The Violation of Equivalence Principle and Four Neutrino Oscillations for Long Baseline Neutrinos

Abstract

Violation of equivalence principle predicts that neutrinos of different flavour couple differently with gravity. Such a scenario can give rise to gravity induced flavour oscillations in addition to the usual mass flavour neutrino oscillations during the neutrino propagation.Even if the equivalence principle is indeed violated, their measure will be extremely small. We explore the possibility to probe the violation of equivalence principle (VEP) for the case of long baseline (LBL) neutrinos in a 4-flavour neutrino framework (3 active + 1 sterile) where both mass and gravity induced oscillations are considered. For the muon neutrino flux from a neutrino factory or accelerator, the muon yields are computed and compared at a far end detector with and without VEP. For the first time, we explore a possibility demonstrating that in 4-neutrino (3 active + 1 sterile) framework considering the neutrino oscillation with both VEP and matter effect, even a very small violation of equivalence principle can be probed in a long baseline neutrino experiment.