相关论文: A Non-Perturbative Treatment of the Pion in the Li…
We formulate lattice theories in which chiral symmetry is realized nonlinearly on the fermion fields. In this framework the fermion mass term does not break chiral symmetry. This property allows us to use the Wilson term to remove the…
We study the O(N) symmetric linear sigma model at finite temperature as the low-energy effective models of quantum chromodynamics(QCD) using the Cornwall-Jackiw-Tomboulis(CJT) effective action for composite operators. It has so far been…
We review our recent study of the pion mass dependence of the rho and sigma resonances, generated from one-loop SU(2) Chiral Perturbation Theory (ChPT) with the Inverse Amplitude Method (IAM). In order to properly account for the Adler zero…
This review of the quark-level linear \sigma model is based upon the dynamical realization of the pseudoscalar and scalar mesons as a linear representation of SU(2) x SU(2) chiral symmetry, with the symmetry weakly broken by current quark…
We make a thermal analysis of the light scalar susceptibilities using SU(3)-Chiral Perturbation Theory to one loop taking into account the QCD source of isospin breaking (IB), i.e corrections coming from $m_u\neq m_d$. The value of the…
The quark-level linear sigma model is revisited, in particular concerning the identification of the f_0(400-1200) (or \sigma(600)) scalar meson as the chiral partner of the pion. We demonstrate the predictive power of the linear sigma model…
By using the symmetry improved CJT effective formalism, we study a pion string of the $O(4)$ linear sigma model at finite temperature in chiral limit. In terms of the Kibble-Zurek mechanism we reconsider the production and evolution of the…
We investigate the 2-flavor QCD with non-degenerate quark masses at low-energy, using the chiral perturbation theory including the $\eta$ meson and anomaly effects. For the fixed $m_d\not=0$, the neutral pion becomes massless at two values…
Working within the linear sigma model at finite temperature, we construct effective one-loop vertices and propagators satisfying the chiral Ward identities, for small pion momentum and mass compared to the sigma mass. We obtain an expansion…
After a brief introduction on QCD and effective models in the first chapter, I analyze the dependence of the QCD transition temperature on the quark (or pion) mass in the second chapter. I found that a linear sigma model, which links the…
We discuss chiral symmetry breaking critical points from the perspective of PCAC, correlation length scaling and the chiral equation of state. A scaling theory for the ratio $R_\pi$ of the pion to sigma masses is presented. The Goldstone…
The four-fermi model with continuous chiral symmetry is studied in three dimensions at non-zero chemical potential $\mu$ using both the $1/N_f$ expansion and computer simulations. For strong coupling this model spontaneously breaks its U(1)…
The chiral nonlinear ($\sigma,\pi,\omega$) mean-field model is an extension of the conserving nonlinear (nonchiral) $\sigma$-$\omega$ hadronic mean-field model which is thermodynamically consistent, relativistic and Lorentz-covariant…
As increased statistics and new ensembles with light pions have become available within the CLS effort, we complete previous work by inspecting the chiral behaviour of the pion decay constant. We discuss the validity of Chiral Perturbation…
We investigate the properties of neutral and charged pions in a constant background magnetic field mainly at zero temperature within the Nambu--Jona-Lasinio model. In the previous calculations, the Ritus method, involving Schwinger phases…
For an exact chiral symmetry which is spontaneously broken at zero temperature, we show that at nonzero temperature, generally pions travel at {\it less} than the speed of light. This effect first appears at next to leading order in an…
We investigate the charged-neutral pion self-energy difference at finite temperature. Within Chiral Perturbation Theory we extend previous analysis in the chiral and soft pion limits. Our analysis with physical masses leads to additional…
The pion structure function is investigated in a simple model, where pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi-> gamma* pi scattering amplitude is…
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…
The s-wave isoscalar amplitude for pion-pion scattering in a nuclear medium is evaluated using a nonperturbative unitary coupled channels method and the standard chiral Lagrangians. The method has proved successful to describe the pion-pion…