A part of this work (high-
prompt photon production)
owes to the study by Yuji Goto. The drawing for the
Siberian Snake has been provided by Masahiro Okamura.
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.
I would like to thank Professor A. Yokosawa of
STAR Collaboration for providing me information on STAR
detector performance.
Finally I would like to thank Prof. T. Morii
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.