Measurements of top quark pair relative differential cross-sections with ATLAS in pp collisions at $\sqrt{s} = 7\ \mbox{TeV}$

Abstract

Measurements are presented of differential crosssections for top quark pair production in pp collisions at √ s = 7 TeV relative to the total inclusive top quark pair production cross-section. A data sample of 2.05 fb −1 recorded by the ATLAS detector at the Large Hadron Collider is used. Relative differential cross-sections are derived as a function of the invariant mass, the transverse momentum and the rapidity of the top quark pair system. Events are selected in the lepton (electron or muon) + jets channel. The backgroundsubtracted differential distributions are corrected for detector effects, normalized to the total inclusive top quark pair production cross-section and compared to theoretical predictions. The measurement uncertainties range typically between 10 % and 20 % and are generally dominated by systematic effects. No significant deviations from the Standard Model expectations are observed.

Search for anomalous couplings in the W tb vertex from the measurement of double differential angular decay rates of single top quarks produced in the t-channel with the ATLAS detector

“…Data-driven techniques are then used to estimate the flavour composition and the overall normalisation as described in ref. [60], and an uncertainty of 18% (15%) for electron (muon) selections is applied.…”

Measurements of normalized differential cross sections fortt¯production inppcollisions atAad1, Abajyan2, Abbott3 et al. 2014Phys. Rev. DSelf Cite

“…The CMS Collaboration has published [10] differential cross sections using the full data set collected in 2011 at ffiffi ffi s p ¼ 7 TeV and corresponding to an integrated luminosity of 5.0 fb −1 . The ATLAS Collaboration has published [11] the differential cross sections as a function of the mass (m tt ), the transverse momentum (p tt T ), and the rapidity (y tt ) of the tt system with a subset of the data collected in 2011 at ffiffi ffi s p ¼ 7 TeV corresponding to an integrated luminosity of 2.05 fb −1 . The measurements shown here improve the statistical precision of the previous ATLAS results by including the full 2011 data set (4.6 fb −1 ).…”

Top quark pair production at NNLO in the quark-antiquark channel

“…Recently, the ATLAS and CMS collaborations reported measurements of normalised differential observables in tt production in several kinematical variables, such as the transverse momentum, rapidity and invariant mass of the tt system, as well as the top quark transverse momentum and rapidity [6][7][8][9][10]. More recently, both LHC collaborations have measured the charge asymmetry in top-pair production, [11,12].…”

“…The evaluation of the master integrals I [3] , I [3,5] , I [3,6] and I [4,6] is straightforward. It can be done to all orders in by employing an all order representation of the tadpole and bubble integrals involved, and integrating over the phase space in eq.…”