Lambda(1405)-induced non-mesonic decay in kaonic nuclei

TL;DR

This paper investigates the non-mesonic decay of kaonic nuclei via the Lambda(1405) resonance, revealing how coupling ratios influence decay channels and providing quantitative decay rates using a chiral unitary approach.

Contribution

It introduces a Lambda(1405)-doorway model for non-mesonic decay in kaonic nuclei and calculates decay ratios and absorption widths with a chiral unitary framework.

Findings

Decay ratio Gamma_{Lambda N} / Gamma_{Sigma^{0} N} .8 to 1.2 depending on couplings

Total two-nucleon absorption in nuclear matter is approximately 22 MeV

Decay ratio is nearly independent of nucleon density

Abstract

Non-mesonic decay of kaonic nuclei is investigated under a Lambda(1405) doorway picture where the Kbar absorptions in nuclei take place through the Lambda(1405) resonance. Calculating Lambda(1405) N to YN transitions in one-meson exchange, we find that the non-mesonic decay ratio Gamma_{Lambda N} / Gamma_{Sigma^{0} N} depends strongly on the ratio of the couplings Lambda(1405)-Kbar N and Lambda(1405)-pi Sigma. Especially a larger Lambda(1405)-Kbar N coupling leads to enhancement of the decay to Lambda N. Using the chiral unitary approach for description of the Kbar N amplitudes, we obtain Gamma_{Lambda N} / Gamma_{Sigma ^{0} N} \approx 1.2 almost independently of the nucleon density, and find the total two-nucleon absorption of the Kbar in uniform nuclear matter to be 22 MeV at the normal density.