论文标题
通过互相关来限制超高能量宇宙射线的组成
Constraining ultra-high-energy cosmic ray composition through cross-correlations
论文作者
论文摘要
超高能量宇宙射线光谱的最高端的化学组成非常难以实验测量，直到今天，它仍然尚不清楚。由于超高能量宇宙射线的轨迹在星系的磁场中以一个取决于其原子数$ z $的角度偏转，因此可以通过量化此类磁性偏转的量来间接测量$ z $。在本文中，我们表明，使用超高能量宇宙射线和星系之间的角度谐波互相关，我们可以有效地区分不同的原子数，并用当前数据区分。例如，我们显示，如果$ z = 1 $，互相关可以排除$ 39 \％$ $ $ $ $ $ $ $2σ$的$ \％$分数。
The chemical composition of the highest end of the ultra-high-energy cosmic ray spectrum is very hard to measure experimentally, and to this day it remains mostly unknown. Since the trajectories of ultra-high-energy cosmic rays are deflected in the magnetic field of the Galaxy by an angle that depends on their atomic number $Z$, it could be possible to indirectly measure $Z$ by quantifying the amount of such magnetic deflections. In this paper we show that, using the angular harmonic cross-correlation between ultra-high-energy cosmic rays and galaxies, we could effectively distinguish different atomic numbers with current data. As an example, we show how, if $Z=1$, the cross-correlation can exclude a $39\%$ fraction of Fe56 nuclei at $2σ$ for rays above $100\text{EeV}$.
