Transverse spin sum rule of the proton

Abstract

The transversely-polarized state of a proton with arbitrary momentum is not an eigenstate of transverse angular momentum operator. The latter does not commute with the QCD Hamiltonian. However, the expectation value of the transverse angular momentum in the state is well-defined and grows proportionally to the energy of the particle. The transverse spin content of the proton is analyzed in terms of the QCD angular momentum structure. In particular, we reconfirm that the generalized parton distributions $H+E$ provide transverse orbital angular momentum densities of quarks and gluons in the infinite momentum frame.

5 pages

References in corpus (1)

• Proton spin after 30 years: what we know and what we don't?

Cited by in corpus (5)

• Generalized parton distributions through universal moment parameterization: zero skewness case
• Proton spin after 30 years: what we know and what we don't?
• Mapping the transverse spin sum rule in position space
• Energy-momentum tensor form factors and spin density distribution in the nucleon calculated in a quantized Skyrme model with vector mesons
• Transverse energy-momentum tensor distributions in polarized nucleons