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Robust Measurement of Mixing Parameters sin2 2θ13 and ∆m2ee With Reactor Antineutrinos at Daya Bay- [electronic resource]
Robust Measurement of Mixing Parameters sin2 2θ13 and ∆m2ee With Reactor Antineutrinos at Daya Bay- [electronic resource]
상세정보
- 자료유형
- 학위논문파일 국외
- 최종처리일시
- 20240214095906
- ISBN
- 9798380684910
- DDC
- 530
- 저자명
- Kramer, Matthew.
- 서명/저자
- Robust Measurement of Mixing Parameters sin2 2θ13 and ∆m2ee With Reactor Antineutrinos at Daya Bay - [electronic resource]
- 발행사항
- [S.l.]: : University of California, Berkeley., 2021
- 발행사항
- Ann Arbor : : ProQuest Dissertations & Theses,, 2021
- 형태사항
- 1 online resource(278 p.)
- 주기사항
- Source: Dissertations Abstracts International, Volume: 85-05, Section: B.
- 주기사항
- Advisor: Luk, Kam-Biu.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Berkeley, 2021.
- 사용제한주기
- This item must not be sold to any third party vendors.
- 초록/해제
- 요약The Daya Bay reactor neutrino experiment measures the oscillation of electron antineutrinos produced by the Daya Bay and Ling Ao-I & II Power Plants (totaling 17.4 GWth) in southern China. The fluxes and spectra of the antineutrinos are observed using eight functionally identical gadolinium-doped liquid scintillator detectors, with a total target mass of 160 tons, divided among two near and one far experimental halls, resulting in baselines of order 500 m (near) and 2 km (far). The oscillation phenomenon appears as a deficit of electron antineutrinos at the far hall relative to the yield at the near halls.This work describes a spectral measurement of the neutrino mixing parameters sin2 2θ13 and ∆m2ee using a six-year sample of over 2 million inverse beta-decay (IBD) events identified via the outgoing neutron's subsequent capture on gadolinium. A defining feature of this analysis is its ability to be efficiently repeated for arbitrary choices of the IBD cuts, that is, the criteria used for selecting IBD events. This required the implementation of a flexible and efficient IBD selection, which was coupled to a parallelized upgrade of the official Daya Bay oscillation fitter developed at Lawrence Berkeley National Laboratory. The generalization of the analysis to arbitrary IBD cuts (beyond the two nominal IBD cuts used in official Daya Bay results) involved studies of various efficiencies and backgrounds and their dependence on the cuts, which we describe here.With this infrastructure, we are able to explore how the best-fit oscillation parameters and their measured uncertainties vary as functions of the cuts, enabling, first, the characterization of the systematic uncertainty associated with the freedom to vary the cuts, and second, the exploration of whether the nominal IBD cuts should be modified in order to gain a reduced uncertainty on the oscillation parameters. We find that, compared to the two nominal cuts, there is no alternative IBD cut that provides a substantial reduction in uncertainty. The cut-variation study suggests the assessment of an additional systematic uncertainty of 0.0006 on sin2 2θ13 and 1.9 x 10−5 eV2 on ∆m2ee, leading to a 2% increase in the total uncertainty of sin2 2θ13 and a 4% increase in that of ∆m2ee. Our final measurement is sin2 2θ13 = 0.0850 ± 0.0030 and ∆m2ee = (2.5010 ± 0.0072) x 10−3 eV2 in the standard three-flavor model.The methods developed here serve to demonstrate that our oscillation fit is both robust and optimal with respect to variations in the cuts. Given the overall similarity between our oscillation analysis and those used in official Daya Bay results, similar conclusions can be drawn for the latter. Our findings thus validate past Daya Bay results, while future results will be able to benefit from this groundwork, enabling additional validation of the results and broadened assessment of their systematic uncertainties.
- 일반주제명
- Physics.
- 일반주제명
- Mathematics.
- 일반주제명
- Applied mathematics.
- 일반주제명
- Computational physics.
- 키워드
- Neutrinos
- 키워드
- Daya Bay reactor
- 키워드
- Uncertainty
- 기타저자
- University of California, Berkeley Physics
- 기본자료저록
- Dissertations Abstracts International. 85-05B.
- 기본자료저록
- Dissertation Abstract International
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008240612s2021 us |||||||||||||||c||eng d■001000016931078
■00520240214095906
■006m o d
■007cr#unu||||||||
■020 ▼a9798380684910
■035 ▼a(MiAaPQ)AAI28868902
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aKramer, Matthew.
■24510▼aRobust Measurement of Mixing Parameters sin2 2θ13 and ∆m2ee With Reactor Antineutrinos at Daya Bay▼h[electronic resource]
■260 ▼a[S.l.]:▼bUniversity of California, Berkeley. ▼c2021
■260 1▼aAnn Arbor :▼bProQuest Dissertations & Theses, ▼c2021
■300 ▼a1 online resource(278 p.)
■500 ▼aSource: Dissertations Abstracts International, Volume: 85-05, Section: B.
■500 ▼aAdvisor: Luk, Kam-Biu.
■5021 ▼aThesis (Ph.D.)--University of California, Berkeley, 2021.
■506 ▼aThis item must not be sold to any third party vendors.
■520 ▼aThe Daya Bay reactor neutrino experiment measures the oscillation of electron antineutrinos produced by the Daya Bay and Ling Ao-I & II Power Plants (totaling 17.4 GWth) in southern China. The fluxes and spectra of the antineutrinos are observed using eight functionally identical gadolinium-doped liquid scintillator detectors, with a total target mass of 160 tons, divided among two near and one far experimental halls, resulting in baselines of order 500 m (near) and 2 km (far). The oscillation phenomenon appears as a deficit of electron antineutrinos at the far hall relative to the yield at the near halls.This work describes a spectral measurement of the neutrino mixing parameters sin2 2θ13 and ∆m2ee using a six-year sample of over 2 million inverse beta-decay (IBD) events identified via the outgoing neutron's subsequent capture on gadolinium. A defining feature of this analysis is its ability to be efficiently repeated for arbitrary choices of the IBD cuts, that is, the criteria used for selecting IBD events. This required the implementation of a flexible and efficient IBD selection, which was coupled to a parallelized upgrade of the official Daya Bay oscillation fitter developed at Lawrence Berkeley National Laboratory. The generalization of the analysis to arbitrary IBD cuts (beyond the two nominal IBD cuts used in official Daya Bay results) involved studies of various efficiencies and backgrounds and their dependence on the cuts, which we describe here.With this infrastructure, we are able to explore how the best-fit oscillation parameters and their measured uncertainties vary as functions of the cuts, enabling, first, the characterization of the systematic uncertainty associated with the freedom to vary the cuts, and second, the exploration of whether the nominal IBD cuts should be modified in order to gain a reduced uncertainty on the oscillation parameters. We find that, compared to the two nominal cuts, there is no alternative IBD cut that provides a substantial reduction in uncertainty. The cut-variation study suggests the assessment of an additional systematic uncertainty of 0.0006 on sin2 2θ13 and 1.9 x 10−5 eV2 on ∆m2ee, leading to a 2% increase in the total uncertainty of sin2 2θ13 and a 4% increase in that of ∆m2ee. Our final measurement is sin2 2θ13 = 0.0850 ± 0.0030 and ∆m2ee = (2.5010 ± 0.0072) x 10−3 eV2 in the standard three-flavor model.The methods developed here serve to demonstrate that our oscillation fit is both robust and optimal with respect to variations in the cuts. Given the overall similarity between our oscillation analysis and those used in official Daya Bay results, similar conclusions can be drawn for the latter. Our findings thus validate past Daya Bay results, while future results will be able to benefit from this groundwork, enabling additional validation of the results and broadened assessment of their systematic uncertainties.
■590 ▼aSchool code: 0028.
■650 4▼aPhysics.
■650 4▼aMathematics.
■650 4▼aApplied mathematics.
■650 4▼aComputational physics.
■653 ▼aNeutrinos
■653 ▼aDaya Bay reactor
■653 ▼aUncertainty
■653 ▼aInverse beta-decay
■653 ▼aOscillation parameters
■690 ▼a0605
■690 ▼a0405
■690 ▼a0216
■690 ▼a0364
■71020▼aUniversity of California, Berkeley▼bPhysics.
■7730 ▼tDissertations Abstracts International▼g85-05B.
■773 ▼tDissertation Abstract International
■790 ▼a0028
■791 ▼aPh.D.
■792 ▼a2021
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T16931078▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
■980 ▼a202402▼f2024
