Journal of High Energy Physics
The results of a first search for CP violation in the production and decay of top quark-antiquark (tt¯) pairs are presented. The search is based on asymmetries in T-odd, triple-product correlation observables, where T is the time-reversal operator. The analysis uses a sample of proton-proton collisions at s=8 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 19.7 fb−1. Events are selected having one electron or muon and at least four jets. The T-odd observables are measured using four-momentum vectors associated with tt¯ production and decay. The measured asymmetries exhibit no evidence for CP-violating effects, consistent with the expectation from the standard model.
Baarmand, M M.; Bhopatkar, Vallary; Colafranceschi, Stefano; Hohlmann, Marcus; Noonan, D; Roy, Tuhin S.; Yumiceva, Francisco X.; and CMS Collaboration, "Search For CP Violation In tt¯ Production And Decay In Proton-Proton Collisions At √s=8 TeV" (2017). Aerospace, Physics, and Space Science Faculty Publications. 50.