Download or read book Measuring theta Via Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment written by and published by . This book was released on 2011 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the primary goals in neutrino physics at the present moment is to make a measurement of the neutrino oscillation parameter $\theta_$. This parameter, in addition to being unknown, could potentially allow for the introduction of CP violation into the lepton sector. The MINOS long-baseline neutrino oscillation experiment has the ability to make a measurement of this parameter, by looking for the oscillation of muon neutrinos to electron neutrinos between a Near and Far Detector over a distance of 735 km. This thesis discusses the development of an analysis framework to search for this oscillation mode. Two major improvements to pre-existing analysis techniques have been implemented by the author. First, a novel particle ID technique based on strip topology, known as the Library Event Matching (LEM) method, is optimized for use in MINOS. Second, a multiple bin likelihood method is developed to fit the data. These two improvements, when combined, increase MINOS' sensitivity to $\sin^2(2\theta_)$ by 27\% over previous analyses. This thesis sees a small excess over background in the Far Detector. A Frequentist interpretation of the data rules out $\theta_=0$ at 91\%. A Bayesian interpretation of the data is also presented, placing the most stringent upper boundary on the oscillation parameter to date, at $\sin^2(2\theta_)
Download or read book Measuring 13 Via Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment written by Ruth Bushnell Toner and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment written by Juan Pedro Ochoa-Ricoux and published by Springer Science & Business Media. This book was released on 2011-04-11 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: The centerpiece of the thesis is the search for muon neutrino to electron neutrino oscillations which would indicate a non-zero mixing angle between the first and third neutrino generations (θ13), currently the “holy grail” of neutrino physics. The optimal extraction of the electron neutrino oscillation signal is based on the novel “library event matching” (LEM) method which Ochoa developed and implemented together with colleagues at Caltech and at Cambridge, which improves MINOS’ (Main Injector Neutrino Oscillator Search) reach for establishing an oscillation signal over any other method. LEM will now be the basis for MINOS’ final results, and will likely keep MINOS at the forefront of this field until it completes its data taking in 2011. Ochoa and his colleagues also developed the successful plan to run MINOS with a beam tuned for antineutrinos, to make a sensitive test of CPT symmetry by comparing the inter-generational mass splitting for neutrinos and antineutrinos. Ochoa’s in-depth, creative approach to the solution of a variety of complex experimental problems is an outstanding example for graduate students and longtime practitioners of experimental physics alike. Some of the most exciting results in this field to emerge in the near future may find their foundations in this thesis.
Download or read book A Measurement of Neutrino Oscillations with Muon Neutrinos in the MINOS Experiment written by and published by . This book was released on 2011 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 [Delta]m232 = (2.32{sub -0.08}{sup +0.12}) x 10−3 eV2/c4 and the mixing angle sin2(2[theta]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[sigma] and the neutrino quantum decoherence hypothesis is disfavored at 9.0[sigma].
Download or read book A Study of Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment written by and published by . This book was released on 2009 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: The observation of neutrino oscillations (neutrino changing from one flavor to another) has provided compelling evidence that the neutrinos have non-zero masses and that leptons mix, which is not part of the original Standard Model of particle physics. The theoretical framework that describes neutrino oscillation involves two mass scales ([Delta]matm2 and [Delta]msol2), three mixing angles ([theta]12, [theta]23, and [theta]13) and one CP violating phase ([delta]CP). Both mass scales and two of the mixing angles ([theta]12 and [theta]23) have been measured by many neutrino experiments. The mixing angle [theta]13, which is believed to be very small, remains unknown. The current best limit on [theta]13 comes from the CHOOZ experiment: [theta]13
Download or read book A Search for Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment written by and published by . This book was released on 2009 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: We perform a search for v[mu] → ve oscillations, a process which would manifest a nonzero value of the [theta]13 mixing angle, in the MINOS long-baseline neutrino oscillation experiment. The analysis consists of searching for an excess of ve charged-current candidate events over the predicted backgrounds, made mostly of neutral-current events with high electromagnetic content. A novel technique to select electron neutrino events is developed, which achieves an improved separation between the signal and the backgrounds, and which consequently yields a better reach in [theta]13. The backgrounds are predicted in the Far Detector from Near Detector measurements. An excess is observed in the Far Detector data over the predicted backgrounds, which is consistent with the background-only hypothesis at 1.2 standard deviations.
Download or read book A Study of Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment written by Tingjun Yang and published by . This book was released on 2009 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Measurement of Neutrino Oscillations with Muon Neutrinos in the Minos Experiment written by Stephen James Coleman and published by . This book was released on 2011 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Results for Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment written by and published by . This book was released on 2010 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: MINOS is a long-baseline neutrino oscillation experiment situated along Fermilab's high-intensity NuMI neutrino beam. MINOS has completed an updated search for muon neutrino to electron neutrino transitions, observation of which would indicate a non-zero value for the neutrino mixing angle [theta]13. The present 7 x 102° protons-on-target data set represents more than double the exposure used in the previous analysis. The new result and its implications are presented.
Download or read book Recent Results from the MINOS Experiment written by and published by . This book was released on 2009 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MINOS experiment utilizes the NuMI beam of muon neutrinos to study the phenomenon of neutrino oscillations. Neutrinos are sent over a baseline of 735 km, with a detector near the production point at Fermilab and one at the Soudan underground laboratory in northern Minnesota. By measuring the disappearance characteristic of oscillations, MINOS has made the best measurement of the atmospheric neutrino mass splitting to date. By looking for electron neutrino appearance, a limit has been placed on the the mixing angle sin2(2[theta]13) of
Download or read book Measurement of Electron Neutrino Appearance with the MINOS Experiment written by and published by . This book was released on 2009 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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. By measuring the neutrino interactions in a detector near the neutrino source and again 735 km away from the production site, it is possible to probe the parameters governing neutrino oscillation. The majority of the [nu]{sub {mu}} oscillate to [nu]{sub {tau}} but a small fraction may oscillate instead to [nu]{sub e}. This thesis presents a measurement of the [nu]{sub e} appearance rate in the MINOS far detector using the first two years of exposure. Methods for constraining the far detector backgrounds using the near detector measurements is discussed and a technique for estimating the uncertainty on the background and signal selection are developed. A 1.6[sigma] excess over the expected background rate is found providing a hint of [nu]{sub e} appearance.
Download or read book Electron Neutrino Appearance in the MINOS Experiment written by A. M. Holin and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The MINOS experiment is a long-baseline neutrino oscillation experiment which sends a high intensity muon neutrino beam through two functionally identical detectors, a Near detector at the Fermi National Accelerator Laboratory in Illinois, 1km from the beam source, and a Far detector, 734km away, in the Soudan Mine in Minnesota. MINOS may be able to measure the neutrino mixing angle parameter sin{ 2}2\theta{_1_3} for the first time. Detector granularity, however, makes it very hard to distinguish any \nu{_e} appearance signal events characteristic of a non-zero value of \theta{_1_3} from background neutral current (NC) and short-track \nu{_\mu} charged current (CC) events. Also, uncertainties in the hadronic shower modeling in the kinematic region characteristic of this analysis are relatively large. A new data-driven background decomposition method designed to address those issues is developed and its results presented. By removing the long muon tracks from \nu{_\mu}-CC events, the Muon Removed Charge Current (MRCC) method creates independent pseudo-NC samples that can be used to correct the MINOS Monte Carlo to agree with the high-statistics Near detector data and to decompose the latter into components so as to predict the expected Far detector background. The MRCC method also provides an important cross-check in the Far detector to test the background in the signal selected region. MINOS finds a 1.0-1.5 \sigma\nu{_e}-CC excess above background in the Far detector data, depending on method used, for a total exposure of 3.14x10{ 20} protons-on-target. Interpreting this excess as signal, MINOS can set limits on sin{ 2}2\theta{_1_3}. Using the MRCC method, MINOS sets a limit of sin{ 2}2\theta{_1_3}
Download or read book Measuring Antineutrino Oscillations with the MINOS Experiment written by and published by . This book was released on 2008 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: MINOS is a long baseline neutrino oscillation experiment. A manmade beam of predominantly muon neutrinos is detected both 1 km and 735 km from the production point by two functionally identical detectors. A comparison of the energy spectra measured by the two detectors shows the energy-dependent disappearance of muon neutrinos characteristic of oscillations and allows a measurement of the parameters governing the oscillations. This thesis presents work leading to measurements of disappearance in the 6% {bar {nu}}{sub {mu}} background in that beam. A calibration is developed to correct for time-dependent changes in the responses of both detectors, reducing the corresponding uncertainty on hadronic energy measurements from 1.8% to 0.4% in the near detector and from 0.8% to 0.4% in the far detector. A method of selecting charged current {bar {nu}}{sub {mu}} events is developed, with purities (efficiencies) of 96.5% (74.4%) at the near detector, and 98.8% (70.9%) at the far detector in the region below 10 GeV reconstructed antineutrino energy. A method of using the measured near detector neutrino energy spectrum to predict that expected at the far detector is discussed, and developed for use in the {bar {nu}}{sub {mu}} analysis. Sources of systematic uncertainty contributing to the oscillation measurements are discussed. In the far detector, 32 charged current {bar {nu}}{sub {mu}} events are observed below a reconstructed energy of 30 GeV, compared to an expectation of 47.8 for [Delta]{bar m}{sub atm}2 = [Delta]m{sub atm}2, sin2(2{bar [theta]}23) = sin2(2{theta}23). This deficit, in such a low-statistics sample, makes the result difficult to interpret in the context of an oscillation parameter measurement. Possible sources for the discrepancy are discussed, concluding that considerably more data are required for a definitive solution. Running MINOS with a dedicated {bar {nu}}{sub {mu}} beam would be the ideal continuation of this work.
Download or read book Measuring the Disappearance of Muon Neutrinos with the MINOS Detector written by and published by . This book was released on 2013 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book A Measurement of Muon Neutrino Disappearance with the MINOS Detectors and NuMI Beam written by Rustem Ospanov and published by . This book was released on 2008 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book First Measurement of Neutrino and Antineutrino Oscillation at T2K written by Kirsty Elizabeth Duffy and published by Springer. This book was released on 2017-09-13 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports the measurement of muon neutrino and antineutrino disappearance and electron neutrino and antineutrino appearance in a muon neutrino and antineutrino beam using the T2K experiment. It describes a result in neutrino physics that is a pioneering indication of charge-parity (CP) violation in neutrino oscillation; the first to be obtained from a single experiment. Neutrinos are some of the most abundant—but elusive—particles in the universe, and may provide a promising place to look for a potential solution to the puzzle of matter/antimatter imbalance in the observable universe. It has been firmly established that neutrinos can change flavour (or ‘oscillate’), as recognised by the 2015 Nobel Prize. The theory of neutrino oscillation allows for neutrinos and antineutrinos to oscillate differently (CP violation), and may provide insights into why our universe is matter-dominated. Bayesian statistical methods, including the Markov Chain Monte Carlo fitting technique, are used to simultaneously optimise several hundred systematic parameters describing detector, beam, and neutrino interaction uncertainties as well as the six oscillation parameters.
Download or read book Identifying Muons for Neutrino Oscillation and Cross Section Experiments written by Jasmine Star Yuko Ma Ratchford and published by . This book was released on 2012 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutrinos (v) are interesting for many reasons; they are the only fundamental fermions which are electrically neutral; their mass is orders of magnitude smaller than the lightest charged lepton, the electron; and their solely weak interactions make them an excellent probe of the weak nuclear force. However, one of the most interesting aspects of neutrinos is that, unlike their charged lepton partners, neutrino mass and flavor eigenstates are not the same. All leptons possess 'lepton flavor', a property which is conserved in neutrino interactions. However, because of the difference in the mass and weak eigenstates of neutrinos, a quantum-interference effect is seen in the time evolution of neutrinos. This results in energy and distance dependent oscillations of the neutrino's lepton flavor called 'neutrino oscillations'. The MINOS experiment (Main Injector Neutrino Oscillation Search) was designed to measure the neutrino oscillation parameters, [Delta]m232 and sin2(2[theta]32). MINOS is composed of two detectors located on a 'beam' of v[subscript mu]s. The MINOS Near Detector is located at Fermilab, and the Far Detector is located at the Soudan Mine in Minnesota, 734 km after the Near Detector. The MINERvA experiment (Main Injector Neutrino Experiment for v - A) is a neutrino experiment placed directly in front of the MINOS Near Detector. MINERvA's goal is to make precision measurements of neutrino cross sections. This will help with uncertainties in oscillation measurements, such as MINOS' at low energy. Although lepton flavor is conserved in neutrino interactions, the final state lepton can be a charged lepton ('charged current' interactions) or a neutrino ('neutral current' interactions) of a particular flavor. The identification of charged current v[subscript mu] interactions through the identification of a muon in the final state is a critical component to both neutrino oscillation and cross section measurements; neutral current events are a background to the oscillation signal because the properties of the incoming neutrino cannot be determined. Such identification is particularly difficult and important for low-energy neutrino events. In this thesis, we will discuss improvements to the MINOS charged current identification at low energies, studies to estimate the effect of the neutral current background on the measurement of the oscillation parameters, and the aspects of muon identification which are similar for the MINOS and MINERvA experiments. In 2010, the MINOS experiment released a measurement of the oscillation parameters based on 7.32x1020POT. The results were [Delta]m232 = 2.320̇12[subscript 0.08] x 103eV2, and sin2(2[theta]32)> 0.90(90%, C.L.). This is the best measurement of the oscillation parameter, [Delta]m232, and a competitive measurement of sin2(2[theta]32). The improvements to the charged current event selection helped MINOS observe a complete oscillation in neutrino energy.
