Final-state kinematic imbalances are measured in mesonless production of νμ+A→μ-+p+X in the MINERvA tracker. Initial- and final-state nuclear effects are probed using the direction of the μ- - p ...transverse momentum imbalance and the initial-state momentum of the struck neutron. Differential cross sections are compared to predictions based on current approaches to medium modeling. These models underpredict the cross section at intermediate intranuclear momentum transfers that generally exceed the Fermi momenta. As neutrino interaction models need to correctly incorporate the effect of the nucleus in order to predict neutrino energy resolution in oscillation experiments, this result points to a region of phase space where additional cross section strength is needed in current models, and demonstrates a new technique that would be suitable for use in fine-grained liquid argon detectors where the effect of the nucleus may be even larger.
Charged-current antineutrino interactions on a hydrocarbon scintillator in the MINERvA detector are used to study activity from their final-state neutrons. To ensure that most of the neutrons are ...from the primary interaction, rather than hadronic reinteractions in the detector, the sample is limited to momentum transfers below 0.8 GeV/c. From 16 129 interactions, 15 246 neutral particle candidates are observed. The reference simulation predicts 64% of these candidates are due to neutrons from the antineutrino interaction directly but also overpredicts the number of candidates by 15% overall. This discrepancy is beyond the standard uncertainty estimates for models of neutrino interactions and neutron propagation in the detector. We explore these two aspects of the models using the measured distributions for energy deposition, time of flight, position, and speed. We also use multiplicity distributions to evaluate the presence of a two-nucleon knockout process. These results provide critical new information toward a complete description of the hadronic final state of neutrino interactions, which is vital to neutrino oscillation experiments.
Elastic neutrino scattering on electrons is a precisely known purely leptonic process that provides a standard candle for measuring neutrino flux in conventional neutrino beams. Using a total sample ...of 810 neutrino-electron scatters after background subtraction, the measurement reduces the normalization uncertainty on the ν μ NuMI beam flux between 2 and 20 GeV from 7.6 to 3.9%. This is the most precise measurement of neutrino-electron scattering to date, will reduce uncertainties on MINER ν A's absolute cross section measurements, and demonstrates a technique that can be used in future neutrino beams such as long baseline neutrino facility.
We present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range ...2–22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a subsample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12–22 GeV. We also report on the antineutrino-neutrino cross section ratio, RCC, which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of ∼5% at low energy. Our results for the antineutrino-nucleus scattering cross section and for RCC are the most precise to date in the energy range Eν<6 GeV.
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.
Design, calibration, and performance of the MINERvA detector Aliaga, L.; Bagby, L.; Baldin, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2014, Letnik:
743
Journal Article
Recenzirano
Odprti dostop
The MINERvA66Main INjector ExpeRiment ν-A. experiment is designed to perform precision studies of neutrino-nucleus scattering using νμ and ν¯μ neutrinos incident at 1–20GeV in the NuMI beam at ...Fermilab. This article presents a detailed description of the MINERvA detector and describes the ex situ and in situ techniques employed to characterize the detector and monitor its performance. The detector is composed of a finely segmented scintillator-based inner tracking region surrounded by electromagnetic and hadronic sampling calorimetry. The upstream portion of the detector includes planes of graphite, iron and lead interleaved between tracking planes to facilitate the study of nuclear effects in neutrino interactions. Observations concerning the detector response over sustained periods of running are reported. The detector design and methods of operation have relevance to future neutrino experiments in which segmented scintillator tracking is utilized.
Faced with unresolved tensions between neutrino interaction measurements at few-GeV neutrino energies, current experiments are forced to accept large systematic uncertainties to cover discrepancies ...between their data and model predictions. The widely used pion production model in GENIE is compared to four MINERνA charged current pion production measurements using nuisance. Tunings, i.e., adjustments of model parameters, to help match GENIE to MINERνA and older bubble chamber data are presented. We find that scattering off nuclear targets as measured in MINERνA is not in good agreement with expectations based upon scattering off nucleon (hydrogen or deuterium) targets in existing bubble chamber data. An additional ad hoc correction for the low−Q2 region, where collective nuclear effects are expected to be large, is presented. While these tunings and corrections improve the agreement of GENIE with the data, the modeling is imperfect. The development of these tunings within the nuisance framework allows for straightforward extensions to other neutrino event generators and models, and allows omitting and including new datasets as they become available.
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