scholarly journals Double parton distributions incorporating perturbative QCD evolution and momentum and quark number sum rules

2010 ◽  
Vol 2010 (3) ◽  
Author(s):  
Jonathan R. Gaunt ◽  
W. James Stirling
2009 ◽  
Vol 24 (31) ◽  
pp. 5845-5860 ◽  
Author(s):  
K. AZIZI ◽  
R. KHOSRAVI ◽  
F. FALAHATI

Using the factorization approach and considering the contributions of the current–current, QCD penguin and electroweak penguin operators at the leading approximation, the decay amplitudes and decay widths of [Formula: see text] and [Formula: see text] transitions, where q = u, d, s and P and V are pseudoscalar and vector mesons, are calculated in terms of the transition form factors of the Bq→Dq and [Formula: see text]. Having computed those form factors in three-point QCD sum rules, the branching fraction for these decays are also evaluated. A comparison of our results with the predictions of the perturbative QCD as well as the existing experimental data is presented.


1987 ◽  
Vol 59 (18) ◽  
pp. 2009-2011 ◽  
Author(s):  
C. Bourrely ◽  
J. Soffer ◽  
Tai Tsun Wu

2015 ◽  
Vol 37 ◽  
pp. 1560037 ◽  
Author(s):  
Koichi Kanazawa ◽  
Cedric Lorcé ◽  
Andreas Metz ◽  
Barbara Pasquini ◽  
Marc Schlegel

Generalized transverse-momentum dependent parton distributions (GTMDs) encode the most general parton structure of hadrons. In this contribution, which is largely based on a recent publication,1 we focus on two twist-2 GTMDs which are denoted by F1,4 and G1,1 in parts of the literature. As already shown previously, both GTMDs have a close relation to orbital angular momentum of partons inside a hadron. However, recently even the mere existence of F1,4 and G1,1 has been doubted. We explain why this claim does not hold. We support our model-independent considerations by calculating the GTMDs in two spectator models and in perturbative QCD. For the model results we also explicitly check the relation to the orbital angular momentum of partons inside hadrons.


2012 ◽  
Vol 20 ◽  
pp. 251-265 ◽  
Author(s):  
ANATOLY V. RADYUSHKIN

We discuss recent developments in building models for GPDs that are based on the formalism of double distributions (DDs). A special attention is given to a careful analysis of the singularity structure of DDs. The DD formalism is applied to construction of a model GPDs with a singular Regge behavior. Within the developed DD-based approach, we discuss the structure of GPD sum rules. It is shown that separation of DDs into the so-called "plus" part and the D-term part may be treated as a renormalization procedure for the GPD sum rules. This approach is compared with an alternative prescription based on analytic regularization.


Sign in / Sign up

Export Citation Format

Share Document