Earth matter effects in detection of supernova neutrinos

We calculated the matter effect, including both the Earth and supernova, on the detection of neutrinos from type II supernovae at the proposed Daya Bay reactor neutrino experiment. It is found that apart from the dependence on the flip probability $P_H$ inside the supernova and the mass hierarchy of neutrinos, the amount of the Earth matter effect depends on the direction of the incoming supernova neutrinos, and reaches the biggest value when the incident angle of neutrinos is around 93°. In the reaction channel ${\overline{\nu }}_e+p\to e^{+}+n$ the Earth matter effect can be as big as about 12%. For other detection processes the amount of the Earth matter effect is a few per cent.