Open heavy flavor measurements in $d$$+$Au collisions at PHENIX   experiment
  The heavy quarks produced in the early stage of heavy-ion collisions are very effective probes of the dense partonic medium produced at RHIC. PHENIX has the ability to measure heavy quark production through single electrons in the central arm spectrometers ($|\eta|<0.35$) and single muons in the forward (backward) muon spectrometers ($1.2<|\eta|<2.2$). As these single leptons are from open heavy-flavor meson semi-leptonic decays, initial state cold nuclear matter effects on heavy quark production can be probed by measuring the single leptons in $d$$+$Au collisions. PHENIX have observed a large enhancement of heavy-flavor electrons in $d$$+$Au collisions at mid-rapidity, which indicates strong CNM effects on heavy quark production, in contrast to the suppression observed in Au$+$Au collisions. Measurement of single muons from open heavy flavor in $d$$+$Au collisions at forward (backward) rapidity provide detailed look into rapidity dependent CNM effects as well as the low (high) $x$ parton distribution function within Au nucleus. We discuss recent PHENIX heavy flavor measurements and how they expand our understanding of CNM effects and contribute to the interpretation of other results in heavy-ion collisions. 
Sanghoon Lim (for the PHENIX collaboration)
hep-ex nucl-ex