50 research outputs found
Next Discoveries in Neutrino Mixing: Electron Neutrino Appearance
The discovery of neutrino oscillation is a clear evidence of new physics beyond the Standard Model. Measurements of electron neutrino () and electron anti-neutrino appearances are the most important channels to complete the neutrino mixing matrix. In a / appearance experiment, a near detector (ND) is used to constrain the neutrino flux and measure the backgrounds to the signal. Backgrounds to the appearance comes from Neutral Current Muon Neutrino Interactions (-NC), Charged Current Muon Neutrino Interactions (-CC), beam events and outside backgrounds. The background components are then extrapolated to the far detector (FD). By looking for excess of signal / -like events in FD, we measure the neutrino mixing angle, neutrino\u27s mass hierarchy and the elusive CP-violation in the lepton sector.
This dissertation focuses on the signals and backgrounds in / appearance measurements. The first part of the dissertation presents an analysis of appearance in a large Water Cherenkov detector such as the one proposed by the LBNE collaboration. The analysis, including scanning thousands of events, aims to distinguish signals from the NC backgrounds. The second part of the dissertation presents measurements of Resonance Neutrino Interactions using the NOMAD data. This process plays a critical role in not only neutrino-nuclear cross section but also in the precision analysis of the next generation of neutrino oscillation experiments such as NOA and LBNE. The last part of the dissertation discusses the method of using low- fit method to measure relative neutrino flux and constrain beam background
First attempt of directionality reconstruction for atmospheric neutrinos in a large homogeneous liquid scintillator detector
The directionality information of incoming neutrinos is essential to
atmospheric neutrino oscillation analysis since it is directly related to the
oscillation baseline length. Large homogeneous liquid scintillator detectors,
while offering excellent energy resolution, are traditionally very limited in
their capabilities of measuring event directionality. In this paper, we present
a novel directionality reconstruction method for atmospheric neutrino events in
large homogeneous liquid scintillator detectors based on waveform analysis and
machine learning techniques. We demonstrate for the first time that such
detectors can achieve good direction resolution and potentially play an
important role in future atmospheric neutrino oscillation measurements.Comment: Prepared for submission to PR
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
International audienceCore-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30 for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
International audienceCore-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30 for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN
JUNO sensitivity to Be, , and CNO solar neutrinos
International audienceThe Jiangmen Underground Neutrino Observatory (JUNO), the first multi-kton liquid scintillator detector, which is under construction in China, will have a unique potential to perform a real-time measurement of solar neutrinos well below the few MeV threshold typical for Water Cherenkov detectors. JUNO's large target mass and excellent energy resolution are prerequisites for reaching unprecedented levels of precision. In this paper, we provide estimation of the JUNO sensitivity to 7Be, pep, and CNO solar neutrinos that can be obtained via a spectral analysis above the 0.45 MeV threshold. This study is performed assuming different scenarios of the liquid scintillator radiopurity, ranging from the most opti mistic one corresponding to the radiopurity levels obtained by the Borexino experiment, up to the minimum requirements needed to perform the neutrino mass ordering determination with reactor antineutrinos - the main goal of JUNO. Our study shows that in most scenarios, JUNO will be able to improve the current best measurements on 7Be, pep, and CNO solar neutrino fluxes. We also perform a study on the JUNO capability to detect periodical time variations in the solar neutrino flux, such as the day-night modulation induced by neutrino flavor regeneration in Earth, and the modulations induced by temperature changes driven by helioseismic waves