近日，DAMPE国际协作组报道了膝区以下原初宇宙射线的电荷依赖型能谱软化。2026年4月29日出版的《自然》杂志发表了这项成果。

在大多数粒子加速或传播理论中，由加速极限或传播相位变化引起的宇宙射线能谱特征，通常与粒子电荷相关。而另一方面，相互作用机制则预期能谱特征一般与质量相关。由于难以测量单个粒子直至极高能量的能谱，目前尚缺乏观测验证哪种关系在自然界中真正成立。

研究组基于“暗物质粒子探测卫星”九年的在轨数据，报告了从约20吉伏特到约100太伏特（铁核能谱至60太伏特）的碳核、氧核和铁核能谱的直接测量结果。据他们所知，首次在这些能谱中直接探测到了明显的能谱软化现象。结合更新的质子和氦核能谱，他们发现这种能谱软化在约15太伏特的刚度处普遍出现。以超过99.999%的置信度排除了能谱软化随核子质量变化的解释。文章讨论了这些结果的可能解释，包括附近存在宇宙射线源以及传播效应等其他模型。

附：英文原文

Title: Charge-dependent spectral softenings of primary cosmic rays below the knee

Author: anonymous

Issue&Volume: 2026-04-29

Abstract: In most particle acceleration or propagation theories, the characteristic features of the cosmic ray spectra due to acceleration limits or propagation phase changes are charge-dependent1,2,3,4. Alternatively, the interaction scenario would expect mass-dependent spectral features in general. The observational verification of which relation takes effect in nature is still lacking because of the difficulty in measuring the spectra of individual particles up to very high energies. Here we report direct measurements of the carbon, oxygen and iron spectra from about 20gigavolts to around 100teravolts (60teravolts for iron) with 9years of on-orbit data collected by the Dark Matter Particle Explorer. Distinct spectral softenings have been directly detected in these spectra for the first time, to our knowledge. Combined with the updated proton and helium spectra, the spectral softening appears universally at a rigidity of about 15teravolts. A nuclei-mass-dependent softening is rejected at a confidence level of >99.999%. Possible interpretations of these results, including a nearby cosmic ray source5,6,7 and other models such as the propagation effect8, are discussed.

DOI: 10.1038/s41586-026-10472-0

Source: https://www.nature.com/articles/s41586-026-10472-0