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arXiv 1302.1208astro-ph.HEhep-ph
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从极高能gamma-ray观测得到的光子-类轴子粒子耦合的第一个下限

First lower limits on the photon-axion-like particle coupling from very high energy gamma-ray observation

Manuel Meyer, Dieter Horns, Martin Raue

摘要:

来自河外源的甚高能量(VHE,能量> 100 GeV)伽马射线的内禀通量由于与河外背景光(EBL)的光子相互作用中的对产生而衰减。根据源的距离,宇宙应该对高于一定能量的VHE光子不透明。然而,有迹象表明,宇宙比以前认为的更透明。最近对VHE光谱的大样本的统计分析表明,对于具有最高衰减的数据点,用当前EBL模型对吸收的校正太强。一种解释可能是VHE光子在环境磁场中振荡成假想的类轴子粒子(ALP)。这种机制将降低不透明度,因为ALP在宇宙学距离上不受阻碍地传播。在这里,一个大样本的VHE伽马射线光谱获得成像空气切伦科夫望远镜是用来设置,第一次,在大范围的ALP质量的光子ALP耦合常数的下限。考虑到振荡的能量依赖性,研究了不同磁场配置下的转换,包括星系团内和星系际磁场以及银河系的磁场.对于乐观的情况下,干预磁场,光子ALP耦合的$10^{-12}\mathrm{GeV}^{-1}$的顺序的下限,而更保守的模型假设结果在$2\times10^{-11}\mathrm{GeV}^{-1}$。后一个值在未来专用ALP搜索的范围内。

英文摘要:

The intrinsic flux of very high energy (VHE, Energy > 100 GeV) gamma-rays from extragalactic sources is attenuated due to pair production in the interaction with photons of the extragalactic background light (EBL). Depending on the distance of the source, the Universe should be opaque to VHE photons above a certain energy. However, indications exist that the Universe is more transparent than previously thought. A recent statistical analysis of a large sample of VHE spectra shows that the correction for absorption with current EBL models is too strong for the data points with the highest attenuation. An explanation might be the oscillation of VHE photons into hypothetical axion-like particles (ALPs) in ambient magnetic fields. This mechanism would decrease the opacity as ALPs propagate unimpeded over cosmological distances. Here, a large sample of VHE gamma-ray spectra obtained with imaging air Cherenkov telescopes is used to set, for the first time, lower limits on the photon-ALP coupling constant over a large range of ALP masses. The conversion in different magnetic field configurations, including intra-cluster and intergalactic magnetic fields together with the magnetic field of the Milky Way, is investigated taking into account the energy dependence of the oscillations. For optimistic scenarios of the intervening magnetic fields, a lower limit on the photon-ALP coupling of the order of $10^{-12}\mathrm{GeV}^{-1}$ is obtained whereas more conservative model assumptions result in $2\times10^{-11}\mathrm{GeV}^{-1}$. The latter value is within reach of future dedicated ALP searches.

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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