Dijet studies with ALICE at the LHC

High energy partons, quarks and gluons, born in relativistic particle collisions create well collimated showers of particles, which are called jets. Jets have been studied for years, and also used widely in heavy ion collisions, where the quark-gluon plasma (QGP) medium forms. Studying jets in heavy ion collisions showed that hard partons lose energy in the QGP medium. Hard parton energy loss has also been studied with dijets. A dijet is a system consisting of two of the most energetic jets in a collision. Previous studies from RHIC and LHC indicate that dijet invariant mass can be sensitive to modifications caused by the QGP medium. In this thesis I present the first measurements of dijet mass distributions in proton-lead and lead-lead collisions at $\sqrt{sNN}$ = 5.02 TeV with the ALICE detector at the LHC. In this work, I have reconstructed jets from charged particles using the anti-$k$$_{t}$ jet reconstruction algorithm with resolution parameter $R$ = 0.4. According to my results, the proton-lead collisions show negligible modification in the dijet mass distribution compared to the proton-proton Monte Carlo simulation results. Comparing the lead-lead results to proton-lead shows possible modifications in the high dijet mass region over 100 GeV. In the experiment some amount of the particles produced are lost to detector inefficiencies. The raw data can be corrected for the inefficiencies, and this procedure is called unfolding. In this thesis I show the unfolded spectra of the proton-lead data, but the lead-lead unfolding needs to be developed so that the jets lost because of the background subtraction get corrected as well.