Design of spectrometer for H-dibaryon search at J-PARC

Sako, Hiroyuki   ; Imai, Kenichi; Sato, Susumu  ; Sugimura, Hitoshi; Ichikawa, Yudai   ; Hasegawa, Shoichi   ; Shirotori, Kotaro; Kiuchi, Ryuta*; Honda, Ryotaro

Recent Lattice-QCD calculations show the baryon-baryon potential corresponding to the H-dibaryon is attactive, and predicts H-dibaryon is either a weakly bound state or a resonance state. On the other hand, KEK-E224, E522 experiments observed a peak near the invariant mass spectrum, which suggests existence of H-dibaryon. However, due to low statistics and low mass resolution, they did not discover the evidence for H-dibaryon. We propose an experiment (P-42) to search for H-dibaryon at J-PARC with Kaon beams with improved statistics and mass resolutions. In this experiment, a dipole magnet spectrometer based on high-rate capable GEM-TPC is designed to reconstruct 2 protons and to 2 s decaying from a H-dibaryon.