extraction using the Analytic Coupling model

Abstract

We summarize the main characteristics and recent results on B → Xu ν decays of a model based on soft-gluon resummation and an analytic time-like QCD coupling.

B-Physics: Theoretical Predictions in the LHC Era

“…The tension, indeed, originates from the difference between |V ub | incl = (43.1 ± 3.9) • 10 −4 and |V ub | excl = (34.0 ± 4.0) • 10 −4 , with the inclusive determination affected by a model-dependence in the non-perturbative contribution of the threshold region. This explanation is supported by a recent inclusive result |V ub | incl = (36.9 ± 1.3 ± 3.1) • 10 −4 [7], lower than the previous inclusive average and in agreement with the exclusive one, obtained with a model based on soft-gluon resummation and an analytic time-like QCD coupling. More recently, in [8] the experimental value of β has been compared to a V ub -independent determination based on the measurements of |V cb |, ∆M s /∆M d and ǫ K .…”

Potential and limitations of machine-learning approaches to inclusive |Vub| determinations

“…Phenomenologically, several theoretical approaches to partial B → X u ν decay rates are used in |V ub | extractions, going under the acronyms ADFR [23], BLNP [24,25], DGE [26] and GGOU [27]. These differ in the treatment of QCD effects in the shape function region, but all reduce to the conventional, local OPE results if the kinematic cuts do not introduce new scales which are parametrically much smaller than the b-quark mass.…”

A Review of the Magnitudes of the CKM Matrix Elements

“…The differential rate needed from theory to extract |V ub | from the experimental results has been calculated using several different theoretical approaches. In chronological order, they are BLNP [26] (a shape function approach, where the shape function represents the momentum distribution function of the b quark in the B meson), DGE [28,29], (a resummation based approach), GGOU [30] (an HQE based structure function parametrization approach) and ADFR [31,32] (a soft gluon resummation and analytic time-like QCD coupling approach). Concerning BLNP, recent NNLO corrections [27] were presented.…”