A part of this work (high-
prompt photon production)
owes to the study by Professor H. En'yo.
I would like
to thank Professor J. Moss for suggesting me the study of open heavy
quark productions.
I am grateful to Professors R.L. Jaffe and J. Soffer for
the discussions related to this work.
I am also grateful to the members of PHENIX Collaboration,
especially Professors S. Nagamiya, M. Tannenbaum, W. Kinnison,
S. Aronson and M. Brooks.
Finally I would like to thank Prof. A. Masaike
who gave me the chance to talk at this conference.
This work has been done within a frame work of RIKEN-BNL collaboration for RHIC/Spin project. This work has been supported by Special Post Doctoral Research Program at RIKEN.