Emerging patterns of New Physics with and without Lepton Flavour Universal contributions
Abstract
We perform a model-independent global fit to 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 and , respectively. Our analysis, updating Refs. [1,2] and including these new data, suggests the presence of right-handed couplings encoded in the Wilson coefficients and . It also strengthens our earlier observation that a lepton flavour universality violating (LFUV) left-handed lepton coupling (), often preferred from the model building point of view, accommodates the data better if lepton-flavour universal (LFU) NP is allowed, in particular in . Furthermore, this scenario with LFU NP provides a simple and model-independent connection to the anomalies, showing a preference of with respect to the SM. It may also explain why fits to the whole set of data or to the subset of LFUV data exhibit stronger preferences for different NP scenarios. Finally, motivated by 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 angular distribution released in 2020 by the LHCb collaboration.
Cite
@article{arxiv.1903.09578,
title = {Emerging patterns of New Physics with and without Lepton Flavour Universal contributions},
author = {Marcel Algueró and Bernat Capdevila and Andreas Crivellin and Sébastien Descotes-Genon and Pere Masjuan and Joaquim Matias and Martín Novoa-Brunet and Javier Virto},
journal= {arXiv preprint arXiv:1903.09578},
year = {2020}
}
Comments
18 pages, 36 figures. Includes Addendum in an appendix with updated fit results and discussion taking into account the LHCb results on $B\to K^{*}\mu\mu$ angular observables of March, 2020. Colours of plots uniformized all over the paper. Version published at EPJC