Related papers: Vacuum Properties of Mesons in a Linear Sigma Mode…
Two pion effective mass and helicity angle distributions in the charged B-meson decays into three charged pions are studied. The weak decay amplitudes are calculated in the framework of the QCD factorization approximation. The strong…
The origin of the lightest scalar mesons is studied in the framework of instanton liquid model (ILM) of the QCD vacuum. The impact of vacuum excitations on the sigma-meson features is analyzed in detail. In particular, it is noticed that…
We generalize the linear sigma model in order to develop a chiral-invariant model of nuclear structure. The model is natural, and contains not only the usual sigma meson which is the chiral partner of the pion but also a new chiral-singlet…
We construct a relativistic $^3P_0$ wavefunction for scalar mesons within the framework of light-front quark model(LFQM). This scalar wavefunction is used to perform relativistic calculations of absolute widths for the radiative decay…
We calculate the masses of the vector and axial-vector mesons as well as the nucleon and the delta resonance in the chiral symmetry restored vacuum. This is accomplished by separating the quark operators appearing in the QCD sum rules for…
We investigate the finite-temperature spectral functions of heavy quarkonia by using the soft-wall AdS/QCD model. We discuss the scalar, the pseudo-scalar, the vector, and the axial-vector mesons and compare their qualitative features of…
We present a detailed study of a linear sigma model containing one chiral nonet transforming under U(1)$_A$ as a quark-antiquark composite and another chiral nonet transforming as a diquark-anti diquark composite (or, equivalently from a…
It is presented a critical consideration of all unusual properties of the scalar $a_0(980)$ and $f_0(980)$-mesons in the four-quark, two-quark and molecular models. The arguments are adduced that the four-quark model is more preferable. It…
After a brief overview of the realization of chiral symmetry in hot and/or dense medium, the implications of the existence of a light scalar-isoscalar meson (which we call $\sigma$ throughout this report) are discussed in the vacuum and in…
We calculate mesonic two-point functions in the epsilon-regime of two-flavor QCD on the lattice with exact chiral symmetry. We use gauge configurations of size 16^3 32 at the lattice spacing a \sim 0.11 fm generated with dynamical overlap…
We evaluate the $a_1(1260) \to \pi \sigma (f_0(500))$ decay width from the perspective that the $a_1(1260)$ resonance is dynamically generated from the pseudoscalar-vector interaction and the $\sigma$ arises from the…
It is presented a critical consideration of all unusual properties of the scalar $a_0(980)$ and $f_0(980)$-mesons in the four-quark, two-quark and molecular models. The arguments are adduced that the four-quark model is more preferable. It…
Underlying mixing of scalar mesons is studied in $\eta'\rightarrow \eta\pi\pi$ decay within a generalized linear sigma model of low-energy QCD which contains two nonets of scalar mesons and two nonets of pseudoscalar mesons (a…
Two-body bound states such as mesons are described by solutions of the Bethe-Salpeter equation. We discuss recent results for the pseudoscalar and vector meson masses and leptonic decay constants, ranging from pions up to c\bar{c} bound…
We review chiral symmetry breaking at the BCS level, in the framework of chiral invariant quark models and in the Schwinger-Dyson formalism. We revisit the pi mass problem beyond the BCS level. We show a theorem on the masses, on the widths…
In this work we study the implications of light-quark pionic matter at finite temperatures on the properties of open and hidden charm mesons. The meson-meson interactions are described by means of a chiral unitary approach accounting for…
We present a model for describing nuclear matter at finite density based on quarks interacting with chiral fields, \sigma and \pi and with vector mesons introduced as massive gauge fields. The chiral Lagrangian includes a logarithmic…
We first review the recent accumulating evidences of the existence of a scalar-isoscalar meson with the mass 500 to 800 MeV which may be identified with the sigma meson as the quantum fluctuation of the amplitude of the chiral order…
The question as to what the relevant effective degrees of freedom at the chiral phase transition are remains largely unanswered and must be addressed in confronting both terrestrial and space laboratory observations purporting to probe…
The meson meson interaction in the scalar isoscalar channel at finite baryonic density is studied in the framework of a chiral unitary approach which generates the f0 and sigma resonances and reproduces well the meson meson phase shifts in…