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• 作者：Guang-Zhi Xu ; Yue Qiu ; Cheng-Ping Shen ; Yu-Jie Zhang
• 刊名：The European Physical Journal C - Particles and Fields
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：76
• 期：11
• 全文大小：547 KB
• 刊物类别：Physics and Astronomy
• 刊物主题：Physics
  Elementary Particles and Quantum Field Theory
  Nuclear Physics, Heavy Ions and Hadrons
  Physics beyond the Standard Model
  Measurement Science and Instrumentation
  Astronomy, Astrophysics and Cosmology
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1434-6052
• 卷排序：76

文摘

This study investigates \(B^*_{s,d}\rightarrow \mu ^+\mu ^-\) in the dimuon distributions and the hadronic contribution \(B_{s,d}\rightarrow B^*_{s,d}\gamma \rightarrow \mu ^+\mu ^-\). The \(\mu ^+\mu ^-\) decay widths of the vector mesons \(B^*_{s,d}\) are approximately a factor of 700 larger than the corresponding scalar mesons \(B_{s,d}\). The ratio of the branching fractions obtained, \(\frac{Br({B_{s,d}^*\rightarrow \mu ^+\mu ^-})}{{Br({B_{s,d}\rightarrow \mu ^+\mu ^-})}}\), is approximately \(\frac{0.3\times \mathrm{eV}}{{\Gamma (B^*_{s,d}\rightarrow B_{s,d}\gamma )}}\). The hadronic contribution \(B_{s,d}\rightarrow B^*_{s,d}\gamma \rightarrow \mu ^+\mu ^-\) is also estimated. The relative increase in the \(B_{s,d}\rightarrow \mu ^+\mu ^-\) amplitude is approximately \((0.01\pm 0.006) \sqrt{\frac{{\Gamma (B^*_{s,d}\rightarrow B_{s,d} \gamma )}}{{100~\mathrm{eV}}}}\). If we select \(\Gamma (B^*_{s,d}\rightarrow B_{s,d}\gamma )=2~\)eV, then the branching fractions of the vector mesons to the lepton pair are \(5.3\times 10^{-10}\) and \(1.6\times 10^{-11}\) for \(B^*_{s}\) and \(B^*_{d}\), respectively. If we select \(\Gamma (B^*_{s,d}\rightarrow B_{s,d}\gamma )=200~\)eV, then the updated branching fractions of the scalar mesons to the muon pair are \((3.78\,\pm \,0.25)\times 10^{-9}\) and \((1.09\,\pm \,0.09)\times 10^{-10}\) for \(B_{s}\) and \(B_{d}\), respectively. If we select the recent predicted M1 widths \(\Gamma (B^*_{s,d}\rightarrow B_{s,d}\gamma )=313, 1230\) eV (arXiv:1607.02169), then the updated branching fractions are \((3.8\,\pm \,0.3)\times 10^{-9}\) and \((1.2\,\pm \,0.1)\times 10^{-10}\) for \(B_{s}\rightarrow \mu ^+\mu ^-\) and \(B_{d}\rightarrow \mu ^+\mu ^-\), respectively. Further studies on \(B^*_{s,d}\), including those on dielectron decay and two-body decay with \(J/\psi \), should be conducted.