Experimental study of neutrino absorption on carbon

The process of electron emission from ∼30 MeV neutrino absorption on carbon, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${\nu }_{\mathit{e}}$,${\mathit{e}}^{\mathrm{-}}$ ${)}^{12}$N, has been observed. The flux-weighted total cross section for the exclusive neutrino-induced nuclear transition ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${\nu }_{\mathit{e}}$,${\mathit{e}}^{\mathrm{-}}$ ${)}^{12}$N(g.s.) is [1.05±0.10(stat)±0.10(syst)]×${10}^{\mathrm{-}41}$ ${\mathrm{cm}}^2$. The measured cross section and angular distribution dσ/dΩ are in agreement with theoretical estimates. The inclusive ${\nu }_{\mathit{e}}$ ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ reaction rate, which accounted for the majority of all neutrino interactions observed in this experiment, was determined from a detailed fit of energy and angular distributions for the observed electrons. The inclusive ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${\nu }_{\mathit{e}}$,${\mathit{e}}^{\mathrm{-}}$)X cross section is measured to be [1.41±0.23(tot)]×${10}^{\mathrm{-}41}$ ${\mathrm{cm}}^2$. An upper limit for the sum of the ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$(${\nu }_{\mathit{e}}$,${\mathit{e}}^{\mathrm{-}}$)X${+}^{27}$Al(${\nu }_{\mathit{e}}$,${\mathit{e}}^{\mathrm{-}}$)X inclusive absorption cross sections is presented.