Dortmund 2021 – scientific programme
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T: Fachverband Teilchenphysik
T 7: Flavour physics V
T 7.10: Talk
Monday, March 15, 2021, 18:15–18:30, Tg
Non-local matrix elements in B(s)→ {K(*),φ}ℓ+ℓ− — •Nico Gubernari1, Danny van Dyk2, and Javier Virto3 — 1Universitaet Siegen, Walter-Flex-Strasse 3, 57068 Siegen — 2Technische Universitaet Muenchen, James-Franck-Strasse 1, 85758 Garching — 3Universitat de Barcelona, Marti Franques 1, E08028 Barcelona, Catalunya
We revisit the theoretical predictions and the parametrization of non-local matrix elements in rare B(s)→ K(*), φℓ+ℓ− and B(s)→ K*, φ γ decays. We improve upon the current state of these matrix elements in two ways. First, we recalculate the hadronic matrix elements needed at subleading power in the light-cone OPE using B-meson light-cone sum rules. Our analytical results supersede those in the literature. We discuss the origin of our improvements and provide numerical results for the processes under consideration. Second, we derive the first dispersive bound on the non-local matrix elements. It provides a parametric handle on the truncation error in extrapolations of the matrix elements to large timelike momentum transfer using the z expansion. We illustrate the power of the dispersive bound at the hand of a simple phenomenological application. As a side result of our work, we also provide numerical results for the Bs → φ form factors from B-meson light-cone sum rules.