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View of and from Lene Kristian's office window. The office mascot, a small pet pug, is sitting on top of a stack of books on the windowsill. Outside, there is a parking lot, trees and sky in the early dusk of a winter's day.

Lene Kristian Bryngemark

Researcher

View of and from Lene Kristian's office window. The office mascot, a small pet pug, is sitting on top of a stack of books on the windowsill. Outside, there is a parking lot, trees and sky in the early dusk of a winter's day.

Measurement of the ratio of cross sections for inclusive isolated-photon production in pp collisions at √s = 13 and 8 TeV with the ATLAS detector

Author

  • M Aaboud
  • Torsten Åkesson
  • Simona Bocchetta
  • Lene Bryngemark
  • Eric Corrigan
  • Caterina Doglioni
  • Kristian Gregersen
  • Eva Brottmann Hansen
  • Vincent Hedberg
  • Göran Jarlskog
  • Charles Kalderon
  • Edgar Kellermann
  • Balazs Konya
  • Else Lytken
  • Katja Mankinen
  • Caterina Marcon
  • Ulf Mjörnmark
  • Geoffrey Mullier
  • Ruth Pöttgen
  • Trine Poulsen
  • Eleni Skorda
  • Oxana Smirnova
  • L Zwalinski

Summary, in English

The ratio of the cross sections for inclusive isolated-photon production in pp collisions at centre-of-mass energies of 13 and 8 TeV is measured using the ATLAS detector at the LHC. The integrated luminosities of the 13 TeV and 8 TeV datasets are 3.2 fb −1 and 20.2 fb −1 , respectively. The ratio is measured as a function of the photon transverse energy in different regions of the photon pseudorapidity. The predictions from next-to-leading-order perturbative QCD calculations are compared with the measured ratio. The experimental systematic uncertainties as well as the uncertainties affecting the predictions are evaluated taking into account the correlations between the two centre-of-mass energies, resulting in a reduction of up to a factor of 2.5 (5) in the experimental (theoretical) systematic uncertainties. The predictions based on several parameterisations of the proton parton distribution functions agree with the data within the reduced experimental and theoretical uncertainties. In addition, this ratio to that of the fiducial cross sections for Z boson production at 13 and 8 TeV using the decay channels Z → e + e − and Z → μ + μ − is made and compared with the theoretical predictions. In this double ratio, a further reduction of the experimental uncertainty is obtained because the uncertainties arising from the luminosity measurement cancel out. The predictions describe the measurements of the double ratio within the theoretical and experimental uncertainties.[Figure not available: see fulltext.]. © 2019, The Author(s).

Department/s

  • Particle and nuclear physics
  • eSSENCE: The e-Science Collaboration

Publishing year

2019

Language

English

Publication/Series

Journal of High Energy Physics

Volume

2019

Issue

4

Document type

Journal article

Publisher

Springer

Topic

  • Subatomic Physics

Keywords

  • Hadron-Hadron scattering (experiments)
  • Photon production
  • QCD

Status

Published

ISBN/ISSN/Other

  • ISSN: 1029-8479