LHC Seminar

New tests of lepton universality using rare B decays with $K_{S}^{0}$ mesons in the final state at LHCb

by Harry Victor Cliff (University of Cambridge (GB))

500/1-001 - Main Auditorium (CERN)

500/1-001 - Main Auditorium


Show room on map

In recent years several intriguing anomalies have been reported in the rare decays of B mesons. Most prominently, in March 2021 a measurement by LHCb of the ratio known as $R_K$ showed 3.1 standard deviation significance for the violation of lepton universality in $B^{+} \rightarrow K^{+} \ell^{+} \ell^{-}$ decays, where $\ell$ is either a muon or an electron. Previous measurements of the ratio $R_{K*}$ using $B^{0}\rightarrow K^{*0} \ell^{+} \ell^{-}$ also hinted at the violation of lepton universality, albeit at a lower statistical significance.

In this seminar we present the first tests at LHCb of lepton universality using these decays’ isospin partners - $B^{0} \rightarrow K^{0}_{S} \ell^{+} \ell^{-}$ and $B^{+} \rightarrow K^{*+} \ell^{+} \ell^{-}$ .

These tests have lower statistical sensitivity than $R_K$ and $R_{K*}$ due to the presence of a $K^0_{\text{S}}$ in the final state. The measurements are performed with data recorded by the LHCb experiment in 2011-2012 and 2016-2018, corresponding to an integrated luminosity of 9 $\text{fb}^{-1}$.


The seminar will take place in "hybrid format" with the speaker present in-person in the Auditorium. Note that the occupancy is currently limited to 70 people due to hygiene rules.  If you want to attend in person you must register.

Organized by

Michelangelo Mangano, Monica Pepe-Altarelli and Pedro Silva.

LHCb seminar 19 October 2021
Zoom Meeting ID
Angela Ricci
Alternative hosts
Pedro Vieira De Castro Ferreira Da Silva, Michelangelo Mangano, Claudia Dupraz, Monica Pepe-Altarelli, Benoit Loyer
Useful links
Join via phone
Zoom URL
70 / 70
  • Admir Greljo
  • Alex Pomarol
  • Alexey Petrov
  • Alibordi Muhammad
  • Andreas Juttner
  • Bernat Capdevila
  • Biplab Dey
  • Carla Marin Benito
  • Chris Parkes
  • Daria Savrina
  • David Marzocca
  • Dominik Stefan Mitzel
  • Federico Betti
  • Felicia Carolin Volle
  • Felipe Luan Souza De Almeida
  • Fidan Suljik
  • Fionn Bishop
  • Gary Robertson
  • Gianluca Inguglia
  • Giovanni Petrucciani
  • Hafeez Hoorani
  • Hassnae El Jarrari
  • J Tobias Tsang
  • Janina Nicolini
  • Juan Leite
  • Keisuke Harigaya
  • Kevin Sedlaczek
  • Kohsaku Tobioka
  • Marcel Golz
  • Marcella Bona
  • Martin Novoa Brunet
  • martino borsato
  • Marzia Bordone
  • Mason Proffitt
  • Matheus Hostert
  • Matthew Birch
  • Maurizio Pierini
  • Meril Reboud
  • Michael Marshall
  • Mindaugas Sarpis
  • Monica Pepe-Altarelli
  • Nathan Heatley
  • Niels Tuning
  • Niladri Sahoo
  • Oliver Lantwin
  • Olivier Schneider
  • Pascal Vincent
  • Patrick Koppenburg
  • Patrick Rieck
  • Pedro Silva
  • Pouya Asadi
  • Ricardo Barrué
  • Riccardo Manzoni
  • Richard Polifka
  • Sahal Yacoob
  • Shalini Epari
  • Siavash Neshatpour
  • Sophie Renner
  • Sudip JANA
  • Tarak Nath Maity
  • Thibaud Humair
  • Tomas Jakoubek
  • Tommaso Fulghesu
  • Valerie Gibson
  • Vladimir Gligorov
  • Xuelong Qin
  • Yasmine Sara Amhis
  • Yoxara Sánchez Villamizar
  • zheng ruyou
There is a live webcast for this event