Abstract
An overview of latest ATLAS measurements of top pair ( tt ) production in proton-proton collisions at the LHC at centre-of-mass energies of 7 and 8 TeV is presented. Measurements of the tt production cross section (σ tt ) in various decay channels, including analyses of differential σ tt distributions and a study of jet multiplicity in tt production, as well as searches for tt resonances using boosted top techniques and standard methods, are discussed.
Highlights
To √date, in pp collisi√on data at the center-of-mass energies of s = 7 TeV and s = 8 TeV, the CERN Large Hadron Collider (LHC) has successfully delivered two orders of magnitude more top quarks than the Fermilab Tevatron Collider
Differential measurements of ttproduction are especially important for discrimination between different Monte Carlo generators, QCD models and parton distribution functions (PDFs)
Ttevents are an important background in various Higgs boson analyses as well as beyond the Standard Model (SM) searches, and it is crucial to understand this process in detail
Summary
New physics [3, 4] can affect both the ttproduction and decay, modifying the observed σttdifferently in different decay channels and/or affecting differential distributions In this scenario, it is critical to correctly evaluate all the contributions from SM processes, the backgrounds are determined using data-driven techniques whenever possible [5]. It is critical to correctly evaluate all the contributions from SM processes, the backgrounds are determined using data-driven techniques whenever possible [5] In these proceedings an overview of latest ATLAS [6] measurements of ttproduction at the LHC at centre-of-mass energies of 7 and 8 TeV is presented. Events are selected in the lepton (electron or muon) + jets channel, requiring 1 high-pT e or μ, at least 4 high-pT jets (at least one should be b-tagged), large ETmiss and transverse mass of the lepton-ETmiss system. Jet-related uncertainties are dominant for mttand pT,tt , whereas for yttthe dominant contributions are from fake leptons and FSR in addition to the jet uncertainties
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
