Henrik Tydesjö May 5 2004 O UTLINE - The Quark Gluon Plasma - The Relativistic Heavy Ion Collider...
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Transcript of Henrik Tydesjö May 5 2004 O UTLINE - The Quark Gluon Plasma - The Relativistic Heavy Ion Collider...
Henrik Tydesjö May 5 2004
OUTLINEOUTLINE- The Quark Gluon Plasma
- The Relativistic Heavy Ion Collider (RHIC)The PHENIX Experiment
- QGP SignalsEvent-by-Event Net-Charge Fluctuations
SimulationsPHENIX Analysis
Phase Diagram of Nuclear MatterPhase Diagram of Nuclear Matter
Early Universe
HadronGas
QGP
Neutron StarsNeutron Stars??????
Ultra-RelativisticHeavy-Ion Collisions
???
Henrik Tydesjö May 5 2004
QUARK GLUON PLASMAQUARK GLUON PLASMA
DECONFINEMENTDECONFINEMENT
PHASETRANSITION
Henrik Tydesjö May 5 2004
QUARK GLUON PLASMAQUARK GLUON PLASMA
CHIRAL SYMMETRY
RESTORATION
CHIRAL SYMMETRY
RESTORATION
Quark Masses 0
Henrik Tydesjö May 5 2004
Relativistic Heavy Ion Collider (RHIC)Relativistic Heavy Ion Collider (RHIC)Au+Au Collisions 100 AGeV per
beam
Henrik Tydesjö May 5 2004
~ 460 Members
57 Institutions
12 Countries
~ 460 Members
57 Institutions
12 Countries
Collaboration
Henrik Tydesjö May 5 2004
Central Magnet
Beam-BeamCounters
Muon ArmSpectrometers Central Arm
Spectrometers
Henrik Tydesjö May 5 2004
Central Arms
Pad Chambers
Charged ParticleTracking
Electron, Photon Detection
Hadron Identification
Henrik Tydesjö May 5 2004
Pad Chambers- Multi-Wire Proportional Chambers
- Fine Granularity Pixel Pad Readout
- Provide Space Points for Track Recognition
Henrik Tydesjö May 5 2004
Pad Chambers- Multi-Wire Proportional Chambers
- Fine Granularity Pixel Pad Readout
- Provide Space Points for Track Recognition
- 172,800 Readout Channels
- Chip-On-Board Technique
Readout Cards (ROCS) Placed on the Chambers
- Data Transfer via Fiber Optic Links
Readout Card (ROC)
Henrik Tydesjö May 5 2004
Event Display
CentralAu+Au
Collision
~ 400tracks in
central arms
Henrik Tydesjö May 5 2004
Henrik Tydesjö May 5 2004
QGP SIGNALS- Jet Quenching
- J/ Suppression
- Strangeness enhancement
- Thermal photon production
- Light vector meson decays
- Fluctuation probes
- Jet Quenching
- J/ Suppression
- Strangeness enhancement
- Thermal photon production
- Light vector meson decays
- Fluctuation probesHenrik Tydesjö May 5 2004
QGP SIGNALS
Henrik Tydesjö May 5 2004
QGP SIGNALS- Jet Quenching
- J/ Suppression
- Strangeness enhancement
- Thermal photon production
- Light vector meson decays
- Fluctuation probes
NET CHARGE FLUCTUATIONS
Event-by-EventNet Charge Fluctuations
in Local Regions of Phase Space
Decrease of Fluctuationsproposed as a signal for the QGP
Predictions range up to an 80% reduction
Henrik Tydesjö May 5 2004
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
charge more evenly spread in plasma,due to the fractional charges of quarks
HADRON GAS QGP
NET CHARGE FLUCTUATIONS
Charge q in each event:
nnq
Variance of q:
22)( qqqV
Random Particle Emission:
chnnnqV )(
chn
qVqv
)()(
Normalized Variance:
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
Henrik Tydesjö May 5 2004
Hadron Gas :1)( qv
QGP (assuming thermal distributions) :
28.018
5
9
1
9
4
2
1)(
2
1)( 22
du qqqv
Hadronized QGP (from theorist calculation) :19.0)( qv
BUT HEY!!! WAIT A MINUTE!!!Wouldn’t this depend very much on acceptance?
NET CHARGE FLUCTUATIONS
SIMULATION
Charge is globally conservedapQv 1)(
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
SIMULATION
Efficiency Dependenceea ppQv 1)(
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
SIMULATION
Uncorrelated Background Contribution)1(1)( bkga fpQv
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
SIMULATION
Decays of Neutral Resonances (e.g. , )introduce positive correlations between n+ and n–
width = 30º
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
SIMULATION
Decays of Neutral Resonances
fres = 0.3
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
SIMULATION
Simple QGP model:yprobabilit equal with hadronize ,,, nscombinatioquark ddudduuu
producing 2 or 3 pions, separated in azimuth (Gaussian width=10º)
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
RHIC 1st run period
GeVsNN 130
~ 500 000 events
|zvertex| < 17 cm
pT > 200 MeV/c
Henrik Tydesjö May 5 2004
b
Centrality of Collision
Impact parameter, b < 10 fm
Henrik Tydesjö May 5 2004
~
NET CHARGE FLUCTUATIONS
BBCs used for triggering
corresponding to 92% of inelastic cross-section
Centrality classes
determined from BBC+ZDC information
0-5%5-10%
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
pT , of positive and negative particles
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
Reduction not as large as predicted for QGPConsistent with resonance gas
Global ChargeConservation
10% most central events
Henrik Tydesjö May 5 2004
NET CHARGE FLUCTUATIONS
Fluctuations independent of centrality
)(019.0)(007.0965.0)( syststatQv 10% most central events:
Henrik Tydesjö May 5 2004
SUMMARYSUMMARY- An introduction was given to: Quark Gluon Plasma Relativistic Heavy-Ion Collider (RHIC) PHENIX Experiment
- The behavior of Net-Charge Fluctuations in different scenarios was described in simulations
- Results on Net-Charge Fluctuations in PHENIX was presented: Fluctuation result below pure global charge conservation Reduction not as drastic as predicted for a QGP Consistent with resonance gas prediction
Henrik Tydesjö May 5 2004