https://doi.org/10.1140/epjc/s10052-021-09419-8
Regular Article - Theoretical Physics
Mapping out the space for new physics with leptonic and semileptonic 
decays
1
Nikhef, Science Park 105, 1098 XG, Amsterdam, The Netherlands
2
Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
3
Theoretische Physik 1, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, Walter-Flex-Strasse 3, 57068, Siegen, Germany
Received:
16
April
2021
Accepted:
5
July
2021
Published online:
27
July
2021
Decays of B mesons with leptons in the final state offer an interesting laboratory to search for possible effects of physics from beyond the Standard Model. In view of puzzling patterns in experimental data, the violation of lepton flavour universality is an interesting option. We present a strategy, utilising ratios of leptonic and semileptonic B decays, where the elements 
and 
of the Cabibbo–Kobayashi–Maskawa (CKM) matrix cancel, to constrain the short-distance coefficients of (pseudo)-scalar, vector and tensor operator contributions. The individual branching ratios allow us then to extract also the CKM matrix elements, even in the presence of new-physics contributions. Bounds on unmeasured leptonic and semileptonic decays offer important additional constraints. In our comprehensive analysis, we give also predictions for decays which have not yet been measured in a variety of scenarios.
© The Author(s) 2021
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Funded by SCOAP3
