Measurement of neutrino oscillation with KamLAND: Evidence of spectral distortion

被引：904

作者：

Araki, T ^{[1
]}

Eguchi, K

Enomoto, S

Furuno, K

Ichimura, K

Ikeda, H

Inoue, K

Ishihara, K

Iwamoto, T

Kawashima, T

Kishimoto, Y

Koga, M

Koseki, Y

Maeda, T

Mitsui, T

Motoki, M

Nakajima, K

Ogawa, H

Owada, K

Ricol, JS

Shimizu, I

Shirai, J

Suekane, F

Suzuki, A

Tada, K

Tajima, O

Tamae, K

Tsuda, Y

Watanabe, H

Busenitz, J

Classen, T

Djurcic, Z

Keefer, G

McKinny, K

Mei, DM

Piepke, A

Yakushev, E

Berger, BE

Chan, YD

Decowski, MP

Dwyer, DA

Freedman, SJ

Fu, Y

Fujikawa, BK

Goldman, J

Gray, F

Heeger, KM

Lesko, KT

Luk, KB

Murayama, H

机构：

[1] Tohoku Univ, Res Ctr Neutrino Sci, Sendai, Miyagi 9808578, Japan

[2] Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA

[3] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA

[4] Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA

[5] CALTECH, WK Kellogg Radiat Lab, Pasadena, CA 91125 USA

[6] Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA

[7] Univ Hawaii Manoa, Dept Phys & Astron, Honolulu, HI 96822 USA

[8] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA

[9] Univ New Mexico, Dept Phys, Albuquerque, NM 87131 USA

[10] Stanford Univ, Dept Phys, Stanford, CA 94305 USA

[11] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA

[12] Triangle Univ Nucl Lab, Durham, NC 27708 USA

[13] Duke Univ, Dept Phys, Durham, NC 27706 USA

[14] Univ N Carolina, Dept Phys, Chapel Hill, NC USA

[15] Inst High Energy Phys, Beijing 100039, Peoples R China

[16] Univ Bordeaux 1, F-33175 Gradignan, France

[17] CEN Bordeaux Gradignan, IN2P3, CNRS, F-33175 Gradignan, France

来源：

PHYSICAL REVIEW LETTERS | 2005年 / 94卷 / 08期

关键词：

D O I：

10.1103/PhysRevLett.94.081801

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 (nu) over bar (e) candidate events with energies above 3.4 MeV compared to 365.2+/-23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8+/-7.3 expected background events, the statistical significance for reactor (nu) over bar (e) disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from (nu) over bar (e) oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam(2)=7.9(-0.5)(+0.6)x10(-5) eV(2). A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam(2)=7.9(-0.5)(+0.6)x10(-5) eV(2) and tan(2)theta=0.40(-0.07)(+0.10), the most precise determination to date.

引用

页数：5

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