scholarly journals Can axial U(1) anomaly disappear at high temperature?

2018 ◽  
Vol 175 ◽  
pp. 01012 ◽  
Author(s):  
Hidenori Fukaya
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Critical Temperature ◽  
Lattice Qcd ◽  
Chiral Symmetry ◽  
Symmetry Violation ◽  
Simulation Data ◽  
Strong Suppression ◽  
Chiral Phase ◽  
Numerical Evidence

In our recent study of two-flavor lattice QCD using chiral fermions, we find strong suppression of axial U(1) anomaly above the critical temperature of chiral phase transition. Our simulation data also indicate suppression of topological susceptibility. In this talk, we present both of our theoretical and numerical evidence for disappearance of axial U(1) anomaly, emphasizing the importance of controlling lattice chiral symmetry violation, which is enhanced at high temperature.

scholarly journals Cooper Pair-Like Systems at High Temperature and their Role on Fluctuations Near the Critical Temperature

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3216-3219 ◽  
Author(s):  
M. Ausloos ◽  
S. Dorbolo
Keyword(s):  
Phase Transition ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Critical Temperature ◽  
Oxygen Diffusion ◽  
Cooper Pair ◽  
Anomalous Behavior ◽  
Anomalous Effect ◽  
Linear Temperature ◽  
Ybco Sample

A logarithmic behavior is hidden in the linear temperature regime of the electrical resistivity R(T) of some YBCO sample below 2T c where "pairs" break apart, fluctuations occur and "a gap is opening". An anomalous effect also occurs near 200 K in the normal state Hall coefficient. In a simulation of oxygen diffusion in planar 123 YBCO, an anomalous behavior is found in the oxygen-vacancy motion near such a temperature. We claim that the behavior of the specific heat above and near the critical temperature should be reexamined in order to show the influence and implications of fluctuations and dimensionality on the nature of the phase transition and on the true onset temperature.

scholarly journals On SU(3) Effective Models and Chiral Phase Transition

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Abdel Nasser Tawfik ◽  
Niseem Magdy
Keyword(s):  
Phase Transition ◽  
Phase Diagram ◽  
Lattice Qcd ◽  
High Energy ◽  
Particle Model ◽  
Chiral Phase ◽  
Chiral Phase Transition ◽  
Thermal Models ◽  
Qcd Phase Diagram ◽  
Freeze Out

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.

scholarly journals Thermodynamic Hadron-Quark Phase Transition of Chiral Nuclear Matter at High Temperature

2021 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Tuan Anh Nguyen
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Nuclear Matter ◽  
Degrees Of Freedom ◽  
Elementary Excitation ◽  
Chiral Phase ◽  
Njl Model ◽  
Limited Temperature ◽  
Quark Phase ◽  
Very High

Based on the extended Nambu-Jona–Lasinio (NJL) model with the scalar-vector eightpoint interaction [15], we consider what ultimately happens to exact chiral nuclear matter as it is heated. In the realm of very high temperature the fundamental degrees of freedom of the strong interaction, quarks and gluons, come into play and a transition from nuclear matter consisting of confined baryons and mesons to a state with ‘liberated’ quarks and gluons is expected. In this paper, the hadron-quark phase transition occurs above a limited temperature and after the chiral phase transition in the nuclear matter. There is a so-called quarkyonic- like phase, in which the chiral symmetry is restored but the elementary excitation modes are nucleonic at high density, appears just before deconfinement.PACS: 21.65.-f, 21.65.Mn, 11.30.Rd, 12.39.Ba, 25.75.Nq, 68.35.Rh

scholarly journals Chiral phase transition in QED3 at finite temperature

2016 ◽  
Vol 31 (36) ◽  
pp. 1650198
Author(s):  
Pei-Lin Yin ◽  
Hai-Xiao Xiao ◽  
Wei Wei ◽  
Hong-Tao Feng ◽  
Hong-Shi Zong
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Critical Temperature ◽  
Finite Temperature ◽  
Chiral Symmetry Breaking ◽  
Chiral Condensate ◽  
The Other ◽  
Thermodynamic Quantities ◽  
Chiral Phase ◽  
Chiral Phase Transition

In the framework of Dyson–Schwinger equations, we employ two kinds of criteria (one kind is the chiral condensate, the other kind is thermodynamic quantities, such as the pressure, the entropy, and the specific heat) to investigate the nature of chiral phase transitions in QED3 for different fermion flavors. It is found that the chiral phase transitions in QED3 for different fermion flavors are all typical second-order phase transitions; the critical temperature and order of the chiral phase transition obtained from the chiral condensate and susceptibility are the same with that obtained by the thermodynamic quantities, which means that they are equivalent in describing the chiral phase transition; the critical temperature decreases as the number of fermion flavors increases and there is a boundary that separates the [Formula: see text] plane into chiral symmetry breaking and restoration regions.

scholarly journals On the Parity Degeneracy of Baryons

1997 ◽  
Vol 12 (31) ◽  
pp. 2373-2386 ◽  
Author(s):  
M. Kirchbach
Keyword(s):  
Phase Transition ◽  
Angular Momentum ◽  
Chiral Symmetry ◽  
Excitation Spectrum ◽  
Orbital Angular Momentum ◽  
Chiral Phase ◽  
Chiral Phase Transition ◽  
Symmetry Mode

The gross features of the observed baryon excitation spectrum below 2 GeV are well explained if the spectrum generating algebra of its intrinsic orbital angular momentum states is o (4) ⊗ su (2)I. The spins of the resonances are obtained through the coupling of a Lorentz bi-spinor {1/2,0} ⊕ {0,1/2} to a multiplet of the type {j,j} in its O(4)/O(3) reduction. The parities of the resonances follow from those of the O(3) members of the {j,j} multiplets. In this way relativistic SL (2,C) representations are constructed. For example, the first S11, P11, and D13 states with masses around 1500 MeV fit into the {1/2,1/2} ⊗ [{1/2,0} ⊕ {0,1/2}] representation. The observed parities of the resonances correspond to natural parities of the {1/2,1/2} states. The second P11, S11, D13 — together with the first P13, F15, D15, and (a predicted) F17-resonances, centered around 1700 MeV, are organized into the {3/2,3/2} ⊗ [{1/2,0} ⊕ {0,1/2}] representation. We argue that the members of the {3/2,3/2} multiplet carry unnatural parities and that in this region chiral symmetry is restored. In the N(939)→ N(1650) transition the chiral symmetry mode is changed, and therefore, a chiral phase transition is predicted to take place.

Sign in / Sign up

Export Citation Format

Share Document