Measurement of θ ₁₃ in Double Chooz using neutron captures on hydrogen with novel background rejection techniques

Journal Article · Wed Jan 27 00:00:00 EST 2016 · Journal of High Energy Physics (Online)

DOI:https://doi.org/10.1007/JHEP01(2016)163· OSTI ID:1326937

Abe, Y.; Appel, S.; Abrahão, T.; Almazan, H.; Alt, C.; dos Anjos, J. C.; Barriere, J. C.; Baussan, E.; Bekman, I.; Bergevin, M.; Bezerra, T. J. C.; Bezrukov, L.; Blucher, E.; Brugière, T.; Buck, C.; Busenitz, J.; Cabrera, A.; Camilleri, L.; Carr, R.; Cerrada, M. ; Chauveau, E.; Chimenti, P.; Collin, A. P.; Conrad, J. M.; Crespo-Anadón, J. I.; Crum, K.; Cucoanes, A. S.; Damon, E.; Dawson, J. V.; Dhooghe, J.; Dietrich, D.; Djurcic, Z.; Dracos, M.; Etenko, A.; Fallot, M.; von Feilitzsch, F.; Felde, J.; Fernandes, S. M.; Fischer, V.; Franco, D.; Franke, M.; Furuta, H.; Gil-Botella, I.; Giot, L.; Göger-Neff, M.; Gomez, H.; Gonzalez, L. F. G.; Goodenough, L.; Goodman, M. C.; Haag, N.; Hara, T.; Haser, J.; Hellwig, D.; Hofmann, M.; Horton-Smith, G. A.; Hourlier, A.; Ishitsuka, M.; Jochum, J.; Jollet, C.; Kaether, F.; Kalousis, L. N.; Kamyshkov, Y.; Kaneda, M.; Kaplan, D. M.; Kawasaki, T.; Kemp, E.; de Kerret, H.; Kryn, D.; Kuze, M.; Lachenmaier, T.; Lane, C. E.; Lasserre, T.; Letourneau, A.; Lhuillier, D.; Lima, H. P.; Lindner, M.; López-Castaño, J. M.; LoSecco, J. M.; Lubsandorzhiev, B.; Lucht, S.; Maeda, J.; Mariani, C.; Maricic, J.; Martino, J.; Matsubara, T.; Mention, G.; Meregaglia, A.; Miletic, T.; Milincic, R.; Minotti, A.; Nagasaka, Y.; Navas-Nicolás, D.; Novella, P.; Oberauer, L.; Obolensky, M.; Onillon, A.; Osborn, A.; Palomares, C.; Pepe, I. M.; Perasso, S.; Porta, A.; Pronost, G.; Reichenbacher, J.; Reinhold, B.; Röhling, M.; Roncin, R.; Rybolt, B.; Sakamoto, Y.; Santorelli, R.; Schilithz, A. C.; Schönert, S.; Schoppmann, S.; Shaevitz, M. H.; Sharankova, R.; Shrestha, D.; Sibille, V.; Sinev, V.; Skorokhvatov, M.; Smith, E.; Soiron, M.; Spitz, J.; Stahl, A.; Stancu, I.; Stokes, L. F. F.; Strait, M.; Suekane, F.; Sukhotin, S.; Sumiyoshi, T.; Sun, Y.; Svoboda, R.; Terao, K.; Tonazzo, A.; Thi, H. H. Trinh; Valdiviesso, G.; Vassilopoulos, N.; Veyssiere, C.; Vivier, M.; Wagner, S.; Walsh, N.; Watanabe, H.; Wiebusch, C.; Wurm, M.; Yang, G.; Yermia, F.; Zimmer, V.

We observed a measurement of the Double Chooz collaboration and the neutrino mixing angle θ₁₃ using reactor $$\bar{v}$$_e via the inverse beta decay reaction in which the neutron is captured on hydrogen. Our measurement is based on 462.72 live days data, approximately twice as much data as in the previous such analysis, collected with a detector positioned at an average distance of 1050 m from two reactor cores. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties. Accidental coincidences, the dominant background in this analysis, are suppressed by more than an order of magnitude with respect to our previous publication by a multi-variate analysis. Furthermore, these improvements demonstrate the capability of precise measurement of reactor $$\bar{v}$$_e without gadolinium loading. Spectral distortions from the $$\bar{v}$$_e reactor flux predictions previously reported with the neutron capture on gadolinium events are confirmed in the independent data sample presented here. A value of sin² 2θ₁₃= 0.095_0.039^+0.038 (stat+syst) is obtained from a fit to the observed event rate as a function of the reactor power, a method insensitive to the energy spectrum shape. A simultaneous fit of the hydrogen capture events and of the gadolinium capture events yields a measurement of sin² 2θ₁₃ = 0.088 ± 0.033(stat+syst).

• Research Organization: Tokyo Inst. of Technology (Japan). Dept. of Physics; Univ. of Hawaii, Honolulu, HI (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: The Double Chooz Collaboration; The Double Chooz collaboration
• Grant/Contract Number: NA0000979; SC0010504
• OSTI ID: 1326937
• Alternate ID(s): OSTI ID: 1598633
• Journal Information: Journal of High Energy Physics (Online), Vol. 2016, Issue 1; ISSN 1029-8479
• Publisher: Springer Berlin
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
oscillation
electroweak interaction
neutrino detectors and telescopes
flavor physics