Probing new physics in dimension-8 neutral gauge couplings at e+e-colliders

• 作者: John Ellis Hong-Jian He Rui-Qing Xiao
• 来源期刊: 中国科学：物理学 力学 天文学（英文版）
• 年，卷（期）: 2021,（2）
• 所属期刊栏目: Editor's Focus
• 页码范围: 1-26
• 页数: 26页
• 语种: 英文

摘要

Neutral triple gauge couplings(nTGCs)are absent in the standard model effective theory up to dimension-6 operators,but could arise from dimension-8 effective operators.In this work,we study the pure gauge operators of dimension-8 that contribute to nTGCs and are independent of the dimension-8 operator involving the Higgs doublet.We show that the pure gauge operators generate both ZγZ* and Zγγ* vertices with rapid energy dependence ∝ E5,which can be probed sensitively via the reaction e+e-→ Zγ.We demonstrate that measuring the nTGCs via the reaction e+e-→ Zy followed by Z→ q(q)decays can probe the new physics scales of dimension-8 pure gauge operators up to the range(1-5)TeV at the CEPC,FCC-ee and ILC colliders with √s =(0.25-1)TeV,and up to the range(10-16)TeV at CLIC with √s =(3-5)TeV,assuming in each case an integrated luminosity of 5 ab-1.We compare these sensitivities with the corresponding probes of the dimension-8 nTGC operators involving Higgs doublets and the dimension-8 fermionic contact operators that contribute to the e+e-Zγ vertex.