We investigate the possibility that an imaginary anomalous tbW coupling can be measured in the process \(pp \rightarrow tW^-X\) by means of T-odd observables. One such observable is the polarization of the top quark transverse to the production plane. Another is the asymmetry between the cross sections with a positive and with a negative value of a certain T-odd correlation constructed out of observable momenta when the top quark decays leptonically. The mean value of this correlation, which is also T-odd, is the third observable. These three T-odd observables are shown to be proportional to the imaginary part of only one of the tbW anomalous couplings, the other couplings giving vanishing contributions. This imaginary part could signal either a CP-odd coupling, or an absorptive part in the effective coupling. We estimate the 1- \(\sigma \) limits that might be derived in the case of each of these observables for centre-of-mass energies 13, 13.6 and 14 TeV at the LHC, corresponding to Run 2, Run 3 and High-Luminosity runs, respectively.
