Measurement of the branching fractions of the B+→ηℓ+νℓ and B+→η′ℓ+νℓ decays with signal-side only reconstruction in the full q2 range

Abstract

The branching fractions of the decays B+→ηℓ+νℓ and B+→η′ℓ+νℓ are measured, where ℓ is either an electron or a muon, using a data sample of 711 fb−1 containing 772×106BB¯ pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. To reduce the dependence of the result on the form factor model, the measurement is performed over the entire q2 range. The resulting branching fractions are B(B+→ηℓ+νℓ)=(2.83±0.55(stat.)±0.34(syst.))×10−5 and B(B+→η′ℓ+νℓ)=(2.79±1.29(stat.)±0.30(syst.))×10−5.Received 28 April 2021Accepted 4 August 2022DOI:https://doi.org/10.1103/PhysRevD.106.032013Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBranching fractionLeptonic, semileptonic & radiative decaysPhysical SystemsBottom quarkTechniquesLepton collidersParticles & Fields