抄録
We report an indication that the elastic scattering rate of solar B8 neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through Earth during nighttime. We determine the day-night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be [-3.2±1.1(stat) ±0.5(syst)]%, which deviates from zero by 2.7σ. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a nonzero day-night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos' flight path. Super-Kamiokande's day-night asymmetry is consistent with neutrino oscillations for 4×10-5 eV2≤Δm212≤7×10-5 eV2 and large mixing values of θ12, at the 68% C.L.
本文言語 | English |
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論文番号 | 091805 |
ジャーナル | Physical review letters |
巻 | 112 |
号 | 9 |
DOI | |
出版ステータス | Published - 2014 3月 7 |
外部発表 | はい |
ASJC Scopus subject areas
- 物理学および天文学(全般)