$\gamma$ spectra for positron annihilation in noble-gas atoms are calculated using many-body theory for positron momenta up to the positronium-formation threshold. These data are used, together with time-evolving positron-momentum distributions determined in the preceding Letter [Phys. Rev. Lett. 119, 203403 (2017)], to calculate the time-varying $\gamma$ spectra produced during positron cooling in noble gases. The $\gamma$ spectra and their $\overline{S}$ and $\overline{W}$ shape parameters are shown to be sensitive probes of the time evolution of the positron momentum distribution and thus provide a means of studying positron cooling that is complementary to positron lifetime spectroscopy.

中文翻译：

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通过An没γ谱探测惰性气体中的正电子冷却

$\gamma$使用多体理论计算正负电子在惰性气体原子中的hil没光谱，直至正电子形成阈值。这些数据与在前一个字母[ Phys.Lett。莱特牧师 119，203403（2017）]，来计算随时间变化$\gamma$在稀有气体中在正电子冷却过程中产生的光谱。这$\gamma$ 光谱及其 $\overline{\mathrm{小号}}$ 和 $\overline{\mathrm{w\; ^}}$ 形状参数被证明是正电子动量分布随时间变化的灵敏探针，因此提供了一种研究正电子冷却的方法，该方法是对正电子寿命谱的补充。