近日，吉林大学的张贺旭及其研究小组与日本富山县立大学的Hiroyuki Ishida合作并取得一项新进展。经过不懈努力，他们对具有多个暗手性标量的希格斯之门尺度起源的引力波足迹进行研究。相关研究成果已于2024年4月15日在国际知名学术期刊《中国物理C》上发表。

该研究团队讨论了由具有大量暗手性味的希格斯门类型的电弱尺度发生预测的引力波(GW)光谱，其中多味量子色东力学（QCD）将成为基础，并给出了触发电弱对称性破缺所需的负希格斯门耦合的动力学解释。研究人员采用线性西格玛模型作为暗多味QCD的低能描述，并基于Gildener-Weinberg机制揭示，由于沿（近似实现的）平直方向产生了强烈的一阶热相变，模型经历了一个超冷过程。

通过深入研究气泡成核与渗透现象，研究人员详细探讨了通常涉及非热和非绝热过程的再加热与弛豫机制。他们利用电子折叠数作为参数，精准地描述了再加热时间，并给出了红移对吉瓦频率和信号频谱影响的准确公式。研究结果表明，基于希格斯门尺度起源的预测，超过冷现象通常不会产生频率低至纳赫兹的引力波信号，除非释放的潜热被传输到宇宙的其他区域，而不是用于再加热。

相反，这类模型更有可能产生更高频率的信号，并且这些信号仍然保持在如LISA、BBO和DECIGO等未来探测器的预期检测灵敏度范围内。此外，研究人员还发现，在暗物质区域的大味情况下，引力波信号会进一步减弱，而峰值频率则会相应升高。与多手性标量紧密相关的特征现象学揭示了一个引人注目的预测：暗介子的质量远小于TeV尺度。

附：英文原文

Title: Gravitational wave footprints from Higgs-portal scalegenesis with multiple dark chiral scalars

Author: He-Xu Zhang, Shinya Matsuzaki, Hiroyuki Ishida

Issue&Volume: 2024-04-15

Abstract: We discuss the gravitational wave (GW) spectra predicted from the electroweak scalegenesis of the Higgs portal type with a large number of dark chiral flavors, which many flavor QCD would underlie and give the dynamical explanation of the negative Higgs portal coupling required to trigger the electroweak symmetry breaking. We employ the linear-sigma model as the low-energy description of dark many flavor QCD and show that the model undergoes ultra-supercooling due to the produced strong first-order thermal phase transition along the (approximately realized) flat direction based on the Gildener-Weinberg mechanism. Passing through evaluation of the bubble nucleation/percolation, we address the reheating and relaxation processes, which are generically non-thermal and nonadiabatic. Parametrizing the reheating epoch in terms of the e-folding number, we propose proper formulae for the redshift effects on the GW frequencies and signal spectra. It then turns out that the ultra-supercooling predicted from the Higgs-portal scalegenesis generically yields none of GW signals with the frequencies as low as nano Hz, unless the released latent heat is transported into another sector other than reheating the universe. Instead, models of this class prefer to give the higher frequency signals and still keeps the future prospected detection sensitivity, like at LISA, BBO, and DECIGO, etc. We also find that with large flavors in the dark sector, the GW signals are made further smaller and the peak frequencies higher. Characteristic phenomenological consequences related to the multiple chiral scalars include the prediction of dark pions with the mass much less than TeV scale, which is also briefly addressed.

DOI: 10.1088/1674-1137/ad2b4f

Source: http://hepnp.ihep.ac.cn/article/doi/10.1088/1674-1137/ad2b4f