The anisotropy parameters $\left(\beta \right)$ of photofragments near a Fano resonance vary with the excitation energies. We call the curve describing such a relationship the $\beta$ profile. In this Rapid Communication, we report measurements of the $\beta$ profiles for the $\mathrm{H}\left(2l\right)$ and $\mathrm{D}\left(2l\right)$ fragments along six Fano resonances in the predissociation of ${\mathrm{H}}_2$ and ${\mathrm{D}}_2$ near the second dissociation threshold. In contrast to a previous theoretical prediction, the measured $\beta$ profiles are found to be asymmetric. An analytical expression of the $\beta$ profile was derived based on the Fano formula and was used to fit the measured $\beta$ profiles. The $\beta$ profiles are found to be more sensitive than the Fano profiles to the Fano $q$ parameters, as well as to the intensity ratios between the interacting and noninteracting continuum states. The $\beta$ values due to the resonance state, the continuum state, and the interference between the resonance and the continuum states in the Fano resonance were also determined. The $\beta$ profile should not only provide us with a tool to measure the parameters characterizing the Fano resonance, but also help gain further physical insight into the Fano resonances.

中文翻译：

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H2光解离中沿Fano共振的碎片各向异性参数的不对称分布

各向异性参数 $（\beta ）$Fano共振附近的光碎片的数量随激发能而变化。我们称描述这种关系的曲线为$\beta$个人资料。在本快速沟通中，我们报告了对$\beta$ 的个人资料 $\mathrm{H}（2升）$ 和 $\mathrm{d}（2升）$ 在预分解中沿着六个Fano共振的碎片 ${\mathrm{H}}_2$ 和 ${\mathrm{d}}_2$接近第二解离阈值。与先前的理论预测相反，$\beta$发现轮廓不对称。的解析表达式$\beta$ 轮廓是根据Fano公式得出的，用于拟合测量值 $\beta$个人资料。的$\beta$ 发现配置文件比Fano配置文件对Fano更为敏感 $q$参数，以及相互作用和非相互作用连续体状态之间的强度比。的$\beta$还确定了由于共振状态，连续体状态以及法诺共振中的共振和连续体状态之间的干扰引起的值。的$\beta$ 轮廓不仅应为我们提供一种测量表征Fano共振的参数的工具，而且还有助于进一步了解Fano共振。