The results of a first search for CP violation in the production and decay of top quark-antiquark (t t-bar) 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 sqrt(s) = 8 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 19.7 inverse femtobarns.. 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 t t-bar production and decay. The measured asymmetries exhibit no evidence for CP-violating effects, consistent with the expectation from the standard model.
CMS, Bakhshiansohi, H., Beluffi, C., Bondu, O., Brochet, S., Bruno, G., Caudron, A., de Visscher, S., Delaere, C., Delcourt, M., François, B., Giammanco, A., Jafari, A., Jez, P., Komm, M., Krintiras, G., Lemaitre, V., Magitteri, A., Mertens, A., et al. (2017). Search for CP violation in t t-bar production and decay in proton-proton collisions at sqrt(s) = 8 TeV. Journal of High Energy Physics, 1703, 101. https://doi.org/10.1007/JHEP03(2017)101 (Original work published 2017)