Abstract :
We examine the Q2 evolution of gluon polarization in polarized nucleons. As is well known, the evolution of αsΔG(Q2) is negligible for typical momentum transfer variations found in experimental deep inelastic scattering. As αs increases, however, the leading non-zero term in the evolution equation for the singlet first moment reduces the magnitude of the gluon spin. At low Q2 the term αsΔG can vanish, and ultimately become negative. Thus, low energy model calculations yielding negative ΔG are not necessarily in conflict with experimental evidence for positive gluon polarization at high Q2.
