Measuring Neutrino Oscillation Parameters Using [nu][mu] Disappearance in MINOS

Measuring Neutrino Oscillation Parameters Using [nu][mu] Disappearance in MINOS PDF Author: Christopher James Backhouse
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ISBN:
Category : Neutrinos
Languages : en
Pages : 358

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Measuring Neutrino Oscillation Parameters Using [nu][mu] Disappearance in MINOS

Measuring Neutrino Oscillation Parameters Using [nu][mu] Disappearance in MINOS PDF Author: Christopher James Backhouse
Publisher:
ISBN:
Category : Neutrinos
Languages : en
Pages : 358

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Measuring Neutrino Oscillation Parameters Using Vu Disappearance in MINOS.

Measuring Neutrino Oscillation Parameters Using Vu Disappearance in MINOS. PDF Author: Christopher James Backhouse
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ISBN:
Category :
Languages : en
Pages :

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Measuring Neutrino Oscillation Parameters Using $\nu_\mu$ Disappearance in MINOS.

Measuring Neutrino Oscillation Parameters Using $\nu_\mu$ Disappearance in MINOS. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 192

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MINOS is a long-baseline neutrino oscillation experiment. It consists of two large steel-scintillator tracking calorimeters. The near detector is situated at Fermilab, close to the production point of the NuMI muon-neutrino beam. The far detector is 735 km away, 716m underground in the Soudan mine, Northern Minnesota. The primary purpose of the MINOS experiment is to make precise measurements of the 'atmospheric' neutrino oscillation parameters (?matm2 and sin2 2?atm). The oscillation signal consists of an energy-dependent deficit of v? interactions in the far detector. The near detector is used to characterize the properties of the beam before oscillations develop. The two-detector design allows many potential sources of systematic error in the far detector to be mitigated by the near detector observations. This thesis describes the details of the v?-disappearance analysis, and presents a new technique to estimate the hadronic energy of neutrino interactions. This estimator achieves a significant improvement in the energy resolution of the neutrino spectrum, and in the sensitivity of the neutrino oscillation fit. The systematic uncertainty on the hadronic energy scale was re-evaluated and found to be comparable to that of the energy estimator previously in use. The best-fit oscillation parameters of the v?-disappearance analysis, incorporating this new estimator were: ?m2 = 2.32-0.08+0.12 x 10-3 eV2, sin 2 2? > 0.90 (90% C.L.). A similar analysis, using data from a period of running where the NuMI beam was operated in a configuration producing a predominantly $ar{v}$? beam, yielded somewhat different best-fit parameters ?$ar{m}$2 = (3.36-0.40+0.46(stat.) ± 0.06(syst.)) x 10-3eV2, sin2 2$ar{θ}$ = 0.86-0.12_0.11(stat.) ± 0.01(syst.). The tension between these results is intriguing, and additional antineutrino data is currently being taken in order to further investigate this apparent discrepancy.

A Measurement of Muon Neutrino Disappearance with the MINOS Detectors and NuMI Beam

A Measurement of Muon Neutrino Disappearance with the MINOS Detectors and NuMI Beam PDF Author: Rustem Ospanov
Publisher:
ISBN:
Category : Muons
Languages : en
Pages : 560

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MINOS is a long-baseline two-detector neutrino oscillation experiment that uses a high intensity muon neutrino beam to investigate the phenomena of neutrino oscillations. The neutrino beam is produced by the NuMI facility at Fermilab, Batavia, Illinois, and is observed at near and far detectors placed 734 km apart. The neutrino interactions in the near detector are used to measure the initial muon neutrino flux. The vast majority of neutrinos travel through the near detector and Earth matter without interactions. A fraction of muon neutrinos oscillate into other flavors resulting in the disappearance of muon neutrinos at the far detector. This thesis presents a measurement of the muon neutrino oscillation parameters in the framework of the two-neutrino oscillation hypothesis.

A Measurement of Neutrino Oscillations with Muon Neutrinos in the MINOS Experiment

A Measurement of Neutrino Oscillations with Muon Neutrinos in the MINOS Experiment PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 258

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Experimental evidence has established that neutrino flavor states evolve over time. A neutrino of a particular flavor that travels some distance can be detected in a different neutrino flavor state. The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline experiment that is designed to study this phenomenon, called neutrino oscillations. MINOS is based at Fermilab near Chicago, IL, and consists of two detectors: the Near Detector located at Fermilab, and the Far Detector, which is located in an old iron mine in Soudan, MN. Both detectors are exposed to a beam of muon neutrinos from the NuMI beamline, and MINOS measures the fraction of muon neutrinos that disappear after traveling the 734 km between the two detectors. One can measure the atmospheric neutrino mass splitting and mixing angle by observing the energy-dependence of this muon neutrino disappearance. MINOS has made several prior measurements of these parameters. Here I describe recently-developed techniques used to enhance our sensitivity to the oscillation parameters, and I present the results obtained when they are applied to a dataset that is twice as large as has been previously analyzed. We measure the mass splitting ?m232 = (2.32-0.08+0.12) x 10-3 eV2/c4 and the mixing angle sin2(2?32) > 0.90 at 90% C.L. These results comprise the world's best measurement of the atmospheric neutrino mass splitting. Alternative disappearance models are also tested. The neutrino decay hypothesis is disfavored at 7.2? and the neutrino quantum decoherence hypothesis is disfavored at 9.0?.

Measuring the Disappearance of Muon Neutrinos with the MINOS Detector

Measuring the Disappearance of Muon Neutrinos with the MINOS Detector PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 191

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MINOS is a long baseline neutrino oscillation experiment. It measures the flux from the predominately muon neutrino NuMI beam first 1 km from beam start and then again 735 km later using a pair of steel scintillator tracking calorimeters. The comparison of measured neutrino energy spectra at our Far Detector with the prediction based on our Near Detector measurement allows for a measurement of the parameters which define neutrino oscillations. This thesis will describe the most recent measurement of muon neutrino disappearance in the NuMI muon neutrino beam using the MINOS experiment.

Measurement of Neutrino Oscillation Parameters Using Anti-fiducial Charged Current Events in MINOS.

Measurement of Neutrino Oscillation Parameters Using Anti-fiducial Charged Current Events in MINOS. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 157

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Abstract The Main Injector Neutrino Oscillation Search (MINOS) obse rves the disappearance of muon neutrinos as they propagate in the long baseline Neutri nos at the Main Injector (NuMI) beam. MINOS consists of two detectors. The near detector sam ples the initial composition of the beam. The far detector, 735 km away, looks for an energy-d ependent deficit in the neutrino spectrum. This energy-dependent deficit is interpreted as q uantum mechanical oscillations be- tween neutrino flavors. A measurement is made of the effective two-neutrino mixing parameters ? m 2 ≈ ? m 2 23 and sin 2 2 ? ≈ sin 2 2 ? 23 . The primary MINOS analysis uses charged current events in the fiducial volume of the far detector. This analysis uses the roughly equal-sized sample of events that fails the fiducial cut, consisting of interact ions outside the fiducial region of the detector and in the surrounding rock. These events provide a n independent and complementary measurement, albeit weaker due to incomplete reconstructi on of the events. This analysis reports on an exposure of 7 . 25 × 10 20 protons-on-target. Due to poor energy resolution, the meas urement of sin 2 2 ? is much weaker than established results, but the measuremen t of sin 2 2 ? > 0 . 56 at 90% confidence is consistent with the accepted value. The measur ement of ? m 2 is much stronger. Assuming sin 2 2 ? = 1 , ? m 2 = (2 . 20 ± 0 . 18[stat] ± 0 . 14[syst]) × 10 - -3 eV 2 .

Measuring $\nu_\mu$ Disappearance with the MINOS Experiment

Measuring $\nu_\mu$ Disappearance with the MINOS Experiment PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 218

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The MINOS Experiment consists of two steel-scintillator calorimeters, sampling the long baseline NuMI muon neutrino beam. It was designed to make a precise measurement of the 'atmospheric' neutrino mixing parameters, [Delta]m2 atm. and sin2 (2 atm.). The Near Detector measures the initial spectrum of the neutrino beam 1km from the production target, and the Far Detector, at a distance of 735 km, measures the impact of oscillations in the neutrino energy spectrum. Work performed to validate the quality of the data collected by the Near Detector is presented as part of this thesis. This thesis primarily details the results of a v[mu] disappearance analysis, and presents a new sophisticated fitting software framework, which employs a maximum likelihood method to extract the best fit oscillation parameters. The software is entirely decoupled from the extrapolation procedure between the detectors, and is capable of fitting multiple event samples (defined by the selections applied) in parallel, and any combination of energy dependent and independent sources of systematic error. Two techniques to improve the sensitivity of the oscillation measurement were also developed. The inclusion of information on the energy resolution of the neutrino events results in a significant improvement in the allowed region for the oscillation parameters. The degree to which sin2 (2[theta])= 1.0 could be disfavoured with the exposure of the current dataset if the true mixing angle was non-maximal, was also investigated, with an improved neutrino energy reconstruction for very low energy events. The best fit oscillation parameters, obtained by the fitting software and incorporating resolution information were.

An Atmospheric Muon Neutrino Disappearance Measurement with the MINOS Far Detector

An Atmospheric Muon Neutrino Disappearance Measurement with the MINOS Far Detector PDF Author: Jeremy Peter Gogos
Publisher:
ISBN:
Category :
Languages : en
Pages : 384

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A Study of Muon Neutrino Disappearance in the MINOS Detectors and the NuMI Beam

A Study of Muon Neutrino Disappearance in the MINOS Detectors and the NuMI Beam PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 242

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Book Description
There is now substantial evidence that the proper description of neutrino involves two representations related by the 3 x 3 PMNS matrix characterized by either distinct mass or flavor. The parameters of this mixing matrix, three angles and a phase, as well as the mass differences between the three mass eigenstates must be determined experimentally. The Main Injector Neutrino Oscillation Search experiment is designed to study the flavor composition of a beam of muon neutrinos as it travels between the Near Detector at Fermi National Accelerator Laboratory at 1 km from the target, and the Far Detector in the Soudan iron mine in Minnesota at 735 km from the target. From the comparison of reconstructed neutrino energy spectra at the near and far location, precise measurements of neutrino oscillation parameters from muon neutrino disappearance and electron neutrino appearance are expected. It is very important to know the neutrino flux coming from the source in order to achieve the main goal of the MINOS experiment: precise measurements of the atmospheric mass splitting.