Measuring neutrino oscillation parameters using vμ disappearance in MINOS
<p>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, 716 m underground in the S...
| Main Authors: | , |
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| Format: | Thesis |
| Language: | English |
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2011
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| _version_ | 1826284250855374848 |
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| author | Backhouse, C Christopher Backhouse |
| author2 | Barr, G |
| author_facet | Barr, G Backhouse, C Christopher Backhouse |
| author_sort | Backhouse, C |
| collection | OXFORD |
| description | <p>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, 716 m underground in the Soudan mine, Northern Minnesota.</p> <p>The primary purpose of the MINOS experiment is to make precise measurements of the "atmospheric" neutrino oscillation parameters (Δ<em>m</em><sup>2</sup><sub style="position: relative; left: -.5em;">atm</sub> and sin<sup>2</sup>2<em>θ</em><sub>atm</sub>). The oscillation signal consists of an energy-dependent deficit of <em>v</em><sub>μ</sub> 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.</p> <p>This thesis describes the details of the <em>v</em><sub>μ</sub>-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.</p> <p>The best-fit oscillation parameters of the <em>v</em><sub>μ</sub>-disappearance analysis, incorporating this new estimator were: Δ<em>m</em><sup>2</sup> = 2.32<sup>+0.12</sup><sub style="position: relative; left: -2.2em;">-0.08</sub> x 10<sup>-3</sup>eV<sup>2</sup> sin<sup>2</sup>2<em>θ</em> > 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 <em>̅v<sub>μ</sub></em> beam, yielded somewhat different best-fit parameters Δ<em>̅m</em><sup>2</sup> = (3.36<sup>+0.46</sup><sub style="position: relative; left: -2.2em;">-0.40</sub> (stat.}) &pm; 0.06(syst.)) x 10<sup>-3</sup>eV<sup>2</sup>, sin<sup>2</sup>2<em>̅θ</em> =0.86<sup>+0.11</sup><sub style="position: relative; left: -2.2em;">-0.12</sub>(stat.)&pm; 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.</p> |
| first_indexed | 2024-03-07T01:11:04Z |
| format | Thesis |
| id | oxford-uuid:8d074071-fdf4-4d3e-a503-4d8a17b9e8e3 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T01:11:04Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:8d074071-fdf4-4d3e-a503-4d8a17b9e8e32022-03-26T22:48:31ZMeasuring neutrino oscillation parameters using vμ disappearance in MINOSThesishttp://purl.org/coar/resource_type/c_db06uuid:8d074071-fdf4-4d3e-a503-4d8a17b9e8e3Particle physicsEnglishOxford University Research Archive - Valet2011Backhouse, CChristopher BackhouseBarr, G<p>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, 716 m underground in the Soudan mine, Northern Minnesota.</p> <p>The primary purpose of the MINOS experiment is to make precise measurements of the "atmospheric" neutrino oscillation parameters (Δ<em>m</em><sup>2</sup><sub style="position: relative; left: -.5em;">atm</sub> and sin<sup>2</sup>2<em>θ</em><sub>atm</sub>). The oscillation signal consists of an energy-dependent deficit of <em>v</em><sub>μ</sub> 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.</p> <p>This thesis describes the details of the <em>v</em><sub>μ</sub>-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.</p> <p>The best-fit oscillation parameters of the <em>v</em><sub>μ</sub>-disappearance analysis, incorporating this new estimator were: Δ<em>m</em><sup>2</sup> = 2.32<sup>+0.12</sup><sub style="position: relative; left: -2.2em;">-0.08</sub> x 10<sup>-3</sup>eV<sup>2</sup> sin<sup>2</sup>2<em>θ</em> > 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 <em>̅v<sub>μ</sub></em> beam, yielded somewhat different best-fit parameters Δ<em>̅m</em><sup>2</sup> = (3.36<sup>+0.46</sup><sub style="position: relative; left: -2.2em;">-0.40</sub> (stat.}) &pm; 0.06(syst.)) x 10<sup>-3</sup>eV<sup>2</sup>, sin<sup>2</sup>2<em>̅θ</em> =0.86<sup>+0.11</sup><sub style="position: relative; left: -2.2em;">-0.12</sub>(stat.)&pm; 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.</p> |
| spellingShingle | Particle physics Backhouse, C Christopher Backhouse Measuring neutrino oscillation parameters using vμ disappearance in MINOS |
| title | Measuring neutrino oscillation parameters using vμ disappearance in MINOS |
| title_full | Measuring neutrino oscillation parameters using vμ disappearance in MINOS |
| title_fullStr | Measuring neutrino oscillation parameters using vμ disappearance in MINOS |
| title_full_unstemmed | Measuring neutrino oscillation parameters using vμ disappearance in MINOS |
| title_short | Measuring neutrino oscillation parameters using vμ disappearance in MINOS |
| title_sort | measuring neutrino oscillation parameters using vμ disappearance in minos |
| topic | Particle physics |
| work_keys_str_mv | AT backhousec measuringneutrinooscillationparametersusingvmdisappearanceinminos AT christopherbackhouse measuringneutrinooscillationparametersusingvmdisappearanceinminos |