What makes the peak structure of the $\hat{I}›p$ invariant-mass spectrum in the $K^{-}{}^3\mathrm{He}\to \hat{I}›pn$ reaction?

Abstract

Recently a peak structure was observed near the $K^{-}pp$ threshold in the in-flight ${}^3\mathrm{He}(K^{-},\hat{I}›p)n$ reaction of the E15 experiment at J-PARC, which could be a signal of a $\bar{K}NN$ bound state. In order to investigate what is the origin of this peak, we calculate the cross section of this reaction, in particular based on the scenario that the $\bar{K}NN$ bound state is indeed generated and decays into $\hat{I}›p$. We find that the numerical result of the $\hat{I}›p$ invariant-mass spectrum in the $\bar{K}NN$ bound scenario is consistent with the J-PARC E15 data.

6 pages, 6 EPS figures, talk given at the 2nd Jagiellonian Symposium on Fundamental and Applied Subatomic Physics, Krakow, Poland, 4-9 June, 2017