Precise determination of the CKM matrix element $$\left| V_{cb}\right|$$ with $$\bar B^0 \to D^{*\,+} \, \ell^- \, \bar ν_\ell$$ decays with hadronic tagging at Belle
The precise determination of the CKM matrix element $$\left| V_{cb}\right|$$ is important for carrying out tests of the flavour sector of the Standard Model. In this article we present a preliminary analysis of the $$\bar B^0 \to D^{*\,+} \, \ell^- \, \bar \nu_\ell$$ decay mode and its charge conjugate, selected in events that contain a fully reconstructed $$B$$-meson, using 772 million $$e^+ \, e^- \to \Upsilon(4S) \to B \bar B$$ events recorded by the Belle detector at KEKB. Unfolded differential decay rates of four kinematic variables fully describing the $$\bar B^0 \to D^{*\,+} \, \ell^- \, \bar \nu_\ell$$ decay in the $$B$$-meson rest frame are presented. We measure the total branching fraction $$\mathcal{B}( \bar B^0 \to D^{*\,+} \, \ell^- \, \bar \nu_\ell ) = \left(4.95 \pm 0.11 \pm 0.22 \right) \times 10^{-2}$$, where the errors are statistical and systematic respectively. The value of $$\left|V_{cb} \right|$$ is determined to be $$\left( 37.4 \pm 1.3 \right) \times 10^{-3}$$. Both results are in good agreement with current world averages.
- Research Organization:
- Univ. of Hawaii, Honolulu, HI (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP); National Science Foundation (NSF)
- Contributing Organization:
- BELLE Collaboration
- DOE Contract Number:
- SC0010504
- OSTI ID:
- 1598597
- Journal Information:
- arXiv.org Repository, Journal Name: arXiv.org Repository; ISSN 9999-0017
- Publisher:
- Cornell University
- Country of Publication:
- United States
- Language:
- English
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