Inclusive and differential cross section measurements of top quark pair (tt¯) production in association with a photon (γ) are performed as a function of lepton, photon, top quark, and tt¯ kinematic observables, using data from proton-proton collisions at s=13 TeV, corresponding to an integrated luminosity of 138 fb−1, collected at the CERN LHC with the CMS detector. Events containing two leptons (electrons or muons) and a photon in the final state are considered. The fiducial cross section of tt¯γ is measured to be 137 ± 8 fb, in a phase space including events with a high momentum, isolated photon. The fiducial cross section of tt¯γ is also measured to be 56 ± 5 fb when considering only events where the photon is emitted in the production part of the process. Both measurements are in agreement with the theoretical predictions, of 126 ± 19 fb and 57 ± 5 fb, respectively. Differential measurements are performed at the particle and parton levels. Additionally, inclusive and differential ratios between the cross sections of tt¯γ and tt¯ production are measured. The inclusive ratio is found to be 0.0133 ± 0.0005, in agreement with the standard model prediction of 0.0127 ± 0.0008. The top quark charge asymmetry in tt¯γ production is also measured to be −0.012 ± 0.042, compatible with both the standard model prediction and with no asymmetry.

Inclusive and differential measurements of the $$ \textrm{t}\overline{\textrm{t}}\upgamma $$ cross section and the $$ \textrm{t}\overline{\textrm{t}}\upgamma /\textrm{t}\overline{\textrm{t}} $$ cross section ratio in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV / Null, N., Hayrapetyan, A., Makarenko, V., Tumasyan, A., Adam, W., Andrejkovic, J.W., Benato, L., Bergauer, T., Dragicevic, M., Giordano, C., Hussain, P.S., Jeitler, M., Krammer, N., Li, A., Liko, D., Matthewman, M., Mikulec, I., Schieck, J., Schwarz, D., Schöfbeck, R., et al.. - In: JOURNAL OF HIGH ENERGY PHYSICS. - ISSN 1029-8479. - 2026:4(2026 Apr). [10.1007/jhep04(2026)086]

Inclusive and differential measurements of the $$ \textrm{t}\overline{\textrm{t}}\upgamma $$ cross section and the $$ \textrm{t}\overline{\textrm{t}}\upgamma /\textrm{t}\overline{\textrm{t}} $$ cross section ratio in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV

Cunqueiro Mendez, L.;De Riggi, F.;Del Re, D.;Frosina, L.;Lombardi, F.;Organtini, G.;Palmeri, N.;Paramatti, R.;Rahatlou, S.;Santanastasio, F.;
2026

Abstract

Inclusive and differential cross section measurements of top quark pair (tt¯) production in association with a photon (γ) are performed as a function of lepton, photon, top quark, and tt¯ kinematic observables, using data from proton-proton collisions at s=13 TeV, corresponding to an integrated luminosity of 138 fb−1, collected at the CERN LHC with the CMS detector. Events containing two leptons (electrons or muons) and a photon in the final state are considered. The fiducial cross section of tt¯γ is measured to be 137 ± 8 fb, in a phase space including events with a high momentum, isolated photon. The fiducial cross section of tt¯γ is also measured to be 56 ± 5 fb when considering only events where the photon is emitted in the production part of the process. Both measurements are in agreement with the theoretical predictions, of 126 ± 19 fb and 57 ± 5 fb, respectively. Differential measurements are performed at the particle and parton levels. Additionally, inclusive and differential ratios between the cross sections of tt¯γ and tt¯ production are measured. The inclusive ratio is found to be 0.0133 ± 0.0005, in agreement with the standard model prediction of 0.0127 ± 0.0008. The top quark charge asymmetry in tt¯γ production is also measured to be −0.012 ± 0.042, compatible with both the standard model prediction and with no asymmetry.
2026-04
Hadron-Hadron Scattering; Particle and Resonance Production; Top Physics
01 Pubblicazione su rivista::01a Articolo in rivista
Inclusive and differential measurements of the $$ \textrm{t}\overline{\textrm{t}}\upgamma $$ cross section and the $$ \textrm{t}\overline{\textrm{t}}\upgamma /\textrm{t}\overline{\textrm{t}} $$ cross section ratio in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV / Null, N., Hayrapetyan, A., Makarenko, V., Tumasyan, A., Adam, W., Andrejkovic, J.W., Benato, L., Bergauer, T., Dragicevic, M., Giordano, C., Hussain, P.S., Jeitler, M., Krammer, N., Li, A., Liko, D., Matthewman, M., Mikulec, I., Schieck, J., Schwarz, D., Schöfbeck, R., et al.. - In: JOURNAL OF HIGH ENERGY PHYSICS. - ISSN 1029-8479. - 2026:4(2026 Apr). [10.1007/jhep04(2026)086]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1779600
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