Hunting stabilization effects of the high-energy resummation at the LHC

Abstract

Studying semi-hard processes in the large center-of-mass energy limit gives us an opportunity to further test perturbative QCD in an unexplored kinematical configuration, contributing to a better understanding of the dynamics of strong interactions. For semi-hard reactions in kinematics at large center-of-mass energy ps, the BFKL resummation of energy logarithms comes into play, since large energy logarithms compensate the smallness of QCD coupling as and must therefore be accounted for to all perturbative orders. Tracing the path toward performing precision calculations via BFKL resummation of high-energy logarithms, in this thesis we present phenomenological analyses for distinct inclusive processes, highlighting the recognized problem of instabilities under higher-order corrections and energy-scales variations, that would abort any possibility to investigate semi-hard reactions with high-precision at natural energy-scales. At the same time, we present new reactions that seem to act as fair stabilizers of the highenergy series. First, the inclusive production at the LHC of a charged light hadron and of a jet, featuring a wide separation in rapidity, is presented making use of optimization methods to fix energy-scale. We report some predictions, tailored on the CMS and CASTOR acceptances, for the cross section averaged over the azimuthal angle between the identified jet and hadron and for azimuthal correlations. Then, we propose as a novel probe channel for the manifestation of the BFKL dynamics, the inclusive hadroproduction of a Higgs boson and of a jet, featuring large transverse momenta and well separated in rapidity. We present predictions for azimuthal Higgs-jet correlations and other observables, to be possibly compared with typical experimental analyses at the LHC. Finlay, we propose the inclusive semi-hard production, in proton-proton collisions, of two bottom-flavored hadrons, as well as of a single bottom-flavored hadron accompanied by a light jet, as novel channels for targeting stabilization effects of the high-energy resummation under higher-order corrections. Moreover, we propose the study of double differential distributions in the transverse momenta of the two finalstate particles as a common basis to investigate the interplay of different resummation approaches.