Measurements of Direct CP Asymmetries in B to X_s gamma decays using Sum of Exclusive Decays
J.P. Lees
(1)
,
V. Poireau
(1)
,
V. Tisserand
(1)
,
N. Arnaud
(2)
,
M. Davier
(2)
,
D. Derkach
(2)
,
G. Grosdidier
(2)
,
F. Le Diberder
(2)
,
A.M. Lutz
(2)
,
B. Malaescu
(2, 3)
,
P. Roudeau
(2)
,
M.H. Schune
(2)
,
A. Stocchi
(2)
,
G. Wormser
(2)
,
D. Bernard
(4)
,
M. Verderi
(4)
,
S. Emery
(5)
,
G. Hamel de Monchenault
(5)
,
G. Vasseur
(5)
,
Ch. Yèche
(5)
,
S. Akar
(3)
,
E. Ben-Haim
(3)
,
M. Bomben
(3)
,
G.R. Bonneaud
(3)
,
H. Briand
(3)
,
G. Calderini
(3)
,
J. Chauvau
(3)
,
O. Hamon
(3)
,
Ph. Leruste
(3)
,
G. Marchiori
(3)
,
J. Ocariz
(3)
,
S. Sitt
(3)
N. Arnaud
- Fonction : Auteur
- PersonId : 16841
- IdHAL : nicolas-arnaud
- ORCID : 0000-0001-6589-8673
G. Vasseur
- Fonction : Auteur
- PersonId : 745439
- IdHAL : georges-vasseur
G. Calderini
- Fonction : Auteur
- PersonId : 10608
- IdHAL : giovanni-calderini
- ORCID : 0000-0002-9495-9145
- IdRef : 172243211
G. Marchiori
- Fonction : Auteur
- PersonId : 741274
- IdHAL : giovanni-marchiori
- ORCID : 0000-0003-2655-7643
- IdRef : 180997203
Résumé
We measure the direct CP violation asymmetry, A_CP, in B to X_s gamma and the isospin difference of the asymmetry, Delta A_CP, using 429 fb^-1 of data collected at Upsilon(4S) resonance with the BaBar detector at the PEP-II asymmetric-energy e+e- storage rings operating at the SLAC National Accelerator Laboratory. B mesons are reconstructed from 10 charged B final states and 6 neutral B final states. We find A_CP = +(1.7 +- 1.9 +- 1.0)%, which is in agreement with the Standard Model prediction and provides an improvement on the world average. Moreover, we report the first measurement of the difference between A_CP for charged and neutral decay modes, Delta A_CP = +(5.0 +- 3.9 +- 1.5)%. Using the value of Delta A_CP, we also provide 68% and 90% confidence intervals on the imaginary part of the ratio of the Wilson coefficients corresponding to the chromo-magnetic dipole and the electromagnetic dipole transitions.