Abstract
We scrutinize the recently further strengthened hints for new physics in semileptonic B-meson decays, focusing on the ‘clean’ ratios of branching fractions R_K and R_{K^*} and examining to which pattern of new effects they point to. We explore in particular the hardly considered, yet fully viable, option of new physics in the right-handed electron sector and demonstrate how a recently proposed framework of leptons in composite Higgs setups naturally solves both the R_K and R_{K^*} anomalies via a peculiar structure of new physics effects, predicted by minimality of the model and the scale of neutrino masses. Finally, we also take into account further observables, such as mathcal{B}(B_s rightarrow mu ^+mu ^-), varDelta M_{B_s}, and angular observables in B rightarrow K^{*} mu ^+ mu ^- decays, to arrive at a comprehensive picture of the model concerning (semileptonic) B decays. We conclude that – since it is in good agreement with the experimental situation in flavor physics and also allows to avoid ultra-light top partners – the model furnishes a very promising scenarios of Higgs compositeness in the light of LHC data.
Highlights
We explore in particular the hardly considered, yet fully viable, option of new physics in the right-handed electron sector and demonstrate how a recently proposed framework of leptons in composite Higgs setups naturally solves both the RK and RK ∗ anomalies via a peculiar structure of new physics effects, predicted by minimality of the model and the scale of neutrino masses
Decays of B mesons offer a promising place to search for new physics (NP), since in the Standard Model (SM) of Particle Physics flavor changing neutral processes are strongly suppressed and effects of NP might be sizable in B decays
Before presenting our final numerical results for these observables, we show in Fig. 2 the pattern of Wilson coefficients generated in the composite Higgs model
Summary
Decays of B mesons offer a promising place to search for new physics (NP), since in the Standard Model (SM) of Particle Physics flavor changing neutral processes are strongly suppressed and effects of NP might be sizable in (flavorchanging) B decays. Expanding again in CbNsXP Y , keeping quadratic terms only in CbNsXP R and neglecting the strongly suppressed interference with CbSsML R , we obtain p From this expression it is evident that RK ∗ probes righthanded quark currents since in their absence it becomes equivalent to RK to leading approximation. Since the interference of NP effects in the right-handed lepton sector with SM contributions is suppressed, generically larger coefficients are required here in order to obtain sizable effects. Consistently explaining the RK and RK ∗ anomalies requires both quark FCNCs involving the b quark and LFU violation in the μ vs e system (with effects either in left-handed currents in both sectors, or with a non-negligible right-handed electron contribution). A positive C9e, on the other hand, allows for a straightforward solution
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
