arXiv:hep-ph/0508001·v1·High Energy Physics — Phenomenology
Space-like and time-like pion electromagnetic form factor and Fock state components within the Light-Front dynamics
J. P. B. C. de Melo (Centro de Ciências Exatas e Tecnológicas, Universidade Cruzeiro do Sul, Sao Paulo, SP., and Instituto de Fisica Teorica, Universidade Estadual Paulista, SP, Brazil) · T. Frederico (Dep. de Fisica, Instituto Tecnologico da Aeronautica, Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP., Brazil) E. Pace (Dipartimento di Fisica, Universita di Roma "Tor Vergata" and Istituto Nazionale di Fisica Nucleare, Sezione Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy) · G. Salme (Istituto Nazionale di Fisica Nucleare, Sezione Roma I, P.le A. Moro 2, Roma, Italy)
Abstract
The simultaneous investigation of the pion electromagnetic form factor in the space- and time-like regions within a light-front model allows one to address the issue of non-valence components of the pion and photon wave functions. Our relativistic approach is based on a microscopic vector meson dominance (VMD) model for the dressed vertex where a photon decays in a quark-antiquark pair, and on a simple parametrization for the emission or absorption of a pion by a quark. The results show an excellent agreement in the space like region up to -10 , while in time-like region the model produces reasonable results up to 10 .
Comments: 74 pages, 11 figures, use revtex4