Precision measurement of the speed of propagation of neutrinos using the MINOS detectors

We report a two-detector measurement of the propagation speed of neutrinos over a baseline of 734 km. The measurement was made with the NuMI beam at Fermilab between the near and far MINOS detectors. The fractional difference between the neutrino speed and the speed of light is determined to be (v/c - 1) = (1.0 +/- 1.1) x 10(-6), consistent with relativistic neutrinos

The NuMI neutrino beam

This paper describes the hardware and operations of the Neutrinos at the Main Injector (NuMI) beam at Fermilab. It elaborates on the design considerations for the beam as a whole and for individual elements. The most important design details of individual components are described. Beam monitoring systems and procedures, including the tuning and alignment of the beam and NuMI long-term performance, are also discussed. (C) 2015 Elsevier B.V. All rights reserved

Measurement of the multiple-muon charge ratio in the MINOS Far Detector

The charge ratio, R-mu = N mu + / N mu-, for cosmogenic multiple-muon events observed at an underground depth of 2070 mwe has been measured using the magnetized MINOS Far Detector. The multiple-muon events, recorded nearly continuously from August 2003 until April 2012, comprise two independent data sets imaged with opposite magnetic field polarities, the comparison of which allows the systematic uncertainties of the measurement to be minimized. The multiple-muon charge ratio is determined to be R mu = 1.104 + / - 0.006(stat)(-0.010)( + 0.009) (syst). This measurement complements previous determinations of single-muon and multiple-muon charge ratios at underground sites and serves to constrain models of cosmic-ray interactions at TeV energies

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

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

Combined Analysis of nu(mu) Disappearance and nu(mu) -\u3e nu(e) Appearance in MINOS Using Accelerator and Atmospheric Neutrinos

We report on a new analysis of neutrino oscillations in MINOS using the complete set of accelerator and atmospheric data. The analysis combines the nu(mu) disappearance and nu(e) appearance data using the three-flavor formalism. We measure vertical bar Delta m(32)(2)vertical bar = [2.28-2.46] x 10(-3) eV(2) (68% C.L.) and sin(2)theta(23) = 0.35-0.65 (90% C.L.) in the normal hierarchy, and vertical bar Delta m(32)(2)vertical bar = [2.32-2.53] x 10(-3) eV(2) (68% C.L.) and sin(2)theta(23) = 0.34-0.67 (90% C.L.) in the inverted hierarchy. The data also constrain delta(CP), the theta(23) octant degeneracy and the mass hierarchy; we disfavor 36% (11%) of this three-parameter space at 68% (90%) C.L

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

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

Study of quasielastic scattering using charged-current nu(mu)-iron interactions in the MINOS near detector

Kinematic distributions from an inclusive sample of 1.41 x 10(6) charged-current nu(mu) interactions on iron, obtained using the MINOS near detector exposed to a wide-band beam with peak flux at 3 GeV, are compared to a conventional treatment of neutrino scattering within a Fermi gas nucleus. Results are used to guide the selection of a subsample enriched in quasielastic nu Fe-mu interactions, containing an estimated 123,000 quasielastic events of incident energies 1 \u3c E-nu \u3c 8 GeV, with \u3c E-nu \u3e = 2.79 GeV. Four additional subsamples representing topological and kinematic sideband regions to quasielastic scattering are also selected for the purpose of evaluating backgrounds. Comparisons using subsample distributions in four-momentum transfer Q(2) show the Monte Carlo model to be inadequate at low Q(2). Its shortcomings are remedied via inclusion of a Q(2)-dependent suppression function for baryon resonance production, developed from the data. A chi-square fit of the resulting Monte Carlo simulation to the shape of the Q(2) distribution for the quasielastic-enriched sample is carried out with the axial-vector mass M-A of the dipole axial-vector form factor of the neutron as a free parameter. The effective M-A which best describes the data is 1.23(-0.09)(+0.13)(fit)(-0.15)(+0.12)(syst) GeV

Observation of muon intensity variations by season with the MINOS near detector

A sample of 1.53 x 10(9) cosmic-ray-induced single muon events has been recorded at 225 m water equivalent using the MINOS near detector. The underground muon rate is observed to be highly correlated with the effective atmospheric temperature. The coefficient alpha(T), relating the change in the muon rate to the change in the vertical effective temperature, is determined to be 0.428 +/- 0.003(stat.) +/- 0.059(syst.). An alternative description is provided by the weighted effective temperature, introduced to account for the differences in the temperature profile and muon flux as a function of zenith angle. Using the latter estimation of temperature, the coefficient is determined to be 0.352 +/- 0.003(stat.) +/- 0.046(syst.)