In this paper we investigate the vacuum stability of the non-minimally coupled Standard-Model Higgs during a phase of kinetic domination following the end of inflation. The non-minimal coupling to curvature stabilises the Higgs fluctuations during inflation while driving them towards the instability scale during kination, when they can classically overcome the potential barrier separating the false electroweak vacuum from the true one at super-Planckian field values. Avoiding the instability of the Standard-Model vacuum sets an upper bound on the inflationary scale that depends both on the strength of the non-minimal interaction and on the top quark Yukawa coupling. Classical vacuum stability is guaranteed if the gravitationally-produced energy density is smaller than the height of barrier in the effective potential. Interestingly enough, thanks to the explosive particle production in the tachyonic phase, the Higgs itself can be also appointed to the role of reheaton field responsible for the onset of the hot Big Bang era, setting an additional lower bound on the inflationary scale $\mathcal{H}_{\rm inf} \gtrsim 10^{5.5} \text{ GeV}$. Overall, these constraints favour lower masses for the top quark, in agreement with the current measurements of the top quark pole mass. We perform our analysis semi-analytically in terms of the one-loop and three-loop running of the Standard-Model Higgs self-coupling and make use of lattice-based parametric formulas for studying the (re)heating phase derived in arXiv:2307.03774. For a specific choice of $m_t=171.3 \text{ GeV}$ we perform also an extensive numerical scanning of the parameter space via classical lattice simulations, identifying stable/unstable regions and supporting the previous analytical arguments. For this fiducial value, the heating of the Universe is achieved at temperatures in the range $10^{-2} - 10^9 \text{ GeV}$.
How fast can the wall move? A study of the electroweak phase transition dynamics
我们考虑在最小标准模型中的电弱相变的气泡生长的动力学和确定的形状和速度的相边界,或气泡壁。我们表明,在半经典近似下,壁面上的摩擦力来自于大质量粒子布居数偏离热平衡。我们对待这些与玻尔兹曼方程在流体近似。这种近似对于顶夸克和轻粒子是合理的,但它低估了红外$W$玻色子和希格斯粒子的摩擦。我们使用两圈有限温度有效势,并找到一个亚音速泡壁的整个范围内的希格斯质量$0<m_H<90$ GeV。结果对$m_H$的依赖性较弱:壁速度$v_w$落在$0.36<v_w<0.44$范围内,而壁厚度在$29> L T > 23 $范围内。壁厚大于相平衡值,因为不平衡的颗粒在移动壁的背面比在底部施加更大的摩擦。我们还考虑了可能存在于对称相的红外规范凝聚的影响;简单地模拟它,我们发现壁可能成为超音速的,但不是超相对论的。
Probing the Electroweak Phase Transition in the Flipped Two-Higgs-Doublet Model at the LHC
Sun Yat-sen University(中山大学);Guangdong Provincial Key Laboratory of Quantum Precision Measurement and Sensing(广东省量子精密测量与传感重点实验室);Shenzhen Campus of Sun Yat-sen University(中山大学深圳校区)
Sensitivity of Standard Model Vacuum Stability to Enhanced Scalar Couplings: A Coupling Scan and its Implications for Radiatively Broken Electroweak Symmetry
Peaceful Society, Science and Innovation Foundation(和平社会、科学与创新基金会);Department of Occupational Science and Occupational Therapy, University of British Columbia(不列颠哥伦比亚大学职业科学与职业治疗系);Department of Mathematics, DePauw University(迪波大学数学系)