Measurement of the neutrino-oxygen neutral-current interaction cross section by observing nuclear deexcitation γ rays
© 2014 American Physical Society. We report the first measurement of the neutrino-oxygen neutral-current quasielastic (NCQE) cross section. It is obtained by observing nuclear deexcitation γ rays which follow neutrino-oxygen interactions at the Super-Kamiokande water Cherenkov detector. We use T2K data corresponding to 3.01×1020 protons on target. By selecting only events during the T2K beam window and with well-reconstructed vertices in the fiducial volume, the large background rate from natural radioactivity is dramatically reduced. We observe 43 events in the 4-30 MeV reconstructed energy window, compared with an expectation of 51.0, which includes an estimated 16.2 background events. The background is primarily nonquasielastic neutral-current interactions and has only 1.2 events from natural radioactivity. The flux-averaged NCQE cross section we measure is 1.55×10-38cm2 with a 68% confidence interval of (1.22,2.20)×10-38cm2 at a median neutrino energy of 630 MeV, compared with the theoretical prediction of 2.01×10-38cm2.
Abe, K; Adam, J; Aihara, H; Akiri, T; Andreopoulos, C; Aoki, S; Ariga, A; Ariga, T; Assylbekov, S; Autiero, D; Barbi, M; Barker, GJ; Barr, G; Bass, M; Batkiewicz, M; Bay, F; Bentham, SW; Berardi, V; Berger, BE; Berkman, S; Bertram, I; Bhadra, S; Blaszczyk, FDM; Blondel, A; Bojechko, C; Bordoni, S; Boyd, SB; Brailsford, D; Bravar, A; Bronner, C; Buchanan, N; Calland, RG; Caravaca Rodríguez, J; Cartwright, SL; Castillo, R; Catanesi, MG; Cervera, A; Cherdack, D; Christodoulou, G; Clifton, A; Coleman, J; Coleman, SJ; Collazuol, G; Connolly, K; Cremonesi, L; Dabrowska, A; Danko, I; Das, R; Davis, S; De Perio, P; De Rosa, G; Dealtry, T; Dennis, SR; Densham, C; Dewhurst, D; Di Lodovico, F; Di Luise, S; Drapier, O; Duboyski, T; Duffy, K; Dufour, F; Dumarchez, J; Dytman, S; Dziewiecki, M; Emery-Schrenk, S; Ereditato, A; Escudero, L; Finch, AJ; Fiorentini Aguirre, GA; Friend, M; Fujii, Y; Fukuda, Y; Furmanski, AP; Galymov, V; Gaudin, A; Giffin, S; Giganti, C; Gilje, K; Goeldi, D; Golan, T; Gomez-Cadenas, JJ; Gonin, M; Grant, N; Gudin, D; Hadley, DR; Haegel, L; Haesler, A; Haigh, MD; Hamilton, P; Hansen, D; Hara, T; Hartz, M; Hasegawa, T; Hastings, NC; Hayato, Y
Volume / Issue
Electronic International Standard Serial Number (EISSN)
International Standard Serial Number (ISSN)
Digital Object Identifier (DOI)