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Beam Energy Scan Program at RHIC. STAR & PHENIX. Bedanga Mohanty NISER, Bhubaneswar. Outline: Motivation Experimental Results Phase – II of BES Program Summary. Motivation. NICA. - PowerPoint PPT Presentation
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Beam Energy Scan Program at RHIC
Bedanga MohantyNISER, Bhubaneswar
Outline:
Motivation Experimental Results Phase – II of BES Program Summary
STAR &PHENIX
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Motivation
Establish phase diagram of strongly interacting matter to the level of phase diagram of water (Electro-magnetic interactions)
NICA
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RHIC BESVarying beam energy in HI collisions varies Temperature and Baryon Chemical Potential
Motivation: Search for signals of phase boundarySearch for signals for critical point
Rapidityp T
(GeV
/c)
Au+Au 7.7 GeV Au+Au 200 GeV
p p
p p
Collider
P. Braun-Munzinger, J. Stachel Nature 448:302-309,2007
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Data SetBeam Energy
(GeV)PHENIX STAR Year
5.0 ✔ 2012 (Test Run)7.7 ✔ ✔ 20109.2 ✔ 2008 (Test Run)11.5 ✔ 201019.6 ✔ ✔ 201127 ✔ ✔ 201139 ✔ ✔ 2010
62.4 ✔ ✔ 2010200 ✔ ✔ 2010
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Energy and Multiplicity Density
A factor of ~ 4 variation in eBJ yet no significant change in centrality dependence of particle density at midrapidity
Jeffery T. Mitchell, QM2012
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Temperature and baryon density
Temperature: 140 – 160 MeV and mB : 20 – 400 MeVTemperature dependence on baryon chemical potential
Lokesh Kumar, QM2012Sabita Das, QM2012
STAR Preliminary
0-5% centrality
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QCD Phase Diagram - RHIC BES
J. Randrup & J. Cleymans,Phys. Rev. C 74 (2006) 047901
206 5851120 420
57.719.639
√sNN (GeV)
mB (MeV)
Region of high net-baryon density
100
120
140
160
T (M
eV)
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Partonic vs. Hadronic Interactions
Number of Constituent Quark scaling broken at/below 11.5 GeV
Daniel Cebra, QM2012Shu Shi, QM2012
STAR PreliminarySTAR Preliminary
v2
mT - m (GeV/c2)
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Role of f-meson
v2 f << v2 other hadrons absence of partonic phaseMd. Nasim, BM, Nu Xu
fN elastic scattering ~ 8 mbfM elastic scattering ~ 5 mb
AMPT: PRC 72 (2005) 064901
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Partonic vs. Hadronic Interactions
Strange baryon to meson ratio, falls off common trend Dominance of hadronic interactions ?
Xiaoping Zhang, QM2012
STAR Preliminary
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Partonic vs. Hadronic InteractionsSTAR Preliminary
Dynamical charge correlations vanishes at/below 11.5 GeV
Gang Wang QM2012
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Partonic and Hadronic Interactions
Nuclear modification factor > unity at high pT at 11.5 GeV
Xiaoping Zhang, QM2012Lokesh Kumar, QM2012
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QCD Phase Diagram
“Scale of QCD phase diagram” Science, 332, 1525 (2011)
200
3962.4
11.57.7
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Search For Critical Point and Order Of Phase Transition
T > TC T~TC T < TC
Distributions become non Gaussian
Correlation length diverges
Susceptibilities diverges
Long wavelength fluctuations or low momentum fluctuations important
L.P. Csernai, D. Rohrich PLB 458, 454 (1999).H. Stoecker, NP A750, 121 (2005).
J. Brachmann et al., PRC 61, 24909 (2000).
Rapidity dependence of v1
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Search for signals of 1st order Phase transition
Proton v1 slope changes sign versus rapidityBecomes positive below 11.5 GeV
Yadav Pandit, QM2012
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Net-proton number fluctuations
Deviations from Poisson expectation observed for central collisions
S ~
Xiaofeng Luo, QM2012Physical Review Letters 105 (2010) 022302
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Net-Charge Number Fluctuations
D. Mishra, P. K. Netrakanti ..PHENIXJeffery T. Mitchell, QM2012
STAR: D. MacDonald, N. Shaoo QM2012
Deviations from HRG expectation observed for central collisions
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Beam Energy Scan Phase - II
Higher statistics data at lower beam energies + 15 GeV (2013)
A. Fedotov, W. Fischer, private discussions, 2012.
STAR BUR - 2013
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Beam Energy Scan Phase - II1% Au target
- Annular 1% gold target inside the STAR beam pipe - 2m away from the center of STAR- Data taking concurrently with collider mode at beginning of each fill
mB reach extended to ~ 750 MeV
STAR BUR - 2013
Summary
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Wealth of information available from RHIC BES data
Towards experimentally establishing the QCD Phase diagram
S. Gupta, QM2011
206 5851120 420
2.557.719.639
775
√sNN (GeV)
mB (MeV)
QG
P p
rope
rties
BE
S p
hase
-I
Test
Run
Fixe
d Ta
rget
BE
S p
hase
-II
Explore QCD Diagram
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List of presentations related to BES Program at RHIC
Baryon Number Fluctuations in RHIC Beam Energy Scan Presenter: Dr. LUO, Xiaofeng (Central China Normal University)
Beam Energy Scan on Hypertriton Production and Lifetime Measurement at STARPresenter: Ms. ZHU, Yuhui (Shanghai Institute of Applied Physics, CAS)
Strangeness production in heavy-ion collisionsPresenter: ZHU, Xianglei (Tsinghua University)
Partonic collectivity at RHIC Presenter: Dr. MASUI, Hiroshi (LBNL)
Di-electron Production in Heavy-ion CollisionsPresenter: Prof. ZHANG, Yifei (University of Science and Technology of China)
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