Seminar

Abstract

Neutrinos, while often considered as Majorana fermions, can also behave
ef- fectively as Dirac fermions, making them candidates for pseudo-Dirac
particles. This concept introduces the possibility of oscillations between active
and sterile neutrinos, driven by a small mass-squared difference. This
phenomenon differs from the standard oscillation scenario involving only the
three active neutrino flavors observed across astrophysical distances. In this
study, we focus on ana- lyzing publicly available data from the IceCube
neutrino observatory, searching for potential pseudo-Dirac signatures in
highenergy neutrinos emitted from as- trophysical sources such as NGC 1068,
TXS 0506+056 and PKS 1424+240. In the pseudo-Dirac framework, the
active neutrino flux from these sources di- minishes due to their oscillation
into sterile states. By employing astrophysical flux models, we fit the IceCube
data for these sources under both the stan- dard neutrino oscillation
framework and the active-sterile oscillation scenario. This enables us to place
constraints on the mass-squared difference driving the active-sterile
oscillations and the intrinsic source flux. These constraints could be improved
by future neutrino observatories such as KM3NeT and IceCube Gen-2.