Vidence for CP-violating asymmetries in B0→π +π- decays and constraints on the CKM angle φ2
Abe, K.; Abe, N.; Abe, T.; Adachi, I.; Aihara, H.; Akai, K.; Akatsu, M.; Akemoto, M.; Asano, Y.; Aushev, T.; Bakich, A.M.; Ban, Y.; Banas, E.; Bay, A.; Bedny, I.; Behera, P.K.; Bizjak, I.; Bondar, A.; Bozek, A.; Bračko, M.; Brodzicka, J.; Browder, T.E.; Casey, B.C.K.; Chang, P.; Chen, K.-F.; Cheon, B.G.; Chistov, R.; Choi, S.-K.; Choi, Y.; Choi, Y.K.; Danilov, M.; Dragic, J.; Drutskoy, A.; Eidelman, S.; Eiges, V.; Everton, C.W.; Flanagan, J.; Fukunaga, C.; Furukawa, K.; Gabyshev, N.; Garmash, A.; Gershon, T.; Golob, B.; Guo, R.; Hagner, C.; Hara, K.; Hastings, N.C.; Hasuko, K.; Hayashii, H.; Hazumi, M.; Higuchi, T.; Hinz, L.; Hojo, T.; Hokuue, T.; Hoshi, Y.; Hou, W.-S.; Hsiung, Y.B.; Huang, H.-C.; Igaki, T.; Igarashi, Y.; Iijima, T.; Ikeda, H.; Inami, K.; Ishikawa, A.; Ishino, H.; Itoh, R.; Iwasaki, H.; Iwasaki, Y.; Jang, H.K.; Kang, J.S.; Kapusta, P.; Kataoka, S.U.; Katayama, N.; Katano, G.; Kawai, H.; Kawamura, N.; Kawasaki, T.; Kichimi, H.; Kikuchi, M.; Kikutani, E.; Kim, D.W.; Kim, H.J.; Kim, H.O.; Kim, H.; Kim, J.H.; Kim, S.K.; Kobayashi, S.; Korpar, S.; Križan, P.; Krokovny, P.; Kubo, T.; Kulasiri, R.; Kumar, S.; Kuzmin, A.; Kwon, Y.-J.; Lange, J.S.; Leder, G.; Lee, S.H.
2003

Abstract

We present an improved measurement of CP-violating asymmetries in B 0→π+π- decays based on a 78 fb -1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ e- collider. We reconstruct one neutral B meson as a B0→π+π - CP eigenstate and identify the flavor of the accompanying B meson from inclusive properties of its decay products. We apply an unbinned maximum likelihood fit to the distribution of the time intervals between the two B meson decay points. The fit yields the CP-violating asymmetry amplitudes A ππ= +0.77 ±0.27(stat) ±0.08(syst) and S ππ=-1.23 ±0.41(stat) -0.07 +0.08(syst), where the statistical uncertainties are determined from the Monte Carlo pseudoexperiments. We obtain confidence intervals for CP-violating asymmetry parameters Aππ and Sππ based on a frequentist approach. We rule out the CP-conserving case, A ππ=Sππ=0, at the 99.93% confidence level. We discuss how these results constrain the value of the Cabibbo-Kobayashi-Maskawa (CKM) angle φ2. © 2003 The American Physical Society.

Details

Title Vidence for CP-violating asymmetries in B0→π +π- decays and constraints on the CKM angle φ2
Author(s) Abe, K. ; Abe, N. ; Abe, T. ; Adachi, I. ; Aihara, H. ; Akai, K. ; Akatsu, M. ; Akemoto, M. ; Asano, Y. ; Aushev, T. ; Bakich, A.M. ; Ban, Y. ; Banas, E. ; Bay, A. ; Bedny, I. ; Behera, P.K. ; Bizjak, I. ; Bondar, A. ; Bozek, A. ; Bračko, M. ; Brodzicka, J. ; Browder, T.E. ; Casey, B.C.K. ; Chang, P. ; Chen, K.-F. ; Cheon, B.G. ; Chistov, R. ; Choi, S.-K. ; Choi, Y. ; Choi, Y.K. ; Danilov, M. ; Dragic, J. ; Drutskoy, A. ; Eidelman, S. ; Eiges, V. ; Everton, C.W. ; Flanagan, J. ; Fukunaga, C. ; Furukawa, K. ; Gabyshev, N. ; Garmash, A. ; Gershon, T. ; Golob, B. ; Guo, R. ; Hagner, C. ; Hara, K. ; Hastings, N.C. ; Hasuko, K. ; Hayashii, H. ; Hazumi, M. ; Higuchi, T. ; Hinz, L. ; Hojo, T. ; Hokuue, T. ; Hoshi, Y. ; Hou, W.-S. ; Hsiung, Y.B. ; Huang, H.-C. ; Igaki, T. ; Igarashi, Y. ; Iijima, T. ; Ikeda, H. ; Inami, K. ; Ishikawa, A. ; Ishino, H. ; Itoh, R. ; Iwasaki, H. ; Iwasaki, Y. ; Jang, H.K. ; Kang, J.S. ; Kapusta, P. ; Kataoka, S.U. ; Katayama, N. ; Katano, G. ; Kawai, H. ; Kawamura, N. ; Kawasaki, T. ; Kichimi, H. ; Kikuchi, M. ; Kikutani, E. ; Kim, D.W. ; Kim, H.J. ; Kim, H.O. ; Kim, H. ; Kim, J.H. ; Kim, S.K. ; Kobayashi, S. ; Korpar, S. ; Križan, P. ; Krokovny, P. ; Kubo, T. ; Kulasiri, R. ; Kumar, S. ; Kuzmin, A. ; Kwon, Y.-J. ; Lange, J.S. ; Leder, G. ; Lee, S.H.
Published in Physical Review D
Volume 68
Issue 1
Pages 012001
Date 2003
ISSN 05562821
DOI https://doi.org/10.1103/PhysRevD.68.012001
Other identifier(s) View record in Scopus
Laboratories LPHE
Record Appears in Scientific production and competences > SB - School of Basic Sciences > IPHYS - Institute of Physics > LPHE - High Energy Physics Laboratory
Peer-reviewed publications
Work produced at EPFL
Journal Articles
Published
Record creation date 2010-11-05