Accelerator Neutrinos

Abstract:

© Published under licence by IOP Publishing Ltd. Conditions data (for example: alignment, calibration, data quality) are used extensively in the processing of real and simulated data in ATLAS. The volume and variety of the conditions data needed by different types of processing are quite diverse, so optimizing its access requires a careful understanding of conditions usage patterns. These patterns can be quantified by mining representative log files from each type of processing and gathering detailed information about conditions usage for that type of processing into a central repository.

Abstract:

© Published under licence by IOP Publishing Ltd. Processing of the large amount of data produced by the ATLAS experiment requires fast and reliable access to what we call Auxiliary Data Files (ADF). These files, produced by Combined Performance, Trigger and Physics groups, contain conditions, calibrations, and other derived data used by the ATLAS software. In ATLAS this data has, thus far for historical reasons, been collected and accessed outside the ATLAS Conditions Database infrastructure and related software. For this reason, along with the fact that ADF are effectively read by the software as binary objects, this class of data appears ideal for testing the proposed Run 3 conditions data infrastructure now in development. This paper describes this implementation as well as the lessons learned in exploring and refining the new infrastructure with the potential for deployment during Run 2.

Abstract:

The T2K experiment reports an updated analysis of neutrino and antineutrino oscillations in appearance and disappearance channels. Asample of electron neutrino candidates at Super-Kamiokande in which a pion decay has been tagged is added to the four single-ring samples used in previous T2K oscillation analyses. Through combined analyses of these five samples, simultaneous measurements of four oscillation parameters, |Δm2/32|, sin2 θ23, sin2 θ13, and δCP and of the mass ordering are made. A set of studies of simulated data indicates that the sensitivity to the oscillation parameters is not limited by neutrino interaction model uncertainty. Multiple oscillation analyses are performed, and frequentist and Bayesian intervals are presented for combinations of the oscillation parameters with and without the inclusion of reactor constraints on sin2 θ13.When combined with reactor measurements, the hypothesis of CP conservation (δCP = 0 or π) is excluded at 90% confidence level. The 90% confidence region for δCP is [−2.95;−0.44] ([−1.47;−1.27]) for normal (inverted) ordering. The central values and 68% confidence intervals for the other oscillation parameters for normal (inverted) ordering are Δm2/32 = 2.54 ± 0.08(2.51 ± 0.08) × 10^−3 eV^2/c^4 and sin2θ23 = 0.55+0.05/−0.09 (0.55+0.05/−0.08 ), compatible with maximal mixing. In the Bayesian analysis, the data weakly prefer normal ordering (Bayes factor 3.7) and the upper octant for sin2 θ23 (Bayes factor 2.4).