南極超高能宇宙微中子陣列之事件重建模擬

Abstract

南極超高能宇宙微中子陣列是一個已被提案的科學計畫，旨在藉由無線電波段之契忍可夫輻射偵測超高能宇宙微中子，以了解宇宙加速器之起源及演化。為評估藉由超高能宇宙微中子指回產生它們的宇宙加速器的可能性，我們採用偏離角來描述此可能性：在百分之一的信心水準下，有九成的宇宙超高能微中子在地球端的觀測偏離小於一度。而為了使南極超高能宇宙微中子陣列的幾何設計能最佳化，我們研究了幾何設計與微中子角度解析度和偵測效率關係，同時也考慮了不同程度的背景雜訊所帶來的影響。我們發現無線電站相距1.6 公里且天線相距40 公尺能讓陣列表現最佳。

Askaryan Radio Array (ARA) is a large-scale radio Cherenekov observatory which scientists propose to develop in Antarctica, aiming for discovering the origin and evolution of the cosmic accelerators that produce the highest energy cosmic rays, by means of observing the ultra high energy (UHE) cosmogenic neutrinos. To determine whether it is probable to use UHE neutrinos for pointing back to the cosmic accelerators, an assessment of the deviation angles of these neutrinos has been made, and its conclusion is that the probability of observing the neutrino deviation angle within 1 degree is 90%. To optimize ARA's angular resolution of the incoming UHE neutrinos, which is also essential to point pack, the relation between the reconstruction capabilities of ARA and its design is studied. It is found that with the noise e ect taken into account, in order to make this neutrino angular resolution as good as possible and detection e ciency as high as possible, the optimal choice for ARA geometry would be the station spacing of 1.6 km and the antenna spacing of 40 m.