An introduction to PYTHIA 8.2

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract The Pythia program is a standard tool for the generation of events in high-energy collisions, comprising a coherent set of physics models for the evolution from a few-body hard process to a complex multiparticle final state. It contains a library of hard processes, models for initial- and final-state parton showers, matching and merging methods between hard processes and parton showers, multiparton interactions, beam remnants, string fragmentation and particle decays. It also has a set of uti... Title of program: Pythia 8.2 Catalogue Id: ACTU_v4_0 Nature of problem High-energy collisions between elementary particles normally give rise to complex final states, with large multiplicities of hadrons, leptons, photons and neutrinos. The relation between these final states and the underlying physics description is not a simple one, for two main reasons. Firstly, we do not even in principle have a complete understanding of the physics. Secondly, any analytical approach is made intractable by the large multiplicities. Versions of this program held in the CPC repository in Mendeley Data ACTU_v1_0; PYTHIA 5.7 AND JETSET 7.4; 10.1016/0010-4655(94)90132-5 ACTU_v2_0; PYTHIA V6.154; 10.1016/S0010-4655(00)00236-8 ACTU_v2_1; PYTHIA Version number: 6.420; 10.1016/j.cpc.2009.08.008 ACTU_v3_0; Pythia 8.1; 10.1016/j.cpc.2008.01.036 ACTU_v4_0; Pythia 8.2; 10.1016/j.cpc.2015.01.024

本程序源自贝尔法斯特女王大学馆藏的CPC程序库（1969-2018年）。
摘要：Pythia程序是高能碰撞事件生成的标准工具，集成了一套连贯统一的物理模型，用于描述从少体硬散射过程（hard process）到复杂多粒子末态（multiparticle final state）的演化。该程序内置硬散射过程库、初态与末态部分子喷注（parton shower）模型、硬散射过程与部分子喷注间的匹配与合并方法、多部分子相互作用（multiparton interactions）、束流残留物（beam remnants）、弦碎裂（string fragmentation）以及粒子衰变模型。此外还包含一套通用工具（原文截断）。
程序名称：Pythia 8.2
目录编号：ACTU_v4_0
问题本质：高能粒子间的碰撞通常会产生包含大量强子、轻子、光子与中微子的复杂末态。此类末态与底层物理描述之间的关联并非简单直接，主要源于两点原因：其一，即便在理论层面，人类也尚未完全掌握相关物理规律；其二，末态粒子多重数庞大，使得任何解析方法都变得难以处理。
Mendeley数据中CPC程序库馆藏的该程序版本：
1. ACTU_v1_0；PYTHIA 5.7 与 JETSET 7.4；DOI: 10.1016/0010-4655(94)90132-5
2. ACTU_v2_0；PYTHIA V6.154；DOI: 10.1016/S0010-4655(00)00236-8
3. ACTU_v2_1；PYTHIA 版本号：6.420；DOI: 10.1016/j.cpc.2009.08.008
4. ACTU_v3_0；Pythia 8.1；DOI: 10.1016/j.cpc.2008.01.036
5. ACTU_v4_0；Pythia 8.2；DOI: 10.1016/j.cpc.2015.01.024