Pion properties at finite nuclear density based on inmedium chiral perturbation theory
Abstract
The inmedium pion properties, i.e. the temporal pion decay constant f_t, the pion mass m_π ^*, and the wave function renormalization in symmetric nuclear matter are calculated in an inmedium chiral perturbation theory up to the nexttoleading order of the density expansion O(k_F^4). The chiral Lagrangian for the pionnucleon interaction is determined in vacuum, and the lowenergy constants are fixed by experimental observables. We carefully define the inmedium state of the pion and find that the pion wave function renormalization plays an essential role in the inmedium pion properties. We show that the linear density correction is dominant and the nexttoleading corrections are not so large at the saturation density, while their contributions can be significant at higher densities. The main contribution of the nexttoleading order comes from the double scattering term. We also discuss whether the lowenergy theorems, the GellMannOakesRenner relation and the GlashowWeinberg relation, are satisfied in the nuclear medium beyond the linear density approximation. We also find that the wave function renormalization is enhanced as much as 50% at the saturation density including the nexttoleading contribution, and that the wave function renormalization can be measured in the inmedium π ^0to γ γ decay.
 Publication:

Progress of Theoretical and Experimental Physics
 Pub Date:
 March 2014
 DOI:
 10.1093/ptep/ptu023
 arXiv:
 arXiv:1312.0832
 Bibcode:
 2014PTEP.2014c3D03G
 Keywords:

 D33;
 Nuclear Theory;
 High Energy Physics  Phenomenology
 EPrint:
 26 pages, 5 figures