Progress in the calculation of parton distributions in QCD

Abstract

Until recently state of the art studies of the moments of parton distributions within lattice QCD have led to discrepancies with experimental data at the level of 50%. Such a large disagreement in a fundamental hadronic observable casts doubt on the attempt to calculate all hadron properties on the lattice. We summarise a recent discovery, concerning the need to correctly incorporate chiral symmetry into the extrapolation to physical quark masses, which removes this discrepancy. In so doing it also opens the exciting possibility that using similar techniques for other observables one may be able to make reliable comparisons with experimental data using the next generation of supercomputers, available within the next two or three years.