Contribution to a conference proceedings

PUBDB-2025-05281

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Measurements of lepton-flavour universality insemileptonic 𝑩 decay at Belle II

Mantovano, M. (Corresponding author)DESY*

2025

Abstract: mass energy corresponding to the Υ(4𝑆) resonance. These data, characterised by low particlemultiplicity, well-constrained initial-state kinematics, and excellent lepton identification, providean ideal environment to study lepton-flavour universality in semileptonic 𝐵 decays. We presentresults on the ratios of semitauonic decay rates compared to those to light leptons in both exclusiveand inclusive 𝐵 decay. These include new measurements of the ratios for exclusive 𝐵 → 𝐷(∗) ℓ𝜈ℓdecays 𝑅(𝐷(∗))𝜏/ℓ in events tagged by a semileptonic 𝐵 decay.

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Contributing Institute(s):

1. BELLE II Experiment (BELLE)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF4-611) (POF4-611)

Experiment(s):

1. KEK: BELLE I/II

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