2016 ◽  
Vol 31 (14) ◽  
pp. 1650086 ◽  
Author(s):  
Jin-Li Zhang ◽  
Yuan-Mei Shi ◽  
Shu-Sheng Xu ◽  
Hong-Shi Zong
Keyword(s):  
Phase Transition ◽  
Chemical Potential ◽  
Chiral Limit ◽  
Proper Time ◽  
Quark Confinement ◽  
Chiral Phase ◽  
Chiral Phase Transition ◽  
Njl Model ◽  
Potential Case ◽  
Chiral Susceptibility

In this paper, we use the two-flavor Nambu–Jona-Lasinio (NJL) model to study the quantum chromodynamics (QCD) chiral phase transition. To deal with the ultraviolet (UV) issue, we adopt the popular proper time regularization (PTR), which is commonly used not only for hadron physics but also for the studies with magnetic fields. This regularization scheme can introduce the infrared (IR) cutoff to include quark confinement. We generalize the PTR to zero temperature and finite chemical potential case use a completely new method, and then study the chiral susceptibility, both in the chiral limit case and with finite current quark mass. The chiral phase transition is second-order in [Formula: see text] and [Formula: see text] and crossover at [Formula: see text] and [Formula: see text]. Three sets of parameters are used to make sure that the results do not depend on the parameter choice.

The two-flavor NJL model with two-cutoff proper time regularization

2014 ◽  
Vol 29 ◽  
pp. 1460232 ◽  
Author(s):  
Zhu-Fang Cui ◽  
Yi-Lun Du ◽  
Hong-Shi Zong
Keyword(s):  
Phase Transition ◽  
Finite Temperature ◽  
Chemical Potential ◽  
Proper Time ◽  
Model Parameters ◽  
Chiral Phase ◽  
Chiral Phase Transition ◽  
Regularization Scheme ◽  
Njl Model

In this paper, we use the two-flavor Nambu–Jona-Lasinio model together with the proper time regularization that has both ultraviolet and infrared cutoffs to study the chiral phase transition at finite temperature and zero chemical potential. The involved model parameters in our calculation are determined in the traditional way. Our calculations show that the dependence of the results on the choice of the parameters are really small, which can then be regarded as an advantage besides such a regularization scheme is Lorentz invariant.

scholarly journals ENERGY RELEASE ASSOCIATED WITH QUARK PHASE TRANSITION IN NEUTRON STARS: COMPARATIVE ANALYSIS OF MAXWELL AND GLENDENNING SCENARIOS

2012 ◽  
Vol 18 ◽  
pp. 1-9
Author(s):  
ANI ALAVERDYAN ◽  
GRIGOR ALAVERDYAN ◽  
SHUSHAN MELIKYAN
Keyword(s):  
Phase Transition ◽  
Mean Field ◽  
Effective Field ◽  
Compact Stars ◽  
Relativistic Mean Field ◽  
Hadron Phase ◽  
First Order Phase Transition ◽  
Deconfinement Phase Transition ◽  
The One ◽  
Quark Phase

We study the compact stars internal structure and observable characteristics alterations due to the quark deconfinement phase transition. To proceed with, we investigate the properties of isospin- asymmetric nuclear matter in the improved relativistic mean-field (RMF) theory, including a scalar-isovector δ-meson effective field. In order to describe the quark phase, we use the improved version of the MIT bag model, in which the interactions between u, d and s quarks inside the bag are taken into account in the one-gluon exchange approximation. We compute the amount of energy released by the corequake for both cases of deconfinement phase transition scenarios, corresponding to the Maxwellian type ordinary first-order phase transition and the phase transition with formation of a mixed quark-hadron phase (Glendenning scenario).

scholarly journals INVESTIGATION OF THE EXISTENCE OF HYBRID STARS USING NAMBU–JONA–LASINIO MODELS

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1521-1524 ◽  
Author(s):  
J. G. COELHO ◽  
C. H. LENZI ◽  
M. MALHEIRO ◽  
R. M. MARINHO ◽  
M. FIOLHAIS
Keyword(s):  
Phase Transition ◽  
Equation Of State ◽  
Neutron Stars ◽  
Quark Matter ◽  
Chemical Potential ◽  
Compact Stars ◽  
Vector Coupling ◽  
Njl Model ◽  
Hybrid Stars ◽  
Quark Phase

We investigate the hadron-quark phase transition inside neutron stars and obtain mass–radius relations for hybrid stars. The equation of state for the quark phase using the standard NJL model is too soft, leading to an unstable star and suggesting a modification of the NJL model by introducing a momentum cutoff dependent on the chemical potential. However, even in this approach, the instability remains. In order to remedy the instability we suggest the introduction of a vector coupling in the NJL model, which makes the EoS stiffer, reducing the instability. We conclude that the possible existence of quark matter inside the stars require high densities, leading to very compact stars.

scholarly journals Strange quark stars within proper time regularized ( 2+1 )-flavor NJL model

2020 ◽  
Vol 101 (6) ◽  
Author(s):  
Cheng-Ming Li ◽  
Shu-Yu Zuo ◽  
Yan Yan ◽  
Ya-Peng Zhao ◽  
Fei Wang ◽  
...  
Keyword(s):  
Strange Quark ◽  
Proper Time ◽  
Quark Stars ◽  
Njl Model

EFFECT OF MAGNETIC FIELD ON THE PHASE TRANSITION FROM NUCLEAR MATTER TO QUARK MATTER DURING PROTO-NEUTRON STAR EVOLUTION

2002 ◽  
Vol 11 (04) ◽  
pp. 545-559 ◽  
Author(s):  
V. K. GUPTA ◽  
ASHA GUPTA ◽  
S. SINGH ◽  
J. D. ANAND
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Quark Matter ◽  
Mean Field Theory ◽  
Mean Field ◽  
Relativistic Mean Field ◽  
Electron Neutrinos ◽  
Hadron Phase ◽  
Frame Work ◽  
Trapped Electron

We have studied phase transition from hadron matter to quark matter in the presence of high magnetic fields incorporating the trapped electron neutrinos at finite temperatures. We have used the density dependent quark mass (DDQM) model for the quark phase while the hadron phase is treated in the frame-work of relativistic mean field theory. It is seen that the energy density in the hadron phase at phase transition decreases with both magnetic field and temperature.

Exploring the α-decay chain of 302122 within relativistic mean field formalism

2020 ◽  
Author(s):  
M. Panigrahi ◽  
R.N. Panda ◽  
M. Bhuyan ◽  
S.K. Patra
Keyword(s):  
Binding Energy ◽  
Chemical Potential ◽  
Energy Charge ◽  
Mean Field ◽  
Neutron Separation Energy ◽  
Isotopic Chain ◽  
Α Decay ◽  
Particle Spacing ◽  
Relativistic Mean Field ◽  
Field Formalism

The ground and first excited state structural properties like binding energy, charge radius, deformation parameter, pairing energy, and two-neutron separation energy for the isotopic chain of Z= 122 are analyzed. The axially deformed relativistic mean-field formalism with NL3* force parameter is used for the present analysis. Based on the analysis of binding energy per particle, chemical potential and single-particle spacing, we predict the isotopes of Z =122 with N = 180. 182 and 184 are the possible stable nuclei over the considered isotopic chain. The α-decay energies and the decay half-lives of <sup>302</sup>122 chains are investigated using four different empirical formulae. The results of our calculations are compared with the available experimental data and Finite Range Droplet Model predictions. We also established a correlation for the decay energy with the half-lives for the considered α-decay chains for various empirical formulae.

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