1. SEARCH FOR EXTRATERRESTRIAL ANTINEUTRINO SOURCES WITH THE KamLAND DETECTOR.
- Author
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Gando, A., Gando, Y., Ichimura, K., Ikeda, H., Inoue, K., Kibe, Y., Kishimoto, Y., Koga, M., Minekawa, Y., Mitsui, T., Morikawa, T., Nagai, N., Nakajima, K., Nakamura, K., Narita, K., Shimizu, I., Shimizu, Y., Shirai, J., Suekane, F., and Suzuki, A.
- Subjects
DARK matter ,INTERSTELLAR medium ,SUPERNOVA remnants ,NEUTRINO interactions ,ANNIHILATION reactions - Abstract
We present the results of a search for extraterrestrial electron antineutrinos (퐯̄
e 's) in the energy range 8.3 MeV < E퐯̄ 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 of8 B solar ve 's converting into 퐯̄e 's at 5.3 x 10-5 (90% CL), if we assume an undistorted 퐯̄e shape. This limit corresponds to a solar 퐯̄e flux of 93 cm-2 s-1 or an event rate of 1.6 events (kton-year)-1 above the energy threshold (E퐯̄ 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. [ABSTRACT FROM AUTHOR]- Published
- 2012
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