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Rights statement: © 2014 American Physical Society
Final published version, 575 KB, PDF document
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Measurement of the neutrino-oxygen neutral-current interaction cross section by observing nuclear deexcitation $γ$ rays
AU - Abe, K.
AU - Adam, J.
AU - Aihara, H.
AU - Akiri, T.
AU - Andreopoulos, C.
AU - Aoki, S.
AU - Ariga, A.
AU - Ariga, T.
AU - Assylbekov, S.
AU - Autiero, D.
AU - Barbi, M.
AU - Barker, G. J.
AU - Barr, G.
AU - Bass, M.
AU - Batkiewicz, M.
AU - Bay, F.
AU - Bentham, S. W.
AU - Berardi, V.
AU - Berger, B. E.
AU - Berkman, S.
AU - Bertram, I.
AU - Bhadra, S.
AU - Blaszczyk, F. d. M.
AU - Blondel, A.
AU - Bojechko, C.
AU - Bordoni, S.
AU - Boyd, S. B.
AU - Brailsford, D.
AU - Bravar, A.
AU - Bronner, C.
AU - Buchanan, N.
AU - Calland, R. G.
AU - Rodríguez, J. Caravaca
AU - Cartwright, S. L.
AU - Castillo, R.
AU - Catanesi, M. G.
AU - Cervera, A.
AU - Cherdack, D.
AU - Christodoulou, G.
AU - Dealtry, T.
AU - Finch, A. J.
AU - Grant, N.
AU - Kormos, L. L.
AU - Lamont, I.
AU - Lawe, M.
AU - Nowak, J.
AU - O'Keeffe, H. M.
AU - Ratoff, P. N.
AU - Reeves, M.
AU - Southwell, L.
AU - T2K Collaboration
N1 - 10 pages, 6 figures © 2014 American Physical Society
PY - 2014/10/31
Y1 - 2014/10/31
N2 - We report the first measurement of the neutrino-oxygen neutral-current quasielastic (NCQE) cross section. It is obtained by observing nuclear deexcitation $\gamma$-rays which follow neutrino-oxygen interactions at the Super-Kamiokande water Cherenkov detector. We use T2K data corresponding to $3.01 \times 10^{20}$ 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 $1.55 \times 10^{-38}$ cm$^2$ with a 68\% confidence interval of $(1.22, 2.20) \times 10^{-38}$ cm$^2$ at a median neutrino energy of 630 MeV, compared with the theoretical prediction of $2.01 \times 10^{-38}$ cm$^2$.
AB - We report the first measurement of the neutrino-oxygen neutral-current quasielastic (NCQE) cross section. It is obtained by observing nuclear deexcitation $\gamma$-rays which follow neutrino-oxygen interactions at the Super-Kamiokande water Cherenkov detector. We use T2K data corresponding to $3.01 \times 10^{20}$ 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 $1.55 \times 10^{-38}$ cm$^2$ with a 68\% confidence interval of $(1.22, 2.20) \times 10^{-38}$ cm$^2$ at a median neutrino energy of 630 MeV, compared with the theoretical prediction of $2.01 \times 10^{-38}$ cm$^2$.
KW - hep-ex
U2 - 10.1103/PhysRevD.90.072012
DO - 10.1103/PhysRevD.90.072012
M3 - Journal article
VL - 90
JO - Physical Review D
JF - Physical Review D
SN - 1550-7998
IS - 7
M1 - 072012
ER -