“数理论坛”第13期： Calories for quarks: the origin of visible mass in this Universe

报告人： Craig D. Roberts

报告人简介：Craig D. Roberts教授是强子物理方面的国际著名理论物理学家。现为美国阿贡国立实验室资深物理学家和理论部领导。Craig D. Roberts教授曾获得中国教育部杰出教授、芝加哥大学/阿贡实验室杰出贡献奖、Helmholtz国际学者奖等奖项，为国际多所大学的客座和访问教授，并任Physical Review C、 Few Body Systems 等国际杂志的编委。Craig D. Roberts教授在国际期刊上已发表论文160余篇，被引用次数1万多次， h-指数为60。

报告时间： 2015年 11 月 19日 下午 2：30  

报告地点：基础楼二楼学术报告厅

摘要：

The 2013 Nobel Prize in Physics was awarded to Higgs and Englert following discovery of the Higgs boson at the Large Hadron Collider. With this discovery the Standard Model of Particle Physics became complete. Its formulation and verification are a remarkable story. However, the most important chapter is the least understood. Quantum Chromodynamics (QCD) is that part of the Standard Model which is supposed to describe all of nuclear physics and yet, almost fifty years after the discovery of quarks, we are only just beginning to understand how QCD builds the basic bricks for nuclei: pions, neutrons, protons. Critically, the Higgs boson is often said to give mass to everything. However, that is wrong. It only gives mass to some very simple particles, accounting for only one or two percent of the mass of more complex objects. The vast majority of mass comes from the energy needed to hold quarks together inside nuclei. I will explain this remarkable emergent phenomenon, contained fundamentally in Nambu's share of the 2008 Nobel Prize, and discuss its connection with the peculiar feature of confinement in QCD, viz. the fact that quarks are forever imprisoned, never reaching the freedom of a particle detector; and show how contemporary and future terrestrial experiments can help complete the book on the Standard Model.

随着Higgs粒子的发现，粒子物理的标准模型的基本结构已经完成。作为粒子物理标准模型的重要组成-量子色动力学（QCD）可以描述所有核物理及相关物理。但是发现夸克之后已经近50年时间，我们还只是开始理解QCD如何由夸克构建原子核的基石-pion介子、质子和中子。一种值得批判的观点认为Higgs粒子给所有粒子以质量，但实际上，这种机制只是提供了一些简单粒子的质量，对于更复杂的系统，他只是提供了1-2%的质量。主要的质量来源于将夸克束缚到一起的能量，其机制由Nambu发现，并分享了2008年诺贝尔奖。本报告会解释这一重要现象，讨论它与QCD中色禁闭的联系，并表明当前和将来的实验如何帮助我们完善标准模型。