Anisotropic Flow in s NN = 200 GeV Cu+Cu and Au+Au collisions at RHIC - PHENIX
Charged Hadron Results from 19.6 GeV Au+Au
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Transcript of Charged Hadron Results from 19.6 GeV Au+Au
QM2008, Jaipur, 09-February-2008 1Daniel Cebra
Charged Hadron Results from 19.6 GeV Au+Au
Daniel CebraUniversity of California, Davis(for the STAR Collaboration)
QM2008, Jaipur, 09-February-2008 2Daniel Cebra
Triggering for the 19.6 GeV dataset
2
ZDC Trigger(147953)
CTB Trigger(27513)
Nch
Coun
ts
The STAR trigger was not optimized for 19.6 GeV Collisions. The correlation betweenZDC and CTB that had been observed in the 130 and 200 GeV data sets was not seen in the lower energy collisions. To approximate a minimum bias trigger, events were selected if they satisfied either a minimum ZDC threshold or a minimum CTB threshold.
Triggering will be a resolvable issue for the future beam energy scan.
QM2008, Jaipur, 09-February-2008 3Daniel Cebra
The STAR 19.6 GeV Au+Au Data Set
3
• One day of running
• 12 data runs
• Total recorded events = 175466
• Events with good vertex = 42412
• 10% centrality events = 5106
QM2008, Jaipur, 09-February-2008 4Daniel Cebra
Centrality Determination
4
The mid-y (||<0.5) charged particle multiplicity is shown on the left for the four RHIC collision energies. The cut lines correspond to percentages of the total minimum bias cross section.
Note the 20 GeV trigger had inefficiencies for collisions in the impact parameter range corresponding to 10-30% and 70-100%
Using a Glauber Model, we estimate that our 0-10% data selection had an average number of participant sof 337.
QM2008, Jaipur, 09-February-2008 5Daniel Cebra
Spectra as a Function of Centrality
STAR PRELIMINARY
Identified Hadron spectra at mid-rapidity are displayed for several centrality selctions.
200 GeV AuAu and pp dataSTAR PRL92, 112301 (2003)
QM2008, Jaipur, 09-February-2008 6Daniel Cebra
Charged Particle Spectra Compared SPS
STAR PRELIMINARY
NA44 PRC66, 044907 (2002) - all NA49 PRC66, 054902 (2002) - pim, kam, and kapNA49 PRC69, 024902 (2004) - protonsNA49 nucl-ex/0512033 - protons and anti-protonsWA98 PRL83, 926 (1999) - pi-zeroWA98 NPA698, 647 (2002) - pimWA98 PRC67, 014906 (2003) - pim and kam
The central mid-rapidity spectra are displayed against the most comparable SPS spectra
QM2008, Jaipur, 09-February-2008 7Daniel Cebra
Correcting the ComparisonsCentrality (Np) Effect
Studied the rapidity densities, then determine the effect of the rapidity slice for each particle
Collaboration System trig/inel <Npart> Ratio
STAR Au+Au 0-10% 337 1.000
NA49 Pb+Pb 0-5% 357 1.059
NA44 Pb+Pb 0-3.7% 340 1.009
WA98 Pb+Pb 0-10% 330 0.979
Particle A B Ratio
-0.132 0.236 0.946
-0.168 0.207 0.942
K- -0.048 0.034 0.919
K+ -0.038 0.039 0.938
p-bar -0.050 0.021 0.781
p +0.300 -1.221 1.019
Energy Dependence
Particle dN/dy (y=0)
180+/-5 1.40+/-0.03
164+/-4 1.44+/-0.04
K- 17.4+/-1.6 1.14+/-0.10
K+ 31.2+/-2.1 1.25+/-0.13
p-bar 3.5+/-0.6 1.10+/-0.26
p 33.9+/-1.7 2.50+/-0.35
Particle Experiment <y> Ratio NA49 -0.1 0.997 NA44 0.4 0.96 WA98 -0.55 0.926 NA44 0.4 0.9260 WA98 -0.3 0.978K- NA49 0 1K- NA44 0.15 0.991K- WA98 -0.8 0.782K+ NA49 0 1K+ NA44 0.15 0.993
p-bar NA49 -0.3 0.963p-bar NA44 -0.45 0.92
p NA49 -0.3 0.993p NA44 -0.45 0.984
NA49 rapidity density dataN(A661, 45c (1999)
QM2008, Jaipur, 09-February-2008 8Daniel Cebra
Comparisons of Pion Yields
Exp dN/dy T(MeV) dN/dy
- STAR 148.2 182+/-1 147.4+/-0.6
WA98 111.1 195+/-5 136.1+/-2.8
NA44 113.9 201+/-8 132.9+/-1.3
NA49 146.0 182+/-3 144.6+/-1.6
+ STAR 143.2 186+/-1 143.7+/-0.6
0 WA98 90.7 179+/-8 95.6+/-7.4
+ NA44 111.5 203+/-3 130.0+/-1.5
Fit all experimental data with exponential over the range 200-800 MeV/c2
Fix
tem
pera
ture
to 1
85 a
nd c
orre
t fo
r dife
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s in
cen
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apid
ity, a
nd b
eam
ean
ergy
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 9Daniel Cebra
Kaon Yields
Exp dN/dy T(MeV) dN/dy
- STAR 18.2 269+/-10 17.7+/-0.3
WA98 10.6 222+/-11 14.5+/-0.4
NA44 15.4 229+/-2 16.3+/-0.1
NA44 14.9 225+/-6 17.2+/-0.1
NA49 16.9 233+/-3 17.5+/-0.1
+ STAR 29.5 277+/-9 28.5+/-0.4
NA44 24.0 225+/-9 27.6+/-0.4
NA44 27.5 245+/-3 29.2+/-0.2
NA49 29.0 238+/-4 29.1+/-0.3
Fit all experimental data with exponential over the range 100-600 MeV/C2
Fix
tem
pera
ture
to 2
50 a
nd c
orre
t fo
r dife
rnce
s in
cen
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ity, r
apid
ity, a
nd b
eam
ean
ergy
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 10Daniel Cebra
Proton Yields – Corrected for Feed-down
Exp dN/dy T (MeV) dN/dy
p-bar STAR 2.09* 339+/-30 2.06+/-0.20
NA44 1.84 323+/-26 2.53+/-0.06
NA49 1.65 305+/-11 2.08+/-0.05
Proton STAR 27.8* 292+/-6 27.6+/-1.24
NA44 27.1 299+/-4 27.7+/-0.16
NA49 25.6 322+/-17 23.9+/-0.75
Fit all experimental data with exponential over the range 200-800 MeV/c2
Fix
tem
pera
ture
to 3
00 a
nd c
orre
t fo
r dife
rnce
s in
cen
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apid
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nd b
eam
ean
ergy
* STAR Data are corrected using NA49 Lambda and anti-Lambda results
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 11Daniel Cebra
Fitting the Shape of the Spectra
STAR PRELIMINARY
In order to estimate the integrated yield, the spectral shapes are modeled and extrapolated
QM2008, Jaipur, 09-February-2008 12Daniel Cebra
Radial Flow Analysis
STAR PRELIMINARY
Statistical Model:Tch = 164.7 +/- 0.5 B = 205.5 +/- 0.6 S = 27.2 +/- 0.9
FoPi NPA612, 493 (1997)FoPi NPA610, 49c (1996)EOS PRL75, 2662 (1995)E866 APPB29, 3253 (1998)NA44 PRL78, 2080 (1997)NA49 PRL82, 2471 (1999)PHENIX NPA715, 498 (2003)BRAHMS nucl-ex/0404011STAR PRL92, 112301 (2003)
200 GeV data STAR PRL92, 112301 (2003)
QM2008, Jaipur, 09-February-2008 13Daniel Cebra
Rapidity Density Distributions
STAR PRELIMINARY STAR PRELIMINARYSTAR PRELIMINARY
The yields are studied as a function of rapidity and centrality
NA44 PRC66, 044907 (2002) - all NA49 PRC66, 054902 (2002) - pim, kam, and kapNA49 PRC69, 024902 (2004) - protonsNA49 nucl-ex/0512033 - protons and anti-protonsWA98 PRL83, 926 (1999) - pi-zeroWA98 NPA698, 647 (2002) - pimWA98 PRC67, 014906 (2003) - pim and kam
QM2008, Jaipur, 09-February-2008 14Daniel Cebra
Particle Ratios
STAR PRELIMINARY
E802 NPA610, 139c (1996)E802 PRL81, 2650 (1998)E866 PLB476, 1 (2000)E917 PLB490, 53 (2000)NA49 PRC66, 054902 (2002)NA44 PRC66, 044907 (2002)PHENIX PRC69, 034909 (2004)STAR PRL92, 112301 (2003)STAR PLB595, 143 (2004)STAR PRL86, 4778 (2001)STAR PLB567, 167 (2003)
QM2008, Jaipur, 09-February-2008 15Daniel Cebra
K/ Ratios
STAR PRELIMINARYE802 PRL81, 2650 (1998)E866 PLB476, 1 (2000)E917 PLB490, 53 (2000)NA44 PLB471, 6 (1999)WA98 PRC67, 104906 (2003)NA49 PRC66, 054902 (2002)NA49 EPJC33, S621 (2004)NA49 arXiv:0710.0118v2PHENIX PRC69, 034909 (2004)PHENIX PRL88, 242301 (2002)STAR PRL92, 112301 (2003)STAR PLB595, 143 (2004)
QM2008, Jaipur, 09-February-2008 16Daniel Cebra
Pion Ratios
STAR PRELIMINARY
KaoS PLB420, 20 (1998)E866 NPA610, 139c (1996)NA44 PLB372, 339 (1996)WA98 nucl-ex/0607018STAR PRL92, 112301 (2003)
The pion ratios are fit with a coulomb model. The extracted potential of the source is 8.5 MeV
QM2008, Jaipur, 09-February-2008 17Daniel Cebra
„Standard” HBT analysis
• impressive agreement: STAR Au+Au @19.6GeV with CERES/NA49 Pb+Pb @17.3 GeV
• weak s dependence of HBT cancels weak Abeam dependence --> ~apples:apples
• Scale and p-dep. of homogeneity regions • follow already-established trends • disfavor signals of increased lifetimes at
intermediate collision energiesSlide courtesy of Z. Chajecki and M. Lisa
QM2008, Jaipur, 09-February-2008 18Daniel Cebra
Summary
• We have measured the pion, kaon, and proton spectra in 19.6 GeV Au+Au collisions• These spectra have been measured as a function of rapidity and centrality• Detailed comparisons of these spectra to the published SPS results have been made, in most cases the results are compatible.• The RHIC Beam Energy Scan will be able to reduce the statistical and systematic errors.
QM2008, Jaipur, 09-February-2008 19Daniel Cebra
Backup Slides
QM2008, Jaipur, 09-February-2008 20Daniel Cebra
STAR PRELIMINARYSTAR PRELIMINARY
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 21Daniel Cebra
2001 19.6 GeV Au+Au collisions• 2 days of 9.8 GeV beams
– 0.4 b-1 integrated luminosity
– *=3m by necessity– 60-90 minute stores– 56 Au bunches,
0.6x109/bunch– 10-30 Hz ZDC rates– IBS and aperture
dominated beam and luminosity lifetime
• Another run at this energy may improve this by factor of 2-5– 1.0+x109/bunch– Raise * to improve
lifetime
• RHIC is best used as a storage ring collider below beam energies of ~12 GeV
21
Figure from T. Satogata
STARPHENIX
QM2008, Jaipur, 09-February-2008 22Daniel Cebra
Added62.5
QM2008, Jaipur, 09-February-2008 23Daniel Cebra
Studied the production trends as a function of Np and root S
Flat as a function of Np for central collisions
Parameterized the energydependence
QM2008, Jaipur, 09-February-2008 24Daniel Cebra
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 25Daniel Cebra
-
STARNA49WA98NA44
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 26Daniel Cebra
+
STARWA98NA44
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 27Daniel Cebra
K-
STARNA49WA98NA44
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 28Daniel Cebra
K+
STARNA49NA44
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 29Daniel Cebra
p-
STARNA49NA44
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 30Daniel Cebra
p+
STARNA49NA44
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 31Daniel Cebra
Proton Yields before correction
Exp dN/dy T(MeV) dN/dy
p-bar STAR 3.42 339+/-30 3.38+/-0.12
NA44 2.66 299+/-16 3.66+/-0.08
NA49 1.65* 305+/-11 3.00+/-0.07
Proton STAR 36.7 292+/-6 36.5+/-0.39
NA44 36.1 279+/-3 36.3+/-0.20
NA49 25.6* 322+/-17 31.8+/-0.98
Fit all experimental data with exponential over the range 200-800 MeV/c2
Fix
tem
pera
ture
to 3
00 a
nd c
orre
t fo
r dife
rnce
s in
cen
tral
ity, r
apid
ity, a
nd b
eam
ean
ergy
* Corrected for hyperon feeddown
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 32Daniel Cebra
STAR62.5 2.72 +/- 0.24200 3.94 +/- 0.28
PHENIX19.6 1.86 +/- 0.15130 3.46 +/- 0.18200 3.89 +/- 0.23
NA4917.2 1.86 +/- 0.0812.4 1.54 +/- 0.078.7 1.24 +/- 0.06
NA45 17.2 1.87 +/- 0.19 8.7 1.35 +/- 0.08NA50 17.2 1.98 +/- 0.16 8.7 0.95 +/- 0.10
PRC 71, 0344908 (2005)
STAR PRELIMINARY
QM2008, Jaipur, 09-February-2008 33Daniel Cebra
NA44
NA49
STAR PRELIMINARY