Light cone view on the applicability of perturbative QCD for exclusive processes

1995
4 pages
Published in:
  • Phys.Rev.D 52 (1995) 4038-4041

Citations per year

199620022008201420201902
Abstract: (APS)
It is pointed out in the example of the pion form factor that the usual factorized hard scattering amplitude TH in perturbative QCD is derived from the light-cone time-ordered perturbative expansion. In the light-cone perturbative expansion, the natural variable to make a separation of perturbative contributions from contributions intrinsic to the bound-state wave function itself is the light-cone energy, rather than the gluon virtuality of TH. We find that the ‘‘legal’’ PQCD contribution defined by the light-cone energy cut saturates to the full PQCD prediction without any cut in the smaller Q2 region as compared to that defined by the gluon four-momentum square cut. This is due to the contribution from highly off-energy-shell gluons in the end-point regions of the phase space.
  • quantum chromodynamics: perturbation theory
  • pi: form factor
  • form factor: pi
  • wave function: light cone
  • scattering amplitude: factorization
  • factorization: scattering amplitude
  • hard scattering
  • effect: higher-twist
  • energy
  • transverse momentum