Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
2011-09-26
Physics
High Energy Physics
High Energy Physics - Phenomenology
4 pages, to be published in the proceedings of the 2011 Europhysics Conference on High Energy Physics-HEP 2011, July 21-27, 20
Scientific paper
Generalized Parton Distributions offer a new way to access the quark and gluon nucleon structure. We review recent progress in this domain, emphasizing the need to supplement the experimental study of DVCS by its crossed version, timelike Compton scattering (TCS), where data at high energy should appear thanks to the study of ultraperipheral collisions at the LHC. This will open the access to very low skewness quark and gluon GPDs. Our leading order estimates show that the factorization scale dependence of the amplitudes is quite high. This fact demands the understanding of higher order contributions with the hope that they will stabilize this scale dependence. The magnitudes of the NLO coefficient functions are not small and neither is the difference of the coefficient functions appearing respectively in the DVCS and TCS amplitudes. The conclusion is that extracting the universal GPDs from both TCS and DVCS reactions requires much care. We also describe the extension of the GPD concept to three quark operators and the relevance of their nucleon to meson matrix elements, namely the transition distribution amplitudes (TDAs) which factorize in hard exclusive pion electroproduction off a nucleon in the backward region and baryon-antibaryon annihilation into a pion and a lepton pair. We discuss the main properties of the TDAs.
Pire Bernard
Semenov-Tian-Shansky Kirill
Szymanowski Lech
Wagner Jakub
No associations
LandOfFree
New results in exclusive hard reactions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with New results in exclusive hard reactions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and New results in exclusive hard reactions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-689016