Intriguing aspects of meson condensation

TL;DR

This paper investigates meson condensation using chiral perturbation theory, confirming phase transitions but revealing discrepancies in mesonic mixings and masses compared to prior studies, and exploring decay behaviors.

Contribution

It provides new calculations of mesonic properties in condensed phases and highlights disagreements with previous results, using both analytical and direct computational methods.

Findings

Reproduces known phase transition results for pion and kaon condensation.

Identifies discrepancies in mesonic mixings and masses with earlier studies.

Discovers nonmonotonic behavior in leptonic decay channels as a function of isospin chemical potential.

Abstract

We analyze various aspects of pion and kaon condensation in the framework of chiral perturbation theory. Considering a system at vanishing temperature and varying the isospin chemical potential and the strange quark chemical potential we reproduce known results about the phase transition to the pion condensation phase and to the kaon condensation phase. However, we obtain mesonic mixings and masses in the condensed phases that are in disagreement with the results reported in previous works. Our findings are obtained both by a theory group analysis and by direct calculation by means of the same low-energy effective Lagrangian used in previous works. We also study the leptonic decay channels in the normal phase and in the pion condensed phase, finding that some of these channels have a peculiar nonmonotonic behavior as a function of the isospin chemical potential. Regarding the semileptonic decays, we find that that they should be efficient feeding processes for the stable charged pion state.