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Search for lepton flavour universality violation in $B^+ \rightarrow K^+ \ell^+ \ell^-$ decays at LHCb

Paula Alvarez Cartelle · CERN

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About

Recent measurements of observables involving the flavour changing neutral current transition $b \rightarrow s \mu^+ \mu^-$ have shown an interesting pattern of tensions with respect to the predictions of the Standard Model (SM). However, the interpretation of these results is limited by our present understanding of the hadronic uncertainties affecting these predictions. Given the lepton-flavour-universal nature of the SM, observables such as $R_{K} = {BR(B^+\rightarrow K^+ \mu^+ \mu^-)}/{BR(B^+\rightarrow K^+ e^+ e^-)}$, so-called Lepton Flavour Universality ratios, profit from large cancellation of the theory uncertainties and provide a very sensitive probe for physics beyond the SM.

The previous measurement of the ratio $R_K$ performed by the LHCb collaboration, using Run 1 data, found a value compatible with the SM expectation at the 2.6$\sigma$ level. In this seminar, a new measurement of $R_K$ at the LHCb experiment will be presented. The new measurement reanalyses the data recorded by LHCb during Run 1, and adds data collected during 2015 and 2016. The total dataset is double the size of that previously analysed. .

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The talk

  1. Search for lepton flavour universality violation in $B^+ \rightarrow K^+ \ell^+ \ell^-$ decays at LHCb 2019-03-26 · 55 min · CERN's player

Credits and licence

Institution
CERN
Department
LHC Seminar
Speaker
Paula Alvarez Cartelle
Year
2019
Language
English
Source
CERN
Licence
CERN, as CERN states it. CERN's terms
Attribution
© CERN. CERN provides its audiovisual media free of charge for educational and informational use, credited to CERN; this lecture is shown in CERN's own player.
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