Top Physics at CMS/LHC

Georgios Daskalakis

doi:10.1051/epjconf/201716407051

Abstract

Recent results on the inclusive and differential production cross sections of top-quark pair and single top-quark processes are presented, obtained using data from proton-proton collisions collected with the CMS detector at the LHC. The large centre-of-mass energies available at LHC allow for the copious production of top-quark pairs in association with other final state particles at high transverse momentum. Measurements of such processes as well as of the top-quark mass and other properties will be discussed. The results are compared with the most up-to-date standard model theory predictions.

Highlights

Today, more than 20 years after the discovery of the top quark, particle physicists still investigate its properties by performing precision measurements
It is possible to measure observables that depend on the top quark spin, providing a unique environment for tests of the Standard Model (SM) and for searches for physics beyond the Standard Model (BSM)
Most of the analyses focus on final states with muons and electrons since the τ leptons are more difficult to reconstruct

Summary

Introduction

More than 20 years after the discovery of the top quark, particle physicists still investigate its properties by performing precision measurements. The top quark is the heaviest known elementary particle with a very short lifetime (τt=1/Γt ∼3.3×10−25s) [1] It decays semi-weakly into a real W boson and a b quark before hadronization (τhadronization ∼10−24s) can occur. It is possible to measure observables that depend on the top quark spin, providing a unique environment for tests of the Standard Model (SM) and for searches for physics beyond the Standard Model (BSM). It is the only quark whose Yukawa coupling to the Higgs boson is of the order of unity so it is often speculated that it might play a special role in the mechanism of electroweak symmetry breaking. In addition to the quarks resulting from the top-quark decays, extra radiation from quarks and gluons in the event can lead to extra jets in the final state

Inclusive Top-quark pair and Single-top production cross sections

Differential cross sections

Top-quark mass measurements

Summary