  The PHENIX experiment has performed a systematic study of identified
charged-hadron ($\pi^\pm$, $K^\pm$, $p$, $\bar{p}$) production at midrapidity
in $p$$+$Al, $^3$He$+$Au, Cu$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV and
U$+$U collisions at $\sqrt{s_{_{NN}}}=193$ GeV. Identified charged-hadron
invariant transverse-momentum ($p_T$) and transverse-mass ($m_T$) spectra are
presented and interpreted in terms of radially expanding thermalized systems.
The particle ratios of $K/\pi$ and $p/\pi$ have been measured in different
centrality ranges of large (Cu$+$Au, U$+$U) and small ($p$$+$Al, $^3$He$+$Au)
collision systems. The values of $K/\pi$ ratios measured in all considered
collision systems were found to be consistent with those measured in $p$$+$$p$
collisions. However the values of $p/\pi$ ratios measured in large collision
systems reach the values of $\approx0.6$, which is $\approx2$ times larger than
in $p$$+$$p$ collisions. These results can be qualitatively understood in terms
of the baryon enhancement expected from hadronization by recombination.
Identified charged-hadron nuclear-modification factors ($R_{AB}$) are also
presented. Enhancement of proton $R_{AB}$ values over meson $R_{AB}$ values was
observed in central $^3$He$+$Au, Cu$+$Au, and U$+$U collisions. The proton
$R_{AB}$ values measured in $p$$+$Al collision system were found to be
consistent with $R_{AB}$ values of $\phi$, $\pi^\pm$, $K^\pm$, and $\pi^0$
mesons, which may indicate that the size of the system produced in $p$$+$Al
collisions is too small for recombination to cause a noticeable increase in
proton production.
