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Title: A Measurement of Electron Neutrino Appearance in the MINOS Experiment After Four Years of Data

Abstract

This work attempts to measure or set a limit on sin 2(2θ 13), the parameter which describes v μ → v e oscillations. The MINOS detectors at Fermilab are used to perform a search for the oscillations utilizing a beam of v μ neutrinos created in the NuMI beamline by the collisions of 120 GeV protons with a carbon target. These collisions create π ± and K ± which are focused with magnetic horns, are allowed to decay, and result in a beam of v μ in the energy range of 1 to 30 GeV. Two functionally identical steel-scintillator calorimetric detectors are utilized to measure the interactions of the generated neutrinos. A detector close to the NuMI beam, located 104 m underground and 1040 m from the target, is used to measure the properties of the neutrino beam, including the flux, composition, and energy spectrum. This information is used in part to generate a predicted spectrum of neutrinos in absence of v μ → v e oscillations in the detector located far from the target, at a distance of 705 m underground and 735.5 km from the target. An excess of predicted v e charged current events in this farmore » detector will be interpreted as v μ → v e oscillations, and a measurement of sin 2(2θ 13) will be made using a Feldman-Cousins analysis. The measurement of v μ → v e requires the separation of v e candidates from background events. New reconstruction software was developed with a focus on identifying v e candidate events in order to reduce systematic errors. The event parameters measured by this software were used as an input to an artificial neutral network event discriminator. The details of this reconstruction software and the other steps of the analysis necessary to making the measurement will be discussed. This work builds on a previous measurement made with this experiment. After two years of running with 3.14 x 10 20 protons-on-target (POT), a limit was set at δCP = 0 for the normal (inverted) hierarchy of sin 2(2θ 13) < 0.29 (0.42) at 90% C.L. This study finds after four years of data with an accumulated intensity of 7 x 10 20 POT that sin 2(2θ 13) < 0.12 (0.20) with δCP = 0 at 90% C.L. for the normal (inverted) hierarchy.« less

Authors:
 [1]
  1. Harvard Univ., Cambridge, MA (United States)
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
980805
Report Number(s):
FERMILAB-THESIS-2010-15
TRN: US1003807
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Thesis/Dissertation
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS, 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CARBON; CHARGED CURRENTS; DECAY; ELECTRON NEUTRINOS; ENERGY RANGE; FERMILAB; NEUTRINO BEAMS; NEUTRINOS; OSCILLATIONS; PROTONS; Astrophysics; Experiment-HEP

Citation Formats

Cavanaugh, Steven. A Measurement of Electron Neutrino Appearance in the MINOS Experiment After Four Years of Data. United States: N. p., 2010. Web. doi:10.2172/980805.
Cavanaugh, Steven. A Measurement of Electron Neutrino Appearance in the MINOS Experiment After Four Years of Data. United States. https://doi.org/10.2172/980805
Cavanaugh, Steven. Sat . "A Measurement of Electron Neutrino Appearance in the MINOS Experiment After Four Years of Data". United States. https://doi.org/10.2172/980805. https://www.osti.gov/servlets/purl/980805.
@article{osti_980805,
title = {A Measurement of Electron Neutrino Appearance in the MINOS Experiment After Four Years of Data},
author = {Cavanaugh, Steven},
abstractNote = {This work attempts to measure or set a limit on sin2(2θ13), the parameter which describes vμ → ve oscillations. The MINOS detectors at Fermilab are used to perform a search for the oscillations utilizing a beam of vμ neutrinos created in the NuMI beamline by the collisions of 120 GeV protons with a carbon target. These collisions create π± and K± which are focused with magnetic horns, are allowed to decay, and result in a beam of vμ in the energy range of 1 to 30 GeV. Two functionally identical steel-scintillator calorimetric detectors are utilized to measure the interactions of the generated neutrinos. A detector close to the NuMI beam, located 104 m underground and 1040 m from the target, is used to measure the properties of the neutrino beam, including the flux, composition, and energy spectrum. This information is used in part to generate a predicted spectrum of neutrinos in absence of vμ → ve oscillations in the detector located far from the target, at a distance of 705 m underground and 735.5 km from the target. An excess of predicted ve charged current events in this far detector will be interpreted as vμ → ve oscillations, and a measurement of sin2(2θ13) will be made using a Feldman-Cousins analysis. The measurement of vμ → ve requires the separation of ve candidates from background events. New reconstruction software was developed with a focus on identifying ve candidate events in order to reduce systematic errors. The event parameters measured by this software were used as an input to an artificial neutral network event discriminator. The details of this reconstruction software and the other steps of the analysis necessary to making the measurement will be discussed. This work builds on a previous measurement made with this experiment. After two years of running with 3.14 x 1020 protons-on-target (POT), a limit was set at δCP = 0 for the normal (inverted) hierarchy of sin2(2θ13) < 0.29 (0.42) at 90% C.L. This study finds after four years of data with an accumulated intensity of 7 x 1020 POT that sin2(2θ13) < 0.12 (0.20) with δCP = 0 at 90% C.L. for the normal (inverted) hierarchy.},
doi = {10.2172/980805},
url = {https://www.osti.gov/biblio/980805}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2010},
month = {5}
}

Thesis/Dissertation:
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