Analysis of reactor-neutrino oscillation experiment based on consideration of internal constituent motion

Experimental data of neutrino oscillation have been obtained for electron antineutrinos from nuclear reactors in recent years. The experimental data have been successfully analyzed by assuming that the oscillation phenomenon is expressed by mixing angle θ and squared eigen neutrino mass difference Δm . It is of interest to explain the phenomena from another point of view. We attempted to find the neutrino internal motion that is consistent to the standard theory for weak interaction. As a test of internal constituent motion, the time evolution of internal particles was calculated. It was found that the oscillation length of 100 km level was explainable without use of Δm . A discussion was provided about possible existence of additional constituent in the neutrino system.