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Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the Upsilon(4S)

文献类型:期刊论文

作者BaBar Collaboration
刊名PHYSICAL REVIEW D
出版日期2002
卷号66期号:3
关键词KOBAYASHI-MASKAWA MATRIX B-0 DECAYS CKM MATRIX SEARCH SYSTEM
通讯作者Aubert, B (reprint author), Phys Particules Lab, F-74941 Annecy Le Vieux, France.
英文摘要We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb-1 recorded at the Y(4S) resonance and 3.9 fb-1 off resonance. One of the neutral B mesons, which are produced in pairs at the Y(4S), is fully reconstructed in the CP decay modes J/psiK(S)(0), psi(2S)K-S(0), chi(c1)K(S)(0), J/psiK(*0) (K-*0-->K(S)(0)pi(0)) and J/psiK(L)(0), or in flavor-eigenstate modes involving D((*))pi/rho/a(1) and J/psiK(*0) (K-*0-->K(+)pi(-)). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural network tagging algorithm is used to recover events without a clear lepton or kaon tag. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities, the time-difference resolution function, and the B-0-(B) over bar (0) oscillation frequency Deltam(d) are measured with a sample of about 6350 fully-reconstructed B-0 decays in hadronic flavor-eigenstate modes. A maximum-likelihood fit to this flavor eigenstate sample finds Deltam(d)=0.516+/-0.016(stat)+/-0.010(syst) ps(-1). The value of the asymmetry amplitude sin 2beta is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged B-0 decays in the CP-eigenstate modes. We find sin 2beta=0.59+/-0.14(stat)+/-0.05(syst), demonstrating that CP violation exists in the neutral B meson system. We also determine the value of the CP violation parameter \lambda\=0.93+/-0.09(stat)+/-0.03(syst), which is consistent with the expectation of \lambda\=1 for no direct CP violation.
学科主题Astronomy & Astrophysics; Physics
类目[WOS]Astronomy & Astrophysics ; Physics, Particles & Fields
收录类别SCI
语种英语
WOS记录号WOS:000177873600007
公开日期2016-02-26
源URL[http://ir.ihep.ac.cn/handle/311005/212228]  
专题高能物理研究所_实验物理中心
作者单位中国科学院高能物理研究所
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GB/T 7714
BaBar Collaboration. Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the Upsilon(4S)[J]. PHYSICAL REVIEW D,2002,66(3).
APA BaBar Collaboration.(2002).Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the Upsilon(4S).PHYSICAL REVIEW D,66(3).
MLA BaBar Collaboration."Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the Upsilon(4S)".PHYSICAL REVIEW D 66.3(2002).

入库方式: OAI收割

来源:高能物理研究所

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