Simultaneous Softening of sigma and rho Mesons associated with Chiral Restoration

Abstract

Complex poles of the unitarized pi-pi scattering amplitude in nuclear matter are studied. Partial restoration of chiral symmetry is modeled by the decrease of in-medium pion decay constant f*_{pi}. For large chiral restoration (f*_{pi}/f_{pi} << 1), 2nd sheet poles in the scalar (sigma) and the vector (rho) mesons are both dictated by the Lambert W function and show universal softening as f*_{pi} decreases. In-medium pi-pi cross section receives substantial contribution from the soft mode and exhibits a large enhancement in low-energy region. Fate of this universality for small chiral restoration (f*_{pi}/f_{pi} ~ 1) is also discussed.

5 pages, 4-eps figures, version accepted by Phys. Rev. C (R) with minor modifications

References in corpus (6)

• ππscattering
• In-medium chiral perturbation theory beyond the mean-field approximation
• Evidence for partial chiral symmetry restoration from pionic atoms
• Finite temperature spectral functions of the linear O(N)-model at large N applied to the $\pi -\sigma$ system
• In-medium pion weak decay constants
• $\pi \to \pi \pi$ results in nuclei

Cited by in corpus (16)

• Hadron properties in the nuclear medium
• On the size of the sigma meson and its nature
• Thermal rho and sigma mesons from chiral symmetry and unitarity
• Properties of hadron screening masses at small baryonic density
• Particle production in Ultra-relativistic Heavy-Ion Collisions : A Statistical-Thermal Model Review
• Nature of the sigma meson as revealed by its softening process
• Pion scattering poles and chiral symmetry restoration
• Second sheet $\sigma$ pole and the threshold enhancement of the spectral function in the scalar-isoscalar meson-sector
• Thermal production of the $\rho$ meson in the ${\pi }^{+}{\pi }^{-}$ channel
• Collective excitations in a superfluid of color-flavor locked quark matter
• Update on pion weak decay constants in nuclear matter
• Universal threshold enhancement
• Degeneracy patterns of chiral companions at finite temperature
• Chiral Symmetry in Nuclei -- Theoretical Expectations and Hard Facts
• Holographic vector mesons in a hot and dense medium
• Hadrons in Medium -- Theory meets Experiment