High-energy factorization for the Drell-Yan process in pp and p(p)over-bar collisions with new unintegrated PDFs

The formalism for uniform description of the Drell-Yan transverse-momentum spectrum is presented in a framework of high-energy factorization, which smoothly interpolates between Collins-Soper-Sterman formalism at vertical bar q(T)vertical bar << Q and usual collinear parton model at vertical bar q(T)vertical bar similar to Q vertical bar root S. The new formula for deriving unintegrated parton distribution functions (UPDFs) from collinear ones is introduced, which leads to excellent description of the shape of Z-boson vertical bar q(T)vertical bar -spectrum at high energies up to vertical bar q(T)vertical bar /root S .similar or equal to 0.02. Description of normalized vertical bar q(T)vertical bar -distributions at low energies is achieved via the fit of nonperturhative parameters of quark UPDFs. Reasonable description of angular distributions of leptons in the dilepton center-of-mass frame is also obtained with new UPDFs.