Improved sensitivity on the electromagnetic dipole moments of the top quark in $\gamma \gamma$, $\gamma {\gamma }^{*}$, and ${\gamma }^{*}{\gamma }^{*}$ collisions at the CLIC

We realize a phenomenological study to examine the sensitivity on the magnetic moment and electric dipole moment of the top quark through the processes $\gamma \gamma \to t\overline{t}$, $e\gamma \to e{\gamma }^{*}\gamma \to et\overline{t}$, and $e^{-}{e}^{+}\to e^{-}{\gamma }^{*}{\gamma }^{*}{e}^{+}\to e^{-}t\overline{t}{e}^{+}$ at the Compact Linear Collider (CLIC). We find that with a center-of-mass energy of the CLIC-1.4 TeV, integrated luminosity of $\mathcal{L}=1500{\mathrm{fb}}^{-1}$ and CLIC-3 TeV, integrated luminosity of $\mathcal{L}=2000{\mathrm{fb}}^{-1}$ with systematic uncertainties of ${\delta }_{\mathrm{sys}}=0$, 5%, 10% at the 95% C.L., it is possible the CLIC may put limits on the electromagnetic dipole moments of the top quark ${\widehat{a}}_V$ and ${\widehat{a}}_A$ with a sensitivity of $\mathcal{O}({10}^{-3}-{10}^{-2})$. Therefore, we show that the sensitivity with the CLIC data is much greater than that for the Large Hadron Collider data.

Figure 1

A schematic diagram for the processes (a) $e^{-}{e}^{+}\to e^{-}{\gamma }^{*}{\gamma }^{*}{e}^{+}\to e^{-}t\overline{t}{e}^{+}$ and (b) $e^{+}\gamma \to e^{+}{\gamma }^{*}\gamma \to e^{+}t\overline{t}$.

Figure 2

Feynman diagrams contributing to the process $\gamma \gamma \to t\overline{t}$ and the subprocesses $\gamma {\gamma }^{*}\to t\overline{t}$ and ${\gamma }^{*}{\gamma }^{*}\to t\overline{t}$.

Figure 3

The total cross sections of the process $\gamma \gamma \to t\overline{t}$ as a function of ${\widehat{a}}_V$ and ${\widehat{a}}_A$ for center-of-mass energy of $\sqrt{s}=1.4\mathrm{TeV}$.

Figure 4

Same as in Fig. 3, but for center-of-mass energy of $\sqrt{s}=3\mathrm{TeV}$.

Figure 5

The total cross sections of the process $e^{+}\gamma \to e^{+}{\gamma }^{*}\gamma \to e^{+}t\overline{t}$ as a function of ${\widehat{a}}_V$ and ${\widehat{a}}_A$ for center-of-mass energy of $\sqrt{s}=1.4\mathrm{TeV}$.

Figure 6

Same as in Fig. 5, but for center-of-mass energy of $\sqrt{s}=3$.

Figure 7

The total cross sections of the process $e^{+}{e}^{-}\to e^{+}{\gamma }^{*}{\gamma }^{*}{e}^{-}\to e^{+}t\overline{t}{e}^{-}$ as a function of ${\widehat{a}}_V$ and ${\widehat{a}}_A$ for center-of-mass energy of $\sqrt{s}=1.4\mathrm{TeV}$.

Figure 8

Same as in Fig. 7, but for center-of-mass energy of $\sqrt{s}=3$.

Figure 9

Bounds contours at the 68% C.L. in the ${\widehat{a}}_V-{\widehat{a}}_A$ plane for the process $\gamma \gamma \to t\overline{t}$ with the ${\delta }_{\mathrm{sys}}=0\%$ and for center-of-mass energy of $\sqrt{s}=3$.

Figure 10

Bounds contours at the 68% C.L. in the ${\widehat{a}}_V-{\widehat{a}}_A$ plane for $e^{+}{e}^{-}\to e^{+}\gamma {\gamma }^{*}{e}^{-}\to e^{+}t\overline{t}{e}^{-}$ with the ${\delta }_{\mathrm{sys}}=0\%$ and for center-of-mass energy of $\sqrt{s}=3$.

Figure 11

Bounds contours at the 68% C.L. in the ${\widehat{a}}_V-{\widehat{a}}_A$ plane for $e^{+}{e}^{-}\to e^{+}{\gamma }^{*}{\gamma }^{*}{e}^{-}\to e^{+}t\overline{t}{e}^{-}$ with the ${\delta }_{\mathrm{sys}}=0\%$ and for center-of-mass energy of $\sqrt{s}=3$.