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Measurements of inclusive and differential cross-sections of $t\bar{t}γ$ production in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
by Carmen Diez Pardos
This is not the latest submitted version.
Submission summary
| Authors (as registered SciPost users): | Carmen Diez Pardos |
| Submission information | |
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| Preprint Link: | https://arxiv.org/abs/2411.15261v1 (pdf) |
| Date submitted: | Nov. 27, 2024, 11:54 a.m. |
| Submitted by: | Carmen Diez Pardos |
| Submitted to: | SciPost Physics Proceedings |
| Proceedings issue: | The 17th International Workshop on Top Quark Physics (TOP2024) |
| Ontological classification | |
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| Academic field: | Physics |
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Abstract
Cross-section measurements of the associated production of a top quark pair and a photon ($t\bar{t}\gamma$) are performed with an integrated luminosity of 140 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the LHC. The measurement focuses on $t\bar{t}\gamma$ topologies where the photon is radiated from an initial-state parton or one of the top quarks. The differential cross-sections are measured for variables characterising the photon, lepton and jet kinematic properties. The distribution of the photon transverse momentum is used to constrain effective field theory operators related to the electroweak dipole moments of the top quark.
Current status:
Reports on this Submission
Report
The text is very clear and provides a nice short summary, nevertheless given the shortness of the proceedings few items might be clarified or referenced. For those I add my request and suggestions below, once they are addressed I recommend these proceedings be published.
Requested changes
Analysis strategy: - L1:"Events in the single-lepton channel are selected if they contain exactly one photon and one isolated lepton" -> is the lepton isolated or passing any quality or pT-relevant criteria? Would be good to add a short description such as "one isolated photon"
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L4: I assume you also request to have at least one photon in this category, at the moment is not explicitly stated.
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L8: "events" -> "background events".
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L14: please add a reference for the ABCD method.
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How do you deal with conversion background? Could a line be added on this?
Cross-section measurements: - L2: "high transverse momentum": can this be quantified?
- L9: "The uncertainties are dominated by the modelling of the t¯tγ processes.". Does this statement apply only to the inclusive cross-section? From Fig 1 I see Jet and b-tagging uncertainties have a similar size to the modelling ones.
EFT interpretation: - Is this performed using both channels?
Fig 2: There is a mismatch between the top right plot and the caption "I(CtW)" vs "R(CtW)", please correct the caption.
Recommendation
Ask for minor revision
Author: Carmen Diez Pardos on 2025-04-24 [id 5413]
(in reply to Report 1 on 2025-01-09)Dear referee,
thank you for reviewing the draft and the comments. Please find below some detailed replies summarising the changes in the resubmitted draft.
All the best, Carmen Diez Pardos
Analysis strategy: - L1:"Events in the single-lepton channel are selected if they contain exactly one photon and one isolated lepton" -> is the lepton isolated or passing any quality or pT-relevant criteria? Would be good to add a short description such as "one isolated photon" ==> Yes, photons and leptons are isolated and all objects pass quality, pT and eta criteria. For all those details please refer to the original publication, doi:10.1007/JHEP10(2024)191. Added the clarification that is an isolated photon.
L4: I assume you also request to have at least one photon in this category, at the moment is not explicitly stated. ==> Yes, rephrased: "Events with exactly one isolated photon are selected. In the single-lepton channel, events must contain exactly one isolated lepton [...]"
L8: "events" -> "background events". ==> Modified as suggested
L14: please add a reference for the ABCD method. ==> Added, the same as in the original publication
How do you deal with conversion background? Could a line be added on this? ==> There is no explicit background category as "conversion background". If the comment refers to fake leptons, this contribution is ~1% (negligible in the dilepton channel), see original publication. For the proceedings, I would rather keep the focus on the main backgrounds.
Cross-section measurements: - L2: "high transverse momentum": can this be quantified? ===> For simplicity and the recommended length of the proceedings for a poster contribution, no detailed pt, eta cuts, etc. are given. Please refer to the publication for the full description of the objects at particle level and the exact requirements.
EFT interpretation: - Is this performed using both channels? ==> Yes, clarified in the text: "the differential cross-section as a function of the photon pT from the combined measurement in the single-lepton and dilepton channels."
Fig 2: There is a mismatch between the top right plot and the caption "I(CtW)" vs "R(CtW)", please correct the caption. ==> Fixed!