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arXiv 1207.0328astro-ph.HEastro-ph.COhep-ph
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类轴子粒子对甚高能天体物理学的重要性

Importance of axion-like particles for very-high-energy astrophysics

Marco Roncadelli, Alessandro De Angelis, Giorgio Galanti

摘要:

标准模型的几个扩展预言了类轴子粒子(ALP)的存在,这是一种具有双光子耦合的非常轻的自旋零玻色子。ALP可以在甚高能天体物理学中产生可观测的效应。在大约100 GeV以上,可观测宇宙的视界随着能量的增加而逐渐缩小,这是由于光束光子从光学和红外波段的背景光子散射,产生了e+e-对。在大尺度磁场存在的情况下,耀变体发射的光子可以在到达地球的途中振荡成ALP,并在到达地球之前返回光子。由于ALP不与背景光子相互作用,因此光束光子的有效平均自由程增加,从而提高光子存活概率。虽然吸收概率随能量而增加,但光子ALP振荡与能量无关,因此与标准预期相比,存活概率随能量而增加。我们已经对这种效应进行了系统的分析,解释了目前关于耀变体的甚高能量光子的数据。我们的预测可以用目前运行的切伦科夫望远镜(如H.E.S.S.)进行测试,MAGIC、VERITAS和CANGAROO III以及ARGO-YBJ和MILAGRO等探测器,以及计划中的切伦科夫望远镜阵列和HAWC射线天文台。具有产生上述效应的正确特性的ALP可能会被FERMILAB的GammeV实验发现,并且肯定会被DESY计划中的光子再生实验ALPS发现。

英文摘要:

Several extensions of the Standard Model predict the existence of Axion-Like Particles (ALPs), very light spin-zero bosons with a two-photon coupling. ALPs can give rise to observable effects in very-high-energy astrophysics. Above roughly 100 GeV the horizon of the observable Universe progressively shrinks as the energy increases, due to scattering of beam photons off background photons in the optical and infrared bands, which produces e+e- pairs. In the presence of large-scale magnetic fields photons emitted by a blazar can oscillate into ALPs on the way to us and back into photons before reaching the Earth. Since ALPs do not interact with background photons, the effective mean free path of beam photons increases, enhancing the photon survival probability. While the absorption probability increases with energy, photon-ALP oscillations are energy-independent, and so the survival probability increases with energy compared to standard expectations. We have performed a systematic analysis of this effect, interpreting the present data on very-high-energy photons from blazars. Our predictions can be tested with presently operating Cherenkov Telescopes like H.E.S.S., MAGIC, VERITAS and CANGAROO III as well as with detectors like ARGO-YBJ and MILAGRO and with the planned Cherenkov Telescope Array and the HAWC-ray observatory. ALPs with the right properties to produce the above effects can possibly be discovered by the GammeV experiment at FERMILAB and surely by the planned photon regeneration experiment ALPS at DESY.

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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