Impact of Family Non-universal $Z^\prime$ Boson on Pure Annihilation $B_s \to \pi^+ \pi^-$ and $B_d \to K^+ K^-$ Decays
| Autor: | Li, Ying, Wang, Wen-Long, Du, Dong-Shuo, Li, Zuo-Hong, Xu, Hong-Xia |
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| Rok vydání: | 2015 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | We study the $B_s \to \pi^+ \pi^-$ and $B_d \to K^+ K^-$ decays in the standard model and the family non-universal $Z^\prime$ model. Since none of the quarks in final states is the same as the initial quark, these decay modes can occur only via power-suppressed annihilation diagrams. Despite the consistence of the standard model prediction with the available data, there is a surviving room for a light $Z^\prime$ boson. Taking into account the $Z^\prime$ contribution, we find theoretical results for branching fractions can better accommodate the data. With the relevant data, we also derive a constraint on the parameter space for the $Z^\prime$. Moreover, for the $B_d \to K^+ K^-$, both the direct and the mixing-induced $CP$ asymmetry are sensitive to the couplings between $Z^\prime$ and fermions in the parameter spaces constrained by data. The measurements at future experimental facilities, including the LHC-b, Belle-II and the proposed high energy $e^+e^-$ collider, will provide us useful hints for direct searching for the light $Z^\prime$ boson. Comment: 10 pages, 7 figures |
| Databáze: | arXiv |
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