Exploring the timelike region for the elastic form factor in the lightfront quantization
Abstract
Even though the DrellYanWest formulation is the most rigorous and wellestablished framework to compute the exclusive processes, its utility has been limited only to the spacelike region because of the intrinsic kinematic constraint q ^{+}=0 . We present an explicit example demonstrating how one may obtain the necessary information (i.e. nonvalence or so called Zgraph contribution) in the timelike region of exclusive process without encountering a formidable task of direct calculation that has hindered so far the progress in this area. In the analysis of q overlineQ bound state form factors using an exactly solvable model of (3+1)dimensional scalar field theory interacting with gauge fields, the results analytically continued from the spacelike region coincide exactly with the direct results in the timelike region. This example verifies that the method of analytic continuation is capable of yielding the effect of complicate nonvalence contributions. The meson peaks analogous to the vector meson dominance (VMD) phenomena are also generated at the usual VMD positions.
 Publication:

Nuclear Physics A
 Pub Date:
 January 2001
 DOI:
 10.1016/S03759474(00)003766
 arXiv:
 arXiv:hepph/9906225
 Bibcode:
 2001NuPhA.679..735C
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 21 pages, 8 figures, we changed the title, added some references and included some paragraphs in the introduction and conclusions