Overview of the Future Programs at JLab and EIC
Jian-Wei Qiu · 2017
² Massless, yet, responsible for nearly all visible mass ² Carry color charge, responsible for color confinement and strong force but, also for asymptotic freedom, as well as the abundance of glue The next QCD frontier q Understanding the glue that binds us all -the Next QCD Frontier!Without gluons, there would be NO nucleons, NO atomic nuclei… NO visible world!JLAB12 EIC Unprecedented Intellectual Challenge!q Facts: q The challenge: How to probe the quark-gluon dynamics, quantify the hadron structure, study the emergence of hadrons, …, if we cannot see quarks and gluons?² We measure/detect leptons and hadrons ² No modern detector has been able to see quarks and gluons in isolation!q Answer to the challenge: Theory advances: QCD factorization -matching the quarks/gluons to hadrons with controllable approximations!Quarks -Need the probe to "see" their existence, … Gluons -Varying the probe's resolution to "see" their effect, … Jets -Footprints of energetic quarks and gluons Energy, luminosity and measurement -Unprecedented resolution, event rates, and precision probes, especially EM probes, … Experimental breakthroughs: How to answer the "big" questions? q How does QCD generate the nucleon mass?Input q Hadron mass from Lattice QCD calculation: "… The vast majority of the nucleon's mass is due to quantum fluctuations of quark-antiquark pairs, the gluons, and the energy associated with quarks moving around at close to the speed of light.…" The 2015 Long Range Plan for Nuclear Science How does QCD generate this?The role of quarks vs that of gluons?If we do not understand proton mass, we do not understand QCD q Three-pronged approach to explore the origin of hadron mass https://phys.cst.temple.edu/meziani/proton-mass-workshop-2016/² Lattice QCD ² Mass decomposition -roles of the constituents ² Model calculation -approximated analytical approach How to answer the "big" questions? q Three-pronged approach to explore the origin of hadron mass ² Lattice QCD ² Mass decomposition -roles of the constituents ² Model calculation -approximated analytical approach How to answer the "big" questions? http://www.ectstar.eu/node/2218How to answer the "big" questions? q How does QCD generate the nucleon mass?"… The vast majority of the nucleon's mass is due to quantum fluctuations of quark-antiquark pairs, the gluons, and the energy associated with quarks moving around at close to the speed of light.…"