Study of CP-violating asymmetries in B0-->pi(+)pi(-) decays.
We present a measurement of CP-violating asymmetries in B0-->pi(+)pi(-) decays based on a 41.8 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We fully reconstruct one neutral B meson as a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we obtain the CP-violating asymmetry parameters S(pipi)=-1.21(+0.38)(-0.27)(stat)+0.16-0.13(syst) and A(pipi)=+0.94(+0.25)(-0.31)(stat)+/-0.09(syst).
High Energy Accelerator Research Organization (KEK), Tsukuba.
K
K
Abe
K
K
Abe
T
T
Abe
I
I
Adachi
Byoung Sup
BS
Ahn
H
H
Aihara
M
M
Akatsu
Y
Y
Asano
T
T
Aso
V
V
Aulchenko
T
T
Aushev
A M
AM
Bakich
Y
Y
Ban
E
E
Banas
I
I
Bedny
S
S
Behari
P K
PK
Behera
A
A
Bondar
A
A
Bozek
M
M
Bracko
J
J
Brodzicka
T E
TE
Browder
B C K
BC
Casey
P
P
Chang
Y
Y
Chao
B G
BG
Cheon
R
R
Chistov
S-K
SK
Choi
Y
Y
Choi
M
M
Danilov
L Y
LY
Dong
J
J
Dragic
A
A
Drutskoy
S
S
Eidelman
V
V
Eiges
Y
Y
Enari
C W
CW
Everton
F
F
Fang
H
H
Fujii
C
C
Fukunaga
M
M
Fukushima
N
N
Gabyshev
A
A
Garmash
T
T
Gershon
B
B
Golob
A
A
Gordon
R
R
Guo
J
J
Haba
H
H
Hamasaki
K
K
Hanagaki
F
F
Handa
K
K
Hara
T
T
Hara
N C
NC
Hastings
H
H
Hayashii
M
M
Hazumi
E M
EM
Heenan
I
I
Higuchi
T
T
Higuchi
T
T
Hojo
T
T
Hokuue
Y
Y
Hoshi
K
K
Hoshina
S R
SR
Hou
W-S
WS
Hou
S-C
SC
Hsu
H-C
HC
Huang
T
T
Igaki
Y
Y
Igarashi
T
T
Iijima
H
H
Ikeda
K
K
Inami
A
A
Ishikawa
H
H
Ishino
R
R
Itoh
M
M
Iwamoto
H
H
Iwasaki
Y
Y
Iwasaki
D J
DJ
Jackson
P
P
Jalocha
H K
HK
Jang
J H
JH
Kang
J S
JS
Kang
P
P
Kapusta
N
N
Katayama
H
H
Kawai
H
H
Kawai
N
N
Kawamura
T
T
Kawasaki
H
H
Kichimi
D W
DW
Kim
Heejong
H
Kim
H J
HJ
Kim
H O
HO
Kim
Hyunwoo
H
Kim
S K
SK
Kim
T H
TH
Kim
K
K
Kinoshita
S
S
Koishi
H
H
Konishi
S
S
Korpar
P
P
Krizan
P
P
Krokovny
R
R
Kulasiri
S
S
Kumar
A
A
Kuzmin
Y-J
YJ
Kwon
J S
JS
Lange
G
G
Leder
S H
SH
Lee
A
A
Limosani
D
D
Liventsev
R-S
RS
Lu
J
J
MacNaughton
G
G
Majumder
F
F
Mandl
D
D
Marlow
T
T
Matsuishi
S
S
Matsumoto
T
T
Matsumoto
Y
Y
Mikami
W
W
Mitaroff
K
K
Miyabayashi
Y
Y
Miyabayashi
H
H
Miyake
H
H
Miyata
G R
GR
Moloney
S
S
Mori
T
T
Mori
A
A
Murakami
T
T
Nagamine
Y
Y
Nagasaka
T
T
Nakadaira
E
E
Nakano
M
M
Nakao
J W
JW
Nam
K
K
Neichi
S
S
Nishida
O
O
Nitoh
S
S
Noguchi
T
T
Nozaki
S
S
Ogawa
F
F
Ohno
T
T
Ohshima
T
T
Okabe
S
S
Okuno
S L
SL
Olsen
W
W
Ostrowicz
H
H
Ozaki
P
P
Pakhlov
H
H
Palka
C W
CW
Park
H
H
Park
K S
KS
Park
L S
LS
Peak
J-P
JP
Perroud
M
M
Peters
L E
LE
Piilonen
E
E
Prebys
J L
JL
Rodriguez
F J
FJ
Ronga
M
M
Rozanska
K
K
Rybicki
H
H
Sagawa
S
S
Saitoh
Y
Y
Sakai
H
H
Sakamoto
M
M
Satapathy
A
A
Satpathy
O
O
Schneider
S
S
Schrenk
C
C
Schwanda
S
S
Semenov
K
K
Senyo
M E
ME
Sevior
H
H
Shibuya
B
B
Shwartz
V
V
Sidorov
J B
JB
Singh
S
S
Stanic
A
A
Sugi
A
A
Sugiyama
K
K
Sumisawa
T
T
Sumiyoshi
K
K
Suzuki
S
S
Suzuki
S Y
SY
Suzuki
S K
SK
Swain
H
H
Tajima
T
T
Takahashi
F
F
Takasaki
M
M
Takita
K
K
Tamai
N
N
Tamura
J
J
Tanaka
M
M
Tanaka
G N
GN
Taylor
Y
Y
Teramoto
S
S
Tokuda
M
M
Tomoto
T
T
Tomura
S N
SN
Tovey
K
K
Trabelsi
W
W
Trischuk
T
T
Tsuboyama
T
T
Tsukamoto
S
S
Uehara
K
K
Ueno
Y
Y
Unno
S
S
Uno
Y
Y
Ushiroda
K E
KE
Varvell
C C
CC
Wang
C H
CH
Wang
J G
JG
Wang
M-Z
MZ
Wang
Y
Y
Watanabe
E
E
Won
B D
BD
Yabsley
Y
Y
Yamada
M
M
Yamaga
A
A
Yamaguchi
H
H
Yamamoto
Y
Y
Yamashita
M
M
Yamauchi
J
J
Yashima
P
P
Yeh
M
M
Yokoyama
K
K
Yoshida
Y
Y
Yuan
Y
Y
Yusa
C C
CC
Zhang
J
J
Zhang
Y
Y
Zheng
V
V
Zhilich
D
D
Zontar