Probing the Effects of Unparticle Decay of Neutrinos on the Possible Ultrahigh Energy Neutrino Signals at a Km$^2$ Detector for 4-Flavour Scenario

Abstract

We address a possibility in which the ultrahigh energy (UHE) neutrinos undergo unparticle decays. In this framework, a neutrino decays to an unparticle and a lighter neutrino. The idea of unparticle has been proposed by Georgi almost a decade back by invoking the concept of the probable existence of a scale-invariant sector at high energies, and at low energies this scale invariant sector manifests itself by non-integral number ($d_\mathcal{{U}}$) of massless invisible particles called “unparticles” below a dimensional transmutation scale $\varLambda _\mathcal{{U}}$. In the 4-flavour framework, we explore here the neutrino signals at a km$^2$ detector like IceCube when the UHE neutrinos from cosmic astrophysical sources undergo possible unparticle decays.