Measurement of the exclusive cross sectionC12(νe,e−)12N(g.s.)

The neutrino-induced nuclear transition ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${\nu }_{\mathit{e}}$,${\mathit{e}}^{\mathrm{-}}$ ${)}^{12}$N (g.s.) has been observed with a 15-ton fine-grained tracking detector. The exclusive final state is identified by both an electron track and the positron decay of the ${}_{}{}^{12}{}_{}{}^{}\mathrm{N}$. From the observation of 181±17 ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${\nu }_{\mathit{e}}$,${\mathit{e}}^{\mathrm{-}}$ ${)}^{12}$N (g.s.) events with subsequent positron decays the flux-averaged cross section, equivalent to the cross section for 35.0-MeV neutrinos, is [1.05±0.10(stat)±0.10(syst)]×${10}^{\mathrm{-}41}$ ${\mathrm{cm}}^2$. This result is in good agreement with recent calculations.