Ramifications of intranuclear re-scattering in MINOS

MINOS will measure the composition of a neutrino beam at two locations, 735km apart, in an effort confirm the (atmospheric) neutrino oscillation hypothesis and measure the associated mixing parameters. Oscillations will be manifested as a difference in the rate and energy spectrum of muon neutrino CC interactions measured in the two detectors. Because most interactions observed in MINOS are inelastic, the neutrino energy is reconstructed as the sum of the energy carried by the muon and that seen in the hadronic shower emanating from the struck nucleus. The latter is sensitive to uncertainties in the hadronisation process, chief among them those due to intranuclear re-scattering (i.e., final state interactions). We discuss the simulation of intranuclear re-scattering currently used by MINOS and its effect on quantities observable in the experiment.Comment: 6 pages, 5 figures, To be published in Nucl.Phys.Proc.Suppl.-- Proceedings of the IV International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region, 26-29, September, 200

Electron Neutrino and Antineutrino Appearance in the Full MINOS Data Sample

We report on v(e) and (v) over bar (e) appearance in v(mu) and (v) over bar (mu) beams using the full MINOS data sample. The comparison of these v(e) and (v) over bar (e) appearance data at a 735 km baseline with theta(13) measurements by reactor experiments probes delta, the theta(23) octant degeneracy, and the mass hierarchy. This analysis is the first use of this technique and includes the first accelerator long-baseline search for (v) over bar (mu) -\u3e (v) over bar (e). Our data disfavor 31% (5%) of the three-parameter space defined by delta, the octant of the theta(23), and the mass hierarchy at the 68% (90%) C.L. We measure a value of 2sin(2)(2 theta(13))sin(2)(theta(23)) that is consistent with reactor experiments. DOI: 10.1103/PhysRevLett.110.17180

Measurement of Neutrino and Antineutrino Oscillations Using Beam and Atmospheric Data in MINOS

We report measurements of oscillation parameters from v(mu) and (v) over bar (mu) disappearance using beam and atmospheric data from MINOS. The data comprise exposures of 10.71 X 10(20) protons on target in the v(mu)-dominated beam, 3.36 X 10(20) protons on target in the (v) over bar (mu)-enhanced beam, and 37.88 kton yr of atmospheric neutrinos. Assuming identical v and (v) over bar oscillation parameters, we measure vertical bar Delta m(2)vertical bar = (2.41(-0.10)(+0.09)) X 10(-3) eV(2) and sin(2)(2 theta) = 0.950(-0.036)(+0.035). Allowing independent v and (v) over bar oscillations, we measure antineutrino parameters of vertical bar(m) over bar (2)vertical bar = (2.50(-0.250)(+0.23)) X 10(-3) eV(2) and sin(2)(2 (theta) over bar) = 0.97(-0.08)(+0.03), with minimal change to the neutrino parameters

Evidence of Coherent K+ Meson Production in Neutrino-Nucleus Scattering

Neutrino-induced charged-current coherent kaon production nu(mu)A -\u3e mu(-)K(+)A is a rare, inelastic electroweak process that brings a K+ on shell and leaves the target nucleus intact in its ground state. This process is significantly lower in rate than the neutrino-induced charged-current coherent pion production because of Cabibbo suppression and a kinematic suppression due to the larger kaon mass. We search for such events in the scintillator tracker of MINERvA by observing the final state K+, mu(-), and no other detector activity, and by using the kinematics of the final state particles to reconstruct the small momentum transfer to the nucleus, which is a model-independent characteristic of coherent scattering. We find the first experimental evidence for the process at 3 sigma significance

Sudden stratospheric warmings seen in MINOS deep underground muon data

The rate of high energy cosmic ray muons as measured underground is shown to be strongly correlated with upper-air temperatures during short-term atmospheric (10-day) events. The effects are seen by correlating data from the MINOS underground detector and temperatures from the European Centre for Medium Range Weather Forecasts during the winter periods from 2003-2007. This effect provides an independent technique for the measurement of meteorological conditions and presents a unique opportunity to measure both short and long-term changes in this important part of the atmosphere. Citation: Osprey, S., et al. (2009), Sudden stratospheric warmings seen in MINOS deep underground muon data, Geophys. Res. Lett., 36, L05809, doi: 10.1029/2008GL036359

Comparisons of annual modulations in MINOS with the event rate modulation in CoGeNT

The CoGeNT Collaboration has recently published results from a fifteen month data set which indicate an annual modulation in the event rate similar to what is expected from weakly interacting massive particle interactions. It has been suggested that the CoGeNT modulation may actually be caused by other annually modulating phenomena, specifically the flux of atmospheric muons underground or the radon level in the laboratory. We have compared the phase of the CoGeNT data modulation to that of the concurrent atmospheric muon and radon data collected by the MINOS experiment which occupies an adjacent experimental hall in the Soudan Underground Laboratory. The results presented are obtained by performing a shape-free chi(2) data-to-data comparison and from a simultaneous fit of the MINOS and CoGeNT data to phase-shifted sinusoidal functions. Both tests indicate that the phase of the CoGeNT modulation is inconsistent with the phases of the MINOS muon and radon modulations at the 3.0 sigma level. DOI: 10.1103/PhysRevD.87.03200

Observation of seasonal variation of atmospheric multiple-muon events in the MINOS Near and Far Detectors

We report the first observation of seasonal modulations in the rates of cosmic ray multiple-muon events at two underground sites, the MINOS Near Detector with an overburden of 225 mwe, and the MINOS Far Detector site at 2100 mwe. At the deeper site, multiple-muon events with muons separated by more than 8 m exhibit a seasonal rate that peaks during the summer, similar to that of single-muon events. In contrast and unexpectedly, the rate of multiple-muon events with muons separated by less than 5-8 m, and the rate of multiple-muon events in the smaller, shallower Near Detector, exhibit a seasonal rate modulation that peaks in the winter

Measurement of partonic nuclear effects in deep-inelastic neutrino scattering using MINERvA

The MINERvA Collaboration reports a novel study of neutrino-nucleus charged-current deep inelastic scattering (DIS) using the same neutrino beam incident on targets of polystyrene, graphite, iron, and lead. Results are presented as ratios of C, Fe, and Pb to CH. The ratios of total DIS cross sections as a function of neutrino energy and flux-integrated differential cross sections as a function of the Bjorken scaling variable x are presented in the neutrino- energy range of 5-50 GeV. Based on the predictions of charged-lepton scattering ratios, good agreement is found between the data and prediction at medium x and low neutrino energy. However, the ratios appear to be below predictions in the vicinity of the nuclear shadowing region, x \u3c 0.1. This apparent deficit, reflected in the DIS cross-section ratio at high E., is consistent with previous MINERvA observations [B. Tice et al. (MINERvA Collaboration), Phys. Rev. Lett. 112, 231801 (2014).] and with the predicted onset of nuclear shadowing with the axial-vector current in neutrino scattering

Measurement of neutrino flux from neutrino-electron elastic scattering

Muon-neutrino elastic scattering on electrons is an observable neutrino process whose cross section is precisely known. Consequently a measurement of this process in an accelerator-based nu(mu) beam can improve the knowledge of the absolute neutrino flux impinging upon the detector; typically this knowledge is limited to similar to 10% due to uncertainties in hadron production and focusing. We have isolated a sample of 135 +/- 17 neutrino-electron elastic scattering candidates in the segmented scintillator detector of MINERvA, after subtracting backgrounds and correcting for efficiency. We show how this sample can be used to reduce the total uncertainty on the NuMI nu(mu) flux from 9% to 6%. Our measurement provides a flux constraint that is useful to other experiments using the NuMI beam, and this technique is applicable to future neutrino beams operating at multi-GeV energies