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Related papers: Selfconsistent Description of a Thermal Piongas

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We have used the Cornwall--Jackiw--Tomboulis method of composite operators and its formulation at finite temperature by Amelino-Camelia and Pi, in order to calculate the effective potential of the O(4) linear sigma model beyond the Hartree…

High Energy Physics - Phenomenology · Physics 2009-11-10 Nicholas Petropoulos

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

We study the effect of thermal width of $\pi$ on the spectral function of $\sigma$ applying a resummation technique called optimized perturbation theory at finite temperature ($T$) to ${\cal O}(4)$ linear sigma model. In order to take into…

High Energy Physics - Phenomenology · Physics 2016-09-06 Yoshimasa Hidaka , Osamu Morimatsu , Tetsuo Nishikawa , Munehisa Ohtani

The mass shift $\Delta m_N$ of a nucleon in the finite temperature pion gas is calculated in the case of an arbitrary nucleon momentum. A general formula is used which relates the in-medium mass shift $\Delta m(E)$ of a particle to the real…

High Energy Physics - Phenomenology · Physics 2009-10-30 V. L. Eletsky , B. L. Ioffe

It was recently pointed out that semi-annihilating dark matter (DM) may experience a novel temperature evolution dubbed as self-heating. Exothermic semi-annihilation converts the DM mass to the kinetic energy. This yields a unique DM…

High Energy Physics - Phenomenology · Physics 2018-07-18 Ayuki Kamada , Hee Jung Kim , Hyungjin Kim

We study chiral symmetry restoration by analyzing thermal properties of QCD's (pseudo-)Goldstone bosons, especially the pion. The meson properties are obtained from the spectral densities of mesonic imaginary-time correlation functions. To…

High Energy Physics - Phenomenology · Physics 2023-02-15 Yin-Zhen Xu , Si-Xue Qin , Hong-Shi Zong

We theoretically examine the finite-temperature spectral function of Fermi polarons in three dimensions, by using a self-consistent many-body $T$-matrix theory in real frequency. In comparison with the previous results from a…

Quantum Gases · Physics 2024-06-27 Hui Hu , Xia-Ji Liu

The two-flavor quark-meson model is used as a low-energy effective model for QCD to study inhomogeneous chiral condensates at finite %temperature $T$ baryon chemical potential $\mu_B$. The parameters of the model are determined by matching…

High Energy Physics - Phenomenology · Physics 2017-10-09 Prabal Adhikari , Jens O. Andersen , Patrick Kneschke

The pion nucleon vertex function at finite temperature is studied in the framework of: (a) the thermal (linear) sigma model to leading (one-loop) order, and (b) a thermal QCD-Finite Energy Sum Rule. Results from both methods indicate that…

High Energy Physics - Phenomenology · Physics 2009-10-31 C. A. Dominguez , C. van Gend , M. Loewe

A semiphenomenological approach to the nucleon self-energy in nuclear matter at finite temperatures is followed. It combines elements of Thermo Field Dynamics for the treatment of finite temperature with a model for the self-energy, which…

Nuclear Theory · Physics 2009-10-30 L. Alvarez-Ruso , P. Fernandez de Cordoba , E. Oset

We present the pion-pion elastic scattering amplitude at finite temperature to one-loop in Chiral Perturbation Theory. The thermal scattering amplitude properly defined allows to generalize the perturbative unitarity relation to the $T\neq…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Gomez Nicola , F. J. LLanes-Estrada , J. R. Pelaez

In this work, the self energies of $\pi^0$ and $\pi^{\pm}$ up to one loop order have been calculated in the limit of weak external magnetic field. The effective masses are explicitly dependent on the magnetic field which are modified…

Nuclear Theory · Physics 2018-07-02 S. P. Adhya , M. Mandal , S. Biswas , P. K. Roy

I study the properties of the scalar sigma-meson [also referred to as f_0(600)] at nonzero temperature in the O(N)-model in the framework of the Cornwall-Jackiw-Tomboulis formalism. In the standard Hartree (or large-N) approximation one…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dirk Roder

We describe how the thermal counterpart of a vacuum two-point function may be obtained in the real time formalism in a simple way by using directly the $2\times 2$ matrices that different elements acquire in this formalism. Using this…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Mallik , Sourav Sarkar

We study the behavior of the pion dispersion relation in a pion medium at finite density and temperature, introducing a chemical potential to describe the finite pion number density. Such description is particularly important during the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Alejandro Ayala

The thermal corrections to the propagator of a loosely bound charm-meson molecule in a pion gas are calculated to next-to-leading order in the heavy-meson expansion using a zero-range effective field theory. Ultraviolet divergences in the…

High Energy Physics - Phenomenology · Physics 2023-09-13 Eric Braaten , Li-Ping He , Kevin Ingles , Jun Jiang

We calculate the specific heat of composite fermion system in the half-filled Landau level. Two different methods are used to examine validity of the quasiparticle approximation when the two-body interaction is given by $V(q) = V_0 /…

Condensed Matter · Physics 2009-10-28 Yong Baek Kim , Patrick A. Lee

Using a non-perturbative method based on the selfconsistent Quasi-particle Random-Phase Approximation (QRPA) we describe the properties of the pion in the linear $\sigma$-model. It is found that the pion is massless in the chiral limit,…

Nuclear Theory · Physics 2009-10-30 Z. Aouissat , G. Chanfray , P. Schuck , J. Wambach

We review the relationship between the pion decay constant $f_\pi$, the chiral symmetry restoration temperature $T_c$ and the phenomenology of low energy chiral symmetry breaking in view of the recent confirmation of the existence of a…

High Energy Physics - Phenomenology · Physics 2009-10-28 N. Bilić , J. Cleymans , M. D. Scadron

We study properties of a gluon plasma above the critical temperature $T_c$ in a generalized quasi-particle approach with a Lorentz spectral function. The model parameters are determined by a fit of the entropy $s$ to lattice QCD data. The…

High Energy Physics - Phenomenology · Physics 2009-11-11 A. Peshier , W. Cassing