Dortmund 2021 – wissenschaftliches Programm
T 81.7: Vortrag
Donnerstag, 18. März 2021, 17:30–17:45, Tf
Measurement of the ratio RKππ with the LHCb experiment — Christoph Langenbruch, •Johannes Heuel, and Stefan Schael — I. Physikalisches Institut B, RWTH Aachen University
In the Standard Model (SM) of particle physics, the coupling of electroweak gauge bosons to all leptons is universal. Stringent tests of this Lepton Flavour Universality (LFU) are possible by measuring ratios of rare b→ sℓℓ decays with different leptons in the final state. These decays are loop-suppressed in the SM and therefore sensitive to new heavy particles beyond the SM.
The LHCb experiment is ideally suited for the study of rare b hadron decays due to its large acceptance, the high trigger efficiencies and the excellent tracking and particle identification. Recent measurements of b→ sℓℓ ratios published by the LHCb Collaboration show tensions with the SM predictions of up to 2.5 standard deviations. Therefore, further studies of LFU tests using other rare B decay channels are crucial.
The current status of the ongoing measurement of the ratio RKππ of the branching fractions of the decays B+→ K+π+π−µ+µ− and B+→ K+π+π−e+e− is presented. The measurement is experimentally challenging as the hadronic system is measured inclusively.