Rare FCNF radiative leptonic decays b → γℓ<sup>+</sup>ℓ<sup>-</sup>
- Autor(en)
- Dmitri Melikhov, Anastasiia Kozachuk, Nikolai Nikitin
- Abstrakt
We present our recent results [1] for long-distance QCD effects in the flavour-changing neutral current radiative leptonic decays B → γ ℓ+ ℓ−, ℓ = {e, µ }. One encounters here two distinct types of long-distance effects: Those encoded in the B → γ transition form factors induced by the b → q quark currents, and those related to the charm-loop effects. We calculate the B → γ form factors in a broad range of the momentum transfers making use of the relativisitc dispersion approach based on the constituent quark picture which has proven to provide reliable predictions for many weak-transition form factors. Concerning the description of the charm-loop contributions, we point out two observations: First, the precise description of the charmonium resonances, in particular, the relative phases between ψ and ψ ′, has impact on the differential distributions and on the forward-backward asymmetry, AFB, in a broad range of q2 ≥ 5 GeV2. Second, the shape of AFB in B → γ ℓ+ ℓ− and in B → V ℓ+ ℓ− (V the vector meson) in the q2-region between ψ and ψ ′ provides an unambiguous probe of the relative phases between ψ and ψ ′. Fixing the latter will lead to a strong reduction of the theoretical uncertainties in AFB at q2 = 5 − 9 GeV2 where it has the sensitivity to physics beyond the SM.
- Organisation(en)
- Teilchenphysik
- Externe Organisation(en)
- Österreichische Akademie der Wissenschaften (ÖAW), Lomonosov Moscow State University (MSU), Universität Wien
- Journal
- Proceedings of Science (PoS)
- Band
- 314
- Anzahl der Seiten
- 6
- DOI
- https://doi.org/10.22323/1.314.0228
- Publikationsdatum
- 2018
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103034 Teilchenphysik
- ASJC Scopus Sachgebiete
- General
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/f45061eb-ce07-46bb-a23f-8f6d825221d1