Related papers: OZI violating eight-quark interactions as a thermo…
We discuss the role of the U(1) axial symmetry for the scalar and pseudoscalar meson mass spectrum of QCD at finite temperature, above the chiral transition at T_c, using a chiral effective Lagrangian model, which, in addition to the usual…
The effective restoration of the chiral U(A)(1) symmetry in strong interactions is studied using the linear chiral SU(3)xSU(3) model at finite temperatures. We find that the disappearance of the chiral anomaly causes a considerable change…
In most of the Nambu:Jona-Lasinio(NJL)-type models, realizing the hidden chiral symmetry, the existence of a scalar particle \sigma is needed with a mass m_\sigma=2 m_q, as a partner of the Nambu-Goldstone boson \pi. However, the results of…
The composite operator formalism is applied to QCD at finite temperature to calculate the masses of scalar and pseudoscalar mesons. In particular the ratio of the sigma mass to the pion mass is an interesting measure of the degree of chiral…
It is shown that a chiral quark model of the Nambu--Jona-Lasinio type can be used to describe "soft"-momenta parts of the amplitudes with large momentum transfer. As a sample, the processes \gamma^* --> \gamma (\pi,\eta,\eta') where one of…
When the quark masses are lighter than those in QCD, the standard lore is that a chiral transition of first order must emerge for three, light flavors. Recently, however, numerical simulations on the lattice suggest that the chiral…
We derive a non-local Nambu-Jona-Lasinio model from QCD with a form factor exactly obtained in the infrared limit. With this model, having all the parameters properly fixed through those of QCD, we consider the case of finite temperature…
We evaluate the pseudoscalar-meson octet-baryon coupling constants and the corresponding axial charges in eight channels ($\pi N\N$, $\pi\Sigma\Sigma$, $\pi\Lambda\Sigma$, $K\Lambda N$, $K \Sigma N $, $\pi\Xi\Xi$, $K\Lambda\Xi$ and…
We present an update on the study of the QCD phase transition with 3 flavors of M\"obius domain wall fermions at zero baryon density. We performed simulations on lattices of size $36^3\times12\times16$ and $24^3\times12\times32$ with a…
We present the status of the MILC collaboration's analysis of the light pseudoscalar meson sector with SU(3) chiral fits. The analysis includes data from new ensembles with smaller lattice spacing, smaller light quark masses and lighter…
The phase diagram for quark matter is investigated within a simple Nambu-Jona-Lasinio model without vector correlations. It is found that the phase structure in the temperature-density plane depends sensitively on the parametrization of the…
Report is made of a systematic scaling study of the finite-temperature chiral phase transition of two-flavor QCD with the Kogut-Susskind quark action based on simulations on $L^3\times4$ ($L$=8, 12 and 16) lattices at the quark mass of…
In this paper, we extend the results obtained in a previous work and investigate the most interesting decay processes involving axions, photons and the lightest pseudoscalar mesons in the more general case in which the quarks (and,…
We investigate the restoration patterns of chiral and $U(1)$ axial symmetries at finite temperature using a soft-wall holographic QCD model. The study employs two distinct parameter sets (Case I and Case II), both calibrated to reproduce a…
We consider a two flavor Polyakov--Nambu--Jona-Lasinio (PNJL) model where the Lagrangian includes an interaction term that explicitly breaks the U$_A(1)$ anomaly. At finite temperature, the restoration of chiral and axial symmetries,…
We investigate the isospin-violating mixing of the light scalar mesons a0(980) and f0(980) within the unitarized chiral approach. Isospin-violating effects are considered to leading order in the quark mass difference and electromagnetism.…
We combine the recently introduced Non-Abelian Quasi-Particle Model (NAQPM) for gluons with an ideal Fermi gas of three quark species with the aim to describe the equation of state (energy density vs. temperature) of $2+1$ - flavour…
We investigate the most interesting decay processes involving axions, photons and the lightest pseudoscalar mesons, making use of a chiral effective Lagrangian model with $L=3$ light quark flavors, which also includes the flavor-singlet…
The available data on $\omega$ and $\phi$ production from $\pi N$ and $pp$ collisions are reanalyzed with respect to an OZI rule violation on the basis of transition matrix elements. The data are found to be compatible with a constant ratio…
The SU(3) breaking effects due to light quark masses on heavy meson masses, decay constants ($F_{D}, F_{D_{s}}$) and the form factor for semileptonic $\overline{B}\rightarrow D^{(\ast)} l\bar{\nu}_{l}$ transitions are formulated in chiral…