Search for high-energy neutrinos from GRB130427A with the ANTARES neutrino telescope

ANTARES is the first deep under-sea high-energy astrophysical neutrino telescope, in operation since 2008, in the Northern Hemisphere. In the light of a multi-messenger approach, one of the most ever intense (photon fluence F_γ ≃10^-3 erg/cm²) and close (redshift z = 0.34) transient γ-source, GRB130427A, is considered in the ANTARES physics program for a co-incident search for photons and high-energy neutrinos. The first time-dependent analysis on GRBs neutrino emissions has been performed for this source: Konus-Wind parameters of the γ time-dependent spectrum are used to predict the expected neutrino flux from each peak of the burst, through the numerical calculation code NeuCosmA. An extended maximum likelihood ratio search is performed in order to maximize the discovery probability of prompt neutrinos from the burst: at the end, ANTARES sensitivity to this source is evaluated to be E²Φ_v ∼ 1 -10 GeV/cm² in the energy range from 2 x 10⁵ GeV to 2 x 10⁷ GeV. (paper)