Direct photon-hadron correlation measurement and a way towards photon-triggered jets at RHIC

We report the results of ${\gamma }_{\mathrm{d}\mathrm{i}\mathrm{r}}$ and ${\pi }^0$-hadron azimuthal correlations as a measure of the away-side jet-like correlated yields in central Au+Au and p+p collisions at $\sqrt{s_{{}_{NN}}}$=200 GeV in the STAR experiment. The charged-hadron per-trigger yields at mid-rapidity with respect to high-$p_T$ ${\gamma }_{\mathrm{d}\mathrm{i}\mathrm{r}}$ and ${\pi }^0$ in central Au+Au collisions are compared with p+p collisions. Within uncertainties, the same $z_T$ (~$p_T^{\mathrm{a}\mathrm{s}\mathrm{s}\mathrm{o}\mathrm{c}}$ / $p_T^{\mathrm{t}\mathrm{r}\mathrm{i}\mathrm{g}}$) dependence of the suppression is observed for ${\gamma }_{\mathrm{d}\mathrm{i}\mathrm{r}}$ and ${\pi }^0$ - triggers. The results are compared with energy-loss model predictions. The $\gamma -\mathrm{j}\mathrm{e}\mathrm{t}$ measurements can provide further understanding on the redistribution of in-medium energy loss. Ongoing $\gamma -\mathrm{j}\mathrm{e}\mathrm{t}$ studies in the STAR experiment are also discussed.