EVOLUTION OF GLUON SPIN IN THE NUCLEON

We examine the Q(2) evolution of gluon polarization in polarized nucle ons. As is well known, the evolution of a(s) Delta G(Q(2)) is negligib le for typical momentum transfer variations found in experimental deep inelastic scattering. As alpha(s) increases, however, the leading non -zero term in the evolution equation for the singlet first moment redu ces the magnitude of the gluon spin. At low Q(2) the term alpha(s) Del ta G can vanish, and ultimately become negative. Thus, low energy mode l calculations yielding negative Delta G are not necessarily in confli ct with experimental evidence for positive gluon polarization at high Q(2). (C) 1997 Elsevier Science B.V.