arXiv subjects
Publications and source records attributed to Hiroyuki Yabu.
The results for meson condensation in the literature vary markedly depending on whether one uses chiral perturbation theory or the current-algebra-plus-PCAC approach. To elucidate the origin of this discrepancy, we re-examine the role of the sigma-term in meson condensation. We find that the resolution of the existing discrepancy requires a knowledge of terms in the Lagrangian that are higher order in density than hitherto considered.
The effective kaon mass in dense baryonic matter is calculated based on PCAC, current algebra and the Weinberg smoothness hypothesis. The off-shell behavior of the K-N scattering amplitudes is treated consistently with PCAC, and the effects of the subthreshold K-N resonances are also included. The effective kaon mass is found to depend crucially on the K-N sigma term. Since the current estimates of K-N Sigma term are very uncertain, we discuss various scenarios treating K-N Sigma term as an input parameter; for certain values of K-N Sigma a collective mode of a hyperon-particle-nucleon-hole state appears at high densities, possibly leading to kaon condensation.