Effects of Violation of Equivalence Principle on UHE Neutrinos at IceCube in 4 Flavour Scenario

Abstract

If weak equivalence principle is violated then different types of neutrinos would couple differently
with gravity and that may produce a gravity induced oscillation for the neutrinos of
different flavour. We explore here the possibility that very small violation of the principle of
weak equivalence (VEP) can be probed by ultra high energy neutrinos from distant astrophysical
sources. The very long baseline length and the ultra high energies of such neutrinos could
be helpful to probe very small VEP. We consider a 4-flavour neutrino scenario (3 active + 1
sterile) with both mass-flavour and gravity induced oscillations and compare the detection signatures
for these neutrinos (muon tracks and shower events) with and without gravity induced
oscillations at a kilometer scale detector such as IceCube. We find that even very small VEP
(∼ 10−42) can considerably affect the detected muon yield produced by UHE neutrinos from
distant Gamma Ray Bursts (GRBs).