Measurement of the production of a W boson in association with a charmed hadron in p p collisions at √{s }=13 TeV with the ATLAS detector
Abstract
The production of a W boson in association with a single charm quark is studied using 140 fb-1 of √{s }=13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. The charm quark is tagged by the presence of a charmed hadron reconstructed with a secondary-vertex fit. The W boson is reconstructed from the decay to either an electron or a muon and the missing transverse momentum present in the event. The charmed mesons reconstructed are D+→K-π+π+ and D*+→D0π+→(K-π+)π+ and the charge conjugate decays in the fiducial regions where pT(e ,μ )>30 GeV , |η (e ,μ )|<2.5 , pT(D(*))>8 GeV , and |η (D(*))|<2.2 . The integrated and normalized differential cross sections as a function of the pseudorapidity of the lepton from the W boson decay, and of the transverse momentum of the charmed hadron, are extracted from the data using a profile likelihood fit. The measured total fiducial cross sections are σfidOS - SS(W-+D+)=50.2 ±0.2 (stat)-2.3 +2.4(syst ) pb , σfidOS - SS(W++D-)=48.5 ±0.2 (stat)-2.2 +2.3(syst ) pb , σfidOS - SS(W-+D*+)=51.1 ±0.4 (stat)-1.8 +1.9(syst ) pb , and σfidOS - SS(W++D*-)=50.0 ±0.4 (stat)-1.8 +1.9(syst ) pb . Results are compared with the predictions of next-to-leading-order quantum chromodynamics calculations performed using state-of-the-art parton distribution functions. Additionally, the ratio of charm to anticharm production cross sections is studied to probe the s -s ¯ quark asymmetry. The ratio is found to be Rc±=0.971 ±0.006 (stat ) ±0.011 (syst ) . The ratio and cross-section measurements are consistent with the predictions obtained with parton distribution function sets that have a symmetric s -s ¯ sea, indicating that any s -s ¯ asymmetry in the Bjorken-x region relevant for this measurement is small.
- Publication:
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Physical Review D
- Pub Date:
- August 2023
- DOI:
- 10.1103/PhysRevD.108.032012
- arXiv:
- arXiv:2302.00336
- Bibcode:
- 2023PhRvD.108c2012A
- Keywords:
-
- High Energy Physics - Experiment
- E-Print:
- 78 pages in total, author list starting page 61, 13 figures, 21 tables, published by Phys. Rev. D. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2019-22