The Physical Constants for Mathematica

The prospects of the further development of the package are briefly considered

High-Energy Forward Scattering and the Pomeron: Simple Pole versus Unitarized Models

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 rho/omega and a/f trajectories. We show that these data cannot discriminate between a simple-pole fit and asymptotic log square 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 sqrt(s)<9 GeV. We also establish bounds on the odderon and the hard pomeron.Comment: 20 pages, 10 figures. Predictions of Table 4 corrected and acknowledgements adde

Soft Pomeron and Lower-Trajectory Intercepts

We present a preliminary report on the determination of the intercepts and couplings of the soft pomeron and of the rho/omega and f/a trajectories from the largest data set available for all total cross sections and real parts of the hadronic amplitudes. Factorization is reasonably satisfied by the pomeron couplings, which allows us to make predictions on gamma gamma and gamma p total cross sections. In addition we show that these data cannot discriminate between fits based on a simple Regge pomeron-pole and on an asymptotic log^2s-type behaviour, implying that the effect of unitarisation is negligible. Also we examine the range of validity in energy of the fit, and the bounds that these data place on the odderon and on the hard pomeron.Comment: 13 pages, LaTeX, 14 figures. Presented by K. Kang at a 4th Workshop on Quantum Chromodynamics, June 1 - 6, 1998, The American University of Paris, Paris, France, and at the 4th Workshop on Small-x and Diffractive Physics, September 17 - 20, 1998, Fermi National Accelerator Laboratory, Batavia, I

New measures of the quality and of the reliability of fits applied to forward hadronic data at t=0

We develop five new statistical measures of the quality of fits, which we combine with the usual confidence level to determine the models which fit best all available data for total cross sections and for the real part of the forward hadronic amplitude.Comment: 7 pages, presented by J.R. Cudell on behalf of the COMPETE collaboration at the 6th workshop on non-perturbative QCD, American University of Paris, 5-9 June 200

Analytic Amplitude Models for Forward Scattering

We report on fits of a large class of analytic amplitude models for forward scattering against the comprehensive data for all available reactions. To differentiate the goodness of the fits of many possible parametrizations to a large sample of data, we developed and used a set of quantitative indicators measuring statistical quality of the fits over and beyond the typical criterion of the $\Chi^2 /dof$. These indicators favor models with a universal $log^2 s$ Pomeron term, which enables one to extend the fit down to $\sqrt s = 4$ GeV.Comment: 13 pages, COMPETE Collaboration, talk presented at the 9th International Conference (Blois Workshop) on Elastic and Diffractive Scatterin