  Recent STAR data for the directed flow of protons, antiprotons, and charged
pions obtained within the beam energy scan program are analyzed within the
parton-hadron-string-dynamics (PHSD and HSD) transport models and a 3-fluid
hydrodynamics (3FD) approach. Both versions of the kinetic approach, HSD and
PHSD, are used to clarify the role of partonic degrees of freedom. The PHSD
results, simulating a partonic phase and its coexistence with a hadronic one,
are roughly consistent with data. The hydrodynamic results are obtained for two
equations of state (EoS), a pure hadronic EoS and an EoS with a crossover type
transition. The latter case is favored by the STAR experimental data. Special
attention is paid to the description of antiproton directed flow based on the
balance of $p\bar{p}$ annihilation and the inverse processes for $p\bar{p}$
pair creation from multimeson interactions. Generally, the semiqualitative
agreement between the measured data and the model results supports the idea of
a crossover type of quark-hadron transition that softens the nuclear EoS but
shows no indication of a first-order phase transition.
