Measurement of the transverse momentum distribution of Drell–Yan lepton pairs in proton–proton collisions at $$\sqrt{s}=13\,$$TeV with the ATLAS detector
G. Aad, B. Abbott, D. C. Abbott, A. Abed Abud, K. Abeling, D. K. Abhayasinghe, S. H. Abidi, O. S. AbouZeid, N. L. Abraham, H. Abramowicz, H. Abreu, Y. Abulaiti, B. S. Acharya, B. Achkar, S. Adachi, L. Adámek, C. Adam Bourdarios, L. Adamczyk, L. Adamek, J. Adelman, M. Adersberger, A. Adiguzel, S. Adorni, T. Adye, A. A. Affolder, Y. Afik, C. Agapopoulou, M. N. Agaras, A. Aggarwal, C. Agheorghiesei, J. A. Aguilar–Saavedra, F. Ahmadov, W. S. Ahmed, X. Ai, G. Aielli, S. Akatsuka, T. P. A. Åkesson, E. Akilli, A. V. Akimov, K. Al Khoury, G. L. Alberghi, J. Albert, M. J. Alconada Verzini, S. Alderweireldt, M. Aleksa, I. N. Aleksandrov, C. Alexa, T. Alexopoulos, A. Alfonsi, F. Alfonsi, M. Alhroob, B. Ali, M. Aliev, G. Alimonti, S. P. Alkire, C. Allaire, B. M. M. Allbrooke, B. W. Allen, P. P. Allport, A. Aloisio, F. Alonso, C. Alpigiani, A. A. Alshehri, E. Alunno Camelia, M. Alvarez Estevez, M. G. Alviggi, Y. Amaral Coutinho, A. Ambler, L. Ambroz, C. Amelung, D. Amidei, S. P. Amor Dos Santos, S. Amoroso, Cherifa Sabrina Amrouche, F. F. An, C. Anastopoulos, N. Andari, T. Andeen, C. F. Anders, J. K. Anders, A. Andreazza, V. Andrei, Christopher Anelli, S. Angelidakis, A. Angerami, A. V. Anisenkov, A. Annovi, C. Antel, M. T. Anthony, E. Antipov, M. Antonelli, D. J. A. Antrim, Fabio Anulli, M. Aoki, J. A. Aparisi Pozo, L. Aperio Bella, J. P. Araque, V. Araujo Ferraz, R. Araujo Pereira, C. Arcangeletti
Abstract
Abstract This paper describes precision measurements of the transverse momentum $$p_\mathrm {T}^{\ell \ell }$$ <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> ( $$\ell =e,\mu $$ <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> ) and of the angular variable $$\phi ^{*}_{\eta }$$ <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> distributions of Drell–Yan lepton pairs in a mass range of 66–116 GeV. The analysis uses data from 36.1 fb $$^{-1}$$ <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> of proton–proton collisions at a centre-of-mass energy of $$\sqrt{s}=13\,$$ <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> 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 $$\sqrt{s}=7$$ <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> and $$8\,$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>8</mml:mn><mml:mspace/></mml:mrow></mml:math> 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 $$\%$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>%</mml:mo></mml:math> for the normalized spectra at low values of $$p_\mathrm {T}^{\ell \ell }$$ <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> . 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.