Identification of high energy electrons in the CMS detector and search for new heavy neutral bosons decaying into an electron-positron pair

by Mr Laurent Thomas

Thursday 8 Nov 2012, 10:00 → 10:30 Europe/Brussels

IIHE Large Seminar Room (IIHE)

Many theories beyond the Standard Model predicts the existence of new heavy (>~ 1 TeV) neutral bosons. Such particles could be produced in significant amounts at the LHC and their decay into an electron-positron pair provides a clean signature together with an excellent mass resolution (2-3%). In this talk, I describe the main features of high energy electrons and how they are identified in the CMS detector. The uncertainty on the selection efficiency at high energy is one of the main systematics involved in the final result and I detail a method to measure this efficiency directly from the data up to transverse energy of several hundreds GeV. I finally present the result of the analysis of the data collected by the LHC at 7 and 8 TeV up to June 2012 (8/fb). As no evidence for new physics is observed, upper limits on the production cross section of a new narrow resonance are computed and used to set a lower limit on the mass of new heavy neutral bosons (up to 2 TeV for some models).