Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at $\sqrt{s}=$ 13 TeV
AbstractThe parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric $ \left({\hat{d}}_{\mathrm{t}}\right) $ and chromomagnetic $ \left({\hat{\mu}}_{\mathrm{t}}\right) $ moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb$^{−1}$. The linearized variable $ {A}_{\mathrm{FB}}^{(1)} $ is used to approximate the asymmetry. Candidate $ \mathrm{t}\overline{\mathrm{t}} $ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for $ \mathrm{t}\overline{\mathrm{t}} $ final states. The values found for the parameters are $ {A}_{\mathrm{FB}}^{(1)}={0.048}_{-0.087}^{+0.095}{\left(\mathrm{stat}\right)}_{-0.029}^{+0.020}\left(\mathrm{syst}\right),{\hat{\mu}}_{\mathrm{t}}=-{0.024}_{-0.009}^{+0.013}{\left(\mathrm{stat}\right)}_{-0.011}^{+0.016}\left(\mathrm{syst}\right), $ and a limit is placed on the magnitude of $ \left|{\hat{d}}_{\mathrm{t}}\right| $< 0.03 at 95% confidence level.[graphic not available: see fulltext]
Bondu, O., Bruno, G., Caputo, C., David, P., Delaere, C., Delcourt, M., Giammanco, A., Lemaitre, V., Prisciandaro, J., Saggio, A., Vidal Marono, M., Vischia, P., Zobec, J., CMS Collaboration, & et al. (2020). Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at $\sqrt{s}=$ 13 TeV. Journal of High Energy Physics, 2006, 146. https://doi.org/10.1007/JHEP06(2020)146 (Original work published 2020)