在羊八井测量初级宇宙线直达质子研究质子和空气核非弹性作用截面

Study of p-Air Inelastic Cross Section with Directly Arrived Protons at Yangbajing

提出了一种在高海拔通过测量直达质子来确定质子和空气核(p-air)的非弹性作用截面的方法,并通过Monte Carlo模拟,研究了其可行性．假定将一台类似于KASCADE的强子量能器设置在西藏羊八井ARGO探测器的中央,选择大气簇射(AS)轴心落在强子量能器内的事例,用全覆盖ARGO阵列作AS的反符合,用强子量能器测量非伴随的高能强子,即能以已知的效率得到一个直达质子事例样本．--利用这个样本,本工作以1%—2%的精确度还原了Monte Carlo模拟中所使用的p-air非弹性作用截面,从而证明了这一方法的可行性．

A method of determining the p-air inelastic cross section by measuring the directly arrived protons at high altitudes is presented. Its feasibility is studied via a Monte Carlo simulation. Assuming a KASCADE-like hadron calorimeter is set up at the center of the Yangbajing ARGO array, selecting events with air shower （AS） cores hitting the calorimeter, using the full-coverage ARGO array as AS anti-coincidence and using the calorimeter to measure energies of the unaccompanied hadrons, the directly arrived primary protons can be registered with a known efficiency. By the obtained event sample of directly arrived protons the p-air inelastic cross section used in the Monte Carlo can be re-produced with a precision of 1%-2% that demonstrates the feasibility of this approach.