2016-12-23T18:47:23

We report a study of ν(μ) charged-current quasielastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a μ- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross section, dσ/dQ², and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ² and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

We have isolatedνµ charged-current quasi-elastic interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross-section, dσ/dQ 2 , and compare to several theoretical models of quasi-elastic scattering. Good agreement is obtained with a model where the nucleon axial mass, MA, is set to 0.99 GeV/c 2 but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross-section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q 2 favor this interpretation over an alternative in which the axial mass is increased.

Charged pion production via charged-current νµ interactions on plastic scintillator (CH) is studied using the MINERvA detector exposed to the NuMI wideband neutrino beam at Fermilab. Events with hadronic invariant mass W < 1.4 GeV and W < 1.8 GeV are selected in separate analyses: the lower W cut isolates single pion production, which is expected to occur primarily through the ∆(1232) resonance, while results from the higher cut include the effects of higher resonances. Cross sections as functions of pion angle and kinetic energy are compared to predictions from theoretical calculations and generator-based models for neutrinos ranging in energy from 1.5-10 GeV. The data are best described by calculations which include significant contributions from pion intranuclear rescattering. These measurements constrain the primary interaction rate and the role of final state interactions in pion production, both of which need to be well understood by neutrino oscillation experiments.

Cross sections for ν_{μ} and ν[over ¯]_{μ} induced pion production on hydrocarbon in the few-GeV region using MINERvA FERMILAB-PUB-16-228-NDCross sections for ν µ andν µ induced pion production on hydrocarbon in the few-GeV region using MINERvA Separate samples of charged-current pion production events representing two semi-inclusive channels νµ-CC(π + ) andνµ-CC(π 0 ) have been obtained using neutrino and antineutrino exposures of the MINERvA detector. Distributions in kinematic variables based upon µ ± -track reconstructions are analyzed and compared for the two samples. The differential cross sections for muon production angle, muon momentum, and four-momentum transfer Q 2 , are reported, and cross sections versus neutrino energy are obtained. Comparisons with predictions of current neutrino event generators are used to clarify the role of the ∆(1232) and higher-mass baryon resonances in CC pion production and to show the importance of pion final-state interactions. For the νµ-CC(π + ) (νµ-CC(π 0 )) sample, the absolute data rate is observed to lie below (above) the predictions of some of the event generators by amounts that are typically 1-to-2 σ. However the generators are able to reproduce the shapes of the differential cross sections for all kinematic variables of either data set.