2-6 November 2015
Playa Mazatlán Beach Hotel
Mexico/BajaSur timezone
- XVMWPF@gmail.com
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Contribution
Ulises2
Long-distance weak annihilation contribution to the $B^{\pm}\to (\pi^{\pm},K^{\pm}) \ell^+\ell^-$ decays
Speakers
- Mr. Sergio TOSTADO
Primary authors
- Mr. Sergio TOSTADO (CINVESTAV-IPN)
- Dr. Gabriel LÓPEZ-CASTRO (CINVESTAV-IPN)
- Dr. Pablo ROIG (CINVESTAV-IPN)
- Mr. Adolfo GUEVARA (CINVESTAV-IPN)
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Description
We propose an alternative evaluation of the long-distance weak annihilation (WA) contribution to the rare semileptonic $B^{\pm}\to (\pi^{\pm},K^{\pm})\ell^+\ell^-$ ($\ell=e,\,\mu$) decays. Although the WA contribution does not contribute to solve the possible breaking of lepton-universality observed by LHCb in the $B^{\pm}\to K^{\pm}(\mu^+\mu^-/e^+e^-)$ ratio, nor provides an important hadronic contamination to their decay rates, its contribution to the branching ratios (and direct CP asymmetry) of the $B^{\pm}\to \pi^{\pm}\ell^+\ell^-$ transitions turns out to be significant. This hadronic pollution should be taken into account when looking for new physics effects in decays into pions, which suggests to restrict these searches to squared lepton-pair invariant mass in the $(1,8)$ GeV$^2$ range. The interference of the one-photon exchange contribution with the dominant short-distance one-loop amplitude induces a sizable CP asymmetry in these rare decays, which calls for dedicated measurements.