Doctoral Dissertation Open Access
Schäfer, Daniela
{ "abstract": "<p>A search for new resonances decaying to WW, WZ or ZZ in the all hadronic final state using<br>\n77.3 fb −1 of data taken with the CMS experiment at the CERN LHC at a center-of-mass<br>\nenergy of 13 TeV is presented. The search focuses on potential new particles with a mass<br>\nat the TeV scale resulting in a high transverse momentum of the produced vector bosons.<br>\nThe subsequent decay products of the vector bosons are therefore highly collimated and<br>\nreconstructed into a single large-radius jet, which are further classified using jet substructure<br>\nmethods. The analysis presented utilizes a new data-driven background modeling technique<br>\nbased on a template fit in a three-dimensional hyperspace spanned by the dijet invariant mass<br>\nand the corrected jet masses of the two final state jets. This method allows the utilization of<br>\nthe full available signal yield while simultaneously constraining the background processes by<br>\nincluding the mass sideband regions in the fit. This grants the opportunity to easily expand<br>\nthis framework to include VH, HH or more exotic signals with different messenger particles<br>\nin the future.<br>\nNo significant excess is observed above the estimated standard model background and limits<br>\nare set at 95% confidence level on the cross section times branching fraction of a new particle,<br>\nwhich are interpreted in terms of various models that predict spin-2 gravitons or spin-1 vector<br>\nbosons. In a heavy vector triplet model, spin-1 Z' and W' resonances with masses below<br>\n3.5 and 3.8 TeV, respectively, are excluded at 95% confidence level. In a narrow-width bulk<br>\ngraviton model, upper limits on cross sections times branching fractions are set between 27<br>\nand 0.2 fb for resonance masses between 1.2 and 5.2 TeV, respectively. The limits presented<br>\nin this thesis are the best to date in the dijet final state.</p>", "author": [ { "family": "Sch\u00e4fer, Daniela" } ], "id": "21712", "issued": { "date-parts": [ [ 2019, 12, 6 ] ] }, "language": "eng", "title": "Search for Diboson Resonances in the All-Hadronic Final State with the CMS Detector", "type": "thesis" }