학술논문
Measurements of atmospheric neutrinos and antineutrinos in the MINOS Far Detector
Document Type
Working Paper
Author
MINOS Collaboration; Adamson, P.; Backhouse, C.; Barr, G.; Bishai, M.; Blake, A. S. T.; Bock, G. J.; Boehnlein, D. J.; Bogert, D.; Cao, S. V.; Chapman, J. D.; Childress, S.; Coelho, J. A. B.; Corwin, L.; Cronin-Hennessy, D.; Danko, I. Z.; de Jong, J. K.; Devenish, N. E.; Diwan, M. V.; Escobar, C. O.; Evans, J. J.; Falk, E.; Feldman, G. J.; Frohne, M. V.; Gallagher, H. R.; Gomes, R. A.; Goodman, M. C.; Gouffon, P.; Graf, N.; Gran, R.; Grzelak, K.; Habig, A.; Hartnell, J.; Hatcher, R.; Himmel, A.; Holin, A.; Hylen, J.; Irwin, G. M.; Isvan, Z.; Jaffe, D. E.; James, C.; Jensen, D.; Kafka, T.; Kasahara, S. M. S.; Koizumi, G.; Kopp, S.; Kordosky, M.; Kreymer, A.; Lang, K.; Ling, J.; Litchfield, P. J.; Loiacono, L.; Lucas, P.; Mann, W. A.; Marshak, M. L.; Mathis, M.; Mayer, N.; Medeiros, M. M.; Mehdiyev, R.; Meier, J. R.; Messier, M. D.; Miller, W. H.; Mishra, S. R.; Mitchell, J.; Moore, C. D.; Mualem, L.; Mufson, S.; Musser, J.; Naples, D.; Nelson, J. K.; Newman, H. B.; Nichol, R. J.; Nowak, J. A.; Oliver, W. P.; Orchanian, M.; Pahlka, R. B.; Paley, J.; Patterson, R. B.; Pawloski, G.; Phan-Budd, S.; Plunkett, R. K.; Qiu, X.; Radovic, A.; Ratchford, J.; Rebel, B.; Rosenfeld, C.; Rubin, H. A.; Sanchez, M. C.; Schneps, J.; Schreckenberger, A.; Schreiner, P.; Sharma, R.; Sousa, A.; Speakman, B.; Strait, M.; Tagg, N.; Talaga, R. L.; Thomas, J.; Thomson, M. A.; Toner, R.; Torretta, D.; Tzanakos, G.; Urheim, J.; Vahle, P.; Viren, B.; Walding, J. J.; Weber, A.; Webb, R. C.; White, C.; Whitehead, L.; Wojcicki, S. G.; Zhang, K.; Zwaska, R.
Source
Subject
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Abstract
This paper reports measurements of atmospheric neutrino and antineutrino interactions in the MINOS Far Detector, based on 2553 live-days (37.9 kton-years) of data. A total of 2072 candidate events are observed. These are separated into 905 contained-vertex muons and 466 neutrino-induced rock-muons, both produced by charged-current $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ interactions, and 701 contained-vertex showers, composed mainly of charged-current $\nu_{e}$ and $\bar{\nu}_{e}$ interactions and neutral-current interactions. The curvature of muon tracks in the magnetic field of the MINOS Far Detector is used to select separate samples of $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ events. The observed ratio of $\bar{\nu}_{\mu}$ to $\nu_{\mu}$ events is compared with the Monte Carlo simulation, giving a double ratio of $R^{data}_{\bar{\nu}/\nu}/R^{MC}_{\bar{\nu}/\nu} = 1.03 \pm 0.08 (stat.) \pm 0.08 (syst.)$. The $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ data are separated into bins of $L/E$ resolution, based on the reconstructed energy and direction of each event, and a maximum likelihood fit to the observed $L/E$ distributions is used to determine the atmospheric neutrino oscillation parameters. This fit returns 90% confidence limits of $|\Delta m^{2}| = (1.9 \pm 0.4) \times 10^{-3} eV^{2}$ and $sin^{2} 2\theta > 0.86$. The fit is extended to incorporate separate $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ oscillation parameters, returning 90% confidence limits of $|\Delta m^{2}|-|\Delta \bar{m}^{2}| = 0.6^{+2.4}_{-0.8} \times 10^{-3} eV^{2}$ on the difference between the squared-mass splittings for neutrinos and antineutrinos.
Comment: 22 pages, 19 figures, submitted to Phys. Rev. D
Comment: 22 pages, 19 figures, submitted to Phys. Rev. D