We study the form factors for a heavy meson into the S-wave Kπ/ππ system with an invariant mass below 1 GeV. The mesonic final state interactions are described in terms of the scalar form factors, which are obtained from unitarized chiral perturbation theory. Employing generalized light-cone distribution amplitudes, we compute the heavy-to-light transition using light-cone sum rules. Our approach simultaneously respects constraints from analyticity and unitarity, and also takes advantage of the power expansion in the 1/mb and the strong coupling constant.
Physics Letters B
- Pub Date:
- March 2014
- High Energy Physics - Phenomenology;
- High Energy Physics - Experiment
- 8 pages, 3 figures, v2: 11 pages, 3 figures, title changed, some clarifications and references added, matches version to appear in Physics Letters B