New Generation of Parton Distributions with Uncertainties from Global QCD Analysis

A new generation of parton distribution functions with increased precisionand quantitative estimates of uncertainties is presented. This worksignificantly extends previous CTEQ and other global analyses on two fronts:(i) a full treatment of available experimental correlated systematic errors forboth new and old data sets; (ii) a systematic and pragmatic treatment ofuncertainties of the parton distributions and their physical predictions, usinga recently developed eigenvector-basis approach to the Hessian method. The newgluon distribution is considerably harder than that of previous standard fits.A number of physics issues, particularly relating to the behavior of the gluondistribution, are addressed in more quantitative terms than before. Extensiveresults on the uncertainties of parton distributions at various scales, and onparton luminosity functions at the Tevatron RunII and the LHC, are presented.The latter provide the means to quickly estimate the uncertainties of a widerange of physical processes at these high-energy hadron colliders, based oncurrent knowledge of the parton distributions. In particular, the uncertaintieson the production cross sections of the $W,Z$ at the Tevatron and the LHC areestimated to be $\pm 4%$ and $\pm 5%$ respectively, and that of a light Higgsat the LHC to be $\pm 5%$.Comment: 44 pages, 25 figures; misprints in tables in Appendix A correcte