Dynamics of \bar{K} and multi-\bar{K} nuclei

TL;DR

This paper presents self-consistent relativistic mean-field calculations of single and multi-antikaon nuclear states in various nuclei, analyzing decay modes, widths, and density saturation to understand kaon interactions and the absence of kaon condensation.

Contribution

It introduces a comprehensive RMF approach including p-wave effects and decay channels, providing new insights into Kbar binding energies, decay widths, and density saturation in multi-kaon systems.

Findings

K^- decay widths of 50-100 MeV for binding energies over 100 MeV

Binding energy per Kbar saturates with increasing Kbar number

No indication of kaon-condensation precursor in dense nuclear matter

Abstract

We report on self-consistent calculations of single-K^- nuclear states and multi-Kbar nuclear states in 12C, 16O, 40Ca and 208Pb within the relativistic mean-field (RMF) approach. Gradient terms motivated by the p-wave resonance Sigma(1385) are found to play a secondary role for single-K^- nuclear systems where the mean-field concept is acceptable. Significant contributions from the Kbar N -> pi Lambda conversion mode, and from the nonmesonic Kbar NN -> YN conversion modes which are assumed to follow a rho^2 density dependence, are evaluated for the deep binding-energy range of over 100 MeV where the decay channel Kbar N -> pi Sigma is closed. Altogether we obtain K^- total decay widths of 50-100 MeV for binding energies exceeding 100 MeV in single-K^- nuclei. Multi-Kbar nuclear calculations indicate that the binding energy per Kbar meson saturates upon increasing the number of Kbar mesons embedded in the nuclear medium. The nuclear and Kbar densities increase only moderately and are close to saturation, with no indication of any kaon-condensation precursor.