摘要
Nowadays,people know that proton has spin 1/2,it is not an elementary particle,and it consists of quarks and gluon,due to the success of quark model and quantum chromodynamics(QCD).The QCD is based on the idea of“gauge symmetry”,i.e.QCD Lagrangian and observables are invariant under the gauge transformation for the quark field and the gluon field.The question is,can we understand proton spin in terms of quarks and gluons?
基金
National Natural Science Foundation of China(11575254)
Chinese Academy of Sciences President’s International Fellowship Initiative(2018VMA0030,2018PM0028)。
