Speaker
Description
Speaker: Ankur Verma
Abstract: Scalar Non-Standard interaction (SNSI) of neutrinos contributes as modifications to the neutrino mass matrix in the oscillation Hamiltonian and can induce a small active-sterile mass splitting due to the matter effect via a Majorana-type interaction. This framework leads to pseudo-Dirac behavior of neutrinos, introducing rich phenomenology in neutrino oscillations, particularly
for high-energy astrophysical neutrinos. These hyperfine active-sterile splittings imprint themselves in two complementary ways on high-energy astrophysical neutrino flux, modifying the flavor composition and energy distribution. The matter effects induced by SNSI with relic neutrinos modify the predicted flavor ratios of high-energy astrophysical neutrinos compared with the standard oscillation expectations. The same hyperfine splittings also modulate the energy dependence of the flux, altering both the diffuse spectrum (tracks and cascades) and the reconstructed spectra of individual point sources. In this work, we exploit both sources to probe light scalar NSI. We confront the predictions with current IceCube measurements and with the projected reach of next-generation detectors such as IceCube-Gen2. The regions excluded by the combined flavor and spectral analyses are translated into limits on the underlying model parameters: Yukawa couplings and scalar mass, providing new sensitivities/constraints on the parameter space of light scalar NSI.