Vcb from inclusive b → c decays: an alternative method

by Keri Vos (Siegen)

3344 (Physikdepartment)




The puzzling discrepancy between the CKM element Vcb extracted from inclusive versus exclusive b → c semileptonic decays remains. In this talk, I focus on the inclusive determination, which depends heavily on the Heavy Quark Expansion. The HQE allows to predict physical observables as a series in ΛQCD/mb, with non-perturbative inputs that can be extracted from data or determined on the lattice. The current best extraction of inclusive Vcb has an impressive precision at the few percent level, and includes matrix elements up to 1/mb^3. However, the proliferation of these non-perturbative matrix elements beyond 1/mb^3 makes it challenging to go to even higher precision. In this talk, I will discuss how reparametrization invariance reduces the number of independent matrix elements. Making use of this, we propose an alternative method to extract Vcb using q2 moments. The method allows for a fully data-driven analysis of Vcb including 1/mb^4 terms and would be interesting to test at Belle (II).

Your browser is out of date!

Update your browser to view this website correctly. Update my browser now