Search for resonances and quantum black holes using dijet mass spectra in proton–proton collisions at √s = 8 TeV

A search for resonances and quantum black holes with the dijet mass spectra measured at √s = 8 TeV in pp collisions data corresponding to an integrated luminosity of 19.7 fb^(-1) at the CMS detector are presented in this thesis. For narrow resonances that decay to quark-quark, quark-gluon, or gluon-gluon pairs, model-independent upper limits, at 95% confidence level, are obtained on the production cross section for specific resonances with mass greater than 1.2 TeV. The limits exclude string resonances with mass below 5.0 TeV, excited quarks with mass below 3.49 TeV, scalar diquarks with mass below 4.7 TeV, W` bosons with mass below 1.9 TeV or between 2.00 and 2.2 TeV, Z` bosons with mass below 1.7 TeV and Randall–Sundrum graviton with mass below 1.6 TeV. Searches are also carried out for wide resonances, assuming for the first time width-to-mass ratios up to 30%, and for Quantum Black Holes with a range of model parameters. The wide resonance search excludes axigluons with mass below 3.6 TeV, and colorons and color-octet scalars with mass below 2.5 TeV. Lower bounds between 5.0 and 6.3 TeV are set on the masses of Quantum Black Holes.