Images of the origin of mass

Craig D Roberts

doi:10.1051/epjconf/20147301016

Abstract

Recent years have brought considerable progress with studies of the bound-state problem in continuum QCD. A small part of that made with Dyson Schwinger equations is highlighted herein. Topics covered include: opportunities provided by precision experimental studies of the (far) valence region; and capitalising upon new data on hadron elastic and transition form factors.

Highlights

Topics covered include: opportunities provided by precision experimental studies of the valence region; and capitalising upon new data on hadron elastic and transition form factors
The international hadron physics programme for the coming decade can be viewed within the context of three overarching challenges: discover the meaning of confinement; determine its connection with dynamical chiral symmetry breaking (DCSB); and elucidate the signals of these phenomena in observables, so that experiment and theory together can map the nonperturbative behaviour of the strongly interacting piece of the Standard Model
The community is exploiting opportunities provided by precision experimental studies of the valence region, and producing theoretical computations of distribution-functions and -amplitudes with a traceable connection to QCD [1, 2]

Summary

Introduction

The international hadron physics programme for the coming decade can be viewed within the context of three overarching challenges: discover the meaning of confinement; determine its connection with dynamical chiral symmetry breaking (DCSB); and elucidate the signals of these phenomena in observables, so that experiment and theory together can map the nonperturbative behaviour of the strongly interacting piece of the Standard Model. Such computation is critical because without it, no amount of data can reveal anything about the theory underlying the phenomena of strong interaction physics It is capitalising upon new data on hadron elastic and transition form factors [2,3,4,5], in order to, e.g.: chart the infrared evolution of QCD’s running coupling and dressed-masses; reveal correlations that are key to baryon structure; and expose the facts and fallacies in modern descriptions of hadron structure. [7], which explains that the potential between infinitely-heavy quarks measured in numerical simulations of quenched lattice-regularised QCD – the so-called static potential – is irrelevant to the question of confinement in a universe in which light quarks are ubiquitous It is a basic feature of QCD that light-particle creation and annihilation effects are essentially nonperturbative and it is impossible in principle to compute a quantum mechanical potential between two light quarks [8]. The proton’s mass would remain almost unchanged even if the current-quarks were truly massless

Parton structure of hadrons

Electromagnetic structure of hadrons

Findings

Epilogue