超高能宇宙射線及其對應微中子之關連性研究

Abstract

本計畫將探討極高能宇宙射線之流量與其相對應極高能微中子流量的關連性。利用 HiRes 與Pierre Auger 兩實驗團隊的最新數據，我們可探討極高能宇宙射線在源頭的能 譜斜率，其在源頭的截斷能量，該宇宙射線從高紅位移到低紅位移的傳播細節，以及 極高能宇宙射線源頭量度隨紅位移的演化。由於極高能宇宙射線可與宇宙背景幅射光 子發生散射而產生微中子，因此從微中子能譜中可望破除極高能宇宙射線源頭諸項資 訊的簡併性。我們亦將嘗試自高能量光子數據破除上述簡併性。最後我們也將探討如 何以高效能微中子望遠鏡量測宇宙微中子能譜。

In this proposal, we investigate the correlation between the flux of ultrahigh energy cosmic rays (UHECR) and that of cosmogenic neutrinos. We use the updated UHECR data from HiRes and Pierre Auger to study the spectral index of UHECR at the source, the energy cutoff of the UHECR spectra at the source, the details of UHECR propagations, and the source luminosity evolution with the redshift.We then also study how the flux of cosmogenic neutrinos, resulting from the interaction between UHECR and cosmic microwave background, may break the degeneracy among above-mentioned UHECR information at the source. The possibility of using high energy gamma ray to break the degeneracy will be investigated as well. The prospects of measuring the spectrum of cosmogenic neutrinos in large acceptance neutrino telescopes will also be studied.