论文标题
重新审视DFSZ Axion耦合
DFSZ Axion Couplings Revisited
论文作者
论文摘要
在许多可能性中，已经提出了太阳轴来解释Xenon1t协作观察到的电子后坐力事件，尽管它与天体物理观察有张力。轴联耦合到光子$ g_ {aγ} $和electron $ g_ {ae} $扮演重要角色。这些耦合与费米子的Peccei-Quinn（PQ）费用$ x_f $有关。在大多数计算中，$ g_ {aγ} $是通过标准化电磁异常因子的比率$ e = trx_f q^2_f n_c $（$ n_c $（$ n_c $ as for quarkss and for quarks and oppage leptons and oppage leptons and oppaged leptons）和QCD Anomaly actor $ n = trx_q t（q） 指数）。损坏的PQ对称发生器用于计算中，似乎并未将轴法中损坏的发生器的组件提取出由$ z $ boson“食用”。但是，使用轴法的物理成分或异常因子的比率应在$ g_ {aγ} $的DFSZ中获得相同的结果。当超出标准DFSZ模型（例如变体DFSZ模型）时，更多的HIGGS Doublets和Fermions具有不同的PQ电荷，人们可能会怀疑结果是否不同。我们表明，这两种方法获得了与预期的结果相同的结果，但是在Quarks和Leptons $ g_ {af} $的轴承耦合（此处f表示SM中的一个Fermions）在物理轴上更方便地计算出来。结果取决于真空期望值的值，导致$ g_ {af} $在标准DFSZ轴上的较宽参数空间。我们还明确地展示了如何在树级的变体DFSZ型号的上下搭配一对高度的doublets夫妇到上下的flygs doublets夫妇时，如何保存$ g_ {af} $耦合，以及如何出现违反味道的风味。
Among many possibilities, solar axion has been proposed to explain the electronic recoil events excess observed by Xenon1T collaboration, although it has tension with astrophysical observations. The axion couplings, to photon $g_{aγ}$ and to electron $g_{ae}$ play important roles. These couplings are related to the Peccei-Quinn (PQ) charges $X_f$ for fermions. In most of the calculations, $g_{aγ}$ is obtained by normalizing to the ratio of electromagnetic anomaly factor $E = TrX_f Q^2_f N_c$ ($N_c$ is 3 and 1 for quarks and charged leptons respectively) and QCD anomaly factor $N = TrX_q T(q)$ ($T(q)$ is quarks' $SU(3)_c$ index). The broken PQ symmetry generator is used in the calculation which does not seem to extract out the components of broken generator in the axion which are "eaten" by the $Z$ boson. However, using the physical components of axion or the ratio of anomaly factors should obtain the same results in the DFSZ for $g_{aγ}$. When going beyond the standard DFSZ models, such as variant DFSZ models, where more Higgs doublets and fermions have different PQ charges, one may wonder if the results are different. We show that the two methods obtain the same results as expected, but the axion couplings to quarks and leptons $g_{af}$ (here f indicates one of the fermions in the SM) are more conveniently calculated in the physical axion basis. The result depends on the values of the vacuum expectation values leading to a wider parameter space for $g_{af}$ in beyond the standard DFSZ axion. We also show explicitly how flavor conserving $g_{af}$ couplings can be maintained when there are more than one Higgs doublets couple to the up and down fermion sectors in variant DFSZ models at tree level, and how flavor violating couplings can arise.
