228 research outputs found
Observation of muon neutrino disappearance with the MINOS detectors in the NuMI neutrino beam
No full textThis Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27x10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336 +/- 14 events. The data are consistent with nu(mu) disappearance via oscillations with vertical bar Delta m(32)(2)vertical bar=2.74(-0.26)(+0.44)x10(-3) eV(2) and sin(2)(2 theta(23))> 0.87 (68% C.L.)
Antineutrino Oscillations in the Atmospheric Sector
No full textThis thesis presents measurements of the oscillations of muon antineutrinos in the atmospheric sector, where world knowledge of antineutrino oscillations lags well behind the knowledge of neutrinos, as well as a search for νμ \to ν̅ μ transitions. Differences between neutrino and antineutrino oscillations could be a sign of physics beyond the Standard Model, including non-standard matter interactions or the violation of CPT symmetry. These measurements leverage the sign-selecting capabilities of the magnetized steel-scintillator MINOS detectors to analyze antineutrinos from the NuMI beam, both when it is in FHC and when it is in RHC. Antineutrino oscillations are observed at |Δm̅2atm| = (3.36+0.46-0.40(stat)±0.06(syst)) x 10- eV2 and sin2(2θ̅23 = 0.860+0.11-0.12(stat)± 0.01(syst). The oscillation parameters measured for antineutrinos and those measured by MINOS for neutrinos differ by a large enough margin that the chance of obtaining two values as discrepant as those observed is only 2%, assuming the two measurements arise from the same underlying mechanism, with the same parameter values. No evidence is seen for neutrino-to-antineutrino transitions
Search for flavor-changing nonstandard neutrino interactions using nu(e) appearance in MINOS
No full textWe report new constraints on flavor-changing nonstandard neutrino interactions from the MINOS long-baseline experiment using nu(e) and (nu) over bar (e) appearance candidate events from predominantly nu(mu) and (nu) over bar (mu) beams. We used a statistical selection algorithm to separate nu(e) candidates from background events, enabling an analysis of the combined MINOS neutrino and antineutrino data. We observe no deviations from standard neutrino mixing, and thus place constraints on the nonstandard interaction matter effect, vertical bar epsilon(e tau)vertical bar, and phase, (delta(CP) + delta(e tau)), using a 30-bin likelihood fit.Physic
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The MINOS Scintillator Calorimeter System
No full textThe MINOS detectors will use extruded plastic scintillator strips, which are read out by wavelength-shifting fibers coupled to multipixel photodetectors. This technique provides excellent energy and spatial resolution. The MINOS detectors are described in detail along with results from light output tests
Precision constraints for three-flavor neutrino oscillations from the full MINOS+ and MINOS dataset
No full textWe report the final measurement of the neutrino oscillation parameters Δm_{32}^{2} and sin^{2}θ_{23} using all data from the MINOS and MINOS+ experiments. These data were collected using a total exposure of 23.76×10^{20} protons on target producing ν_{μ} and ν[over ¯]_{μ} beams and 60.75 kt yr exposure to atmospheric neutrinos. The measurement of the disappearance of ν_{μ} and the appearance of ν_{e} events between the Near and Far detectors yields |Δm_{32}^{2}|=2.40_{-0.09}^{+0.08}(2.45_{-0.08}^{+0.07})×10^{-3} eV^{2} and sin^{2}θ_{23}=0.43_{-0.04}^{+0.20}(0.42_{-0.03}^{+0.07}) at 68% C.L. for normal (inverted) hierarchy
Observation of muon neutrino disappearance with the MINOS detectors in the NuMI neutrino beam
No full textThis letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rate and energy spectra of charged current muon neutrino interactions are compared in two detectors located along the beam axis at distances of 1 km and 735 km. With 1.27 x 10^{20} 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336 \pm 14.4 events. The data are consistent with muon neutrino disappearance via oscillation with |\Delta m^2_{23}| = 2.74^{+0.44}_{-0.26} x 10^{-3} eV^2/c^4 and sin^2(2\theta_{23}) > 0.87 (at 60% C.L.)
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The Fermilab long-baseline neutrino program
No full textFermilab is embarking upon a neutrino oscillation program which includes a long-baseline neutrino experiment MINOS. MINOS will be a 10 kiloton detector located 730 km Northwest of Fermilab in the Soudan underground laboratory. It will be sensitive to neutrino oscillations with parameters above {Delta}m{sup 2} {approximately} 3 {times} 10{sup {minus}3} eV{sup 2} and sin{sup 2}(2{theta}) {approximately} 0.02
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Search for flavor-changing nonstandard neutrino interactions using ?e appearance in MINOS
No full textWe report new constraints on flavor-changing nonstandard neutrino interactions from the MINOS longbaseline experiment using ?e and ¯?e appearance candidate events from predominantly ?µ and ¯?µ beams. We used a statistical selection algorithm to separate ?e candidates from background events, enabling an analysis of the combined MINOS neutrino and antineutrino data. We observe no deviations from standard neutrino mixing, and thus place constraints on the nonstandard interaction matter effect, |eet|, and phase, (dCP + det), using a 30-bin likelihood fit
Search for flavor-changing nonstandard neutrino interactions using ?e appearance in MINOS
No full textWe report new constraints on flavor-changing nonstandard neutrino interactions from the MINOS longbaseline experiment using ?e and ¯?e appearance candidate events from predominantly ?µ and ¯?µ beams. We used a statistical selection algorithm to separate ?e candidates from background events, enabling an analysis of the combined MINOS neutrino and antineutrino data. We observe no deviations from standard neutrino mixing, and thus place constraints on the nonstandard interaction matter effect, |eet|, and phase, (dCP + det), using a 30-bin likelihood fit
Neutrino oscillations with MINOS and MINOS+
No full textThe MINOS experiment ran from 2003 until 2012 and collected a data sample including 10.71 × 1020
protons-on-target (POT) of beam neutrinos, 3.36 × 1020 POT of beam antineutrinos and an atmospheric
neutrino exposure of 37.88 kt yrs. The final measurement of the atmospheric neutrino oscillation parameters,
m2
32 and θ23, came from a full three flavour oscillation analysis of the combined CC νμ and CC νμ
beam and atmospheric samples and the CC νe and CC νe appearance samples. This analysis yielded the
most precise measurement of the atmospheric mass splitting m2
32 performed to date. The results are
|m2
32| = [2.28–2.46] × 10−3 eV2 (68%) and sin2 θ23 = 0.35–0.65 (90%) in the normal hierarchy, and
|m2
32| = [2.32–2.53] × 10−3 eV2 (68%) and sin2 θ23 = 0.34–0.67 (90%) in the inverted hierarchy. The
successor to MINOS in the NOνA era at FNAL, MINOS+, is now collecting data mostly in the 3–10 GeV
region, and an analysis of νμ disappearance using the first 2.99 × 1020 POT of data produced results very
consistent with those from MINOS. Future data will further test the standard neutrino oscillation paradigm
and allow for improved searches for exotic phenomena including sterile neutrinos, large extra dimensions
and non-standard interactions
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