Diffraction at the LHC

We show that the diffractive pp (and p (p) over bar) data (on sigma(tot), d sigma(el)/dt, proton dissociation into low-mass systems, sigma(D)(lowM), and high-mass dissociation, d sigma/d(Delta eta)) in a wide energy range from CERN-ISR to LHC energies, may be described in a two-channel eikonal model with only one 'effective' pomeron. By allowing the pomeron coupling to the diffractive eigenstates to depend on the collider energy (as is expected theoretically) we are able to explain the low value of sigma(D)(lowM) measured at the LHC. We calculate the survival probability, S-2, of a rapidity gap to survive 'soft rescattering'. We emphasise that the values found for S-2 are particularly sensitive to the detailed structure of the diffractive eigenstates.