标题： 带有向量-like夸克稳定性的希格斯暴涨与ACT谱指数 显示英文标题

标题： Higgs Inflation with Vector-Like Quark Stabilisation and the ACT spectral index

摘要： 近日，阿塔卡马宇宙学望远镜（ACT）合作组报告了一个标量谱指数$n_s~=~0.9743~\pm~0.0034$。 这比希格斯暴胀的经典预测值$n_s \approx 0.965$大得多，后者比 ACT 的平均值低 2.74$\sigma$。 我们表明，当一个原本亚稳态的标准模型希格斯暴胀势通过添加矢量型夸克对而得到稳定，并且势在约旦框架下重新正规化时，$n_s$的值通常大于 0.965，可以解释 ACT 的观测结果。 例如，假设2022年PDG直接测量的顶夸克质量中心值为$m_{t} = 172.69$GeV，并且使用重整化群方程的SM输入的中心值，对于存在三个同位旋单态矢量-like B夸克的情况（其质量$m_{Q}$在1-3 TeV范围内），我们得到$n_s = 0.9792 - 0.9844$，其中$n_s$范围的最低值比ACT平均值高1.44$\sigma$。 该模型预测原初引力波的张量-标量比为$r = 7.87 \times 10^{-3} - 1.21 \times 10^{-2}$，对应质量范围为$m_{Q} =$1-3 TeV，在即将进行的CMB实验中很容易被观测到。 观测到接近1 TeV质量的矢量型夸克与较大的张量-标量比$r \sim 0.1$相结合，将支持该模型。 显示英文摘要

摘要： Recently, the Atacama Cosmology Telescope (ACT) collaboration has reported a scalar spectral index $n_s~=~0.9743~\pm~0.0034$. This is substantially larger than the classical prediction of Higgs Inflation, $n_s \approx 0.965$, which is 2.74$\sigma$ below the ACT mean value. We show that when an otherwise metastable Standard Model Higgs Inflation potential is stabilised by the addition of vector-like quark pairs and the potential is renormalised in the Jordan frame, the value of $n_s$ is generally larger than 0.965 and can explain the ACT observation. As an example, assuming the 2022 PDG direct measurement central value for the t quark mass, $m_{t} = 172.69$ GeV, and central values for the SM inputs to the renormalisation group equations, we obtain $n_s = 0.9792 - 0.9844$ for the case of three isosinglet vector-like B quarks with mass $m_{Q}$ in the range 1-3 TeV, with the lowest value of the $n_s$ range being 1.44$\sigma$ above the ACT mean value. The model predicts primordial gravitational wave with tensor-to-scalar ratio $r = 7.87 \times 10^{-3} - 1.21 \times 10^{-2}$ for $m_{Q} =$ 1-3 TeV, which will be easily observable in forthcoming CMB experiments. Observation of vector-like quarks of mass close to 1 TeV mass combined with a large tensor-to-scalar ratio $r \sim 0.1$ would support the model.