6 research outputs found
A Search for Anti-electron-neutrinos from the Sun at Super-Kamiokande(Abstracts of Doctoral Dissertations,Annual Report(from April 2003 to March 2004))
Latest results from KamLAND-Zen second phase
AbstractWe report on preliminary results from the second phase of KamLAND-Zen double beta decay search experiment based on 114.8 days with 383 kg of 136Xe. Second phase of KamLAND-Zen was started after the purification to reduce the dominant 110mAg background identified by first phase data. The background was reduced by more than a factor of 10 by purification for liquid scintillator and xenon gas. By combining the first and second phase data and applying the improved event selection, we obtained a preliminary lower limit for the neutrinoless double-beta decay half-life, T1/20Îœ>2.6Ă1025 yr at 90% C.L. We also present the prospects about current phase of KamLAND-Zen and next phases with upgrades
Combined Pre-Supernova Alert System with Kamland and Super-Kamiokande
International audiencePreceding 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 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 is 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 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