We investigate the statistical properties of a randomly branched
3--functional N--link polymer chain without excluded volume, whose one point
is fixed at the distance d from the impenetrable surface in a 3--dimensional
space. Exactly solving the Dyson-type equation for the partition function
Z(N,d)=N−θeγN in 3D, we find the "surface" critical
exponent θ=5/2, as well as the density profiles of 3--functional units
and of dead ends. Our approach enables to compute also the pairwise correlation
function of a randomly branched polymer in a 3D semi-space.Comment: 15 pages 7 figsures; section VII is slightly reorganized, discussion
is revise