Search for low-energy ν_{e, μ, τ} and$\bar \nu _{e,\mu ,\tau }$ in coincidence with BATSE gamma-ray burstsin coincidence with BATSE gamma-ray bursts

Summary

Since neutrinos and gamma-rays productions are often associated in many astrophysical processes, the detection of neutrinos in correlation with γ-ray bursts (GRBs) could be a very important step towards the discovery of the sources of these events. A search for low-energy neutrinos of all flavours in correlation with ≈ 200 γ-ray bursts detected by BATSE aboard the Compton Observatory has been performed by the LSD (Liquid-Scintillator Detector) neutrino telescope. This kind of telescope, differently from the water Čerenkov detectors, is also sensitive to ν_{μ, τ} and$\bar \nu _{\mu , \tau }$ fluxes, through the charged-and neutral-current interactions of neutrinos with carbon nuclei. No ν_{e, μ, τ} or$\bar \nu _{e,\mu ,\tau }$ candidate has been detected by LSD during the time interval in which BATSE detected 90% of the photon flux for any of the GRBs analysed. The corresponding upper limits to the neutrino fluxes, summed over 197 GRBs, are:$F(\bar \nu _e ) \leqslant 1.5 \cdot 10^{11} cm^{ - 2}$, 9≤E _ν≤50 MeV,$F(\bar \nu _e ) \leqslant 2.5 \cdot 10^{10} cm^{ - 2}$, 20≤E _ν≤50 MeV,F(ν_e)≤5.1·10¹¹ cm⁻², 25≤E _ν ≤50 MeV,F(ν_{μ, τ})≤7.5·10¹² cm⁻², 20≤E _ν≤100 MeV,$F(\bar \nu _{\mu , \tau } ) \leqslant 7.9 \cdot 10^{12} cm^{ - 2}$, 20≤E _ν≤100 MeV.