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arXiv · 1907.00279

Radiative leptonic decays on the lattice

Christopher Kane·Christoph Lehner·Stefan Meinel·Amarjit Soni
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Abstract

Adding a hard photon to the final state of a leptonic pseudoscalar-meson decay lifts the helicity suppression and can provide sensitivity to a larger set of operators in the weak effective Hamiltonian. Furthermore, radiative leptonic $B$ decays at high photon energy are well suited to constrain the first inverse moment of the $B$-meson light-cone distribution amplitude, an important parameter in the theory of nonleptonic $B$ decays. We demonstrate that the calculation of radiative leptonic decays is possible using Euclidean lattice QCD, and present preliminary numerical results for $D_s^+ \to \ell^+ νγ$ and $K^- \to \ell^-\barνγ$.

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Christopher Kane, Christoph Lehner, Stefan Meinel, Amarjit Soni. 2019-09-11. Radiative leptonic decays on the lattice. https://arxiv.org/abs/1907.00279

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