Top quark tensor couplings

TL;DR

This paper calculates electroweak one-loop corrections to tensor couplings in the top-bottom-W vertex within the Standard Model, highlighting their significance for future LHC measurements and new physics searches.

Contribution

It provides the first detailed computation of electroweak contributions to tensor couplings, showing they are comparable to QCD effects and crucial for interpreting experimental data.

Findings

Electroweak corrections are about 10% of QCD contributions.

Real and imaginary parts of right coupling are similar in magnitude.

Predictions are close to current experimental sensitivity.

Abstract

We compute the real and imaginary parts of the one-loop electroweak contributions to the left and right tensorial anomalous couplings of the $tbW$ vertex in the Standard Model (SM). For both tensorial couplings we find that the real part of the electroweak SM correction is close to 10$%$ of the leading contribution given by the QCD gluon exchange. We also find that the electroweak real and imaginary parts for the anomalous right coupling are almost of the same order of magnitude. The one loop SM prediction for the real part of the left coupling is close to the 3$\sigma$ discovery limit derived from $b\rightarrow s \gamma$. Besides, taking into account that the predictions of new physics interactions are also at the level of a few percents when compared with the one loop QCD gluon exchange, these electroweak corrections should be taken into account in order to disentangle new physics effects from the standard ones. These anomalous tensorial couplings of the top quark will be investigated at the LHC in the near future where sensitivity to these contributions may be achieved.