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Sheng-Zhi Zhao

Publications and source records attributed to Sheng-Zhi Zhao.

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Detecting quark anomalous electroweak couplings at the LHC

We study the dimension-6 quark anomalous electroweak couplings in the formulation of linearly realized effective Lagrangian. We investigate the constraints on these anomalous couplings from the $pp \rightarrow W^+W^-$ process in detail at the LHC. With additional kinematic cuts, we find that the 14 TeV LHC can provide a test of anomalous couplings of $O(0.1-1)\,{\rm TeV}^{-2}$. The $pp \rightarrow ZZ/Zγ/γγ$ processes can provide a good complement as they are sensitive to those anomalous couplings which do not affect the $pp \rightarrow W^+W^-$ process. Those processes that only contain anomalous triple vertices, like $p p \to W^* \to l ν_l$ or $p p \to γ^* / Z^* \to l^+ l^-$, can improve the sensitivities to $O(0.01-0.1)\,{\rm TeV}^{-2}$. We also study the kinematic differences between different anomalous couplings and discuss the potential of the $χ^2$-analysis to distinguish them. Finally, we discuss the detection ability of the possible future 100 TeV proton-proton collider(SPPC), and find that the detection sensitivity is improved by about one order of magnitude compared with the LHC.

hep-ph

Leptonic anomalous gauge couplings detection on electron positron colliders

We studied the dimension-6 leptonic anomalous gauge couplings in the formulation of linearly realized gauge symmetry effective Lagrangian and investigated the constraints on these anomalous couplings from the existed experimental data including LEP2 and $W$/$Z$ boson decay. Some bounds of $O(0.1-10){\rm TeV}^{-2}$ on four relevant anomalous couplings are given by the Z factories. We studied the sensitivity of testing the leptonic anomalous couplings via the process $e^+e^-\rightarrow W^+W^-$ at future $e^+e^-$ linear colliders. We discussed different sensitivities to anomalous couplings at polarized and unpolarized $e^+e^-$ colliders, respectively, with 500 GeV and 1 TeV collision energy. Our results show that the a 500 GeV ILC can provide a test of the anomalous couplings, with the same relative uncertainty of cross section measurement, of $O(0.1-1){\rm TeV}^{-2}$, and a 1 TeV ILC can test the anomalous couplings of $O(0.01-0.1){\rm TeV}^{-2}$.

hep-ph