Theory Overview

Abstract

We set the scene for theoretical issues in charm physics that were discussed at CHARM 2016 in Bologna. In particular we emphasize the importance of improving our understanding of standard model contributions to numerous charm observables and we discuss also possible tests of our theory tools, like the Heavy Quark Expansion via the lifetime ratios of D-mesons.

Opportunities in Flavour Physics at the HL-LHC and HE-LHC

“…Broadly speaking, there are two approaches: (i) an inclusive one employing the operator product expansion (OPE), which expands in powers of Λ QCD /m c , as in the heavy quark expansion (HQE), and assumes that local quark-hadron duality holds [206][207][208][209]; and (ii) an exclusive one in which y is estimated by summing over contributions of exclusive states, and x is estimated via a dispersion relation which relates it to y. In the first approach, the HQE applied to Γ D 12 , combined with the relevant non-perturbative dimension six operator matrix elements evaluated in [210][211][212][213], yields contributions of the individual Γ ij to y that are five times larger than the experimental value [214]. This corresponds to Γ ij ∼ Γ D , which is not surprising, given that the HQE can accommodate the charm meson lifetimes [213,215].…”