  Azimuthal angle (Delta phi) correlations are presented for a broad range of
transverse momentum (0.4 < pT < 10 GeV/c) and centrality (0-92%) selections for
charged hadrons from di-jets in Au+Au collisions at sqrt(s_NN) = 200 GeV. With
increasing pT, the away-side Delta phi distribution evolves from a broad and
relatively flat shape to a concave shape, then to a convex shape. Comparisons
to p+p data suggest that the away-side distribution can be divided into a
partially suppressed head region centered at Delta phi ~ \pi, and an enhanced
shoulder region centered at Delta phi ~ \pi \pm 1:1. The pT spectrum for the
associated hadrons in the head region softens toward central collisions. The
spectral slope for the shoulder region is independent of centrality and trigger
pT . The properties of the near-side distributions are also modified relative
to those in p + p collisions, reflected by the broadening of the jet shape in
Delta phi and Delta eta, and an enhancement of the per-trigger yield. However,
these modifications seem to be limited to pT < 4 GeV/c, above which both the
dihadron pair shape and per-trigger yield become similar to p + p collisions.
These observations suggest that both the away- and near-side distributions
contain a jet fragmentation component which dominates for pT \ge 5GeV and a
medium-induced component which is important for pT \le 4 GeV/c. We also
quantify the role of jets at intermediate and low pT through the yield of
jet-induced pairs in comparison to binary scaled p + p pair yield. The yield of
jet-induced pairs is suppressed at high pair proxy energy (sum of the pT
magnitudes of the two hadrons) and is enhanced at low pair proxy energy. The
former is consistent with jet quenching; the latter is consistent with the
enhancement of soft hadron pairs due to transport of lost energy to lower pT.
