## Abstract

This paper reports measurements of atmospheric neutrino and antineutrino interactions in the MINOS Far Detector, based on 2553 live-days (37.9kton-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 ν _{μ} and ν _{̄μ} interactions, and 701 contained-vertex showers, composed mainly of charged-current ν _{e} and ν _{̄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 ν _{μ} and ν _{̄μ} events. The observed ratio of ν _{̄μ} to ν _{μ} events is compared with the MonteCarlo (MC) simulation, giving a double ratio of Rν̄/νdata/ Rν̄/νMC=1.03±0.08(stat)±0.08(syst). The ν _{μ} and ν _{̄μ} 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 |Δm2|=(1.9±0.4)×10 ^{-}3eV2 and ^{sin}22θ>0.86. The fit is extended to incorporate separate ν _{μ} and ν _{̄μ} oscillation parameters, returning 90% confidence limits of |Δm2|-|Δm ^{̄}2|=0.6- 0.8+2.4×10 ^{-}3eV2 on the difference between the squared-mass splittings for neutrinos and antineutrinos.

Original language | English (US) |
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Article number | 052007 |

Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |

Volume | 86 |

Issue number | 5 |

DOIs | |

State | Published - Sep 17 2012 |