Search for H-dibaryon with Hyperon spectrometer at J-PARC

Recent Lattice QCD calculations have suggested a possible existence of H-dibaryon near the $\Lambda \Lambda $ threshold. In the previous experiments at KEK-PS, a hint of peak structure was observed in the $\Lambda \Lambda $ invariant mass spectrum at just above the $\Lambda \Lambda $ threshold. An experiment to search for H-dibaryon through $\Lambda \Lambda $ and $\Lambda \pi $-p mass spectra was proposed at J-PARC (E42). Much better statistics and mass resolution than the previous data are expected. For this experiment, we have been constructing a novel hyperon spectrometer with use of a GEM-TPC and a superconducting Helmholtz magnet. The expected performance of the spectrometer and the proposed experiment is reported based on the R{\&}D results of the TPC and simulations. Possible physics with the hyperon spectrometer other than the H-dibaryon is also discussed.