2001 Fiscal Year Final Research Report Summary
Experimental study of quark gluon plasma with single photon measurement
| Project/Area Number |
11440075
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HAMAGAKI Hideki Graduate School of Sciences, The University of Tokyo, Associate Professor, 大学院・理学系研究科, 助教授 (90114610)
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| Project Period (FY) |
1999 – 2000
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| Keywords | RHIC / PHENIX / quark gluon plasma / calorimeter / pion / single photon / jet energy loss |
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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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