Detection prospects for multi-GeV neutrinos from collisionally heated GRBs

¹ Dipartimento di Fisica, Università Sapienza, P.le Aldo Moro 2, I-00185 Rome, Italy
² Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le Aldo Moro 2, I-00185 Rome, Italy
³ Dipartimento di Fisica, Università Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy

^* e-mail: angela.zegarelli@roma1.infn.it

Published online: 20 March 2023

Abstract

Neutrinos with energies ranging from GeV to sub-TeV are expected to be produced in γ-ray Bursts (GRBs) as a result of the dissipation of the jet kinetic energy through nuclear collisions occurring around or below the photosphere, where the jet is still optically thick to high-energy radiation. So far, neutrino emission from the inelastic collisional model in GRBs has been poorly investigated from the experimental point of view. In the present work, we discuss prospects for identifying neutrinos produced in such collisionally heated GRBs with the large-volume neutrino telescopes KM3NeT and IceCube, including their low-energy extensions, KM3NeT/ORCA and DeepCore, respectively. We evaluated the detection sensitivity for neutrinos from both individual and stacked GRBs, exploring bulk Lorentz factor values ranging from 100 to 600. As a result of our analysis, individual searches appear feasible only for extreme sources, characterized by γ-ray fluence values at the level of Fγ ≥ 10⁻² erg cm⁻². In turn, it is possible to detect a significant flux of neutrinos from a stacking sample of ∼ 900 long GRBs (which could be detected by current γ-ray satellites in about five years) already with DeepCore and KM3NeT/ORCA. The detection sensitivity increases with the inclusion of data from the high-energy telescopes, IceCube and KM3NeT/ARCA, respectively.