Abstract
The production of virtual photons is a very sensitive probe of the properties of the quark-gluon plasma. As they are experimentally detected by lepton pairs, they suffer from a large background arising from hadron decays. Light-flavour hadrons dominate at low invariant masses below mee ~ 0.5 GeV and heavy flavours above. These contributions must therefore also be taken into account in experimental analyses at the LHC. In this paper, we calculate the direct contribution from virtual photons produced in the Drell-Yan process with an additional jet in POWHEG and find that it is significant at low invariant masses. We also simulate the background contributions from \( c\overline{c} \) and \( b\overline{b} \) production with POWHEG and quantify the theoretical uncertainties due to variations of the perturbative scales and parton distribution functions. We find larger relative and absolute uncertainties for the lighter c quarks than for heavier b quarks.
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Acknowledgments
T.J. and A.P.N. are grateful to Raphaelle Bailhache and Jerome Jung for insightful discussions. This work has been supported by the BMBF under contract 05P21PMCAA and by the DFG through the Research Training Network 2149 “Strong and Weak Interactions — from Hadrons to Dark Matter”.
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Andronic, A., Ježo, T., Klasen, M. et al. Di-electron production at the LHC: unravelling virtual-photon and heavy-flavour contributions. J. High Energ. Phys. 2024, 222 (2024). https://doi.org/10.1007/JHEP05(2024)222
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DOI: https://doi.org/10.1007/JHEP05(2024)222