  We present a precise measurement of the cross section, proton and $\rm ^3He$
analyzing powers, and spin correlation coefficient $C_{y,y}$ for $p$-$\rm ^3He$
elastic scattering near 65 MeV, and a comparison with rigorous four-nucleon
scattering calculations based on realistic nuclear potentials and a model with
$\Delta$-isobar excitation. Clear discrepancies are seen in some of the
measured observables in the regime around the cross section minimum.
Theoretical predictions using scaling relations between the calculated cross
section and the $\rm ^3 He$ binding energy are not successful in reproducing
the data. Large sensitivity to the $NN$ potentials and rather small
$\Delta$-isobar effects in the calculated cross section are noticed as
different features from those in the deuteron-proton elastic scattering. The
results obtained above indicate that $p$-$\rm ^3He$ scattering at intermediate
energies is an excellent tool to explore nuclear interactions not accessible by
three-nucleon scattering.
