The Peak Structure in the In-Flight ${}^3\text{He}(K^{-},\hat{I}›p)n$ Reaction Around the $\bar{K}NN$ Threshold

Abstract

We theoretically investigate the origin of the peak structure around the $K^{-}pp$ threshold observed in the in-flight ${}^3\text{He}(K^{-},\hat{I}›p)n$ reaction in the recent E15 experiment at J-PARC. For this purpose, we consider two scenarios to produce the peak. One is that the $\hat{I}›(1405)$ is generated but it does not correlate with $p$, and the uncorrelated $\hat{I}›(1405)p$ system subsequently decays into $\hat{I}›p$. The other one is that the $\bar{K}NN$ bound state is indeed generated and decays into $\hat{I}›p$. As a result, the experimental signal is qualitatively well reproduced in the $\bar{K}NN$ bound scenario, definitely discarding the uncorrelated $\hat{I}›(1405)p$ one.

5 pages, 9 EPS figures, talk given at the 14th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU2016), Kyoto, Japan, 25-30 July. 2016