  Two-particle angular correlations have long been used as an observable for
measuring the initial-state partonic transverse momentum $k_T$. Sensitivity to
this small transverse momentum scale allows nonperturbative transverse momentum
dependent effects to be probed in high $p_T$ dihadron and direct photon-hadron
correlations. The observable $p_{out}$, the out-of-plane transverse momentum
component from a near-side $\pi^0$ or direct photon, is sensitive to
initial-state $k_T$ and final-state fragmentation transverse momentum $j_T$ and
thus can probe nonperturbative transverse-momentum-dependent effects. In the
transverse-momentum-dependent framework, nearly back-to-back particle
production in $p$+$p$ collisions with a measured final-state hadron has been
predicted to break factorization due to the possibility of gluon exchanges with
colored remnants in the initial and final states. For this reason, the
interacting partons are predicted to be correlated; however, there is so far no
quantitative prediction for the magnitude of such effects. In this talk, recent
measurements of dihadron and direct-photon hadron correlations in $p$+$p$
collisions at $\sqrt{s}$=510 GeV at the PHENIX experiment will be presented.
