QED factorization of two-body non-leptonic and semi-leptonic $B$ to charm decays

Understand

The QCD$\times$QED factorization is studied for two-body non-leptonic and semi-leptonic $B$ decays with heavy-light final states.

• These non-leptonic decays, like $\bar{B}^0_{(s)}\to D^+_{(s)} \pi^-$ and $\bar{B}_d^0 \to D^+ K^-$, are among the theoretically cleanest non-leptonic decays as penguin loops do not contribute and colour-suppressed tree amplitudes are suppressed in the heavy-quark limit or even completely absent.
• Advancing the theoretical calculations of such decays requires therefore also a careful analysis of QED effects.
• Including QED effects does not alter the general structure of factorization which is analogous for both semi-leptonic and non-leptonic decays.