Revisiting the top quark chromomagnetic dipole moment in the SM
Facultad de Ciencias Físico Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Av. Francisco J. Mújica s/n, 58060, Morelia, Michoacán, México
2 Cátedras Conacyt, Av. Insurgentes Sur 1582, Col. Crédito Constructor, Alc. Benito Juárez, 03940, Ciudad de México, México
Accepted: 9 January 2021
Published online: 2 February 2021
We revisit the anomalous chromomagnetic dipole moment in the Standard Model and show that its triple gluon vertex contribution, with the on-shell gluon (), generates an infrared divergent pole. Consequently, the chromomagnetic dipole should not be perturbatively evaluated at . Focusing on this top quark anomaly, denoted as , we compute it with the off-shell gluon with a large momentum transfer, just as the convention scale, for both spacelike and timelike cases. We found that and . Our matches well with the current experimental value , and the part is induced by flavour changing charged currents.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021