Measurements of atmospheric neutrinos and antineutrinos in the MINOS far detector

Citations Over TimeTop 10% of 2012 papers

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 ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ and ${\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}$ interactions, and 701 contained-vertex showers, composed mainly of charged-current ${\ensuremath{\nu}}_{e}$ and ${\overline{\ensuremath{\nu}}}_{e}$ 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 ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ and ${\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}$ events. The observed ratio of ${\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}$ to ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ events is compared with the Monte Carlo (MC) simulation, giving a double ratio of ${R}_{\overline{\ensuremath{\nu}}/\ensuremath{\nu}}^{\mathrm{data}}/{R}_{\overline{\ensuremath{\nu}}/\ensuremath{\nu}}^{\mathrm{MC}}=1.03\ifmmode\pm\else\textpm\fi{}0.08(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.08(\mathrm{syst})$. The ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ and ${\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}$ 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 $|\ensuremath{\Delta}{m}^{2}|=(1.9\ifmmode\pm\else\textpm\fi{}0.4)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\text{ }\text{ }{\mathrm{eV}}^{2}$ and ${sin}^{2}2\ensuremath{\theta}>0.86$. The fit is extended to incorporate separate ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ and ${\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}$ oscillation parameters, returning 90% confidence limits of $|\ensuremath{\Delta}{m}^{2}|\ensuremath{-}|\ensuremath{\Delta}{\overline{m}}^{2}|={0.6}_{\ensuremath{-}0.8}^{+2.4}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\text{ }\text{ }{\mathrm{eV}}^{2}$ on the difference between the squared-mass splittings for neutrinos and antineutrinos.

Related Papers

• → Search for the disappearance of muon antineutrinos in the NuMI neutrino beam(2011)27 cited
• → Muon neutrino to electron neutrino oscillations in the MINOS experiment(2012)
• → Long-baseline accelerator neutrino experiments(2011)
• → A search for muon neutrino to electron neutrino oscillation mediated by sterile neutrinos in MINOS+(2017)