文档介绍：Solving the RHIC HBT Puzzle
John G. Cramer (with Gerald A. Miller)
University of Washington
Seattle, Washington
Physics Colloquium
University of Washington
February 28, 2004
February 28, 2005
1
UW Physics Colloquium
Nuclear Matter
(confined)
Hadronic Matter
(confined)
Quark Gluon Plasma
deconfined !
Recipe for Cooking Up a Quark Gluon Plasma
Quantum Chromodynamics (QCD) gives this recipe:
take some matter,
heat it up,
compress it,
and you should get deconfined color matter !
Lattice QCD calculations tell us what pressure and temperature are needed.
February 28, 2005
2
UW Physics Colloquium
RHIC
BRAHMS
PHOBOS
PHENIX
STAR
AGS
TANDEMS
Here’s our cooker: The BNL Relativistic Heavy Ion Collider (RHIC)
Diameter = 1 km
v = c = 186,000 miles/sec
Collision Energy = 200 GeV/A
February 28, 2005
3
UW Physics Colloquium
The RHIC HBT Puzzle
The data from the first four years of RHIC operation paint a confusing picture. Some evidence supports the presence of a QGP in the early stages of Au+Au collisions:
There is evidence that relativistic hydrodynamics works very well in describing the low and medium energy dynamics of the collision, suggesting a fluid-like medium.
There is evidence from elliptic flow data of very high initial pressure and collective behavior.
February 28, 2005
4
UW Physics Colloquium
Kolb and U. Heinz (2002)
Hydrodynamics and Elliptic Flow
Elliptic flow (V2) provides evidence of very large initial pressure. Relativistic hydrodynamics works very well in explaining this and the particle spectra (Examples: p- and p)
J
February 28, 2005
5
UW Physics Colloquium
The RHIC HBT Puzzle
The data from the first four years of RHIC operation paint a confusing picture. Some evidence supports the presence of a QGP in the early stages of Au+Au collisions:
There is evidence that relativistic hydrodynamics works very well in describing the low and medium energy dynamics of the collision, suggesting a fluid-like medium.
There is