Second sheet $\sigma$ pole and the threshold enhancement of the spectral function in the scalar-isoscalar meson-sector

Abstract

The scalar-isoscalar propagator of the effective linear $\sigma$ model of meson dynamics is investigated with the help of an expansion in the number of the Goldstone bosons. A generic scenario is suggested for the temperature and density driven evolution of its pole in the second Riemann sheet. An extended temperature range, correlated with characteristic pole locations, is found where the phenomenon of threshold enhancement takes place in the corresponding spectral function.

RevTeX4 12 pages, 7 figures, final version with modified abstract and introduction, to be published in Phys. Rev. D

References in corpus (4)

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• Thermal rho and sigma mesons from chiral symmetry and unitarity
• Finite temperature spectral functions of the linear O(N)-model at large N applied to the $\pi -\sigma$ system
• Simultaneous Softening of sigma and rho Mesons associated with Chiral Restoration

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