De-excitation gamma-rays from the s-hole state in N-15 associated with proton decay in O-16

1.0 %. Taking into account the spectroscopic factor of the s-hole state, the total emission probability is found to be 3.1%. This is about 1/10 compared with the emission probability of the 6.32 MeV -ray from the 3/2 p-hole state in 15 N. Moreover, we searched for a 15.1 MeV -ray from the 12 C 1 + state which may be populated after the particle-decay of the s-hole state in 15 N. Such a high energy -ray from the hole state would provide a new method to search for mode-independent nucleon decay even if the emission probability is small. No significant signal is found within a statistical uncertainty.