Electromagnetic pion and kaon form factors in light-cone resummed perturbative QCD
- Department of Physics, University of Basel (Switzerland)
We analyze the electromagnetic pion and kaon form factor by including radiative and higher-twist effects within the framework of resummed perturbative QCD in the spacelike region. We focus on the transition from the perturbative to nonperturbative behavior in the phenomenological intermediate-energy regime. Using a modified ''k{sub T}'' factorization scheme with transverse degrees of freedom, we evaluate the nonperturbative soft contributions as distinct from the hard contributions, ensuring no double counting via the Ward identity at Q{sup 2}=0. The soft contributions are obtained via local quark-hadron duality, while the hard contributions rest on the well-known collinear factorization theorem using model wave functions with modified Brodsky-Huang-Lepage-type ansatz and distribution amplitudes derived from light-cone QCD sum rules. Our analysis shows that the perturbative hard part prevails for large Q{sup 2} beyond 50-100 GeV{sup 2}, while for low and moderate momentum transfers below 10-16 GeV{sup 2}, the soft contributions dominate over the hard part. Thus, we demonstrate the importance of including the soft contributions for explaining the experimental form-factor data.
- OSTI ID:
- 21259901
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 79, Issue 3; Other Information: DOI: 10.1103/PhysRevD.79.034015; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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