Measurement of the transverse momentum distribution of Drell-Yan lepton pairs in proton-proton collisions at root s=13TeV with the ATLAS detector

Abstract

<jats:title>Abstract</jats:title> <jats:p>This paper describes precision measurements of the transverse momentum <jats:inline-formula><jats:alternatives><jats:tex-math>$$p_\mathrm {T}^{\ell \ell }$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>p</mml:mi><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mrow><mml:mi>ℓ</mml:mi><mml:mi>ℓ</mml:mi></mml:mrow></mml:msubsup></mml:math></jats:alternatives></jats:inline-formula> (<jats:inline-formula><jats:alternatives><jats:tex-math>$$\ell =e,\mu $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>ℓ</mml:mi><mml:mo>=</mml:mo><mml:mi>e</mml:mi><mml:mo>,</mml:mo><mml:mi>μ</mml:mi></mml:mrow></mml:math></jats:alternatives></jats:inline-formula>) and of the angular variable <jats:inline-formula><jats:alternatives><jats:tex-math>$$\phi ^{*}_{\eta }$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>ϕ</mml:mi><mml:mi>η</mml:mi><mml:mrow><mml:mrow /><mml:mo>∗</mml:mo></mml:mrow></mml:msubsup></mml:math></jats:alternatives></jats:inline-formula> distributions of Drell–Yan lepton pairs in a mass range of 66–116 GeV. The analysis uses data from 36.1 fb<jats:inline-formula><jats:alternatives><jats:tex-math>$$^{-1}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mrow><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math></jats:alternatives></jats:inline-formula> of proton–proton collisions at a centre-of-mass energy of <jats:inline-formula><jats:alternatives><jats:tex-math>$$\sqrt{s}=13\,$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn><mml:mspace /></mml:mrow></mml:math></jats:alternatives></jats:inline-formula>TeV collected by the ATLAS experiment at the LHC in 2015 and 2016. Measurements in electron-pair and muon-pair final states are performed in the same fiducial volumes, corrected for detector effects, and combined. Compared to previous measurements in proton–proton collisions at <jats:inline-formula><jats:alternatives><jats:tex-math>$$\sqrt{s}=7$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>7</mml:mn></mml:mrow></mml:math></jats:alternatives></jats:inline-formula> and <jats:inline-formula><jats:alternatives><jats:tex-math>$$8\,$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>8</mml:mn><mml:mspace /></mml:mrow></mml:math></jats:alternatives></jats:inline-formula>TeV, these new measurements probe perturbative QCD at a higher centre-of-mass energy with a different composition of initial states. They reach a precision of 0.2<jats:inline-formula><jats:alternatives><jats:tex-math>$$\%$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>%</mml:mo></mml:math></jats:alternatives></jats:inline-formula> for the normalized spectra at low values of <jats:inline-formula><jats:alternatives><jats:tex-math>$$p_\mathrm {T}^{\ell \ell }$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>p</mml:mi><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mrow><mml:mi>ℓ</mml:mi><mml:mi>ℓ</mml:mi></mml:mrow></mml:msubsup></mml:math></jats:alternatives></jats:inline-formula>. The data are compared with different QCD predictions, where it is found that predictions based on resummation approaches can describe the full spectrum within uncertainties.</jats:p>