Chromomagnetic and chromoelectric dipole moments of quarks in the reduced 331 model

Abstract

The one-loop contributions to the chromomagnetic dipole moment ${\hat{\mu }}_t(q^2)$ and electric dipole moment ${\hat{d}}_t(q^2)$ of the top quark are calculated within the reduced 331 model (RM331) in the general case of an off-shell gluon. It is argued that the results are gauge independent for $q^2\ne 0$ and represent valid observable quantities. In the RM331 ${\hat{\mu }}_t(q^2)$ receives new contributions from two heavy gauge bosons $Z^{\prime }$ and $V^{+}$ and a new neutral scalar boson $h_2$, along with a new contribution from the standard model Higgs boson via flavor changing neutral currents. The latter, which are also mediated by the $Z^{\prime }$ gauge boson and the scalar boson $h_2$, can give a non-vanishing ${\hat{d}}_t$ provided that there is a $CP$-violating phase. The analytical results are presented in terms of both Feynman parameter integrals and Passarino-Veltman scalar functions, which are useful to cross-check the numerical results. Both ${\hat{\mu }}_t(q^2)$ and ${\hat{d}}_t$ are numerically evaluated for parameter values still allowed by the constraints from experimental data. It is found that the new one-loop contributions of the RM331 to ${\hat{\mu }}_t(q^2)$ are of the same order of magnitude or larger than in other standard model extensions, with the dominant contribution arising from the $V^{+}$ gauge boson for $\Vert q\Vert$ in the 30-1000 GeV interval and a mass $m_V$ of the order of a few hundreds of GeVs. As for ${\hat{d}}_t(q^2)$, it receives the largest contribution from $h_2$ exchange and can reach values of the order of $10^{-20}$, which is smaller than the contributions predicted by other standard model extensions.

accepted in Chinese Physics C

References in corpus (15)

• Pinch Technique: Theory and Applications
• Connection of $g-2_{\mu }$, electroweak, dark matter, and collider constraints on 331 models
• Chromomagnetic Dipole Moment of the Top Quark Revisited
• The Chromoelectric Dipole Moment of the Top Quark in Models with Vector Like Multiplets
• Simple 3-3-1 model and implication for dark matter
• The seesaw mechanism at TeV scale in the 3-3-1 model with right-handed neutrinos
• Anomalous gtt couplings in the Littlest Higgs Model with T-parity
• Anomalous chromomagnetic moment of quarks
• New estimate of the chromomagnetic dipole moment of quarks in the standard model
• Revisiting the top quark chromomagnetic dipole moment in the SM
• Charged Bilepton Pair Production at LHC Including Exotic Quark Contribution
• Vector- and Scalar-Bilepton Pair Production in Hadron Colliders
• Top quark chromomagnetic dipole moment in the littlest Higgs model with T-parity
• Radiative generation of neutrino masses in a 3-3-1 type model
• Triangular mass matrices for quarks and leptons

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• $H\to Z\gamma$ decay and $CP$ violation
• $CP$ violation in the $HZZ$ vertex and left-right asymmetries
• $CP$-odd form factor in the $HWW$ vertex