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Probing the PeV Astrophysical Neutrino Spectral Cutoff Using Downgoing Tracks at IceCube
Probing the PeV Astrophysical Neutrino Spectral Cutoff Using Downgoing Tracks at IceCube
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211151459
- ISBN
- 9798384453437
- DDC
- 530
- 저자명
- Lyu, Yang.
- 서명/저자
- Probing the PeV Astrophysical Neutrino Spectral Cutoff Using Downgoing Tracks at IceCube
- 발행사항
- [Sl] : University of California, Berkeley, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 187 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-03, Section: B.
- 주기사항
- Advisor: Klein, Spencer R.;Shapiro, Marjorie D.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Berkeley, 2024.
- 초록/해제
- 요약IceCube has observed a diffuse astrophysical neutrino flux from ∼100 TeV to a few PeV, with an energy spectrum consistent with a single power law (SPL). In the PeV region, the spectral shape has not been precisely measured: starting track and cascade searches have a relatively small effective volume, upgoing tracks are mostly absorbed by the Earth, while the Extremely High Energy (EHE) analyses target cosmogenic neutrinos above 10 PeV. This analysis fills the gap between 1 PeV and 10 PeV by selecting high-energy down-going, through-going tracks. To reject the large atmospheric muon background, two largely complementary techniques are combined. The first technique selects events with high stochasticity to reject atmospheric muon bundles whose stochastic energy losses are smoothed due to high muon multiplicity. The second technique vetoes atmospheric muons with the IceTop surface array. Using 9 years of data, we found two events in the signal region, each with relatively high signal probabilities. A joint maximum likelihood estimation is performed using this sample with the previous 9.5-year upgoing track sample to measure the neutrino spectrum, and a likelihood ratio test is performed for the single power-law (SPL) vs. SPL+cutoff hypothesis. The best-fit cutoff energy is 1.83+6.92 −0.81 PeV. The p-value of the likelihood ratio test is 0.62, and the SPL+cutoff model is not significant over SPL. High-energy astrophysical objects from four source catalogs are also searched for around the direction of the two events. A BL Lac object is found inside the 90% directional uncertainty region of one event, while the second event does not have any associated objects.
- 일반주제명
- Physics
- 일반주제명
- Particle physics
- 일반주제명
- Astrophysics
- 일반주제명
- Atmospheric sciences
- 키워드
- IceCube
- 키워드
- Single power law
- 키워드
- Spectral shape
- 기타저자
- University of California, Berkeley Physics
- 기본자료저록
- Dissertations Abstracts International. 86-03B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008250123s2024 us c eng d■001000017161894
■00520250211151459
■006m o d
■007cr#unu||||||||
■020 ▼a9798384453437
■035 ▼a(MiAaPQ)AAI31297584
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aLyu, Yang.
■24510▼aProbing the PeV Astrophysical Neutrino Spectral Cutoff Using Downgoing Tracks at IceCube
■260 ▼a[Sl]▼bUniversity of California, Berkeley▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a187 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-03, Section: B.
■500 ▼aAdvisor: Klein, Spencer R.;Shapiro, Marjorie D.
■5021 ▼aThesis (Ph.D.)--University of California, Berkeley, 2024.
■520 ▼aIceCube has observed a diffuse astrophysical neutrino flux from ∼100 TeV to a few PeV, with an energy spectrum consistent with a single power law (SPL). In the PeV region, the spectral shape has not been precisely measured: starting track and cascade searches have a relatively small effective volume, upgoing tracks are mostly absorbed by the Earth, while the Extremely High Energy (EHE) analyses target cosmogenic neutrinos above 10 PeV. This analysis fills the gap between 1 PeV and 10 PeV by selecting high-energy down-going, through-going tracks. To reject the large atmospheric muon background, two largely complementary techniques are combined. The first technique selects events with high stochasticity to reject atmospheric muon bundles whose stochastic energy losses are smoothed due to high muon multiplicity. The second technique vetoes atmospheric muons with the IceTop surface array. Using 9 years of data, we found two events in the signal region, each with relatively high signal probabilities. A joint maximum likelihood estimation is performed using this sample with the previous 9.5-year upgoing track sample to measure the neutrino spectrum, and a likelihood ratio test is performed for the single power-law (SPL) vs. SPL+cutoff hypothesis. The best-fit cutoff energy is 1.83+6.92 −0.81 PeV. The p-value of the likelihood ratio test is 0.62, and the SPL+cutoff model is not significant over SPL. High-energy astrophysical objects from four source catalogs are also searched for around the direction of the two events. A BL Lac object is found inside the 90% directional uncertainty region of one event, while the second event does not have any associated objects.
■590 ▼aSchool code: 0028.
■650 4▼aPhysics
■650 4▼aParticle physics
■650 4▼aAstrophysics
■650 4▼aAtmospheric sciences
■653 ▼aIceCube
■653 ▼aSingle power law
■653 ▼aSpectral shape
■653 ▼aNeutrino spectrum
■653 ▼aAtmospheric muons
■690 ▼a0605
■690 ▼a0798
■690 ▼a0596
■690 ▼a0725
■71020▼aUniversity of California, Berkeley▼bPhysics.
■7730 ▼tDissertations Abstracts International▼g86-03B.
■790 ▼a0028
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17161894▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
