Further Theoretical Analysis on the $K^{-}{}^3\text{He}\to \hat{I}›pn$ Reaction for the $\bar{K}NN$ Bound-State Search in the J-PARC E15 Experiment

Abstract

Based on the scenario that a $\bar{K}NN$ bound state is generated and it eventually decays into $\hat{I}›p$, we calculate the cross section of the $K^{-}{}^3\text{He}\to \hat{I}›pn$ reaction, which was recently measured in the J-PARC E15 experiment. We find that the behavior of the calculated differential cross section $d^2\ddot{I}ƒ/d{M}_{\hat{I}›p}d{q}_{\hat{I}›p}$, where $M_{\hat{I}›p}$ and $q_{\hat{I}›p}$ are the $\hat{I}›p$ invariant mass and momentum transfer in the $(K^{-},n)$ reaction in the laboratory frame, respectively, is consistent with the experiment. Furthermore, we can reproduce almost quantitatively the experimental data of the $\hat{I}›p$ invariant mass spectrum in the momentum transfer window $350\text{ MeV}/c<q_{\hat{I}›p}<650\text{ MeV}/c$. These facts strongly suggest that the $\bar{K}NN$ bound state was indeed generated in the J-PARC E15 experiment.

4 pages, 4 EPS figures, talk given at the 8th International Conference on Quarks and Nuclear Physics (QNP2018), Tsukuba, Japan, 13-17 November, 2018