Charmed baryon spectroscopy using a hadron beam at J-PARC

One of main subjects in the hadron physics is to understand how hadrons are originated by quarks. Charmed baryon spectroscopy gives us opportunities to understand degree of freedoms to describe the hadron structure. For understanding the charmed baryon structure, it is essential for the diquark correlation which is generated by the isolated two quarks and the charm quark. Properties of the diquark correlation are expected to be emerged as excitation modes in the excited states. We proposed a spectroscopy experiment to measure excited states of charmed baryons at the J-PARC high-momentum beam line. The systematic measurement such as excitation energies, production rates and the decay properties of charmed baryons will be performed by a spectroscopy experiment with a general purpose spectrometry system. In particular, the measurement of hadronic production rates of the π^- + p -> Y_c^*+ + D^*- reaction which can excite a particular diquark motion called λ-mode give us information of the collective motion between diquark and charm quark in the excited charmed baryons. From the experimental results of systematic measurements, the diquark correlation which is expectedly an essential degree of freedom to describe the hadron structure can be established.