  $N \rightarrow \Delta$ transitions offer new possibilities for exploring the
isovector component of the QCD quark angular momentum (AM) operator causing the
$J^{u - d}$ flavor asymmetry in the nucleon. We extend the concept of QCD AM to
transitions between baryon states, using light-front densities of the
energy-momentum tensor in transversely localized states. We calculate the $N
\rightarrow \Delta$ transition AM in the $1/N_c$ expansion, connect it with the
$J^{u - d}$ flavor asymmetry in the nucleon, and estimate the values using
lattice QCD results. In the same setup we connect the transition AM to the
transition GPDs sampled in hard exclusive electroproduction processes with $N
\rightarrow \Delta$ transitions, enabling experimental study of the transition
AM.
