Measurement of (nu)over-bar(mu) and nu(mu) charged current inclusive cross sections and their ratio with the T2K off-axis near detector
Physical Review D American Physical Society 96:5 (2017) 052001
Abstract:
We report a measurement of cross section σ(νμ+nucleus→μ-+X) and the first measurements of the cross section σ(ν-μ+nucleus→μ++X) and their ratio R(σ(ν-)σ(ν)) at (anti) neutrino energies below 1.5 GeV. We determine the single momentum bin cross section measurements, averaged over the T2K ν-/ν-flux, for the detector target material (mainly carbon, oxygen, hydrogen and copper) with phase space restricted laboratory frame kinematics of θμ < 32° and pμ > 500 MeV/c. The results are σ(ν-)=(0.900±0.029(stat)±0.088(syst))×10-39 and σ(ν)=(2.41±0.022(stat)±0.231(syst))×10-39 in units of cm2/nucleon and R(σ(ν-)σ(ν))=0.373±0.012(stat)±0.015(syst).First oscillation analysis using neutrino and antineutrino data at T2K
Journal of Physics Conference Series IOP Publishing 888:1 (2017) 012216
Updated T2K measurements of muon neutrino and antineutrino disappearance using 1.5 × 10^21 protons on target
Physical Review D American Physical Society 96:1 (2017) 011102
Abstract:
We report measurements by the T2K experiment of the parameters θ23 and Δm322 governing the disappearance of muon neutrinos and antineutrinos in the three-flavor neutrino oscillation model. Utilizing the ability of the experiment to run with either a mainly neutrino or a mainly antineutrino beam, the parameters are measured separately for neutrinos and antineutrinos. Using 7.482×1020 POT in neutrino running mode and 7.471×1020 POT in antineutrino mode, T2K obtained sin2(θ23)=0.51-0.07+0.08 and Δm322=2.53-0.13+0.15×10-3 eV2/c4 for neutrinos, and sin2(θ-23)=0.42-0.07+0.25 and Δm-232=2.55-0.27+0.33×10-3 eV2/c4 for antineutrinos (assuming normal mass ordering). No significant differences between the values of the parameters describing the disappearance of muon neutrinos and antineutrinos were observed.Search for Lorentz and violation using sidereal time dependence of neutrino flavor transitions over a short baseline
Physical Review D American Physical Society 95:11 (2017)
Abstract:
A class of extensions of the Standard Model allows Lorentz and CPT violations, which can be identified by the observation of sidereal modulations in the neutrino interaction rate. A search for such modulations was performed using the T2K on-axis near detector. Two complementary methods were used in this study, both of which resulted in no evidence of a signal. Limits on associated Lorentz and CPT-violating terms from the Standard Model extension have been derived by taking into account their correlations in this model for the first time. These results imply such symmetry violations are suppressed by a factor of more than 1020 at the GeV scale.Combined analysis of neutrino and antineutrino oscillations at T2K
Physical Review Letters American Physical Society 118:15 (2017) 151801