arXiv subjects

A. Habig

Publications and source records attributed to A. Habig.

At least 73 records · Page 4Linked to original sources

arXiv2014

Combined analysis of $ν_μ$ disappearance and $ν_μ \rightarrow ν_{e}$ 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 $ν_μ$ disappearance and $ν_{e}$ appearance data using the three-flavor formalism. We measure $|Δm^{2}_{32}|=[2.28-2.46]\times10^{-3}\mbox{\,eV}^{2}$ (68% C.L.) and $\sin^{2}θ_{23}=0.35-0.65$ (90% C.L.) in the normal hierarchy, and $|Δm^{2}_{32}|=[2.32-2.53]\times10^{-3}\mbox{\,eV}^{2}$ (68% C.L.) and $\sin^{2}θ_{23}=0.34-0.67$ (90% C.L.) in the inverted hierarchy. The data also constrain $δ_{CP}$, the $θ_{23}$ octant degeneracy and the mass hierarchy; we disfavor 36% (11%) of this three-parameter space at 68% (90%) C.L.

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arXiv2013

R&D Argon Detector at Ash River (RADAR) - Letter of Intent

In the RADAR project described in this Letter of Intent, we propose to deploy a 6 kton liquid argon TPC at the NOvA Far Detector building in Ash River, Minnesota, and expose it to the NuMI beam during NOvA running. It will significantly add to the physics capabilities of the NOvA program while providing LBNE with an R&D program based on full-scale TPC module assemblies. RADAR offers an excellent opportunity to improve the full Homestake LBNE project in physics reach, timeline, costs, and fostering international partnership. The anticipated duration of the project's construction is 5 years, with running happening between 2018 and 2023.

physics.ins-det↗

arXiv2013

CHerenkov detectors In mine PitS (CHIPS) Letter of Intent to FNAL

This Letter of Intent outlines a proposal to build a large, yet cost-effective, 100 kton fiducial mass water Cherenkov detector that will initially run in the NuMI beam line. The CHIPS detector (CHerenkov detector In Mine PitS) will be deployed in a flooded mine pit, removing the necessity and expense of a substantial external structure capable of supporting a large detector mass. There are a number of mine pits in northern Minnesota along the NuMI beam that could be used to deploy such a detector. In particular, the Wentworth Pit 2W is at the ideal off-axis angle to contribute to the measurement of the CP violating phase. The detector is designed so that it can be moved to a mine pit in the LBNE beam line once that becomes operational.

physics.ins-det↗

arXiv2013

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

We report measurements of oscillation parameters from $ν_{mu}$ and $\barν_μ$ disappearance using beam and atmospheric data from MINOS. The data comprise exposures of \unit[$10.71 \times 10^{20}$]{protons on target (POT)} in the $ν_μ$-dominated beam, $\unit[3.36\times10^{20}]{POT}}$ in the $\barν_μ$-enhanced beam, and 37.88 kton-years of atmospheric neutrinos. Assuming identical $ν$ and $\barν$ oscillation parameters, we measure \mbox{$|Δm^2}| = \unit[2.41^{+0.09}_{-0.10}) \times 10^{-3}]{eV^{2}}$} and $\sin^{2}/!/left(2θ\right) = 0.950^{+0.035}_{-0.036}$. Allowing independent $ν$ and $\barν$ oscillations, we measure antineutrino parameters of $|Δ\bar{m}^2| = \unit[(2.50 ^{+0.23}_{-0.25}) \times 10^{-3}]{eV^{2}}$ and $\sin^{2}/!/left(2\barθ \right) = 0.97^{+0.03}_{-0.08}$, with minimal change to the neutrino parameters.

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arXiv2013

Electron neutrino and antineutrino appearance in the full MINOS data sample

We report on $ν_e$ and $\barν_e$ appearance in $ν_μ$ and $\barν_μ$ beams using the full MINOS data sample. The comparison of these $ν_e$ and $\barν_e$ appearance data at a 735 km baseline with $θ_{13}$ measurements by reactor experiments probes $δ$, the $θ_{23}$ octant degeneracy, and the mass hierarchy. This analysis is the first use of this technique and includes the first accelerator long-baseline search for $\barν_μ\rightarrow\barν_e$. Our data disfavor 31% (5%) of the three-parameter space defined by $δ$, the octant of the $θ_{23}$, and the mass hierarchy at the 68% (90%) C.L. We measure a value of 2sin$^2(2θ_{13})$sin$^2(θ_{23})$ that is consistent with reactor experiments.

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arXiv2013

A search for flavor-changing non-standard neutrino interactions by MINOS

We report new constraints on flavor-changing non-standard neutrino interactions (NSI) using data from the MINOS experiment. We analyzed a combined set of beam neutrino and antineutrino data, and found no evidence for deviations from standard neutrino mixing. The observed energy spectra constrain the NSI parameter to the range $-0.20 < \varepsilon_{μτ} < 0.07\;\text{(90% C.L.)}$

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arXiv2012

Measurements of atmospheric neutrinos and antineutrinos in the MINOS Far Detector

This paper reports measurements of atmospheric neutrino and antineutrino interactions in the MINOS Far Detector, based on 2553 live-days (37.9 kton-years) of data. A total of 2072 candidate events are observed. These are separated into 905 contained-vertex muons and 466 neutrino-induced rock-muons, both produced by charged-current $ν_μ$ and $\barν_μ$ interactions, and 701 contained-vertex showers, composed mainly of charged-current $ν_{e}$ and $\barν_{e}$ interactions and neutral-current interactions. The curvature of muon tracks in the magnetic field of the MINOS Far Detector is used to select separate samples of $ν_μ$ and $\barν_μ$ events. The observed ratio of $\barν_μ$ to $ν_μ$ events is compared with the Monte Carlo simulation, giving a double ratio of $R^{data}_{\barν/ν}/R^{MC}_{\barν/ν} = 1.03 \pm 0.08 (stat.) \pm 0.08 (syst.)$. The $ν_μ$ and $\barν_μ$ data are separated into bins of $L/E$ resolution, based on the reconstructed energy and direction of each event, and a maximum likelihood fit to the observed $L/E$ distributions is used to determine the atmospheric neutrino oscillation parameters. This fit returns 90% confidence limits of $|Δm^{2}| = (1.9 \pm 0.4) \times 10^{-3} eV^{2}$ and $sin^{2} 2θ> 0.86$. The fit is extended to incorporate separate $ν_μ$ and $\barν_μ$ oscillation parameters, returning 90% confidence limits of $|Δm^{2}|-|Δ\bar{m}^{2}| = 0.6^{+2.4}_{-0.8} \times 10^{-3} eV^{2}$ on the difference between the squared-mass splittings for neutrinos and antineutrinos.

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arXiv2012

An improved measurement of muon antineutrino disappearance in MINOS

We report an improved measurement of muon anti-neutrino disappearance over a distance of 735km using the MINOS detectors and the Fermilab Main Injector neutrino beam in a muon anti-neutrino enhanced configuration. From a total exposure of 2.95e20 protons on target, of which 42% have not been previously analyzed, we make the most precise measurement of the anti-neutrino "atmospheric" delta-m squared = 2.62 +0.31/-0.28 (stat.) +/- 0.09 (syst.) and constrain the anti-neutrino atmospheric mixing angle >0.75 (90%CL). These values are in agreement with those measured for muon neutrinos, removing the tension reported previously.

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arXiv2012

Search for Lorentz invariance and CPT violation with muon antineutrinos in the MINOS Near Detector

We have searched for sidereal variations in the rate of antineutrino interactions in the MINOS Near Detector. Using antineutrinos produced by the NuMI beam, we find no statistically significant sidereal modulation in the rate. When this result is placed in the context of the Standard Model Extension theory we are able to place upper limits on the coefficients defining the theory. These limits are used in combination with the results from an earlier analysis of MINOS neutrino data to further constrain the coefficients.

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arXiv2011

The 2010 Interim Report of the Long-Baseline Neutrino Experiment Collaboration Physics Working Groups

In early 2010, the Long-Baseline Neutrino Experiment (LBNE) science collaboration initiated a study to investigate the physics potential of the experiment with a broad set of different beam, near- and far-detector configurations. Nine initial topics were identified as scientific areas that motivate construction of a long-baseline neutrino experiment with a very large far detector. We summarize the scientific justification for each topic and the estimated performance for a set of far detector reference configurations. We report also on a study of optimized beam parameters and the physics capability of proposed Near Detector configurations. This document was presented to the collaboration in fall 2010 and updated with minor modifications in early 2011.

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arXiv2011

Search for the disappearance of muon antineutrinos in the NuMI neutrino beam

We report constraints on antineutrino oscillation parameters that were obtained by using the two MINOS detectors to measure the 7% muon antineutrino component of the NuMI neutrino beam. In the Far Detector, we select 130 events in the charged-current muon antineutrino sample, compared to a prediction of 136.4 +/- 11.7(stat) ^{+10.2}_{-8.9}(syst) events under the assumption |dm2bar|=2.32x10^-3 eV^2, snthetabar=1.0. Assuming no oscillations occur at the Near Detector baseline, a fit to the two-flavor oscillation approximation constrains |dm2bar|<3.37x10^-3 eV^2 at the 90% confidence level with snthetabar=1.0.

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arXiv2011

First direct observation of muon antineutrino disappearance

This letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for muon antineutrino production, accumulating an exposure of $1.71\times 10^{20}$ protons on target. In the Far Detector, 97 charged current muon antineutrino events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at $6.3σ$. The best fit to oscillation yields $Δ\bar{m}^{2}=(3.36^{+0.46}_{-0.40}\textrm{(stat.)}\pm0.06\textrm{(syst.)})\times 10^{-3}\,\eV^{2}$, $\sin^{2}(2\barθ)=0.86^{+0.11}_{-0.12}\textrm{(stat.)}\pm0.01\textrm{(syst.)}$. The MINOS muon neutrino and muon antineutrino measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.

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arXiv2011

Improved search for muon-neutrino to electron-neutrino oscillations in MINOS

We report the results of a search for $ν_{e}$ appearance in a $ν_μ$ beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of $8.2\times10^{20}$ protons on the NuMI target at Fermilab, we find that $2\sin^2(θ_{23})\sin^2(2θ_{13})<0.12\ (0.20)$ at 90% confidence level for $δ\mathord{=}0$ and the normal (inverted) neutrino mass hierarchy, with a best fit of $2\sin^2(θ_{23})\sin^2(2θ_{13})\,\mathord{=}\,0.041^{+0.047}_{-0.031}\ (0.079^{+0.071}_{-0.053})$. The $θ_{13}\mathord{=}0$ hypothesis is disfavored by the MINOS data at the 89% confidence level.

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arXiv2011

Active to sterile neutrino mixing limits from neutral-current interactions in MINOS

Results are reported from a search for active to sterile neutrino oscillations in the MINOS long-baseline experiment, based on the observation of neutral-current neutrino interactions, from an exposure to the NuMI neutrino beam of $7.07\times10^{20}$ protons on target. A total of 802 neutral-current event candidates is observed in the Far Detector, compared to an expected number of $754\pm28\rm{(stat.)}\pm{37}\rm{(syst.)}$ for oscillations among three active flavors. The fraction $f_s$ of disappearing \numu that may transition to $ν_s$ is found to be less than 22% at the 90% C.L.

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arXiv2011

Measurement of the neutrino mass splitting and flavor mixing by MINOS

Measurements of neutrino oscillations using the disappearance of muon neutrinos from the Fermilab NuMI neutrino beam as observed by the two MINOS detectors are reported. New analysis methods have been applied to an enlarged data sample from an exposure of $7.25 \times 10^{20}$ protons on target. A fit to neutrino oscillations yields values of $|Δm^2| = (2.32^{+0.12}_{-0.08})\times10^{-3}$\,eV$^2$ for the atmospheric mass splitting and $\rm \sin^2\!(2θ) > 0.90$ (90%\,C.L.) for the mixing angle. Pure neutrino decay and quantum decoherence hypotheses are excluded at 7 and 9 standard deviations, respectively.

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arXiv2010

The atmospheric charged kaon/pion ratio using seasonal variation methods

Observed since the 1950's, the seasonal effect on underground muons is a well studied phenomenon. The interaction height of incident cosmic rays changes as the temperature of the atmosphere changes, which affects the production height of mesons (mostly pions and kaons). The decay of these mesons produces muons that can be detected underground. The production of muons is dominated by pion decay, and previous work did not include the effect of kaons. In this work, the methods of Barrett and MACRO are extended to include the effect of kaons. These efforts give rise to a new method to measure the atmospheric K/$π$ ratio at energies beyond the reach of current fixed target experiments. These methods were applied to data from the MINOS far detector. A method is developed for making these measurements at other underground detectors, including OPERA, Super-K, IceCube, Baksan and the MINOS near detector.

hep-ex↗

arXiv2010

A Search for Lorentz Invariance and CPT Violation with the MINOS Far Detector

We searched for a sidereal modulation in the MINOS far detector neutrino rate. Such a signal would be a consequence of Lorentz and CPT violation as described by the Standard-Model Extension framework. It also would be the first detection of a perturbative effect to conventional neutrino mass oscillations. We found no evidence for this sidereal signature and the upper limits placed on the magnitudes of the Lorentz and CPT violating coefficients describing the theory are an improvement by factors of $20-510$ over the current best limits found using the MINOS near detector.

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arXiv2008

Current NuMI/MINOS Oscillation Results

The MINOS experiment is now making precise measurements of the nu_mu disappearance oscillations seen in atmospheric neutrinos, and will extend our reach towards the so far unseen theta_13 by looking for nu_e appearance in the nu_mu beam. It does so by using the intense, well-understood NuMI neutrino beam created at Fermilab and observing it 735 km away at the Soudan Mine in Northeast Minnesota. Results from MINOS' first two years of operations will be presented.

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