Exclusive decays of heavy and light mesons

Observing b ? s ?+?? decays at hadron colliders

“…Even though this leaves open the possibility of deviations in the remainingsσ µν b matrix elements, the two sets of form factors can be related by the plausible assumption that the b quark is static within the B meson [13].…”

“…In spite of the fact that m s ≫ Λ QCD , it is shown in refs. [13,14] that these relations amongst form factors coninue to hold to about 10%, mainly as a result of the heaviness of the b quark, and also the fact that the K * meson is in some sense "weakly bound".…”

“…The K meson, on the other hand, is a relativistic bound state, and it might not be appropriate to apply the constituent quark model analysis of [13,14] here. Nevertheless, if one performs a general decomposition of the matrix elements in equation (7), one finds that only two of the three resulting form factors contribute to B → K µ + µ − .…”

Semileptonic and exclusive rare B decays

“…Theoretically, this rare decay is not well understood, as there is still an uncertainty of a factor of about 10 in the branching ratio depending on the way the large recoil of the K * is handled [2] in the form factors. Burdman and Donoghue [3] pointed out that the heavy-quark symmetry together with the SU (3) flavor symmetry could relate the rare decay B → K * γ to a measurement of the semileptonic decay B → ρeν, independent of the form factors.…”

“…Although there is now only one form factor to calculate in Eq. (3), this is still a controversial model-dependent calculation [2].…”