Related papers: `$f_0 (600)$' and chiral dynamics
We extend an effective Lagrangian embodying broken scale and chiral symmetry to include explicit chiral symmetry breaking and an additional chiral invariant term which allows for an axial coupling constant greater than unity. We also…
We study the mass of a nucleon in a nucleus using a model recently introduced for a nucleon current with a pion cloud component. The method of QCD sum rules is used to determine the mass shifts for nucleons to first order in nuclear density…
In this review I discuss the role of chiral extrapolations for the determination of several phenomenologically relevant quantities, including light quark masses, meson decay constants and the axial charge of the nucleon. In particular, I…
Properties of cold nuclear matter are studied within a generalized Nambu-Jona-Lasinio model formulated on the level of constituent nucleons. The model parameters are chosen to reproduce simultaneously the observed nucleon and pion masses in…
Previous extrapolations of lattice QCD results for the nucleon mass to the physically relevant region of small quark masses, using chiral effective field theory, are extended and expanded in several directions. A detailed error analysis is…
We report results of masses and decay constants of light and charmed pseudo-scalar mesons using lattice QCD with M\"obius domain-wall fermions. Using this formulation we are able to compute pseudo-scalar decay constants through the…
The following topics are considered. 1) Confinement, chiral dynamics, and light scalar mesons. 2) Chiral shielding of the \sigma(600) 3)The \phi meson radiative decays about nature of light scalar resonances. 4) The J/\psi decays about…
We evaluate the width of the $\omega$ meson in nuclear matter. We consider the free decay mode of the $\omega$ into three pions, which is dominated by $\rho \pi$ decay, and replace the $\rho$ and $\pi$ propagators by their medium modified…
The effective mass of phi meson at non-zero temperature is re-examined with an effective chiral Lagrangian. We find that the phi mass decreases with temperature but the effect is small compared to the result obtained from calculations using…
We review recent developments in exploring possible precursory phenomena of partial restoration of chiral symmetry in nuclear medium by examining the spectral function in the scalar channel. We emphasize that the wave function…
A scalar field, $\eta({\bf r})$, is coupled to the skyrmion. Its classical value in the vacuum ("condensate") reduces to the pion decay constant, $f_{\pi}$, being thus proportional to the chiral condensate $<\bar{q} q>$. A quadratic…
We construct an effective chiral theory for the nucleon, based on the low-energy effective QCD partition function from the QCD instanton vacuum. We fully consider the momentum-dependent dynamical quark mass whose value at the zero…
We present a two-flavour linear sigma model with global chiral symmetry and vector and axial-vector mesons. We calculate pion-pion scattering lengths and the decay widths of scalar, vector, and axial-vector mesons. It is demonstrated that…
We calculate the decay rate of light scalar mesons, using a diquark chiral effective theory, recently proposed to describe exotic hadrons. In the effective theory the light scalar mesons are postulated to be bound states of diquark and…
We derive bounds on the Higgs boson coupling $g^{\prime}$ to a stable light scalar which is regarded as a collisional dark matter candidate. We study the behaviour of this scalar, that we refer to as phion ($\phi$), in the early Universe…
Using heavy-baryon chiral perturbation theory, we have calculated all the diagrams up to two-loop order which contribute to the S-wave pion self-energy in symmetric nuclear matter. Some subtleties related to the definition of pion fields…
We investigate the modification of the pion self-energy at finite temperature due to its interaction with a low-density, isospin-symmetric nuclear medium embedded in a constant magnetic background. To one loop, for fixed temperature and…
An important role of the scalar isoscalar sigma-meson in the low-energy physics is discussed. The behavior of the sigma-meson in the hot and dense medium is studied. It is shown that in the vicinity of critical values of temperature(T) and…
We investigate the bulk properties of symmetric nuclear matter within the framework of an in-medium modified chiral solitonic model with $\pi$, $\rho$ and $\omega$ mesons. We consider the modification of meson degrees of freedom in nuclear…
We calculate the light pseudoscalar decay constants, f_pi and f_K, and their ratio using domain wall valence quarks and 2+1 flavors of dynamical staggered quarks. Use of the MILC gauge configurations allows us to simulate at several sea…