arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2303.02593hep-phastro-ph.CO
收藏

Z2对称性破缺畴壁普遍消失的引力波信号

Gravitational wave signature of generic disappearance of $Z_2$-symmetry breaking domain walls

Piyali Banerjee, Urjit A. Yajnik

备注：
31 pages, v3 contains is a major upgrade showing via the percolation theory arguments how the two types of domain walls can be removed simultaneously. Recent NanoGrav data directly constrains the parameters of our upgraded mechanism
发表信息：
JHEP Volume 2024, article number 7, (2024)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

AI总结：

本文研究左右对称理论和双希格斯二重态模型中Z2畴壁的两步形成与QCD瞬子诱导的偶然消失机制，并预测其引力波峰值频率在10^-7--10^-6 Hz，可用脉冲星计时阵列实验检验。

摘要：

在高能标下离散宇称的破缺会产生Z2畴壁（DW）。这类畴壁的亚稳性可能使它们寿命相对较长，从而与标准宇宙学相矛盾。我们考虑两类具有相似底层特征的理论：左右对称理论和双希格斯二重态模型。两者都包含某种Z2离散对称性的破缺。第一步，在宇称破缺期间，畴在高能标下形成。第二步，由于双希格斯二重态模型中更接近电弱能标的Z2对称性破缺，这些畴进一步分解为子畴。我们证明，经过这种畴和子畴的两步形成之后，QCD瞬子诱导的能量差可以在大致同一时间成功移除畴壁和子畴壁。这种移除纯粹是概率非常接近0.25的偶然事件的结果，并不需要在拉格朗日量中引入任何不可重整化的Z2对称性破缺项。随后，我们研究了这类畴壁坍缩所产生的引力波，并证明这些波的峰值频率位于10^-7--10^-6 Hz频段，对应于1--10 GeV的湮灭温度。该频段对基于脉冲星计时阵列的实验（如SKA和NANOGrav）敏感。最近的NANOGrav结果排除了宇称破缺能标高于10^7 GeV的畴壁坍缩模型。宇称破缺能标低于10^7 GeV的畴壁坍缩模型仍与当前NANOGrav结果一致，并且有很大机会在未来的脉冲星计时实验中得到严格检验。

英文摘要：

Breaking of discrete parity at high scale gives rise to $Z_2$-domain walls (DW). The metastability of such walls can make them relatively long lived and contradict standard cosmology. We consider two classes of theories with similar underlying feature, the left right symmetric theories and two Higgs doublet models. Both of them possess some breaking of $Z_2$ discrete symmetries. As a first step, domains form at a high energy scale during parity breaking. In the second step, these domains further decompose into subdomains due to $Z_2$ symmetry breaking in two Higgs doublet models closer to the electroweak scale. We show that after this two step formation of domains and subdomains, a QCD instanton induced energy difference can remove the domain walls as well as the subdomain walls at around the same time successfully. The removal occurs purely as the result of a chance event taking place with probability very close to 0.25, and does not require one to introduce any non-renormalisable $Z_2$-symmetry breaking term to the Lagrangian. We then investigate the gravitational waves arising from the collapse of such domain walls and show that the peak frequency of these waves lies in the $10^{-7}$--$10^{-6}~\mbox{Hz}$ band, corresponding to annihilation temperatures of $1$--$10$ GeV. This frequency band is sensitive to pulsar timing array based experiments such as SKA and NANOGrav. The recent NANOGrav results rule out our DW collapse model for higher values of parity breaking scale above $10^7$ GeV. Our DW collapse model with parity breaking scales below $10^7$ GeV remains consistent with the current NANOGrav results and has a good chance of being seriously tested in future pulsar timing based experiments.

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。

↑