重离子物理.ppt

Heavy-Ion Physics
Raimond Snellings
XXIII Physics in Collision
Zeuthen, Germany
June 26-28, 2003
Outline
Brief introduction to Heavy-Ion Physics
CERN SPS: a new state of matter
BNL Relativistic Heavy Ion Collider
BRAHMS, PHOBOS, PHENIX and STAR
(a few selected) RHIC results from year 1-3
Summary
Collisions of “Large” nuclei convert beam energy to temperatures above 200 MeV or 1,500,000,000,000 K
~100,000 times higher temperature than the center of our sun.
“Large” pared to mean-free path of produced particles.
QCD Phase Diagram
We normally think of 4 phases:
Plasma
Gas
Liquid
Solid
Phase diagram of water
Phase diagram of nuclear matter
F. Karsch, hep-lat/0106019
QCD on the Lattice
Z. Fodor and . Katz, hep-lat/01060002
Schematic Space-Time Diagram of a Heavy Ion Collision
space
time
Schematic Time Evolution
e
g
Hard Scattering
Au
Au
 Expansion -----------
Hadronization
f
Freeze-out
jet
J/Y
QGP?
Thermalization?
g
e
p
K
p
L
p
CERN SPS: A New State of Matter?
J/Y suppression indication of deconfinement?
Strangeness enhancement
Melting of the r
NA50
Are hadronic scenarios ruled out? Co-mover absorption? canonical suppression?
SPS, NA49: Indications of a Phase Transition at ≈ 30 GeV ?
A New Era for Heavy Ion Physics: The Relativistic Heavy Ion Collider at BNL
km circumference
Two independent rings
120 bunches/ring
106 ns crossing time
Capable of colliding ~any nuclear species on ~any other species
Energy:
200 GeV for Au-Au(per N-N collision)
500 GeV for p-p
Luminosity
Au-Au: 2 x 1026 cm-2 s-1
p-p : 2 x 1032 cm-2 s-1 (polarized)
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