QED in B→Kℓ+ℓ− LFU ratios: theory versus experiment, a Monte Carlo study

Gino Isidori, Davide Lancerini, Saad Nabeebaccus, Roman Zwicky*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Using analytic results obtained in a meson effective theory, that includes all infrared sensitive logs, we build a dedicated Monte Carlo framework to describe QED corrections in B K+ for a generic form factor. For the neutral mode B¯¯0 K¯¯0+, we perform a detailed numerical comparison versus those obtained with the general-purpose photon-shower tool PHOTOS. The comparison indicates a good agreement, at the few per-mil level, when focusing on the rare mode only. In addition, our framework allows us to investigate the impact of the charmonium resonances. Interference effects, not described by PHOTOS in the experimental analysis, are found to be small in the dilepton invariant mass region q2 < 6GeV2, which is used to determine RK(∗). Using a semi-analytic framework we assess the full, rare and resonant, mode. Based thereupon, we discuss strategies to check the subtraction of the resonant mode, which has a sizeable impact at q2 ≈ 6GeV2 in the electron mode.
Original languageEnglish
Article number146
Pages (from-to)1-26
Number of pages26
JournalJournal of High Energy Physics
Issue number10
Publication statusPublished - 20 Oct 2022

Keywords / Materials (for Non-textual outputs)

  • hep-ph
  • hep-ex
  • Bottom Quarks
  • Precision QED
  • Rare Decays


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