Search

The presence of multi-boson self-interactions is implied by the non-Abelian gauge structure of the Standard Model (SM). Precise measurements of these interactions allow not only testing the nature of the SM but also new physics contribution arising from the beyond SM. The investigation of these interactions can be approached in a model-independent manner using an effective theory approach, which forms the main motivation of this study. In this paper, we examine the anomalous neutral quartic gauge couplings through the process $\gamma \gamma \rightarrow Z Z$ at the Compact Linear Collider (CLIC) with the center-of-mass energy of $\sqrt{s}=3$ TeV, integrated luminosities of ${\cal L}=5$ $\rm ab^{-1}$. The anomalous neutral quartic gauge couplings is implemented into FeynRules to generate a UFO module inserted into Madgraph to generate both background and signal events. These events are then passed through Pythia 8 for parton showering and Delphes to include realistic detector effects. We obtain that the sensitivities on the anomalous quartic neutral gauge couplings with $95\%$ Confidence Level are given as: $f_{T0}/\Lambda^{4}=[-1.06; 1.08]\times 10^{-3}$ ${\rm TeV^{-4}}$, $f_{T1}/\Lambda^{4}=[-1.06; 1.08]\times 10^{-3}$ ${\rm TeV^{-4}}$,$f_{T2}/\Lambda^{4}=[-1.06; 1.08]\times 10^{-3}$ ${\rm TeV^{-4}}$,$f_{T0}/\Lambda^{4}=[-1.06; 1.08]\times 10^{-3}$ ${\rm TeV^{-4}}$, $f_{T5}/\Lambda^{4}=[-4.08; 4.08]\times 10^{-4}$ ${\rm TeV^{-4}}$ and $f_{T8}/\Lambda^{4}=[-1.10; 1.10]\times10^{-4}$ ${\rm TeV^{-4}}$. Our results on the anomalous quartic neutral gauge couplings are set more stringent sensitivity with respect to the recent experimental limits., Comment: 21 pages, 6 figures

In this paper, we consider the electroweak production cross-section of a single anti-top-quark, a neutrino and a photon via charged current through the $e^-p \to e^-\bar b \to \bar t \nu_e \gamma \to \bar t(\to W^- \to (qq', l^- \bar\nu_l)+b) \nu_e\gamma$ signal. Further, we derived the sensitivity expected to the magnetic dipole moment $(\hat a_V)$ and the electric dipole moment $(\hat a_A)$ of the top-quark at the Future Circular Collider Hadron Electron (FCC-he). We present our study for $\sqrt{s}=7.07, 10\hspace{0.8mm}TeV$, ${\cal L}=50, 100, 300, 500, 1000\hspace{0.8mm}fb^{-1}$, $\delta_{sys}=0, 3, 5\hspace{0.8mm}\%$ and $P_{e^-}=0\%, 80\%, -80\%$, respectively. We find that the sensitivity estimated on dipole moments of the top-quark is of the order of magnitude ${\cal O}(10^{-1})$ for both hadronic and leptonic decay modes of $W^-$: $\hat a_V=[-0.2308, 0.2204]$, $|\hat a_A|=0.2259$ at $95\%$ C.L. in the hadronic channel with unpolarized electron beam $P_{e^-}=0\%$. Our results with polarized electron beam for $P_{e^-}=80\%$ and $P_{e^-}=-80\%$ are $\hat a_V=[-0.3428, 0.3321]$, $|\hat a_A|=0.3371$ and $\hat a_V=[-0.2041, 0.1858]$, $|\hat a_A|=0.1939$ at $95\%$ C.L. in the hadronic channel. The corresponding results for the leptonic channel with $P_{e^-}=0\%, 80\% -80\%$ are $\hat a_V=[-0.3067, 0.2963]$, $|\hat a_A|=0.3019$, $\hat a_V=[-0.4563, 0.4456]$, $|\hat a_A|=0.4505$ and $\hat a_V=[-0.2695, 0.2512]$, $|\hat a_A|=0.2592$, respectively. The results for $\hat a_V$ and $\hat a_A$ in the leptonic channel are weaker by a factor of 0.75 than those corresponding to the hadronic channel. Given these prospective sensitivities we highlight that the FCC-he is potential top-quark factory that is particularly well suited to sensitivity study on its dipole moments and with cleaner environments., Comment: 28 pages, 10 figures and 7 tables. arXiv admin note: text overlap with arXiv:1812.08971