arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1504.01768hep-phhep-ex
收藏

从重胶子衰变到矢量类夸克的Z峰过剩

Z-peaked excess from heavy gluon decays to vector-like quarks

Natascia Vignaroli

摘要:

ATLAS最近宣布,在具有Z峰双轻子对、喷流和大横向缺失能量的事件中,存在3 σ过剩。我们解释这一发现的背景下,复合希格斯/ RS理论。我们发现,复合希格斯理论与保管对称性保护的$Zb\bar{b}$耦合预测的显着贡献,$ZZbb$(和$hhbb$)的最终状态来自重胶子衰变到对底伙伴矢量夸克。如果$ZZbb$末态中的一个$Z$玻色子发生轻子衰变,而另一个发生中微子衰变,那么重胶子到类矢量夸克的信号在很大程度上被ATLAS选择所接受。对于$\sim$ 900 GeV的底部伙伴,我们发现,ATLAS过剩可以复制复合希格斯模型,在实验允许的参数空间,重胶子质量约在1.87 - 2.15 TeV的范围内,并为重胶子耦合到轻夸克内$\sim(0.3-0.65) g_S$。我们简要地讨论了这一结果的影响,为今后的实验测试。

英文摘要:

A 3 sigma excess has been recently announced by ATLAS in events with Z-peaked dilepton pairs, jets, and large transverse missing energy. We interpret this finding in the context of composite Higgs / RS theories. We find that composite Higgs theories with custodial symmetry protection to the $Zb\bar{b}$ coupling predict a significant contribution to $ZZbb$ (and to $hhbb$) final states coming from heavy gluon decays to pairs of bottom-partner vector-like quarks. The heavy gluon to vector-like quarks signal is largely accepted by the ATLAS selection if one of the $Z$ boson in the $ZZbb$ final state decays leptonically and the other to neutrinos. For a bottom partner of $\sim$900 GeV, we find that the ATLAS excess can be reproduced by composite Higgs models, in an experimentally allowed parameter space, for heavy gluon masses roughly in a range 1.87 - 2.15 TeV and for heavy gluon couplings to light quarks within $\sim(0.3-0.65) g_S$. We briefly discuss the implication of this result for future experimental tests.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑