arXiv:2605.07997·v1·High Energy Physics — Phenomenology
Symmetry-Breaking Effects on Form Factors and Observables in Decay
Saba Ayub🇵🇰 · Saba Shafaq🇵🇰 · Arslan Sikandar🇵🇰 · M. Jamil Aslam🇵🇰
Abstract
In the heavy-quark and large-energy limits, symmetry relations reduce the number of independent form factors governing heavy-to-light -meson decays. Exploiting these relations, the form factors can be parametrized while systematically incorporating symmetry-breaking corrections from perturbative QCD. Using vertex renormalization together with light-cone distribution amplitudes, we compute the vertex and hard-spectator contributions for the transition. We then analyze the impact of these form factors on physical observables, including the branching ratio and lepton polarization asymmetries , in . Our results indicate that perturbative corrections induce modest shifts of in both the branching ratio and the normal lepton polarization asymmetry. Consequently, any significant deviation observed experimentally from these predictions would provide a clear signal of potential New Physics effects.
Comments: 18 pages, 7 figures