Fotoprodução de quarks pesados em colisões próton-próton no Grande Colisor de Hádrons

Abstract

In hadron-hadron and lepton-hadron collisions the cross sections for heavy quark production at high energies are strongly dependent on the behavior of the gluon distribution, which is determined by the underlying quantum cromodynamics dynamics. At high energies the QCD evolution leads to a system with high gluon density, characterized by the limitation on the maximum phase-space parton density that can be reached in the hadron wavefunction (parton saturation). The transition is specified by a typical scale, which is energy dependent and is called saturation scale. Signals of parton saturation have already been observed both in ep deep inelastic scattering at HERA and in deuteron-gold collisions at Relativistic Heavy Ion Collider (RHIC). Then, alternative descriptions that disregard the saturation also describe these data. However, the observation of this new regime still needs confirmation and so there is an active search for new experimental signatures. In this dissertation we study the inclusive and diffractive photoproduction of heavy quarks in proton-proton collisions considering three phenomenological models based on the Color Glass Condensate, which describe quite well the current experimental Hadron Electron Ring Accelerator (HERA) data for inclusive and exclusive observables. Our goal is twofold: update existing studies considering these new parameterizations for the dipole scattering amplitude and present a comparison between the inclusive and diffractive production mechanisms using an identical theoretical input.