Speaker
Emmanuel de Oliveira
(IF - USP, Brazil)
Description
We show that the observation of the Drell-Yan production of low-mass lepton-pairs (M < 20 GeV) at high rapidities (Y > 3) at the LHC can make a direct measurement of parton distribution functions (PDFs) in the low x region, x < 10^{-4}. We describe a procedure that greatly reduces the sensitivity of the predictions to the choice of the factorization scale and, in particular, show how, by imposing a cutoff on the transverse momentum of the lepton-pair, the data are able to probe PDFs in the important low scale, low x domain. We also show that the conventional prescription used for DGLAP parton evolution at NLO has an inconsistent treatment of the contribution from the infrared (IR) region. The deficiency is not present in a physical approach which removes the IR divergency and allows calculation in the normal 4-dimensional space.
Authors
A. Martin
(Durham, UK)
Emmanuel de Oliveira
(IF - USP, Brazil)
Mikhail Ryskin
(Petersburg Nuclear Physics Institute)
