Study of top quark dipole interactions in $t\overline{t}$ production associated with two heavy gauge bosons at the LHC

In this paper, we investigate the prospects of measuring the strong and weak dipole moments of the top quark at the Large Hadron Collider (LHC). Measurements of these couplings provide an excellent opportunity to probe new physics interactions as they have quite small magnitudes in the standard model. Our analyses are performed using the production cross sections of $t\overline{t}WW$ and $t\overline{t}ZZ$ processes in the same sign dilepton and four-lepton final states, respectively. The sensitivities to strong and weak top quark dipole interactions at the 95% confidence level for various integrated luminosity scenarios are derived and compared with other studies. To estimate the constraints, the main source of backgrounds and a realistic simulation of the detector response are considered.

Figure 1

Lowers-order representative Feynman diagrams for $t\overline{t}WW$ production at the LHC. The vertices which receive contribution from $O_{uG\varphi }^{33}$ operator are shown with red filled circles.

Figure 2

Representative Feynman diagrams for $t\overline{t}ZZ$ production at leading-order.

Figure 3

The limits at 95% CL on $d_V^g$ (right panel) and on $d_A^g$ (left panel) from $t\overline{t}WW$ (same-sign leptons) and $t\overline{t}ZZ$ (four-lepton) with 300 and $3000{\mathrm{fb}}^{-1}$ are shown. The indirect limits on $d_A^g$ (neutron electric dipole moment) and on $d_V^g$ (rare B meson decays) are presented as well as the limits from the combination of $t\overline{t}$ cross section at the LHC8 and Tevatron. Also, the limits which could be derived from tail of $t\overline{t}$ mass spectrum at the FCC-hh and LHC are shown.