No abstract

We present predictions on the total cross sections and on the ratio of the real part to the imaginary part of the elastic amplitude (ρ parameter) for present and future pp andpp colliders, and on total cross sections for γp → hadrons at cosmic-ray energies and for γγ → hadrons up to √ s = 1TeV. These predictions are based on an extensive study of possible analytic parametrisations invoking the biggest hadronic dataset available at t = 0. The uncertainties on total cross sections, including the systematic errors due to contradictory data points from FNAL, can reach 1.9%at RHIC, 3.1% at the Tevatron, and 4.8% at the LHC, whereas those on the ρ parameter are respectively 5.4%, 5.2%, and 5.4%.

The Donnachie-Landshoff fit of total cross sections has now become a standard reference for models of total, elastic and diffractive cross-sections. Adopting their philosophy that simple-pole exchanges should account for all data to present energies, we assess the uncertainties on their fits. Our best estimate for the pomeron intercept is 1.096 +0.012 −0.009 , but several models have a good χ 2 for intercepts in the range [1.07,1.11].

Using the largest data set available, we determine the best values that the data at t = 0 (total cross sections and real parts of the hadronic amplitudes) give for the intercepts and couplings of the soft pomeron and of the ρ/ω and a/f trajectories. We show that these data cannot discriminate between a simple-pole fit and asymptotic log 2 s and log s fits, and hence are not sufficient to reveal the ultimate nature of the pomeron. However, we evaluate the existing evidence (factorization, universality, quark counting) favouring the simple-pole hypothesis. We also examine the range of validity in energy of the fits, and show that one cannot rely on such fits in the region √ s < 9 GeV. We also establish bounds on the odderon and the hard pomeron.

We study pp and p p collisions which lead to the exclusive production of J= or from the pomeronodderon and the pomeron-photon fusion. We calculate scattering amplitudes of these processes in the lowest-order approximation and in the framework of k ? factorization. We present estimates of cross sections for the kinematic conditions of the Tevatron and of the LHC.