Related papers: Neutral Pion Decay Width in a Hot and Dense Medium
We consider the phenomenological description of the two pion invariant mass spectrum in the $V' \to V \pi\pi$ decays. We study the parametrization of the amplitude involving both $S$ and $D$ wave contributions. From a fit to the two pion…
The rare $K^\pm\to\pi^\pm\pi^0 e^+e^-$ decay, currently under analysis by the NA48/2 Collaboration, is considered. We have performed two theoretical approaches to calculate the differential decay width -- in the kaon rest frame, where we…
We study the propagation properties of the rho vector in a dense and hot pion medium. We introduce a finite value of the chemical potential associated to a conserved pion number and argue that such description is valid during the hadronic…
A phenomenological pion-nucleon interaction is used to obtain pionic mass modification in presence of constant homogeneous magnetic field background at finite temperature and chemical potential in the real time formalism of thermal field…
Dynamical Symmetry breaking and meson masses are studied in the Nambu-Jona-Lasinio (NJL) model at finite temperature and chemical potential using the dimensional regularization. Since the model is not renormalizable in four space-time…
We consider the $O(N+1)/O(N)$ Non-Linear Sigma Model for large $N$ as an effective theory for low-energy QCD at finite temperature $T$, in the chiral limit. At $T=0$ this formulation provides a good description of scattering data in the…
A thermodynamically consistent excluded volume model is proposed to account for the particle multiplicities obtained from lowest SIS energies to the highest RHIC energies. The chemical freeze-out volumes lying in a slice of one unit of…
We present a novel framework for analyzing unstable composite particles using Green's functions and dispersion relations. As an illustrative example, we explore the $\rho$ vector meson decay process $\rho\to\pi\pi$ within the Nambu -- Jona…
The modification of the rho-meson self-energy due to the coupling to in-medium pions is calculated consistently at finite baryon density and temperature, keeping the full 3-momentum dependence in a gauge invariant way. As a function of…
We have searched for the pion decay pi^+ --> mu^+ X, where X is a neutral particle of mass 33.905 MeV. This process was suggested by the KARMEN Collaboration to explain an anomaly in their observed time distribution of neutrino induced…
The effective mass and decay width of the $\phi$ meson in the isospin asymmetric hot and dense resonance matter are studied using the effective Lagrangian framework considering the $\phi K \bar K $ interactions at one-loop level. In…
We evaluate widths and shifts of pionic atoms using a theoretical microscopical potential in which the pion decay constant $f_\pi$ is changed by an in--medium density dependent one ($f_\pi(\rho)$), predicted by different partial Chiral…
Within the framework of the thermal soft-wall model of AdS/QCD, we investigate phenomenological properties of pions at finite temperature. This includes the electromagnetic (EM) form factor $F_{\pi}(Q^{2}, T)$, the thermal mass…
We study pion condensation and the phase structure in a two-flavor Nambu-Jona-Lasinio model in the presence of baryon chemical potential $\mu$ and isospin chemical potential $\mu_I$at zero and finite temperature. There is a competition…
The decay width of the $\omega$ meson at finite temperature is calculated using the Gell-Mann Sharp Wagner model of $\rho$ pole dominance. Effective masses of the $\rho$ and $\omega$ are determined within the framework of real-time…
A general algorithm for handling the energy dependence of meson-nucleon amplitudes in the nuclear medium has been recently applied to antikaons and to eta mesons. Here we test this approach on $\pi N$ amplitudes in pionic atoms where direct…
The phenomenological implications to the decay of the neutral pion from the introduction of new dark particles are discussed. We calculate the contribution to the $\pi^0$ decay width and then we extend the theory by adding dark sector…
The structure and electroweak properties of the pion in symmetric nuclear matter are presented in the framework of the Nambu--Jona-Lasinio model. The pion is described as a bound state of a dressed quark-antiquark pair governed by the…
In the framework of the Nambu--Jona-Lasino (NJL) model, we study the effect of an intense external uniform magnetic field on neutral and charged pion masses and decay form factors. In particular, the treatment of charged pions is carried…
We evaluate the shear viscosity of a pion gas in the relativistic kinetic theory approach. The in-medium propagator of the $\rho$ meson at finite temperature is used to evaluate the $\pi-\pi$ scattering amplitude in the medium. The real and…