Probing Charm Production with Three-Particle Correlations in pp Collisions

Abstract: This thesis aims to investigate possible correlations between charm production and baryon production in proton-proton collisions through three-particle correlations. The question attempted to be answered is where, for a given charmed baryon, the balancing anti-charm particle and balancing anti-baryon are located. The relative azimuthal angle ∆φ and pseudorapidity ∆η between the trigger charmed baryon, light baryons and charmed mesons are calculated for different combinations of quantum numbers in the triplet of particles, using data simulated with the event generator Pythia8. Two different data sets are considered: forced charm production, in which each event starts with a primary hard scattering producing a charm anti-charm pair back-to-back, and minimum bias. Two approaches are taken to answer the research question. Firstly, the balance function for the triplet of a trigger charmed baryon, light baryon with opposite baryon number to the trigger and charmed meson with opposite charm quantum number than the trigger is produced. This balance function is corrected for possible uncorrelated pairs and shows the true correlation between baryon number and charm quantum number conservation. Secondly, the baryon pair is restricted to a certain interval in momentum space and the effect on the charmed particle's placement is investigated. It is found that with forced charm production in place, the balancing charmed particle is produced back-to-back to the balancing baryon. The charmed hadrons are produced back-to-back in azimuthal angle and are uncorrelated in pseudorapidity. The baryons with opposite baryon number are found close to each other in momentum-space. In the more realistic case of minimum bias events, both the balancing baryon and balancing charmed particle follow each other and are found close to the triggering charmed baryon. These results can be understood when considering the production mechanisms used in the event generator.