No abstract

Amplitudes derived from scattering data on elementary targets are basic inputs to neutrinonucleus cross section predictions. A prominent example is the isovector axial nucleon form factor, FA(q 2 ), which controls charged current signal processes at accelerator-based neutrino oscillation experiments. Previous extractions of FA from neutrino-deuteron scattering data rely on a dipole shape assumption that introduces an unquantified error. A new analysis of world data for neutrinodeuteron scattering is performed using a model-independent, and systematically improvable, representation of FA. A complete error budget for the nucleon isovector axial radius leads to r 2 A = 0.46(22) fm 2 , with a much larger uncertainty than determined in the original analyses. The quasielastic neutrino-neutron cross section is determined as σ(νµn → µ − p) Eν =1 GeV = 10.1(0.9) × 10 −39 cm 2 . The propagation of nucleon-level constraints and uncertainties to nuclear cross sections is illustrated using MINERvA data and the GENIE event generator. These techniques can be readily extended to other amplitudes and processes.

We report on measurements of differential cross sections dσ/dp T for prompt charm meson production in pp collisions at √ s = 1.96 TeV using 5.8 ± 0.3 pb −1 of data from the CDF II detector at the Fermilab Tevatron. The data are collected with a new trigger that is sensitive to the long lifetime of hadrons containing heavy flavor. The charm meson cross sections are measured in the central rapidity region |y| ≤ 1 in four fully reconstructed decay modes:

There are emerging tensions for theory results of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment both within recent lattice QCD calculations and between some lattice QCD calculations and R-ratio results. In this paper we work towards scrutinizing critical aspects of these calculations. We focus in particular on a precise calculation of Euclidean position-space windows defined by RBC/UKQCD that are ideal quantities for cross-checks within the lattice community and with R-ratio results. We perform a lattice QCD calculation using physical up, down, strange, and charm sea quark gauge ensembles generated in the staggered formalism by the MILC collaboration. We study the continuum limit using inverse lattice spacings from a −1 ≈ 1.6 GeV to 3.5 GeV, identical to recent studies by FNAL/HPQCD/MILC and Aubin et al. and similar to the recent study of BMW. Our calculation exhibits a tension for the particularly interesting window result of a ud,conn.,isospin,W µ from 0.4 fm to 1.0 fm with previous results obtained with a different discretization of the vector current on the same gauge configurations. Our results may indicate a difficulty related to estimating uncertainties of the continuum extrapolation that deserves further attention. In this work we also provide results for a ud,conn.,isospin µ , a s,conn.,isospin µ , a SIB,conn. µ for the total contribution and a large set of windows. For the total contribution, we find a HVP LO µ = 714(27)(13)10 −10 , a ud,conn.,isospin µ = 657(26)(12)10 −10 , a s,conn.,isospin µ = 52.83(22)(65)10 −10 , and a SIB,conn. µ = 9.0(0.8)(1.2)10 −10 , where the first uncertainty is statistical and the second systematic. We also comment on finite-volume corrections for the strong-isospin-breaking corrections.

This document is one of a series of whitepapers from the USQCD collaboration. Here, we discuss opportunities for lattice QCD in neutrino-oscillation physics, which inevitably entails nucleon and nuclear structure. In addition to discussing pertinent lattice-QCD calculations of nucleon and nuclear matrix elements, the interplay with models of nuclei is discussed. This program of lattice-QCD calculations is relevant to current and upcoming neutrino experiments, becoming increasingly important on the timescale of LBNF/DUNE and HyperK. * Editor, ask@fnal.gov † Editor, dgr@jlab.org arXiv:1904.09931v1 [hep-lat]