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  • Letter
  • Open Access

Lepton universality violation from neutral pion decays in RK(*) measurements

Dean J. Robinson

  • Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA

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Phys. Rev. D 105, L031903 – Published 17 February, 2022

DOI: https://doi.org/10.1103/PhysRevD.105.L031903

Abstract

I show that the neutral pion decay in B→K(*)π0γ, with π0→eeγ, might generate large sources of lepton flavor universality violation (LFUV) in measurements of the ratios, RK(*): If the photons in the K(*)eeγγ final state are reconstructed as bremsstrahlung, the recovered electron-positron invariant mass can be pushed into the 1–6  GeV2 signal region, artificially enhancing the measured B→K(*)ee branching ratio compared to B→K(*)μμ. I present a conservative estimate and simulation of the B→Kπ0γ LFUV background at LHCb, that together suggest this effect could reduce the recovered RK up to several percent. A reliable assessment of the size of this effect will require dedicated simulations within experimental frameworks themselves.

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Phys. Rev. D 105, L031903– Published 17 February, 2022
  • Received 2 November 2021
  • Accepted 23 January 2022
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Published 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.

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