Dimuon Production in Cu+Au Collisions in PHENIX

We study for the first time the open heavy quark and Drell-Yan production in the forward (Cu going) and backward (Au going) directions in asymmetric Cu+Au collision through dimuon measurements at a center of mass energy of $\sqrt{s_{NN}}=200$ GeV. We expect heavy quark production is sensitive to final state parton energy loss in QGP while Drell-Yan is more sensitive to the initial state effects. During the latest 2012 run, the PHENIX experiment at RHIC has collected 5 nb$^{-1}$ Cu+Au collisions data with the new Forward Silicon Vertex Detectors (FVTX). FVTX detectors cover the whole PHENIX muon arm acceptance and significantly improve the physics reach of the muon probe for the QGP study. We present the latest status of dimuon measurements in Cu+Au collisions with the FVTX in the rapidity range of $1.2< |\eta| < 2.4$ in the PHENIX experiment.