LAUSR

In this work, the P-P(P̄) Drell-Yan lepton pair production (DY) differential cross sections at hadrons colliders, such as LHC and TEVATRON, are studied in the kt-factorization framework. In order to take into account the transverse momenta of incoming partons, we use the unintegrated parton distribution functions (UPDF) of Kimber et al (KMR) and Martin et al (MRW) in the leading order (LO) and next-to-leading-order (NLO) levels with the input MMHT2014 PDF libraries. Based on the different off-shell partonic matrix elements, we analyze the behaviors of DY differential cross sections with respect to the invariant mass, the transverse momentum and the rapidity as well as the specific angular correlation between the produced leptons. The numerical results are compared with the experimental data, in different energies, which are reported by various collaborations, such as CDF, CMS, ATLAS and LHCb. It is shown that the NLO-MRW and KMR schemes predict closer results to the data compared to the LO-MRW, since we do not have fragmentation. It is demonstrated that while the q∗ + q̄∗ → γ∗/Z + g → l+ + l− + g sub-process has a negligible contribution, it has a sizable effect in the low dilepton transverse momentum. In agreement with the NNLO pQCD report (PYTHIA, SHERPA, etc), by including the higher order perturbative contributions the better results are archived. On the other hand as the scale of energy increases, for the LHC energies, the Compton sub-process, i.e., q∗+ g∗ → γ∗/Z → l+ + l− + q, has the largest contribution to the differential cross section in the most intervals of some observables, as it is expected. The variation of the differential cross-section with respect to the various variables such as the invariant mass, the center of mass energy, etc are discussed. In order to validate our results, we also consider the strong ordering constraint and the KaTie parton-level event generator. PACS numbers: 12.38.Bx, 13.85.Qk, 13.60.-r