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arXiv 0902.3993astro-ph.HEhep-ph
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超高能cosmic ray质子的中微子诊断

Neutrino diagnostics of ultra-high energy cosmic ray protons

Markus Ahlers, Luis A. Anchordoqui, Subir Sarkar

摘要:

来自河外源的宇宙射线开始支配来自星系源的宇宙射线的能量是天体粒子物理学中一个重要的未决问题。一个自然的候选者是在近似幂律能谱中的“脚踝”处的能量,这表明从下降的银河分量到平坦的河外分量的交叉。过渡可以在没有这种平坦化的情况下发生,但这需要一定程度的谱形状的共谋和两个分量的归一化。然而,有人认为,如果交叉能量低到光谱中的“第二膝盖”,那么在CMB上发生相互作用的宇宙射线质子的银河系外源可以重现脚踝以下的能谱。这个低交叉模型受到皮埃尔俄歇天文台的直接测量的限制,这些测量表明在这些能量下有更重的成分。我们证明了宇宙扩散中微子通量的上限提供了一个补充约束质子分数在超高能河外宇宙射线和即将到来的数据冰立方将提供一个明确的测试这个模型。

英文摘要:

The energy at which cosmic rays from extra-galactic sources begin to dominate over those from galactic sources is an important open question in astroparticle physics. A natural candidate is the energy at the 'ankle' in the approximately power-law energy spectrum which is indicative of a cross-over from a falling galactic component to a flatter extra-galactic component. The transition can occur without such flattening but this requires some degree of conspiracy of the spectral shapes and normalizations of the two components. Nevertheless it has been argued that extra-galactic sources of cosmic ray protons which undergo interactions on the CMB can reproduce the energy spectrum below the ankle if the cross-over energy is as low as the 'second knee' in the spectrum. This low cross-over model is constrained by direct measurements by the Pierre Auger Observatory which indicate a heavier composition at these energies. We demonstrate that upper limits on the cosmic diffuse neutrino flux provide a complementary constraint on the proton fraction in ultra-high energy extra-galactic cosmic rays and forthcoming data from IceCube will provide a definitive test of this model.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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