When:
Monday, May 4, 2015
4:00 PM - 5:00 PM CT
Where: Technological Institute, F160, 2145 Sheridan Road, Evanston, IL 60208 map it
Audience: Public
Contact:
Liz Lwanga
(847) 491-3645
Group: Physics and Astronomy High Energy Physics Seminars
Category: Academic
Title: A search for resonant tt production in all final states in pp collisions at √s=8 TeV
Speaker: Doug Berry, UIC
Abstract: A search is presented for heavy resonances decaying into t¯t pairs. The analysis covers three distinct decay channels based on the number of leptons in the final state: all leptonic, semi-leptonic, and all hadronic. The search was performed on 19.7 fb-1of integrated luminosity recorded by CMS from proton-proton collisions at the LHC with a√s = 8 TeV. The selection criteria are optimized for the reconstruction of highly boosted top quarks. In this regime, jet substructure techniques are utilized in order to tag events with top quarks. No significant excess of events over the expected standard model background is observed. 95% CL upper limits on the production cross-section is calculated for three different models of heavy resonances using Bayesian techniques. These models include a leptophobic top-color Z’ resonance with widths of 1.2% and 10% and a Kaluza-Klein excitation of the gluon in the Randal-Sundrum model. The presented analysis will exclude all of these models to above the 2 TeV invariant mass scale.