Hadronic interactions: From LHC to Ultra-High Energy Cosmic Rays

解释高能宇宙线数据和解开超高能宇宙线起源之谜，关键取决于描述大气中宇宙线粒子相互作用所需的强子蒙特卡罗模型的有效性。该项目旨在充分利用新的理论方法和现有的和即将出现的加速器数据，进一步开发一种现代强子蒙特卡罗发生器。这种改进的蒙特卡罗生成器的核心是在现有的QGSJET-II模型中实现了对强子和核碰撞的自洽处理，该处理基于与多部分子相互作用相关的非线性相互作用效应的微扰描述。该模型将用相关的加速器数据进行彻底的测试和校准，特别是来自大型强子对撞机的数据。它将被应用于宇宙线引起的大范围空气簇射特征的计算。结果将与Pierre Auger天文台的实验数据进行比较，并将得出关于超高能宇宙线通量的核组成的结论。该项目的跨学科方面有两个方面：第一，将使用现代理论方法和加速器数据来开发用于高能宇宙线研究的可靠工具。其次，发展的模型将在对撞机物理中有广泛的应用，例如关于强子和核相互作用中一般最小偏置碰撞的研究，软和硬衍射，以及多部分子相互作用的研究。

The interpretation of high energy cosmic ray data and the solution of the enigma of the origin of ultra-high energy cosmic rays depend crucially on the validity of hadronic Monte Carlo models which are required for the description of the interactions of cosmic ray particles in the atmosphere. The project is aimed at the further development of a modern hadronic Monte Carlo generator, taking the full advantage of new theoretical approaches and of existing and forthcoming accelerator data. Core element of this improved Monte Carlo generator is the implementation of a self-consistent treatment of hadronic and nuclear collisions, based on the perturbative description of nonlinear interaction effects related to multi-parton interactions, into the existing QGSJET-II model. The model will be thoroughly tested and calibrated with relevant accelerator data, notably, from the Large Hadron Collider. It will be applied to the calculations of characteristics of cosmic ray induced extensive air showers. The results will be compared to experimental data of the Pierre Auger Observatory and conclusions on the nuclear composition of the ultra-high energy cosmic ray flux will be drawn. The interdisciplinary aspect of the project is twofold: First, modern theoretical approaches and accelerator data will be used to develop a reliable tool for high energy cosmic ray studies. Secondly, the developed model will have a vast range of applications in collider physics, e.g. in relation to studies of general minimum bias collisions in hadronic and nuclear interactions, soft and hard diffraction, and multi-parton interactions.