Inclusive Higgs boson production at the LHC in the kT-factorization approach

We investigate the inclusive Higgs boson production in proton-proton collisions at the CERN LHC conditions using the k(T)-factorization approach. Our analysis is based on the dominant off-shell gluon-gluon fusion subprocess (where the transverse momenta of initial gluons are taken into account) and covers H -> gamma gamma, H -> ZZ* -> 4l (where l = e, mu) and H -> W+W- -> e(+/-)mu(-/+)nu(nu) over bar. decay channels. The transverse momentum dependent (or unintegrated) gluon densities in a proton were derived from Ciafaloni-Catani-Fiorani-Marchesini equation, which resums large logarithmic terms proportional to ln s similar to ln 1/x, important at high energies. As an alternative choice, we apply the Kimber-Martin-Ryskin prescription, where the transverse momentum dependent gluon density is constructed from the known conventional parton distributions. We estimate the theoretical uncertainties of our calculations and compare our results with next-to-next-to-leading-order plus next-to-next-to-leading-logarithmic ones obtained using collinear QCD factorization. Our predictions agree well with the latest experimental data taken by the CMS and ATLAS Collaborations at root s = 8 and 13 TeV.