Measurement Of Jets Produced In Top Quark Events Using The Emu Final State With 2 B Tagged Jets In Pp Collisions At 8 Tev With The Atlas Detector

Measurement of Jets Produced in Top Quark Events Using the Emu Final State with 2 B-tagged Jets in Pp Collisions at 8 TeV with the ATLAS Detector

The transverse momentum and multiplicity of jets produced in top quark events are measured using 20.3 inverse fb of pp collision data at a center-of-mass energy of 8 tev. Jets are selected from top events requiring an opposite-charge $e\mu$ pair and two b-tagged jets in the final state. The data are corrected to obtain the particle-level fiducial cross section for additional jets with rank 1-4, where rank=1 is the leading additional jet. These distributions are used to obtain the extra jet multiplicity as a function of minimum jet pt threshold. The results are compared with several next to leading order Monte Carlo generators. The resulting measurements can be used to tune Monte Carlo QCD modelling and may also reduce associated modelling uncertainties for LHC top quark physics measurements.

Measurement of Jet Activity in Top Quark Events Using the E[mu] Final State with Two B-tagged Jets in Pp Collisions at $\sqrt{s}

Measurement of the Top-quark Mass in All-jets $t\bar{t}$ Events in Pp Collisions at $\sqrt{s}$

The mass of the top quark is measured using a sample of $t\bar{t}$ candidate events with at least six jets in the final state. The sample is selected from data collected with the CMS detector in pp collisions at $\sqrt{s}$ = 7 TeV in 2011 and corresponds to an integrated luminosity of 3.54 inverse femtobarns. The mass is reconstructed for each event employing a kinematic fit of the jets to a $t\bar{t}$ hypothesis. The top-quark mass is measured to be 173.49 $\pm$ 0.69 (stat.) $\pm$ 1.21 (syst.) GeV. A combination with previously published measurements in other decay modes by CMS yields a mass of 173.54 $\pm$ 0.33 (stat.) $\pm$ 0.96 (syst.) GeV.