| Budget Amount *help |
¥15,200,000 (Direct Cost: ¥15,200,000)
Fiscal Year 2000: ¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1999: ¥9,500,000 (Direct Cost: ¥9,500,000)
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| Research Abstract |
In the summer of 2000, collisions between Au nuclei were realized at RHIC, and experimental studies have started. This project aims to confirm the realization of quark gluon plasma (QGP), and to study the properties of QGP, in the PHENIX experiment at RHIC. Primary device was a electro-magnetic calorimeter, in order to measure photons emitted from the collisions between 65 AGeV Au nuclei. With photon measurements, neutral pion yield and spectra would be determined and ultimate goal was to deduce single-photon yield. Analysis frame was constructed, which consists of PC's connected via high-speed network and RAID disks.
Neutral pions with high pT are mainly produced as a residue of jets which are produced with the scattering between partons. Jet will suffer large energy loss due to strong interactions when it passes through the matter at high temperature in the initial stage of collisions. The result provided the first evidence of the jet energy-loss.
Single photon is a probe of QGP, which directly provides information from the QGP. Large photon yield is predicted in the theory, which assumes fast thermalisation due to gluon contributions. Large enhancement in the photon yield was not observed in this study, which places strong restriction to the models.
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