Tensor-polarized parton density in the $N\to \Delta$ transition

Abstract

The generalized parton distributions for transitions between baryon states with different masses have a forward limit in which they behave as parton densities (light-front momentum transfer ${\Delta }^{+},{\Delta }_T=0$, energy transfer ${\Delta }^{-}\ne 0$). These "transition parton densities'' can realize spin/isospin quantum numbers not accessible in the ground-state nucleon. The $N\to \Delta$ transition gives rise to a new parton density proportional to the $1/2\to 3/2$ spin transition tensor. Its properties are derived, and its magnitude is estimated in the chiral quark-soliton model based on the large-$N_c$ limit of QCD.

Comments: 7 pages, 1 figure