An investigation of unitarity at ISR energies

We analyse the unitarity equation in impact-parameter space using recent ISR data (at s=930 GeV²) on σ_T, dσ/dt (elastic) and d²σ/dtdM² (diffractive) as input. The assumption of s-channel helicity conservation for the diffractive process leads to a diffractive overlap function which is central. Unitarity then restricts single diffraction to satisfy 2σ_d?5.8 mb. The assumption of t-channel helicity conservation, on the other hand, gives the interesting result that diffractive processes are peripheral in b-space if the diffractively produced state has high spin. Unitarity in this case gives no significant bound on 2σ_d. For both cases, non-diffractive processes are peripheral.