Central exclusive quark-antiquark dijet and Standard Model Higgs boson production in proton-(anti)proton collisions

We consider the central exclusive production of $q\bar{q}$ pairs and Higgs boson at proton-proton collisions at LHC. The amplitude for the process is derived within the $k_{\perp}$-factorization approach and considered in different kinematical asymptotics, in particular, in the important high quark transverse momenta and massless quark limits. Quark helicity and spin-projection amplitudes in two different frames are shown in extenso. Rapidity distributions, quark jet $p_{\perp}$ distributions, invariant $q\bar{q}$ mass distributions, angular azimuthal correlations between outgoing protons and jets are presented. Irreducible $b{\bar b}$ background to the central exclusive Higgs boson production is analyzed in detail, in particular how to impose cut to maximize signal-to-background ratio.