Strong final state interactions in γγ→WW

Abstract

We study the effects of a possible strong final state interaction among longitudinal W's in γγ→WW. The relevant partial wave amplitudes are modified by an Omnès function approximated by a Breit–Wigner form factor. We study the fractional cross section f00=σLL/σtot with both W's longitudinally polarised, in the presence of a J=2 resonance (M=2.5 TeV, Γ=500 GeV) or a J=0 resonance (M=1 TeV, Γ=1 TeV), whose parameters are scaled up from the f2 and σ resonances in the ππ system. We also examine the effects of final state interaction in the case of polarised photons (Jz=0 or Jz=2), and the impact on the Drell–Hearn–Gerasimov sum rule.