Measurement of the decay B →dℓνℓ in fully reconstructed events and determination of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb |
Measurement of the decay B →dℓνℓ in fully reconstructed events and determination of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb |
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DOI：
10.1103/physrevd.93.032006
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发表时间：
2015-10
影响因子：
5
通讯作者：
R. Glattauer;C. Schwanda;A. Abdesselam;I. Adachi;K. Adamczyk;H. Aihara;S. Said;D. Asner;
中科院分区：
文献类型：
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作者：
R. Glattauer;C. Schwanda;A. Abdesselam;I. Adachi;K. Adamczyk;H. Aihara;S. Said;D. Asner;
基于Belle探测器记录的e(+)e(-) -> Upsilon（4S）数据的711 fb(-1)，包含772 x 10(6) B (B)对，我们提出了利用衰减B -> Dl nu(l) （l = e,mu）来确定Cabibbo-Kobayashi-Maskawa矩阵元素竖条V-cb竖条的大小。事件中的一个B介子在强子衰变模式下完全重建，而另一个在信号侧，由带电轻子和D+或D-0介子在总共23个强子衰变模式下部分重建。发现衰变的同位旋平均分支分数B- > Dl nu(l)为B(B-0 -> D(-)l（竖条）nu(l)) = (2.31 +/- 0.03(stat) +/- 0.11(syst))%。利用capryini、Lellouch和Neubert的参数化分析了差分衰减率作为强子后坐力的函数，并利用FNAL/MILC计算的形状因子预测G(1) = 1.0541 +/- 0.0083，得到eta（EW）纵杆V-cb纵杆= (40.12 +/- 1.34)× 10(-3)，其中eta（EW）为电弱校正因子。另外，假设Boyd， Grinstein和Lebed的模型无关的形状因子参数化，并使用来自FNAL/MILC和HPQCD合作的晶格QCD数据，我们发现eta（EW）竖条V-cb竖条= (41.10 +/- 1.14)x 10（-3）。
We present a determination of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar using the decay B -> Dl nu(l) (l = e,mu) based on 711 fb(-1) of e(+)e(-) -> Upsilon(4S) data recorded by the Belle detector and containing 772 x 10(6) B (B) over bar pairs. One B meson in the event is fully reconstructed in a hadronic decay mode, while the other, on the signal side, is partially reconstructed from a charged lepton and either a D+ or D-0 meson in a total of 23 hadronic decay modes. The isospin-averaged branching fraction of the decay B -> Dl nu(l) is found to be B(B-0 -> D(-)l(vertical bar)nu(l)) = (2.31 +/- 0.03(stat) +/- 0.11(syst))%. Analyzing the differential decay rate as a function of the hadronic recoil with the parametrization of Caprini, Lellouch, and Neubert and using the form-factor prediction G(1) = 1.0541 +/- 0.0083 calculated by FNAL/MILC, we obtain eta(EW)vertical bar V-cb vertical bar = (40.12 +/- 1.34) x 10(-3), where eta(EW) is the electroweak correction factor. Alternatively, assuming the model-independent form-factor parametrization of Boyd, Grinstein, and Lebed and using lattice QCD data from the FNAL/MILC and HPQCD collaborations, we find eta(EW)vertical bar V-cb vertical bar = (41.10 +/- 1.14) x 10(-3).