Probing axionlike particles via cosmic microwave background polarization
Probing axionlike particles via cosmic microwave background polarization
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DOI：
10.1103/physrevd.103.063508
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发表时间：
2020-08
影响因子：
5
通讯作者：
Tomohiro Fujita;Y. Minami;Kai Murai;Hiromasa Nakatsuka
中科院分区：
文献类型：
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作者：
Tomohiro Fujita;Y. Minami;Kai Murai;Hiromasa Nakatsuka
类轴子粒子（ALPs）通过alp -光子耦合旋转光子的线性偏振，将宇宙微波背景（CMB）的$E$ -模式转换为$B$ -模式。我们通过假设ALP $\phi$具有二次势$V=m^2\phi^2/2$推导出ALP动力学与旋转角度之间的关系。我们计算了CMB测量对alp -光子耦合$g$的当前和未来灵敏度，对于$10^{-32}\,\mathrm{eV}\lesssim m\lesssim 10^{-28}\,\mathrm{eV}$可以达到$g=4\times 10^{-21}\,\mathrm{GeV}^{-1}$，并且远远超过对任何质量的$m\lesssim 10^{-25}\,\mathrm{eV}$的其他搜索。我们还发现，在观测者处ALP场的波动可以引起CMB极化的显著各向同性旋转，而这在以往的研究中被忽略了。各向同性和各向异性旋转的测量使我们能够对相关量（如ALP质量$m$和ALP密度参数$\Omega_\phi$）设置界限。特别是，如果LiteBIRD检测到各向异性旋转，我们得到张量-标量比的下限为$r > 5 \times 10^{-9}$。
Axion-like particles (ALPs) rotate linear polarization of photons through the ALP-photon coupling and convert the cosmic microwave background (CMB) $E$-mode to the $B$-mode. We derive the relation between the ALP dynamics and the rotation angle by assuming that the ALP $\phi$ has a quadratic potential, $V=m^2\phi^2/2$. We compute the current and future sensitivity of the CMB measurements to the ALP-photon coupling $g$, which can reach $g=4\times 10^{-21}\,\mathrm{GeV}^{-1}$ for $10^{-32}\,\mathrm{eV}\lesssim m\lesssim 10^{-28}\,\mathrm{eV}$ and extensively exceed the other searches for any mass with $m\lesssim 10^{-25}\,\mathrm{eV}$. We also find that the fluctuation of the ALP field at the observer, which has been neglected in previous studies, can induce the significant isotropic rotation of the CMB polarization. The measurements of isotropic and anisotropic rotation allow us to put bounds on relevant quantities such as the ALP mass $m$ and the ALP density parameter $\Omega_\phi$. In particular, if LiteBIRD detects anisotropic rotation, we obtain the lower limit on the tensor-to-scalar ratio as $r > 5 \times 10^{-9}$.