High sensitivity search for nu;e's from the sun and other sources at KamLAND.
Data corresponding to a KamLAND detector exposure of 0.28 kton yr has been used to search for nu;(e)'s in the energy range 8.3<E(nu;(e))<14.8 MeV. No candidates were found for an expected background of 1.1+/-0.4 events. This result can be used to obtain a limit on nu;(e) fluxes of any origin. Assuming that all nu;(e) flux has its origin in the Sun and has the characteristic 8B solar nu(e) energy spectrum, we obtain an upper limit of 3.7 x 10(2) cm(-2) s(-1) (90% C.L.) on the nu;(e) flux. We interpret this limit, corresponding to 2.8 x 10(-4) of the standard solar model 8B nu(e) flux, in the framework of spin-flavor precession and neutrino decay models.
Eguchi
K
K
Research Center for Neutrino Science, Tohoku University, Sendai 980-8578, Japan.
Enomoto
S
S
Furuno
K
K
Ikeda
H
H
Ikeda
K
K
Inoue
K
K
Ishihara
K
K
Iwamoto
T
T
Kawashima
T
T
Kishimoto
Y
Y
Koga
M
M
Koseki
Y
Y
Maeda
T
T
Mitsui
T
T
Motoki
M
M
Nakajima
K
K
Ogawa
H
H
Owada
K
K
Piquemal
F
F
Shimizu
I
I
Shirai
J
J
Suekane
F
F
Suzuki
A
A
Tada
K
K
Tajima
O
O
Takayama
T
T
Tamae
K
K
Watanabe
H
H
Busenitz
J
J
Djurcic
Z
Z
McKinny
K
K
Mei
D-M
DM
Piepke
A
A
Yakushev
E
E
Berger
B E
BE
Chan
Y D
YD
Decowski
M P
MP
Dwyer
D A
DA
Freedman
S J
SJ
Fu
Y
Y
Fujikawa
B K
BK
Goldman
J
J
Heeger
K M
KM
Lesko
K T
KT
Luk
K-B
KB
Murayama
H
H
Nygren
D R
DR
Okada
C E
CE
Poon
A W P
AW
Steiner
H M
HM
Winslow
L A
LA
Horton-Smith
G A
GA
Mauger
C
C
McKeown
R D
RD
Tipton
B
B
Vogel
P
P
Lane
C E
CE
Miletic
T
T
Gorham
P W
PW
Guillian
G
G
Learned
J G
JG
Maricic
J
J
Matsuno
S
S
Pakvasa
S
S
Dazeley
S
S
Hatakeyama
S
S
Svoboda
R
R
Dieterle
B D
BD
DiMauro
M
M
Detwiler
J
J
Gratta
G
G
Ishii
K
K
Tolich
N
N
Uchida
Y
Y
Batygov
M
M
Bugg
W
W
Efremenko
Y
Y
Kamyshkov
Y
Y
Kozlov
A
A
Nakamura
Y
Y
Gould
C R
CR
Karwowski
H J
HJ
Markoff
D M
DM
Messimore
J A
JA
Nakamura
K
K
Rohm
R M
RM
Tornow
W
W
Young
A R
AR
Chen
M-J
MJ
Wang
Y-F
YF