Nucleon internal structure: a new set of quark, gluon momentum, angular momentum operators and parton distribution functions
It is unavoidable to deal with the quark and gluon momentum and angular momentum contributions to the nucleon momentum and spin in the study of nucleon internal structure. However we never have the quark and gluon momentum, orbital angular momentum and gluon spin operators which satisfy both the gauge invariance and the canonical momentum and angular momentum commutation relation. The conflicts between the gauge invariance and canonical quantization requirement of these operators are discussed. A new set of quark and gluon momentum, orbital angular momentum and spin operators, which satisfy both the gauge invariance and canonical momentum and angular momentum commutation relation, are proposed. The key point to achieve such a proper decomposition is to separate the gauge field into the pure gauge and the gauge covariant parts. The same conflicts also exist in QED and quantum mechanics and have been solved in the same manner. The impacts of this new decomposition to the nucleon internal structure are discussed.
nucleon internal structure quark-gluon momentum and angular momentum canonical commutation relation gauge invariance
WANG Fan CHEN Xiang-Song L(U) Xiao-Fu SUN Wei-Min T.Goldman
Department of Physics,Nanjing University,Nanjing 210093,China;Joint Institute of Particle Nuclear Ph Department of Physics,Sichuan University,Chengdu 610064,China Theoretical Division,Los Alamos National Laboratory,Los Alamos,NM 87545,USA
国际会议
The 12th International Workshop on the Physics of Ezcited Nucleon NSTAR2009(2009激发态核子物理研讨会)
北京
英文
1197-1204
2009-04-19（万方平台首次上网日期，不代表论文的发表时间）