arXiv subjects

M. D. Messier

Publications and source records attributed to M. D. Messier.

42 records · Page 3Linked to original sources

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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arXiv2010

Charged Kaon Mass Measurement using the Cherenkov Effect

The two most recent and precise measurements of the charged kaon mass use X-rays from kaonic atoms and report uncertainties of 14 ppm and 22 ppm yet differ from each other by 122 ppm. We describe the possibility of an independent mass measurement using the measurement of Cherenkov light from a narrow-band beam of kaons, pions, and protons. This technique was demonstrated using data taken opportunistically by the Main Injector Particle Production experiment at Fermi National Accelerator Laboratory which recorded beams of protons, kaons, and pions ranging in momentum from +37 GeV/c to +63 GeV/c. The measured value is 491.3 +/- 1.7 MeV/c^2, which is within 1.4 sigma of the world average. An improvement of two orders of magnitude in precision would make this technique useful for resolving the ambiguity in the X-ray data and may be achievable in a dedicated experiment.

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arXiv2009

First Measurement of $ν_μ$ and $ν_e$ Events in an Off-Axis Horn-Focused Neutrino Beam

We report the first observation of off-axis neutrino interactions in the MiniBooNE detector from the NuMI beamline at Fermilab. The MiniBooNE detector is located 745 m from the NuMI production target, at 110 mrad angle ($6.3^{\circ}$) with respect to the NuMI beam axis. Samples of charged current quasi-elastic $ν_μ$ and $ν_e$ interactions are analyzed and found to be in agreement with expectation. This provides a direct verification of the expected pion and kaon contributions to the neutrino flux and validates the modeling of the NuMI off-axis beam.

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arXiv2006

Review of Neutrino Oscllations Experiments

Several experiments have sought evidence for neutrino mass and mixing via the phenomenon of neutrino flavor oscillations. In a three neutrino model, these oscillations are described by three angles, two mass splittings, and one CP violating phase. Experiments using neutrinos from the Sun, the atmosphere, nuclear reactors, and particle accelerators have gathered considerable information on these angles and splittings. Two of the three angles are known to be large: $θ_{12} \simeq 33^\circ$, $θ_{23} \simeq 45^\circ$, and an upper limit is known on the third, $θ_{13}<10^\circ$. Likewise, the mass splittings are known to fall in the range $Δm^2_{12} \simeq 8 \times 10^{-5}$ and $|Δm^2_{23}| \simeq 2.4 \times 10^{-3}$ eV$^2$. Several questions remain: the sign of the 2--3 mass splitting, the size of the unknown angle $θ_{13}$, and the size of the CP violating phase are yet to be measured. Also, a report of short-baseline $\barν_e \to \barν_mu$ oscillations has yet to be confirmed. These open questions are the target of an experimental neutrino oscillation program currently underway. This report will attempt to summarize the current state of neutrino oscillation measurements and the future program in as succinct a manner as possible.

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arXiv2004

Search for Dark Matter WIMPs using Upward Through-going Muons in Super-Kamiokande

We present the results of indirect searches for Weakly Interacting Massive Particles (WIMPs) with 1679.6 live days of data from the Super-Kamiokande detector using neutrino-induced upward through-going muons. The search is performed by looking for an excess of high energy muon neutrinos from WIMP annihilations in the Sun, the core of the Earth, and the Galactic Center, as compared to the number expected from the atmospheric neutrino background. No statistically significant excess was seen. We calculate flux limits in various angular cones around each of the above celestial objects. We obtain conservative model-independent upper limits on WIMP-nucleon cross-section as a function of WIMP mass and compare these results with the corresponding results from direct dark matter detection experiments.

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arXiv2002

The Hadron Hose: Continuous Toroidal Focusing for Conventional Neutrino Beams

We have developed a new focusing system for conventional neutrino beams. The ``Hadron Hose'' is a wire located in the meson decay volume, downstream of the target and focusing horns. The wire is pulsed with high current to provide a toroidal magnetic field which continuously focuses mesons. The hose increases the neutrino event rate and reduces differences between near-field and far-field neutrino spectra for oscillation experiments. We have studied this device as part of the development of the Neutrinos at the Main Injector (NuMI) project, but it might also be of use for other conventional neutrino beams.

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