Are there any narrow K − -nuclear states?

Abstract

We performed self-consistent calculations of K − -nuclear quasi-bound states using a single-nucleon K − optical potential derived from chiral meson-baryon coupled-channel interaction models, supplemented by a phenomenological K − multinucleon potential introduced recently to achieve good fits to kaonic atom data [1]. Our calculations show that the effect of K − multinucleon interactions on K − widths in nuclei is decisive. The resulting widths are considerably larger than corresponding binding energies. Moreover, when the density dependence of the K − -multinucleon interactions derived in the fits of kaonic atoms is extended to the nuclear interior, the only two models acceptable after imposing as additional constraint the single-nucleon fraction of K − absorption at rest do not yield any kaonic nuclear bound state in majority of considered nuclei.

Single- and two-nucleon antikaon absorption in nuclear matter with chiral meson-baryon interactions

“…However, the K − multi-nucleon absorption may have serious implications for existence of the K − -nuclear states, particularly in heavier systems. The K − single-nucleon optical potential based on the P and KM models, supplemented by a phenomenological multi-nucleon potential fitted to reproduce kaonic atom data, was applied in the calculations of K − quasibound states in nuclei with A ≥ 6 [26]. The multi-nucleon absorption potential was found to have a significant contribution to the total K − -nuclear absorptive potential.…”

On the widths and binding energies of K− nuclear states and the role of K− multi-nucleon interactions

“…Figure 3 illustrates the strong density dependence of δ √ s in 208 Pb, calculated selfconsistently within the P and KM models augmented by the FD variant of V (2) K − with α = 1 (P1, KM1) and α = 2 (P2, KM2). The P1 and KM1 models yield smaller energy shift with respect to the K − N threshold than the original single-nucleon potentials V (1) K − (P and KM). The P2 and KM2 models yield energy shifts closer to the single-nucleon potentials.…”

“…Here we present only few selected results, for more details see Refs. [1,2]). The self-consistently evaluated energy shift δ √ s from Eq (5) is strongly density dependent which plays important role in calculations of kaonic nuclear, as well as atomic states.…”

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We report on our recent self-consistent calculations of K − nuclear quasi-bound states using K − optical potentials derived from chirally motivated meson-baryon coupled channels models [1,2]. The K − single-nucleon potentials were supplemented by a phenomenological K − multi-nucleon interaction term introduced to achieve good fits to K − atom data.

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Deformed K− nuclei in the Skyrme–Hartree–Fock approach

“…However, there is still much controversy on the K − -nucleus bound state and the depth of the kaon nuclear optical potential. Theoretical coupled-channel calculations employing only (chiral) two-body forces yield widely varying results for the real and imaginary part of the optical potential [37,38]. The recent K − -nuclear experiments investigate the possible existence of a deeply bound K − pp state [8,9] in order to obtain experimental constraints on this problem, but currently the issue is still unsolved.…”