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Combined Pre-Supernova Alert System with Kamland and Super-Kamiokande
Authors:
KamLAND,
Super-Kamiokande Collaborations,
:,
Seisho Abe,
Minori Eizuka,
Sawako Futagi,
Azusa Gando,
Yoshihito Gando,
Shun Goto,
Takahiko Hachiya,
Kazumi Hata,
Koichi Ichimura,
Sei Ieki,
Haruo Ikeda,
Kunio Inoue,
Koji Ishidoshiro,
Yuto Kamei,
Nanami Kawada,
Yasuhiro Kishimoto,
Masayuki Koga,
Maho Kurasawa,
Tadao Mitsui,
Haruhiko Miyake,
Daisuke Morita,
Takeshi Nakahata
, et al. (290 additional authors not shown)
Abstract:
Preceding a core-collapse supernova, various processes produce an increasing amount of neutrinos of all flavors characterized by mounting energies from the interior of massive stars. Among them, the electron antineutrinos are potentially detectable by terrestrial neutrino experiments such as KamLAND and Super-Kamiokande via inverse beta decay interactions. Once these pre-supernova neutrinos are ob…
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Preceding a core-collapse supernova, various processes produce an increasing amount of neutrinos of all flavors characterized by mounting energies from the interior of massive stars. Among them, the electron antineutrinos are potentially detectable by terrestrial neutrino experiments such as KamLAND and Super-Kamiokande via inverse beta decay interactions. Once these pre-supernova neutrinos are observed, an early warning of the upcoming core-collapse supernova can be provided. In light of this, KamLAND and Super-Kamiokande, both located in the Kamioka mine in Japan, have been monitoring pre-supernova neutrinos since 2015 and 2021, respectively. Recently, we performed a joint study between KamLAND and Super-Kamiokande on pre-supernova neutrino detection. A pre-supernova alert system combining the KamLAND detector and the Super-Kamiokande detector was developed and put into operation, which can provide a supernova alert to the astrophysics community. Fully leveraging the complementary properties of these two detectors, the combined alert is expected to resolve a pre-supernova neutrino signal from a 15 M$_{\odot}$ star within 510 pc of the Earth, at a significance level corresponding to a false alarm rate of no more than 1 per century. For a Betelgeuse-like model with optimistic parameters, it can provide early warnings up to 12 hours in advance.
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Submitted 1 July, 2024; v1 submitted 15 April, 2024;
originally announced April 2024.
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Search for electron antineutrinos associated with gravitational wave events GW150914 and GW151226 using KamLAND
Authors:
KamLAND Collaboration,
A. Gando,
Y. Gando,
T. Hachiya,
A. Hayashi,
S. Hayashida,
H. Ikeda,
K. Inoue,
K. Ishidoshiro,
Y. Karino,
M. Koga,
S. Matsuda,
T. Mitsui,
K. Nakamura,
S. Obara,
T. Oura,
H. Ozaki,
I. Shimizu,
Y. Shirahata,
J. Shirai,
A. Suzuki,
T. Takai,
K. Tamae,
Y. Teraoka,
K. Ueshima
, et al. (23 additional authors not shown)
Abstract:
We present a search for low energy antineutrino events coincident with the gravitational wave events GW150914 and GW151226, and the candidate event LVT151012 using KamLAND, a kiloton-scale antineutrino detector. We find no inverse beta-decay neutrino events within $\pm 500$ seconds of either gravitational wave signal. This non-detection is used to constrain the electron antineutrino fluence and th…
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We present a search for low energy antineutrino events coincident with the gravitational wave events GW150914 and GW151226, and the candidate event LVT151012 using KamLAND, a kiloton-scale antineutrino detector. We find no inverse beta-decay neutrino events within $\pm 500$ seconds of either gravitational wave signal. This non-detection is used to constrain the electron antineutrino fluence and the luminosity of the astrophysical sources.
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Submitted 3 October, 2016; v1 submitted 22 June, 2016;
originally announced June 2016.
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Measurement of the 8B Solar Neutrino Flux with the KamLAND Liquid Scintillator Detector
Authors:
KamLAND Collaboration,
S. Abe,
K. Furuno,
A. Gando,
Y. Gando,
K. Ichimura,
H. Ikeda,
K. Inoue,
Y. Kibe,
W. Kimura,
Y. Kishimoto,
M. Koga,
Y. Minekawa,
T. Mitsui,
T. Morikawa,
N. Nagai,
K. Nakajima,
K. Nakamura,
M. Nakamura,
K. Narita,
I. Shimizu,
Y. Shimizu,
J. Shirai,
F. Suekane,
A. Suzuki
, et al. (55 additional authors not shown)
Abstract:
We report a measurement of the neutrino-electron elastic scattering rate from 8B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5 MeV analysis threshold is 1.49+/-0.14(stat)+/-0.17(syst) events per kton-day. Interpreted as due to a pure electron flavor flux with a 8B neutrino spectrum, this corresponds to a spectrum integrated…
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We report a measurement of the neutrino-electron elastic scattering rate from 8B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5 MeV analysis threshold is 1.49+/-0.14(stat)+/-0.17(syst) events per kton-day. Interpreted as due to a pure electron flavor flux with a 8B neutrino spectrum, this corresponds to a spectrum integrated flux of 2.77+/-0.26(stat)+/-0.32(syst) x 10^6 cm^-2s^-1. The analysis threshold is driven by 208Tl present in the liquid scintillator, and the main source of systematic uncertainty is due to background from cosmogenic 11Be. The measured rate is consistent with existing measurements and with Standard Solar Model predictions which include matter enhanced neutrino oscillation.
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Submitted 25 August, 2011; v1 submitted 4 June, 2011;
originally announced June 2011.
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Search for extraterrestrial antineutrino sources with the KamLAND detector
Authors:
The KamLAND Collaboration
Abstract:
We present the results of a search for extraterrestrial electron antineutrinos ($\barν_{e}$'s) in the energy range $8.3 MeV < E_{\barν_{e}} < 31.8 MeV$ using the KamLAND detector. In an exposure of 4.53 kton-year, we identify 25 candidate events. All of the candidate events can be attributed to background, most importantly neutral current atmospheric neutrino interactions, setting an upper limit o…
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We present the results of a search for extraterrestrial electron antineutrinos ($\barν_{e}$'s) in the energy range $8.3 MeV < E_{\barν_{e}} < 31.8 MeV$ using the KamLAND detector. In an exposure of 4.53 kton-year, we identify 25 candidate events. All of the candidate events can be attributed to background, most importantly neutral current atmospheric neutrino interactions, setting an upper limit on the probability of $^{8}$B solar $ν_{e}$'s converting into $\barν_{e}$'s at $5.3 \times 10^{-5}$ (90% C.L.), if we assume an undistorted $\barν_{e}$ shape. This limit corresponds to a solar $\barν_{e}$ flux of $93 cm^{-2} s^{-1}$ or an event rate of $1.6 events (kton-year)^{-1}$ above the energy threshold $(E_{\barν_{e}} > 8.3 MeV)$. The present data also allows us to set more stringent limits on the diffuse supernova neutrino flux and on the annihilation rates for light dark matter particles.
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Submitted 7 February, 2012; v1 submitted 17 May, 2011;
originally announced May 2011.
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Production of Radioactive Isotopes through Cosmic Muon Spallation in KamLAND
Authors:
The KamLAND Collaboration
Abstract:
Radioactive isotopes produced through cosmic muon spallation are a background for rare-event detection in $ν$ detectors, double-$β$-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation produc…
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Radioactive isotopes produced through cosmic muon spallation are a background for rare-event detection in $ν$ detectors, double-$β$-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation production of $^{11}$C. Data from the Kamioka liquid-scintillator antineutrino detector (KamLAND) provides valuable information for better understanding these backgrounds, especially in liquid scintillators, and for checking estimates from current simulations based upon MUSIC, FLUKA, and GEANT4. Using the time correlation between detected muons and neutron captures, the neutron production yield in the KamLAND liquid scintillator is measured to be $(2.8 \pm 0.3) \times 10^{-4} μ^{-1} g^{-1} cm^{2}$. For other isotopes, the production yield is determined from the observed time correlation related to known isotope lifetimes. We find some yields are inconsistent with extrapolations based on an accelerator muon beam experiment.
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Submitted 23 March, 2010; v1 submitted 1 July, 2009;
originally announced July 2009.