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arXiv · 2108.09283

Measurement of the $B^0_s\to\mu^+\mu^-$ decay properties and search for the $B^0\to\mu^+\mu^-$ and $B^0_s\to\mu^+\mu^-\gamma$ decays

LHCb collaboration·R. Aaij·C. Abellán Beteta·T. Ackernley·B. Adeva·M. Adinolfi·H. Afsharnia·C. A. Aidala·S. Aiola·Z. Ajaltouni·S. Akar·J. Albrecht·F. Alessio·M. Alexander·A. Alfonso Albero·Z. Aliouche·G. Alkhazov·P. Alvarez Cartelle·S. Amato·Y. Amhis·L. An·L. Anderlini·A. Andreianov·M. Andreotti·F. Archilli·A. Artamonov·M. Artuso·K. Arzymatov·E. Aslanides·M. Atzeni·B. Audurier·S. Bachmann·M. Bachmayer·J. J. Back·P. Baladron Rodriguez·V. Balagura·W. Baldini·J. Baptista Leite·R. J. Barlow·S. Barsuk·W. Barter·M. Bartolini·F. Baryshnikov·J. M. Basels·G. Bassi·B. Batsukh·A. Battig·A. Bay·M. Becker·F. Bedeschi·I. Bediaga·A. Beiter·V. Belavin·S. Belin·V. Bellee·K. Belous·I. Belov·I. Belyaev·G. Bencivenni·E. Ben-Haim·A. Berezhnoy·R. Bernet·D. Berninghoff·H. C. Bernstein·C. Bertella·A. Bertolin·C. Betancourt·F. Betti·Ia. Bezshyiko·S. Bhasin·J. Bhom·L. Bian·M. S. Bieker·S. Bifani·P. Billoir·M. Birch·F. C. R. Bishop·A. Bitadze·A. Bizzeti·M. Bjørn·M. P. Blago·T. Blake·F. Blanc·S. Blusk·D. Bobulska·J. A. Boelhauve·O. Boente Garcia·T. Boettcher·A. Boldyrev·A. Bondar·N. Bondar·S. Borghi·M. Borisyak·M. Borsato·J. T. Borsuk·S. A. Bouchiba·T. J. V. Bowcock·A. Boyer·C. Bozzi·M. J. Bradley
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Abstract

An improved measurement of the decay $B^0_s\to\mu^+\mu^-$ and searches for the decays $B^0\to\mu^+\mu^-$ and $B^0_s\to\mu^+\mu^-\gamma$ are performed at the LHCb experiment using data collected in proton-proton collisions at $\sqrt{s} = 7,~8$ and $13$ TeV, corresponding to integrated luminosities of 1, 2 and 6 fb$^{-1}$, respectively. The $B^0_s\to\mu^+\mu^-$ branching fraction and effective lifetime are measured to be ${\mathcal{B}}(B^0_s\to\mu^+\mu^-)=\left(3.09^{+0.46+0.15}_{-0.43-0.11}\right)\times 10^{-9}$ and $\tau(B^0_s\to\mu^+\mu^-)=(2.07\pm 0.29\pm 0.03)$ ps, respectively, where the uncertainties include both statistical and systematic contributions. No significant signal for $B^0\to\mu^+\mu^-$ and $B^0_s\to\mu^+\mu^-\gamma$ decays is found and the upper limits $\mathcal{B}(B^0\to\mu^+\mu^-)<2.6\times 10^{-10}$ and $\mathcal{B}(B^0_s\to\mu^+\mu^-\gamma)<2.0\times 10^{-9}$ at 95% confidence level are determined, where the latter is limited to the range $m_{\mu\mu} > 4.9$ GeV$/c^2$. Additionally, the ratio between the $B^0\to\mu^+\mu^-$ and $B^0_s\to\mu^+\mu^-$ branching fractions is measured to be $\mathcal{R}_{\mu^+\mu^-}<0.095$ at 95% confidence level. The results are in agreement with the Standard Model predictions.

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LHCb collaboration, R. Aaij, C. Abellán Beteta, T. Ackernley, B. Adeva, M. Adinolfi, H. Afsharnia, C. A. Aidala, S. Aiola, Z. Ajaltouni, S. Akar, J. Albrecht, F. Alessio, M. Alexander, A. Alfonso Albero, Z. Aliouche, G. Alkhazov, P. Alvarez Cartelle, S. Amato, Y. Amhis, L. An, L. Anderlini, A. Andreianov, M. Andreotti, F. Archilli, A. Artamonov, M. Artuso, K. Arzymatov, E. Aslanides, M. Atzeni, B. Audurier, S. Bachmann, M. Bachmayer, J. J. Back, P. Baladron Rodriguez, V. Balagura, W. Baldini, J. Baptista Leite, R. J. Barlow, S. Barsuk, W. Barter, M. Bartolini, F. Baryshnikov, J. M. Basels, G. Bassi, B. Batsukh, A. Battig, A. Bay, M. Becker, F. Bedeschi, I. Bediaga, A. Beiter, V. Belavin, S. Belin, V. Bellee, K. Belous, I. Belov, I. Belyaev, G. Bencivenni, E. Ben-Haim, A. Berezhnoy, R. Bernet, D. Berninghoff, H. C. Bernstein, C. Bertella, A. Bertolin, C. Betancourt, F. Betti, Ia. Bezshyiko, S. Bhasin, J. Bhom, L. Bian, M. S. Bieker, S. Bifani, P. Billoir, M. Birch, F. C. R. Bishop, A. Bitadze, A. Bizzeti, M. Bjørn, M. P. Blago, T. Blake, F. Blanc, S. Blusk, D. Bobulska, J. A. Boelhauve, O. Boente Garcia, T. Boettcher, A. Boldyrev, A. Bondar, N. Bondar, S. Borghi, M. Borisyak, M. Borsato, J. T. Borsuk, S. A. Bouchiba, T. J. V. Bowcock, A. Boyer, C. Bozzi, M. J. Bradley. 2021-08-20. Measurement of the $B^0_s\to\mu^+\mu^-$ decay properties and search for the $B^0\to\mu^+\mu^-$ and $B^0_s\to\mu^+\mu^-\gamma$ decays. https://doi.org/10.1103/physrevd.105.012010

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