相关论文: OZI violating eight-quark interactions as a thermo…
Phase transitions in hot and dense matter and the in--medium behavior of pseudoscalar mesons ($\pi^{\pm}, \pi^0, K^{\pm}, K^0 ,\bar K^0,\eta {and} \eta' $) are investigated, in the framework of the three flavor Nambu--Jona-Lasinio model,…
We investigate the isospin symmetry breaking effects within a recently derived Nambu-Jona-Lasinio related model by fitting the measured pseudoscalar meson masses and weak decay couplings $f_\pi$, $f_K$. Our model contains the next to…
We suggest and discuss in detail a multi-quark three flavor Lagrangian of the Nambu -- Jona-Lasinio type, which includes a set of effective interactions proportional to the current quark masses. It is shown that within the dynamical chiral…
We call attention to a class of current-quark mass dependent multi-quark interaction terms which break explicitly the chiral $SU(3)_L\times SU(3)_R$ and $U_A(1)$ symmetries. They complete the set of effective quark interactions that…
We study the thermal transition of QCD with two degenerate light flavours by lattice simulations using $\mathcal{O}(a)$-improved Wilson quarks. Particular emphasis lies on the pattern of chiral symmetry restoration, which we probe via the…
We explore patterns of effective restoration of the chiral U$_A$(1) symmetry using an extended three-flavor Nambu-Jona-Lasinio model that incorporates explicitly the axial anomaly through the 't Hooft interaction, and assuming that the…
The effect that the current quark mass $M_0$ may result in nonzero-ness of chiral condensates is systematically reexamined and analyzed in a two-flavor Nambu-Jona-Lasinio model simulating Quantum Chromodynamics (QCD) at temperature $T$ and…
The chiral phase transition and equation of state are studied within a new self-consistent mean-field approximation of the two-flavor Nambu$-$Jona-Lasinio model. In this newly developed model, modifications to the chemical potential $\mu$…
The mass sensitivity of the chiral phase transition of QCD with and without axial $U_A(1)$-symmetry breaking at vanishing and finite quark chemical potential is investigated. To focus on the low-energy sector of QCD, a quark-meson model…
The chiral phase transition is studied in an extended Nambu--Jona-Lasinio model with eight-quark interactions. Equations for scalar and vector quark densities, derived in the mean field approximation, are nonlinear and mutually coupled. The…
Violation of the $U(1)$ axial symmetry in QCD is stricter than the chiral $SU(2)$ breaking, simply because of the presence of the quantum axial anomaly. If the QCD gauge coupling is sent to zero, the strength of the $U(1)$ axial breaking…
We extend the modified Nambu-Jona-Lasinio (NJL) model -- incorporating exchange interactions via the Fierz transformation -- to finite temperatures in both two- and three-flavor scenarios, and investigate the properties of protoquark stars…
We have simulated lattice QCD with 2 flavours of massless staggered quarks. An irrelevant chiral 4-fermion interaction was added to the standard quark action to allow us to simulate at zero quark mass. Thermodynamics was studied on lattices…
In this study, we investigate the mass spectrum of $\pi$ and $\sigma$ mesons at finite chemical potential using the self-consistent NJL model and the Fierz-transformed interaction Lagrangian. The model introduces an arbitrary parameter…
Based on the analogy between the Nambu--Jona-Lasinio model of chiral symmetry breaking and the BCS theory of superconductivity, we investigate the effect of $\bar q q$ pair fluctuations on the chiral phase transition. We include uncondensed…
We have studied lattice QCD with an additional, irrelevant 4-fermion interaction having a U(1)xU(1) chiral symmetry, at finite temperatures. Adding this 4-fermion term allowed us to work at zero quark mass, which would have otherwise been…
We study the transition between spontaneous chiral symmetry breaking and conformal behavior in the SU(3) theory with multiple fermion flavors. Instead of the traditional approach of changing the number of flavors, we keep the number of…
We present updated studies on the chiral phase transition in $N_{f}=2+1$ QCD. Simulations have been carried out using Highly Improved Staggered Quarks (HISQ) on lattices with temporal extent $N_{\tau} = 6$ at vanishing baryon chemical…
We base our chiral symmetry approach on the quark-level linear sigma model Lagrangian. Then we review the Nambu--Goldstone theorem with vanishing pi, K, eta_8 masses. Next we dynamically generate the pi, K, eta_8 masses away from the chiral…
By considering the one loop background field method for a quark-antiquark interaction, mediated by one (non perturbative) gluon exchange, sixth order quark effective interactions are derived and investigated in the limit of zero momentum…