Single particles and jets in deeply inelastic scattering at low x are measu
red with the Hl detector in the region away from the current jet and toward
s the proton remnant, known as the forward region. Hadronic final stale mea
surements in this region are expected to be particularly sensitive to QCD e
volution effects. Jet cross sections are presented as a function of Bjorken
-x for forward jets produced with a polar angle to the proton direction, th
eta(jet), in the range 7 degrees < theta(jet) < 20 degrees. Azimuthal corre
lations are studied between the forward jet and the scattered lepton. Charg
ed and neutral single particle production in the forward region are measure
d as a function of Bjorken-x, in the range 5 degrees < theta < 25 degrees,
for particle transverse momenta larger than 1 GeV. QCD based Monte Carlo pr
edictions and analytical calculations based on BFKL, CCFM and DGLAP evoluti
on are compared to the data. Predictions based on the DGLAP approach fail t
o describe the data, except for those which allow for a resolved photon con
tribution. (C) 1999 Elsevier Science B.V.