The Second period of event hunting in the J-PARC E07

Yoshida, Junya; Hayakawa, Shuhei; Ekawa, Hiroyuki*; Yoshimoto, Masahiro*; Kasagi, Ayumi*; Lin, P. M.*; Nyaw, A. N. L.*; Nakazawa, Kazuma*

J-PARC E07 is an experiment to detect double hypernuclear events with the largest statistics in the past using photographic emulsion sheets. Experimental data on - and -nucleon interaction, are obtained by mass measurements of various double hypernuclei. The main step in the analysis of this experiment is the tracking of particles in emulsion sheets under optical microscopes. We expect to complete the first period analysis of all the sheets by March 2020. The number of events obtained in the first period is about 40% of the planned yield. The remaining events will be detected in the second search in the near future. It is considered that the cause of missing particles was that the prediction of the incident position of particles was incorrect due to poor flatness of the uppermost stream sheet. Therefore, we are trying to correct the surface position and find the missing particles.