First Observation of the Decay <i>B<sub>s</sub></i><SUP>0</SUP> → <i>K</i><SUP>-</SUP>μ<SUP>+</SUP>ν<sub>μ</sub> and a Measurement of |<i>V<sub>ub</sub></i>|/|<i>V<sub>cb</sub></i>|

Aaij, R, Beteta, C Abellan, Ackernley, T, Adeva, B, Adinolfi, M, Afsharnia, H, Aidala, CA, Aiola, S, Ajaltouni, Z, Akar, S
et al (show 961 more authors) (2021) First Observation of the Decay <i>B<sub>s</sub></i><SUP>0</SUP> → <i>K</i><SUP>-</SUP>μ<SUP>+</SUP>ν<sub>μ</sub> and a Measurement of |<i>V<sub>ub</sub></i>|/|<i>V<sub>cb</sub></i>|. PHYSICAL REVIEW LETTERS, 126 (8). 081804-.

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The first observation of the suppressed semileptonic B_{s}^{0}→K^{-}μ^{+}ν_{μ} decay is reported. Using a data sample recorded in pp collisions in 2012 with the LHCb detector, corresponding to an integrated luminosity of 2  fb^{-1}, the branching fraction B(B_{s}^{0}→K^{-}μ^{+}ν_{μ}) is measured to be [1.06±0.05(stat)±0.08(syst)]×10^{-4}, where the first uncertainty is statistical and the second one represents the combined systematic uncertainties. The decay B_{s}^{0}→D_{s}^{-}μ^{+}ν_{μ}, where D_{s}^{-} is reconstructed in the final state K^{+}K^{-}π^{-}, is used as a normalization channel to minimize the experimental systematic uncertainty. Theoretical calculations on the form factors of the B_{s}^{0}→K^{-} and B_{s}^{0}→D_{s}^{-} transitions are employed to determine the ratio of the Cabibbo-Kobayashi-Maskawa matrix elements |V_{ub}|/|V_{cb}| at low and high B_{s}^{0}→K^{-} momentum transfer.

Item Type: Article
Additional Information: Submitted to Phys.Rev.Lett. All figures and tables, along with any supplementary material and additional information, are available at
Uncontrolled Keywords: LHCb Collaboration
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 21 Apr 2021 10:26
Last Modified: 16 Oct 2023 18:00
DOI: 10.1103/PhysRevLett.126.081804
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