https://doi.org/10.1140/epjc/s10052-020-08653-w
Letter
Optimized lepton universality tests in $$B\rightarrow V \ell {\bar{\nu }}$$ decays
Physik-Institut, Universität Zürich, 8057, Zurich, Switzerland
* e-mail: olcyr.sumensari@physik.uzh.ch
Received:
21
July
2020
Accepted:
10
November
2020
Published online:
20
November
2020
We propose improved lepton flavor universality (LFU) ratios in semileptonic $$P\rightarrow V \ell {\bar{\nu }}$$ decays, when comparing $$\mu $$ and $$\tau $$ modes, that minimize the theoretical form-factor uncertainties. These optimized ratios are obtained with simple cuts or reweighting of the dilepton mass distributions, which imply a minimum loss of signal on the rare tauonic modes while maximizing the cancellation of theoretical uncertainties among the two modes. We illustrate the usefulness of these observables in $$B_c\rightarrow J/\psi $$, $$B_c\rightarrow \psi (2S)$$, $$B\rightarrow D^*$$ and $$B_s\rightarrow D_s^*$$ transitions, showing that in all cases we can reach $${\mathcal {O}}(1\%)$$ uncertainties on the SM predictions of the improved LFU ratios employing conservative form-factor uncertainties.
© The Author(s), 2020
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3