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We present a model independent study of the chiral condensate evolution in a hadronic gas, in terms of temperature and baryon chemical potential. The meson-meson interactions are described within Chiral Perturbation Theory and the…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Garcia Martin , J. R. Pelaez

The leading twist parametrization of dipion mass distribution in hard exclusive reactions is proposed. Its parameters are related to quark distributions (usual and skewed) in the pion and to distributions amplitudes of mesons ($\pi$,…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. V. Polyakov

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…

Nuclear Theory · Physics 2009-06-25 M. Urban , M. Buballa , R. Rapp , J. Wambach

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…

High Energy Physics - Phenomenology · Physics 2025-05-13 Manpreet Kaur , Arvind Kumar

The Vector Pion form factor below 1 GeV is analyzed using experimental data on its modulus, the P-wave pion pion phase shifts and dispersion relation. It is found that causality is satisfied. Using dispersion relation, terms proportional to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Tran N. Truong

We examine the behavior of charged pions in neutron-rich matter using heavy-baryon chiral perturbation theory. This study is motivated by the prospect that pions, or pion-like excitations, may be relevant in neutron-rich matter encountered…

Nuclear Theory · Physics 2023-10-12 Bryce Fore , Norbert Kaiser , Sanjay Reddy , Neill C. Warrington

We reinvestigate the interaction of massless fermions with massless bosons at finite temperature. Specifically, we calculate the self-energy of massless fermions due the interaction with massless bosons at high temperature, which is the…

High Energy Physics - Phenomenology · Physics 2015-06-25 H. C. de Godoy Caldas

We investigate the dilepton production rates from annihilation processes of charged pion pairs with modified pion dispersion relations in the inhomogeneous chiral condensed phase. We assume a dual chiral density wave as an inhomogeneous…

High Energy Physics - Phenomenology · Physics 2024-12-03 Kentaro Hayashi , Yasuhiko Tsue

Within the relativistic mean-field framework with hadron masses and coupling constants dependent on the mean scalar field we study properties of nuclear matter at finite temperatures, baryon densities and isospin asymmetries relevant for…

Nuclear Theory · Physics 2022-10-12 K. A. Maslov , D. N. Voskresensky

The kinetic Freeze Out process of a pion gas through a finite layer with time-like normal is considered. The pion gas is described by a Boltzmann gas with elastic collisions among the pions. Within this model, the impact of the in-medium…

High Energy Physics - Phenomenology · Physics 2009-03-12 Sven Zschocke , Laszlo P. Csernai

We report a calculation of the shear viscosity in a relativistic multicomponent meson gas as a function of temperature and chemical potentials. We approximately solve the Uehling-Uhlenbeck transport equation of kinetic theory, appropriate…

High Energy Physics - Phenomenology · Physics 2009-11-10 Antonio Dobado , Felipe J. Llanes-Estrada

We consider the problem of soft scattering for the analogue of pion states in gauge-fermion theories which approach a conformal fixed point in the infrared limit. Introducing a fermion mass into such a theory will explicitly break both…

High Energy Physics - Phenomenology · Physics 2023-08-09 Daniel C. Hackett , Ethan T. Neil

Recent attempts to determine the pion polarizability by dispersion relations yield values that disagree with the predictions of chiral perturbation theory. These dispersion relations are based on specific forms for the absorptive part of…

High Energy Physics - Phenomenology · Physics 2014-11-20 B. Pasquini , D. Drechsel , S. Scherer

We investigate the properties of the pion quasiparticle in the low-temperature phase of two-flavor QCD on the lattice with support from chiral effective theory. We find that the pion quasiparticle mass is significantly reduced compared to…

High Energy Physics - Lattice · Physics 2015-11-18 Bastian B. Brandt , Anthony Francis , Harvey B. Meyer , Daniel Robaina

We analyze the dilepton emission rates from the hot pion gas confined to a finite space-time volume. Two models of pion(+) pion(-) annihilation to dileptons are under consideration. The first model mimics an extreme influence of the dense…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Anchishkin , V. Khryapa , V. Ruuskanen

The transverse charge density in the pion can be represented as a dispersion integral of the imaginary part of the pion form factor in the timelike region. This formulation incorporates information from e+e- annihilation experiments and…

High Energy Physics - Phenomenology · Physics 2011-02-25 G. A. Miller , M. Strikman , C. Weiss

In close analogy to fermionic many-body theory the truncation of the bosonic BBGKY density matrix hierarchy on the two-body level leads to a coupled set of nonlinear equations of motion for the one-body density matrix and the two-body…

Nuclear Theory · Physics 2009-10-28 J. M. Haeuser , W. Cassing , A. Peter

The modifications of hadronic masses and decay widths at finite temperature and baryon density are investigated using a phenomenological model of hadronic interactions in the Relativistic Hartree Approximation. We consider an exhaustive set…

Nuclear Theory · Physics 2016-01-07 Pradip Roy , Sourav Sarkar , Jan-e Alam , Bikash Sinha

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…

Nuclear Theory · Physics 2009-11-07 C. Garcia-Recio , J. Nieves , E. Oset

The spectral function of pions interacting with a gas of nucleons and Delta-33-resonances is investigated using the formalism of Thermo Field Dynamics. After a discussion of the zero Delta-width approximation at finite temperature, we take…

Nuclear Theory · Physics 2009-10-22 P. A. Henning , H. Umezawa