Measurements of the inclusive and differential top-quark pair production cross sections in proton-proton collisions with the ATLAS detector at the Large Hadron Collider are presented at center-of-mass energies of 8 TeV and 13 TeV. The inclusive measurements reach high precision and are compared to the best available theoretical calculations. These measurements, including results using boosted...
We investigate various kinematic methods to resolve two fold ambiguities in paring b-quark and lepton in the $t\bar t$-like events at the LHC. We generalize the methods to physics beyond the standard model.
Measurements of single top-quark production in proton proton collisions at the Large Hadron Collider are presented at center-of-mass energies of 8 TeV and 13 TeV. For the t-channel measurement, the single top-quark and anti-top-quark total production cross-sections, their ratio, as well as measurements of the inclusive production cross sections are presented. Differential cross-section...
We propose a new method for measuring the top-quark width based on the on-/off-shell ratio of b-charge asymmetry in pp>Wbj production at the LHC. The charge asymmetry removes virtually all backgrounds and related uncertainties, while remaining systematic and theoretical uncertainties can be taken under control by the ratio of cross sections. Limited only by statistical errors, we find that our...
to update the newest result of the top mass and property measurement at ATLAS experiment.
Resonances in the ttbar mass spectrum are well-motivated signatures of new physics and can be used to discover or constrain many proposed extensions to the Standard Model. Such models often make further predictions about the nature of these resonances, for example the polarisation of the top quarks. I will present a realistic study of the improvements in sensitivity that can be made when...
Any particle that is charged under $SU(3)_C$ and $U(1)_{EM}$ can mediate the $gg \rightarrow \gamma\gamma$ process through loops. Near the threshold for the particle pair production, gauge boson exchanges necessitate the resummation of ladder diagrams. We discuss the leading log order matching of the one-loop result with non-relativistic effective theory resummed result. We show how the...
We present a search for new massive particles decaying to heavy-flavour quarks with the CMS detector at the LHC. The prominent signature is the resonant production of top quark pairs. Decay channels to vector-like top partner quarks, such as T', are also considered for the first time. We use proton-proton collision data recorded at a centre-of-mass energy of 13 TeV. The search is performed in...
