A search for Supernova Relic Neutrinos $\bar{\nu}_e$'s is first conducted viainverse-beta-decay by tagging neutron capture on hydrogen atSuper-Kamiokande-IV. The neutron tagging efficiency is determined to be$(17.74\pm0.04_{stat.}\pm1.05_{sys.})%$, while the corresponding accidentalbackground probability is $(1.06\pm0.01_{stat.}\pm 0.18_{sys.})$%. Using 960days of data, we obtain 13 inverse-beta-decay candidates in the range of$E_{\bar{\nu}_e}$ between 13.3 MeV and 31.3 MeV. All of the observed candidatesare attributed to background. Upper limits at 90% C.L. are calculated in theabsence of a signal.
展开▼