Mass Composition Studies of the Highest Energy Cosmic Rays
msra(2009)
摘要
The determination of the mass composition of the highest energy cosmic rays
is one of the greatest challenges in cosmic ray experiments. The highest energy
cosmic rays are only detected indirectly because of their very low flux. Using
the atmosphere as a large target, Air Fluorescence Detectors are capable of
tracing the evolution of the size of the Extensive Air Shower through the
atmosphere (the shower longitudinal profile). The analysis of the
characteristics of the detected longitudinal profiles is currently the most
reliable way for extracting some information about the primary cosmic ray mass
composition. In this proceeding, I will describe in some detail the Pierre
Auger elongation rate studies, and I will show the potential for mass
composition studies using the surface and the fluorescence detectors
information as part of a single analysis. The interpretation of the current
data with regard to mass composition, relies heavily on high energy hadron
interaction models. Using standard hadron interaction models, the data suggest
that the composition becomes lighter up to about 2 $\times$ 10$^{18}$ $eV$ and
above that it becomes heavier again. This apparent change in the mass
composition at 2 $\times$ 10$^{18}$ $eV$ seems to be correlated with a spectrum
index change in the observed energy spectrum.
更多查看译文
关键词
spectrum,indexation,cosmic ray,high energy astrophysics,fluorescence detector
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要