Measurement of the integrated and differential<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>t</mml:mi><mml:mover accent="true"><mml:mi>t</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover></mml:math>production cross sections for high-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>p</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">T</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>top quarks

133

126

We report on a new fully differential calculation of the next-to-next-to-leadingorder (NNLO) QCD radiative corrections to the production of top-quark pairs at hadron colliders. The calculation is performed by using the q T subtraction formalism to handle and cancel infrared singularities in real and virtual contributions. The computation is implemented in the Matrix framework, thereby allowing us to efficiently compute arbitrary infrared-safe observables for stable top quarks. We present NNLO predictions for several single-and double-differential kinematical distributions in pp collisions at the centre-of-mass energy √ s = 13 TeV, and we compare them with recent LHC data by the CMS collaboration.

Section: Introductionmentioning

confidence: 99%

Top-quark pair production at the LHC: fully differential QCD predictions at NNLO

Catani

Devoto

Grazzini

et al. 2019

133

126

“…The measurement of tt differential cross sections can provide a test of perturbative quantum chromodynamic (QCD) calculations and also improve the knowledge of parton distribution functions (PDFs) [1]. Previous measurements of differential cross sections for tt production have been performed in proton-proton (pp) collisions at the CERN LHC at center-of-mass energies of 7 [2,3] and 8 TeV [4][5][6][7][8][9][10][11][12]. The dilepton (electron or muon) final state of the tt decay helps in the suppression of background events.…”

Section: Introductionmentioning

confidence: 99%

Measurement of normalized differential $$ \mathrm{t}\overline{\mathrm{t}} $$ cross sections in the dilepton channel from pp collisions at $$ \sqrt{s}=13 $$ TeV

Sirunyan¹,

Tumasyan²,

Adam³

et al. 2018

Self Cite

Normalized differential cross sections for top quark pair production are measured in the dilepton (e + e − , µ + µ − , and µ ∓ e ± ) decay channels in proton-proton collisions at a center-of-mass energy of 13 TeV. The measurements are performed with data corresponding to an integrated luminosity of 2.1 fb −1 using the CMS detector at the LHC. The cross sections are measured differentially as a function of the kinematic properties of the leptons, jets from bottom quark hadronization, top quarks, and top quark pairs at the particle and parton levels. The results are compared to several Monte Carlo generators that implement calculations up to next-to-leading order in perturbative quantum chromodynamics interfaced with parton showering, and also to fixed-order theoretical calculations of top quark pair production up to next-to-nextto-leading order.

“…[49] does not provide unfolded values for the parton level cross section. Previous measurements of the differential tt cross section have been performed by ATLAS [51-57] and CMS [58][59][60][61][62]. While we use differential cross section measurements to look for smooth effects parameterized by the Effective Field Theory, we note that top pair production measurements have also been used to search for sharp resonances by ATLAS [63][64][65] and CMS [66][67][68].…”

Section: Introductionmentioning

confidence: 99%

New physics from high energy tops

Farina

Mondino

Pappadopulo

et al. 2019

Precision measurements of high energy top quarks at the LHC constitute a powerful probe of new physics. We study the effect of four fermion operators involving two tops and two light quarks on the high energy tail of the tt invariant mass distribution. We use existing measurements at a center of mass energy of 13 TeV, and state of the art calculations of the Standard Model contribution, to derive bounds on the coefficients of these operators. We estimate the projected reach of the LHC at higher luminosities and discuss the validity of these limits within the Effective Field Theory description. We find that current measurements constrain the mass scale of these operators to be larger than about 1-2 TeV, while we project that future LHC data will be sensitive to mass scales of about 3-4 TeV. We apply our bounds to constrain composite Higgs models with partial compositeness and models with approximate flavor symmetries. We find our limits to be most relevant to flavor non-universal models with a moderately large coupling of the heavy new physics states to third generation quarks.