Narrow Results

We investigate the parton distribution functions (PDFs) of the pion and kaon from the eigenstates of a light-front effective Hamiltonian in the constituent quark-antiquark representation suitable for low-momentum scale applications. By taking these scales as the only free parameters, the valence quark distribution functions of the pion, after QCD evolving, are consistent with the E615 experiment at Fermilab. In addition, the ratio of the up quark distribution in the kaon to that in the pion also agrees with the NA3 experimental result at CERN.

The COMPASS experiment is investigating possible physics aspects connect with the use of the polarized target (PT) together with the secondary (CERN–SPS) hadron beams. The main purpose of this project is to study the Drell–Yan reactions as a clear tool to measure the parton distribution functions, in particular the Boer-Mulders, the Sivers and the transversity functions.