Emerging patterns of New Physics with and without Lepton Flavour Universal contributions


الملخص بالإنكليزية

We perform a model-independent global fit to $bto sell^+ell^-$ observables to confirm existing New Physics (NP) patterns (or scenarios) and to identify new ones emerging from the inclusion of the updated LHCb and Belle measurements of $R_K$ and $R_{K^*}$, respectively. Our analysis, updating Refs. [1,2] and including these new data, suggests the presence of right-handed couplings encoded in the Wilson coefficients ${cal C}_{9mu}$ and ${cal C}_{10mu}$. It also strengthens our earlier observation that a lepton flavour universality violating (LFUV) left-handed lepton coupling (${cal C}_{9mu}^{rm V}=-{cal C}_{10mu}^{rm V}$), often preferred from the model building point of view, accommodates the data better if lepton-flavour universal (LFU) NP is allowed, in particular in ${cal C}_{9}^{rm U}$. Furthermore, this scenario with LFU NP provides a simple and model-independent connection to the $bto ctau u$ anomalies, showing a preference of $approx 7,sigma$ with respect to the SM. It may also explain why fits to the whole set of $bto sell^+ell^-$ data or to the subset of LFUV data exhibit stronger preferences for different NP scenarios. Finally, motivated by $Z^prime$ models with vector-like quarks, we propose four new scenarios with LFU and LFUV NP contributions that give a very good fit to data. We provide also an addendum collecting our updated results after including the data for the $Bto K^*mumu$ angular distribution released in 2020 by the LHCb collaboration.

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