Sonderkolloquium: Application of light-cone sum rules (LCSRs) to D(s)->Pl+l- decays

D+ → π+ℓℓ decays are of much interest from the point of view of GIM cancellation and potential new sources of the FCNC c → u transitions. The hadronic amplitude of this decay is dominated by the combination of weak annihilation with the emission of a virtual photon which are purely long-distance effects.

In this talk, I will discuss a new method to analyse these decays, combining QCD light-cone sum rules (LCSRs) with hadronic dispersion relations. This method allows us to determine relative strong phases of the ρ-,ω- and ϕ-meson resonances and to estimate of the contributions of heavier hadronic states. The final results for D+ → π+ℓℓ width are obtained to be not much smaller than the current upper bound measured by LHCb collaboration. In the later part of my talk, I will discuss the relations of these decays to other Cabibbo favoured and Cabbbo suppressed modes using U-spin symmetry. Finally, I present results for Cabibbo-favoured modes, Ds+ → π+ℓℓ and D0 → K0ℓℓ, which proceed via the same weak annihilation mechanism as a byproduct of our analysis.

Weitere Informationen sind dem indico-Beitrag zu entnehmen.