Measurement of the branching fractions of the B+ →ηâ +νâ and B+ →η′â +νâ decays with signal-side only reconstruction in the full q2 range

Abstract

The branching fractions of the decays B+→ηâ +νâ and B+→η′â +νâ are measured, where â is either an electron or a muon, using a data sample of 711 fb-1 containing 772×106BB¯ pairs collected at the I (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+→ηâ +νâ )=(2.83±0.55(stat.)±0.34(syst.))×10-5 and B(B+→η′â +νâ )=(2.79±1.29(stat.)±0.30(syst.))×10-5. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the https://creativecommons.org/licenses/by/4.0/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.