2024 Articles

Measurement of the total and differential cross-sections of 𝑡𝑡̄𝑊 production in 𝑝𝑝 collisions at √𝑠= 13 TeV with the ATLAS detector

Aad, G.; Abbott, B.; Abeling, K.; Abicht, N. J.; Abidi, S. H.; Aboulhorma, A.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Abusleme Hoffman, A. C.; Acharya, B. S.; Adam Bourdarios, C.; Adamczyk, L.; Adamek, L.; Addepalli, S. V.; Addison, M. J.; Adelman, J.; Adiguzel, A.; Adye, T.; Affolder, A. A.; Afik, Y.; Agaras, M. N.; Agarwala, J.; Aggarwal, A.; Agheorghiesei, C.; Ahmad, A.; Ahmadov, F.; Ahmed, W. S.; Ahuja, S.; Ai, X.; Aielli, G.; Ait Tamlihat, M.; Aitbenchikh, B.; Aizenberg, I.; Akbiyik, M.; Åkesson, T. P. A.; Akimov, A. V.; Akiyama, D.; Akolkar, N. N.; Al Khoury, Konie

Measurements of inclusive and differential production cross-sections of a top-quark-top-antiquark pair in association with a 𝑊 boson (𝑡𝑡̄𝑊) are presented. They are performed by targeting final states with two same-sign or three isolated leptons (electrons or muons) and are based on √𝑠= 13 TeV proton-proton collision data with an integrated luminosity of 140 fb⁻¹, recorded from 2015 to 2018 with the ATLAS detector at the Large Hadron Collider.

The inclusive 𝑡𝑡̄𝑊 production cross-section is measured to be 880 ± 80 fb, compared to a reference theoretical prediction of 745 ± 50 (scale) ± 13 (2-loop approx.) ± 19 (PDF, 𝛼_s) fb. Differential cross-section measurements characterise this process in detail for the first time. Several particle-level observables are compared with a variety of theoretical predictions, which generally agree well with the normalised differential cross-section results. Additionally, the relative charge asymmetry of 𝑡𝑡̄𝑊 ⁺ and 𝑡𝑡̄𝑊 ⁻ is measured inclusively to be 𝐴∧rel_C = 0.33 ± 0.05, in very good agreement with the theoretical prediction of 0.322 ± 0.003 (scale) ± 0.007 (PDF), as well as differentially.