Journal of High Energy Physics > 2019 > 2019 > 4 > 1-47
Study of the rare decays of Bs0 and B0 mesons into muon pairs using data collected during 2015 and 2016 with the ATLAS detector
Source
Abstract
A study of the decays Bs0 → μ+μ− and B0 → μ+μ− has been performed using 26.3 fb−1 of 13 TeV LHC proton-proton collision data collected with the ATLAS detector in 2015 and 2016. Since the detector resolution in μ+μ− invariant mass is comparable to the Bs0 -B0 mass difference, a single fit determines the signal yields for both decay modes. This results in a measurement of the branching fraction ℬ B s 0 → μ + μ − = 3.2 − 1.0 + 1.1 × 10 − 9 $$ \mathrm{\mathcal{B}}\left({B}_s^0\to {\mu}^{+}{\mu}^{-}\right)=\left({3.2}_{-1.0}^{+1.1}\right)\times {10}^{-9} $$ and an upper limit ℬ B 0 → μ + μ − < 4.3 × 10 − 10 $$ \mathrm{\mathcal{B}}\left({B}^0\to {\mu}^{+}{\mu}^{-}\right)<4.3\times {10}^{-10} $$ at 95% confidence level. The result is combined with the Run 1 ATLAS result, yielding ℬ B s 0 → μ + μ − = 2.8 − 0.7 + 0.8 × 10 − 9 $$ \mathrm{\mathcal{B}}\left({B}_s^0\to {\mu}^{+}{\mu}^{-}\right)=\left({2.8}_{-0.7}^{+0.8}\right)\times {10}^{-9} $$ and ℬ B 0 → μ + μ − < 2.1 × 10 − 10 $$ \mathrm{\mathcal{B}}\left({B}^0\to {\mu}^{+}{\mu}^{-}\right)<2.1\times {10}^{-10} $$ at 95% confidence level. The combined result is consistent with the Standard Model prediction within 2.4 standard deviations in the ℬ B 0 → μ + μ − − ℬ B s 0 → μ + μ − $$ \mathrm{\mathcal{B}}\left({B}^0\to {\mu}^{+}{\mu}^{-}\right)-\mathrm{\mathcal{B}}\left({B}_s^0\to {\mu}^{+}{\mu}^{-}\right) $$ plane.
Identifiers
journal e-ISSN : | 1029-8479 |
DOI | 10.1007/JHEP04(2019)098 |
Authors
The ATLAS collaboration
- University Politehnica Bucharest, Bucharest, Romania
- Centre National de l’Energie des Sciences Techniques Nucleaires (CNESTEN), Rabat, Morocco
- Universidade Nova de Lisboa, Dep Física and CEFITEC of Faculdade de Ciências e Tecnologia, Caparica, Portugal
- CERN, Geneva 23, Switzerland
B. Abbott
- University of Oklahoma, Homer L. Dodge Department of Physics and Astronomy, Norman, United States of America