Transverse momentum and Sudakov effects in exclusive QCD processes: {gamma}{sup *}{gamma}{pi}{sup 0} form factor
Journal Article
·
· Phys.Rev. D56 (1997) 2713-2735
OSTI ID:756283
The authors analyze effects due to transverse degrees of freedom in QCD calculations of the fundamental hard exclusive amplitude of {gamma}{sup *}{gamma}{r_arrow}{pi}{sup 0} transition. A detailed discussion is given of the relation between the modified factorization approach (MFA) of Sterman et al. and standard factorization (SFA). Working in Feynman gauge, they construct basic building blocks of MFA from the one-loop coefficient function of the SFA, demonstrating that Sudakov effects are distinctly different from higher-twist corrections. They show also that the handbag-type diagram, contrary to naive expectations, does not contain an infinite chain of (M{sup 2}/Q{sup 2}){sup n} corrections: they come only from diagrams with transverse gluons emitted from the hard propagator. A simpler picture emerges within the QCD sum rule approach: the sum over soft {anti q}G ... Gq Fock components is dual to {anti q}q states generated by the local axial current. They combine the results based on QCD sum rules with pQCD radiative correct ions and observe that the gap between their curves for the asymptotic and CZ distribution amplitudes is sufficiently large for an experimental discrimination between them.
- Research Organization:
- Thomas Jefferson National Accelerator Facility, Newport News, VA (US)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC05-84ER40150
- OSTI ID:
- 756283
- Report Number(s):
- DOE/ER/40150-1544; JLAB-THY-97-07; hep-ph/9702443
- Journal Information:
- Phys.Rev. D56 (1997) 2713-2735, Journal Name: Phys.Rev. D56 (1997) 2713-2735 Journal Issue: 56 Vol. D
- Country of Publication:
- United States
- Language:
- English
Similar Records
Transverse momentum and Sudakov effects in exclusive QCD processes: {gamma}{sup {asterisk}}{gamma}{pi}{sup 0} form factor
QCD sum rule calculation of {gamma}{gamma}{sup *} {r_arrow} {pi}{sup 0} transition form factor
The asymptotics of the transition form factor {gamma}{gamma}{sup *} {r_arrow} {pi}{sup 0}
Journal Article
·
Mon Sep 01 00:00:00 EDT 1997
· Physical Review, D
·
OSTI ID:538702
QCD sum rule calculation of {gamma}{gamma}{sup *} {r_arrow} {pi}{sup 0} transition form factor
Journal Article
·
Tue Oct 31 23:00:00 EST 1995
· Phys.Lett. B374 (1996) 173-180
·
OSTI ID:756818
The asymptotics of the transition form factor {gamma}{gamma}{sup *} {r_arrow} {pi}{sup 0}
Conference
·
Thu May 01 00:00:00 EDT 1997
·
OSTI ID:756324