标题： 审视KM3-230213A事件的宇宙成因：多信使视角 显示英文标题

标题： Scrutinizing the cosmogenic origin of the KM3-230213A event: A Multimessenger Perspective

摘要： 最近，KM3NeT/ARCA望远镜检测到了中微子事件KM3-230213A（$\sim$~220 PeV），这是迄今为止观测到的能量最高的事件，可能代表了期待已久的宇宙起源的证据，这种证据来源于超高能宇宙射线与背景光子的相互作用。 其确认将标志着高能天体物理学的重大进展。 我们对来自宇宙学演化源的质子及其次级$\gamma$-射线和中微子进行了自洽的多信使传输计算，并将预测结果与皮埃尔·奥格尔观测站、IceCube、KM3NeT以及费米-LAT各向同性$\gamma$-射线背景的数据进行对比。 一个陡峭的亚踝区质子成分饱和了弥散的$\gamma$-射线背景并被排除，而一个延伸至$10^{20}$~eV以上的硬质子谱并伴随演化$\propto (1+z)^3$能够重现KM3-230213A而不违反任何限制。 此情景要求质子分数为$\lesssim 10$% 在$3\times 10^{19}$~eV 并排除演化更快的源。 联合超高能中微子和$\gamma$-射线观测因此加强了对河外宇宙射线源的约束，并为AugerPrime和下一代中微子望远镜设定了目标。 显示英文摘要

摘要： The recent detection of the neutrino event KM3-230213A ($\sim$~220 PeV) by the KM3NeT/ARCA telescope, the most energetic ever observed, could represent the long-awaited evidence for a cosmogenic origin, arising from the interaction of an ultra-high-energy cosmic ray with background photons. Its secure confirmation would mark a major advance in high-energy astrophysics. We perform a self-consistent multimessenger transport calculation of protons and their secondary $\gamma$-rays and neutrinos from cosmologically evolving sources, confronting predictions with data from the Pierre Auger Observatory, IceCube, KM3NeT, and the Fermi-LAT isotropic $\gamma$-ray background. A steep sub-ankle proton component saturates the diffuse $\gamma$-ray background and is disfavoured, whereas a hard proton spectrum extending beyond $10^{20}$~eV with evolution $\propto (1+z)^3$ reproduces KM3-230213A without violating any limits. This scenario requires a proton fraction $\lesssim 10$\% at $3\times 10^{19}$~eV and excludes faster-evolving sources. Joint UHE-neutrino and $\gamma$-ray observations thus sharpen constraints on extragalactic cosmic-ray sources and set targets for AugerPrime and next-generation neutrino telescopes.