超高能宇宙线大气簇射平均纵向发展曲线的测量(英文)  

A Measurement of the Average Longitudinal Development Profile of UHECR Air Showers by the HiRes Experiment

作　　者：张丙开[1] 

机构地区：[1]阜阳师范学院,安徽阜阳236041

出　　处：《天文研究与技术》2011年第3期213-219,共7页Astronomical Research & Technology

基　　金：国家自然科学基金(10975145,1075133);安徽省教育厅科学研究项目(KJ2010B159)资助

摘　　要：利用HiRes宇宙线实验的观测数据,通过扣除测量信号中的切仑科夫光成份,测量了广延大气簇射的纵向发展曲线。把所有的纵向发展曲线归一并且平均,获得平均纵向发展曲线。根据所得曲线,检验了3个簇射模型,它们都能较好地描述纵向发展曲线。如果利用高斯函数来描述簇射的纵向发展曲线,发现纵向发展曲线的宽度(σ)与簇射发展最大的深度有一定的关联,而且该参量从1017eV到1020 eV能量范围内几乎保持不变。另外还对平均纵向发展曲线的不确定性进行了讨论。A method of subtracting Cherenkov light component is presented and applied to the HiRes stereo data to measure longitudinal development profiles of extensive air showers.By normalizing and averaging over all showers,an average longitudinal development profile of extensive air showers is obtained.The Gaisser-Hillas,Gaussian-in-Age,and Greisen functional forms are tested as models of the average profile.They all describe the average profile well.Uncertainties of the average profile are discussed.A correlation is found between the profile width and shower maximum depth.The parameter σ in the Gaussian-in-Age model（as the width of profile）is also found to be near constant over shower energies from 1017 eV to 1020 eV.

关 键 词：纵向发展曲线 超高能宇宙线 HiRes实验 

分 类 号：O572.13[理学—粒子物理与原子核物理]