18th KAGRA face to face meeting at Tokyo Institute of Technology
On September 14, 2015, Advanced LIGO observed a gravitational wave (GW) event, GW150914. One of the possible origins of GW150914 is the Population III (Pop III) stars. We discussed a method for confirmation of the existence of the Pop III stars using likelihood analysis of mass distributions of binary black hole mergers. In typical cases, our analysis can distinguish `Pop I/II/III model' from `Pop I/II model' with 90% probability by 22 GW signals from binary black hole mergers using KAGRA.