Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
2011-10-23
Physics
High Energy Physics
High Energy Physics - Phenomenology
talk presented at the "2011 Europhysics Conference on High Energy Physics - EPS-HEP 2011", 21 - 27 July 2011, Grenoble, Rhone-
Scientific paper
We present the results of our recent analyses of the form factors F_pi(Q^2) and F_{P gamma}(Q^2), P = pi, eta, eta', within the local-duality version of QCD sum rules. To probe the expected accuracy of this method, we consider, in parallel to QCD, a quantum-mechanical potential model. In the latter case, the exact form factor may be calculated from the solutions of the Schr\"odinger equation and confronted with the result from the quantum-mechanical local-duality sum rule. We find that the local-duality sum rule is expected to yield reliable predictions for both F_pi(Q^2) and F_{pi gamma}(Q^2) in the region Q^2 > 5-6 GeV^2. Moreover, in this region the accuracy of this approach improves rather fast with increasing Q^2. For the elastic form factor F_pi(Q^2), we are therefore forced to conclude that large deviations from the local-duality limit in the region Q^2 = 20-50 GeV^2 reported in some recent theoretical studies seem to us unlikely. The data on the eta, eta' to gamma gamma* transition form factors meet pretty well the predictions of a "local-duality model." Interestingly, recent results for the pi to gamma gamma* transition form factor hint at a violation of local duality rising with Q^2; this is at odds with the eta and eta' cases and all our experience from quantum mechanics.
Balakireva Irina
Lucha Wolfgang
Melikhov Dmitri
No associations
LandOfFree
Pion Elastic and pi to gamma gamma* Transition Form Factors at Large Momentum Transfers 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 Pion Elastic and pi to gamma gamma* Transition Form Factors at Large Momentum Transfers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pion Elastic and pi to gamma gamma* Transition Form Factors at Large Momentum Transfers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-526863