2007 Fiscal Year Final Research Report Summary
Study of nonperturbative correlations inthe quark gluon plasma
| Project/Area Number |
17540255
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Osaka University |
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Principal Investigator |
ASAKAWA Masayuki Osaka University, Graduate School of Science, Professor (50283453)
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| Project Period (FY) |
2005 – 2007
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| Keywords | hiah energy nucleus collision / finite temperature field theory / magnetic instability / phase transition / viscosities / quantumchromo dynamics |
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| Research Abstract |
1 It has been known that hydrodynamical calculations which assume zero viscosities can explain observables at RHIC reasonably well. At RHIC, it has been also known that thermalization is unexpectedly fast. This has been explained by a mechanism in which color magnetic field caused and amplified by Weibel instability thermalizes partons. We proposed a mechanism that these two are explained in a unified way. Namely, the anomalous transport of partons caused by this color magnetic field dominates the usual transport by two body collisions and as a result the system behaves like an ideal field. The viscosity caused by this mechanism is anomalous in that it is not constant as a function of shear, but decreases.
2 The shear and bulk viscosities in equilibrium states have been measured recently by two groups by measuring the slope of the spectral functions of the energy momentum tensors at the origin. They used lattice gauge theory to calculate the spectral functions. However, there still remain several difficulties which originate from the analytic continuation from the imaginary time calculation on the lattice to the real time, and as a result it is not yet uncertain whether the value of the shear viscosity in the quark-gluon plasma is close to that predicted in the AdS/CFT correspondence or the bulk viscosity increases near the phase transition. In order to circumvent these difficulties, we developed a new method to calculate the viscosities, which does not require the analytic continuation, and carried out a preliminary research on the method.
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