High Level Trigger of Muon Spectrometer Indranil Das Saha Institute of Nuclear Physics.
Shandong University, Qingdao, China · 3. Analysis details γ rich trigger event Purity of direct...
1
3. Analysis details γ rich trigger event Purity of direct photon for different trigger E T trig bins 8 10 12 14 16 18 20 [GeV] trig T E 10 15 20 25 30 35 sample rich γ Background (%) in STAR Preliminary Au+Au 200 GeV [year 2014], 0%-15% Uncertainty σ 1 ± 1 - 0.5 - 0 0.5 1 h 3 - 2 - 1 - 0 1 2 3 f 0 2 4 6 8 10 [GeV/c] T p -Trigger Event g Au+Au 200 GeV [2014], Event number=37362, Run number=15098037 Measurement of semi-inclusive +jet and π 0 +jet distributions in central Au+Au collisions at GeV by the STAR experiment γ dir s NN = 200 Nihar Ranjan Sahoo, for the STAR Collaboration Shandong University, Qingdao, China The STAR Collaboration: https://drupal.star.bnl.gov/STAR/presentations/ Jet Jet Abstract 2. STAR detector setup 1. Motivation 5. Summary References 4. Results and discussion γ dir +jet vs π 0 +jet: Recoil jet suppression for two jet radii R jet = 0.2 R jet = 0.5 2 4 6 8 10 12 14 16 18 20 1 - 10 1 PYTHIA AA I Au+Au 200 GeV, 0-15% = 0.2 jet R T anti-k STAR Preliminary < 15 GeV/c const. T < 11 GeV, p trig T 9 < E 2 4 6 8 10 12 14 16 18 20 [GeV/c] ch T,jet p 1 - 10 1 PYTHIA AA I < 15 GeV/c const. T < 15 GeV, p trig T 11 < E +jet 0 p +jet dir g 5 10 15 20 25 1 − 10 1 PYTHIA AA I Au+Au 200 GeV, 0-15% = 0.5 jet R T anti-k STAR Preliminary < 11 GeV trig T 9 < E 5 10 15 20 25 [GeV/c] ch T,jet p 1 − 10 1 PYTHIA AA I < 15 GeV trig T 11 < E +jet 0 π +jet dir γ • Recoil jet with a jet resolution parameter of R jet =0.2 shows strong suppression whereas a negligible suppression is observed for R jet =0.5, within uncertainties. • I AA PYTHIA values are comparable between the two E T trig bins. • The same level of suppression is seen between γ dir +jet and π 0 +jet for different E T trig bins and the two jet resolution parameters within uncertainties. γ rich trigger events: enriched-γ dir trigger events with admixture of photons from π 0 . Caption- I AA PYTHIA as a function of p T,jet ch for γ dir - (red band) and π 0 - trigger (blue band). Top: 9 < E T trig < 11 GeV. Bottom: 11 < E T trig < 15 GeV. Lighter and darker bands represent systematic and statistical uncertainties, respectively. • A clear difference between recoil-jet spectra for different trigger E T : 9-11 GeV and 11-15 GeV. • Recoil jet p T is suppressed with respect to PYTHIA8. • γ dir +jet: downward arrow represents upper limit in the yield at: p T,jet ch = 11 GeV/c for 9-11 GeV, p T,jet ch = 15 GeV/c for 11-15 GeV. • Jet quenching is an important signature of the hot and dense QCD matter produced in heavy-ion collisions [1]. • A direct photon (γ dir ) produced in coincidence with a recoil jet (γ dir +jet) is a good probe to study the parton energy loss in the QGP [2]. • Comparison between γ dir+ jet vs π 0 +jet provides quantitative understanding of parton energy loss in the QCD medium • Energy loss as a function of path length, color factor, parton energy, etc. • Redistribution of lost energy inside the medium; by varying jet radius 1. J. Adams et al. (STAR Collaboration), Nucl. Phys. A 757, 102 (2005) 2. X.-N. Wang, Z. Huang, and I. Sarcevic, Phys. Rev. Lett. 77, 231 (1996) 3. L. Adamczyk et al. (STAR Collaboration), Phys. Lett. B 760 (2016) 689-696 4. M. Cacciari, G. P. Salam, and G. Soyez, Eur. Phys. J. C (2012) 72:1896 5. L. Adamczyk et al. (STAR Collaboration), Phys. Rev. C 96 (2017) no.2, 024905 6. PYTHIA8: T. Sjöstrand, S. Askb, J. R. Christiansen, et al.,Comput. Phys. Commun. 191 (2015) 159-177; arXiv:1410.3012; With default setting for π 0 +jet and γ+jet Full analysis chain: 1. Discrimination between π 0 /γ rich -triggered events Transverse Shower Profile method [3] 2. Recoil charged jets from high-tower-triggered events Using FastJet package [4]; Recoil jet region:[π-π/4, π+π/4]; Jet radius = 0.2 and 0.5; |η jet | < 1-R 3. Subtraction of uncorrelated jet background in recoil region Based on the mixed-event technique [5] 4. Correction for detector and heavy-ion background fluctuations effects using unfolding technique Factorizing detector and heavy-ion background fluctuation effects 5. Conversion from γ rich +jet to γ dir +jet [4]; as γ rich +jet contains admixture of π 0 +jet Using π 0 +jet yield and purity of γ dir 6. Major sources of systematic uncertainty Unfolding, mixed-event normalization region, detector effects, γ dir background subtraction [contributes only to γ dir +jet] • Recoil charged jets dominate (above ~10 GeV/c) over the uncorrelated jets for different E T trig bins and jet radii. • A clear trigger dependence can been seen. p ch T,jet Y (p ch T,jet ) p+p Y (p ch T,jet ) Au+Au Recoil jet yield suppression with respect to p+p: and represent recoil jet yield per trigger as a function of in Au+Au and p+p collisions, respectively, For p+p baseline, PYTHIA8 result is used. I AA (p ch T,jet ) = Y (p ch T,jet ) Au+Au Y (p ch T,jet ) p+p We present the semi-inclusive measurement of charged jets recoiling from direct-photon and π 0 triggers in central Au+Au collisions at 200 GeV center of mass energy per neucleon, using a dataset with integrated luminosity 13 nb −1 recorded by the STAR experiment in 2014. The photon and π 0 triggers have 9 < E T trig < 15 GeV. Charged jets are reconstructed with the anti-k T algorithm with resolution parameters R=0.2 and 0.5. A mixed-event technique developed previously by STAR is used to correct the recoil jet yield for uncorrelated background, enabling recoil jet measurements over a broad p T,jet range with large jet radius. We report the corrected semi-inclusive recoil jet yields for both triggers and compare them to those in p+p collisions. Such measurements have different trigger bias, in terms of both the path-length distribution and quark/gluon contributions to the recoil jet population. MTD TOF Magnet VPD BBC EEMC BEMC TPC § Special High Tower trigger for π 0 /γ event [BEMC] § Discrimination between π 0 γγ and γ dir § By Transverse Shower Profile (TSP) method [3] § Using Barrel Shower Maximum Detector [BSMD] p+p baseline: PYTHIA8 [6] is used for both triggers - 10 - 10 - 10 - 10 - 10 10 10 ] -1 ) [(GeV/c) jet h d reco,ch T,jet /(d p jets N 2 ) d trig (1/N Au+Au 200 GeV, 0-15% T anti-k +jet rich g < 11 GeV [SE] T trig 9 < E < 15 GeV [SE] T trig 11 < E ME 10 - 0 10 20 30 raw,ch 10 ME SE 10 - 0 10 20 30 raw,ch 1 6 - 10 5 - 10 4 - 10 3 - 10 2 - 10 1 - 10 1 10 Au+Au 200 GeV, 0-15% T anti-k +jet 0 p < 11 GeV [SE] T trig 9 < E < 15 GeV [SE] T trig 11 < E ME 10 - 0 10 20 30 raw,ch 1 10 ME SE 10 - 0 10 20 30 raw,ch 1 R jet = 0.2 R jet = 0.2 R jet = 0.5 R jet = 0.5 γ rich +jet: SE and ME π 0 +jet: SE and ME (1/N trig )d 2 N jets /(dp reco,ch T,jet d⌘ jet )[GeV/c] p reco,ch T,jet (= p raw,ch T,jet - ⇢.A) [GeV/c] STAR Preliminary STAR Preliminary STAR Preliminary STAR Preliminary Caption- The reconstructed jet p T,jet reco distributions for the same event (SE) and mixed event (ME) for two triggers (E T trig ) bins: 9-11 GeVand 11-15 GeV. Left and right panels are for R jet =0.2 and 0.5, respectively. Lower panels shows the ratio between SE and normalized ME. 2 4 6 8 10 12 14 16 [GeV/c] ch p 5 - 10 4 - 10 3 - 10 2 - 10 1 - 10 1 -1 ) [GeV/c] jet h d ch T,jet /(dp jets 2 dN trig 1/N Au+Au, 0-15% =0.5 jet , R T anti-k < 30 GeV/c const T p +jet dir g PYTHIA < 11 GeV trig T 9 < E < 15 GeV trig T 11 < E STAR Preliminary γ dir +jet: Recoil jet p T spectra 0 5 10 15 20 25 [GeV/c] p 4 - 10 3 - 10 2 - 10 1 - 10 -1 ) [GeV/c] jet h d ch T,jet /(dp jet 2 dN trig 1/N =0.5 jet , R T anti-k < 30 GeV/c const T p +jet 0 p PYTHIA < 15 GeV trig T 11 < E < 11 GeV trig T 9 < E STAR Preliminary π 0 +jet: Recoil jet p T spectra R jet = 0.2 R jet = 0.5 R jet = 0.2 R jet = 0.5 p ch T,jet [GeV/c] Au+Au 200 GeV, 0-15% Au+Au 200 GeV, 0-15% Au+Au 200 GeV, 0-15% Au+Au 200 GeV, 0-15% • First γ dir +jet and π 0 +jet measurement at RHIC within 9 < E T trig < 15 GeV is presented in central Au+Au collisions at center of mass energy 200 GeV • Recoil jet with jet radius 0.2 is strongly suppressed at high jet p T whereas a noticeable recovery of jet energy loss is observed at jet radius 0.5 for both the γ dir and π 0 trigger cases; consistent with the previous h+jet analysis [5] • Recoil jet suppression is seen to be independent of E T trig ; whereas γ dir +jet and π 0 +jet show similar level of suppression Caption- Fully corrected semi-inclusive recoil charged jet p T,jet ch spectra for the above two E T trig bins. Dashed lines are PYTHIA8 expectation. Left panel (R jet =0.2) and Right panel (R jet =0.5). Lighter (darker) bands represent systematic (statistical) uncertainties.
Transcript of Shandong University, Qingdao, China · 3. Analysis details γ rich trigger event Purity of direct...
![Page 1: Shandong University, Qingdao, China · 3. Analysis details γ rich trigger event Purity of direct photon for different trigger E Ttrig bins 8 10 12 14 16 18 20 trig [GeV] E T 10 15](https://reader035.fdocument.org/reader035/viewer/2022081522/5fa4bfc0f6eb2551d61b8e04/html5/thumbnails/1.jpg)
3. Analysis detailsγrich trigger event
Purity of direct photon for different trigger ETtrig bins
8 10 12 14 16 18 20 [GeV]trig
TE10
15
20
25
30
35
sam
ple
rich
γBa
ckgr
ound
(%) i
n
STAR Preliminary
Au+Au 200 GeV [year 2014], 0%-15% Uncertaintyσ1±
1-0.5-
00.5
1h
3- 2-1-
0 12
3
f
0
2
4
6
8
10
[GeV
/c]
Tp
-Trigger EventgAu+Au 200 GeV [2014], Event number=37362, Run number=15098037
Measurement of semi-inclusive +jet and π0+jet distributions in central Au+Au collisions at GeV by the STAR experiment
γdirsNN = 200
Nihar Ranjan Sahoo, for the STAR Collaboration Shandong University, Qingdao, China
The STAR Collaboration: https://drupal.star.bnl.gov/STAR/presentations/
JetJet
Abstract
2. STAR detector setup1. Motivation
5. SummaryReferences
4. Results and discussion
γdir+jet vs π0+jet: Recoil jet suppression for two jet radii Rjet = 0.2 Rjet = 0.5
2 4 6 8 10 12 14 16 18 20
1-10
1
PYTH
IAAAI Au+Au 200 GeV, 0-15%
= 0.2jet RTanti-kSTAR Preliminary
< 15 GeV/cconst.T
< 11 GeV, ptrigT9 < E
2 4 6 8 10 12 14 16 18 20 [GeV/c]ch
T,jetp
1-10
1
PYTH
IAAAI
< 15 GeV/cconst.T
< 15 GeV, ptrigT11 < E
+jet0p +jetdirg
5 10 15 20 251−10
1
PYTH
IAAAI Au+Au 200 GeV, 0-15%
= 0.5jet RTanti-k
STAR Preliminary
< 11 GeVtrigT9 < E
5 10 15 20 25 [GeV/c]ch
T,jetp
1−10
1
PYTH
IAAAI
< 15 GeVtrigT11 < E +jet0π +jet
dirγ
• Recoil jet with a jet resolution parameter of Rjet =0.2 shows strong suppression whereas anegligible suppression is observed for Rjet=0.5, within uncertainties.
• IAAPYTHIA values are comparable between the two ETtrig bins.• The same level of suppression is seen between γdir+jet and π0+jet for different ETtrig bins andthe two jet resolution parameters within uncertainties.
γrich trigger events: enriched-γdir trigger events with admixtureof photons from π0.
Caption- IAAPYTHIA as a function ofpT,jetch for γdir- (red band) and π0-trigger (blue band). Top: 9 < ETtrig<11 GeV. Bottom: 11 < ETtrig< 15GeV. Lighter and darker bandsrepresent systematic and statisticaluncertainties, respectively.
• A clear difference between recoil-jetspectra for different trigger ET: 9-11GeV and 11-15 GeV.
• Recoil jet pT is suppressed withrespect to PYTHIA8.
• γdir+jet: downward arrow representsupper limit in the yield at: pT,jetch =11 GeV/c for 9-11 GeV, pT,jetch = 15GeV/c for 11-15 GeV.
• Jet quenching is an important signature of the hot and denseQCD matter produced in heavy-ion collisions [1].
• A direct photon (γdir) produced in coincidence with a recoiljet (γdir+jet) is a good probe to study the parton energy loss inthe QGP [2].
• Comparison between γdir+jet vs π0+jet provides quantitativeunderstanding of parton energy loss in the QCD medium
• Energy loss as a function of path length, colorfactor, parton energy, etc.
• Redistribution of lost energy inside the medium; byvarying jet radius
1. J. Adams et al. (STAR Collaboration), Nucl. Phys. A 757, 102 (2005)2. X.-N. Wang, Z. Huang, and I. Sarcevic, Phys. Rev. Lett. 77, 231 (1996)3. L. Adamczyk et al. (STAR Collaboration), Phys. Lett. B 760 (2016) 689-6964. M. Cacciari, G. P. Salam, and G. Soyez, Eur. Phys. J. C (2012) 72:18965. L. Adamczyk et al. (STAR Collaboration), Phys. Rev. C 96 (2017) no.2,
0249056. PYTHIA8: T. Sjöstrand, S. Askb, J. R. Christiansen, et al.,Comput. Phys.
Commun. 191 (2015) 159-177; arXiv:1410.3012; With default setting for π0+jet and γ+jet
Full analysis chain:1. Discrimination between π0/γrich-triggered events
Transverse Shower Profile method [3]2. Recoil charged jets from high-tower-triggered events
Using FastJet package [4]; Recoil jet region:[π-π/4,π+π/4]; Jet radius = 0.2 and 0.5; |ηjet| < 1-R
3. Subtraction of uncorrelated jet background in recoilregion
Based on the mixed-event technique [5]4. Correction for detector and heavy-ion backgroundfluctuations effects using unfolding technique
Factorizing detector and heavy-ion backgroundfluctuation effects5. Conversion from γrich+jet to γdir+jet [4]; as γrich+jetcontains admixture of π0+jet
Using π0+jet yield and purity of γdir6. Major sources of systematic uncertainty
Unfolding, mixed-event normalization region, detectoreffects, γdir background subtraction [contributes only to
γdir+jet]
• Recoil charged jets dominate (above ~10GeV/c) over the uncorrelated jets for differentETtrig bins and jet radii.
• A clear trigger dependence can been seen.
pchT,jet<latexit sha1_base64="eA/vN+HGIBEOXPe77PzZ7X5UhCY=">AAAB+3icbVDLSsNAFJ3UV62vWJduBovgQkqigi6LblxW6AvaGCbTm3bsTBJmJmIJ+RU3LhRx64+482+cPhbaeuDC4Zx7ufeeIOFMacf5tgorq2vrG8XN0tb2zu6evV9uqTiVFJo05rHsBEQBZxE0NdMcOokEIgIO7WB0M/HbjyAVi6OGHifgCTKIWMgo0Uby7XJPCpz4WeP0AXR+n9Fh7tsVp+pMgZeJOycVNEfdt796/ZimAiJNOVGq6zqJ9jIiNaMc8lIvVZAQOiID6BoaEQHKy6a35/jYKH0cxtJUpPFU/T2REaHUWASmUxA9VIveRPzP66Y6vPIyFiWphojOFoUpxzrGkyBwn0mgmo8NIVQycyumQyIJ1SaukgnBXXx5mbTOqu559ezuolK7nsdRRIfoCJ0gF12iGrpFddREFD2hZ/SK3qzcerHerY9Za8GazxygP7A+fwD8u5Rp</latexit>
Y (pchT,jet)p+p
<latexit sha1_base64="6+UVogA8WOjhoVjlFCKUIAMqNCI=">AAACCHicbVDLSsNAFJ3UV62vqEsXDhahopSkCrosunFZoS9p0zCZTuzYSTLMTIQSsnTjr7hxoYhbP8Gdf+O0zUJbD1w4nHMv997jcUalsqxvI7ewuLS8kl8trK1vbG6Z2ztNGcUCkwaOWCTaHpKE0ZA0FFWMtLkgKPAYaXnDq7HfeiBC0iisqxEnToDuQupTjJSWXHP/tgS7IoDcTeon90SlvQQPUnjUS/gxTyF0zaJVtiaA88TOSBFkqLnmV7cf4TggocIMSdmxLa6cBAlFMSNpoRtLwhEeojvS0TREAZFOMnkkhYda6UM/ErpCBSfq74kEBVKOAk93BkgN5Kw3Fv/zOrHyL5yEhjxWJMTTRX7MoIrgOBXYp4JgxUaaICyovhXiARIIK51dQYdgz748T5qVsn1artycFauXWRx5sAcOQAnY4BxUwTWogQbA4BE8g1fwZjwZL8a78TFtzRnZzC74A+PzB6UwmHY=</latexit>
Y (pchT,jet)Au+Au
<latexit sha1_base64="zigbS5R/LzI21j1DC04XMUYN9G4=">AAACCnicbVDLSsNAFJ3UV62vqEs3o0WoKCWpgi5b3bis0Je0aZhMp3bsTBJmJkIJWbvxV9y4UMStX+DOv3HaZqGtBy4czrmXe+/xQkalsqxvI7OwuLS8kl3Nra1vbG6Z2zsNGUQCkzoOWCBaHpKEUZ/UFVWMtEJBEPcYaXrDq7HffCBC0sCvqVFIHI7ufNqnGCktueb+bQF2BIehG9dO7olKujEeJPCoG1ei40qUQOiaeatoTQDniZ2SPEhRdc2vTi/AESe+wgxJ2batUDkxEopiRpJcJ5IkRHiI7khbUx9xIp148koCD7XSg/1A6PIVnKi/J2LEpRxxT3dypAZy1huL/3ntSPUvnJj6YaSIj6eL+hGDKoDjXGCPCoIVG2mCsKD6VogHSCCsdHo5HYI9+/I8aZSK9mmxdHOWL1+mcWTBHjgABWCDc1AG16AK6gCDR/AMXsGb8WS8GO/Gx7Q1Y6Qzu+APjM8f2RSZFg==</latexit>
Recoil jet yield suppression withrespect to p+p:
andrepresent recoil jet yield pertrigger as a function of inAu+Au and p+p collisions,respectively, For p+p baseline,PYTHIA8 result is used.
IAA(pchT,jet) =
Y (pchT,jet)Au+Au
Y (pchT,jet)p+p
<latexit sha1_base64="VZc9Whq+eNH7BMlzDvSZkryAmCk=">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</latexit>
We present the semi-inclusive measurement of charged jets recoiling from direct-photon and π0 triggers in central Au+Au collisions at 200 GeV center of mass energy per neucleon, using a datasetwith integrated luminosity 13 nb−1 recorded by the STAR experiment in 2014. The photon and π0 triggers have 9 < ETtrig < 15 GeV. Charged jets are reconstructed with the anti-kT algorithm withresolution parameters R=0.2 and 0.5. A mixed-event technique developed previously by STAR is used to correct the recoil jet yield for uncorrelated background, enabling recoil jet measurementsover a broad pT,jet range with large jet radius. We report the corrected semi-inclusive recoil jet yields for both triggers and compare them to those in p+p collisions. Such measurements have differenttrigger bias, in terms of both the path-length distribution and quark/gluon contributions to the recoil jet population.
MTD TOF Magnet VPD BBC EEMCBEMC TPC
§ Special High Tower trigger for π0/γ event [BEMC] § Discrimination between π0 γγ and γdir
§ By Transverse Shower Profile (TSP) method [3] § Using Barrel Shower Maximum Detector [BSMD]
p+p baseline: PYTHIA8 [6] is used for both triggers
6-10
5-10
4-10
3-10
2-10
1-10
1
10]
-1) [
(GeV
/c)
jet
h d
reco
,ch
T,je
t/(d
pje
tsN2
) dtri
g(1
/NAu+Au 200 GeV, 0-15%
= 0.2jet RTanti-k+jet
richg
< 11 GeV [SE]Ttrig9 < E
< 15 GeV [SE]Ttrig11 < E
ME
= 0.5jetR
10- 0 10 20 30 A) [GeV/c]× r - raw,ch
T,jet (= preco,ch
T,jetp
1
10
ME
SE
10- 0 10 20 30 A) [GeV/c]× r - raw,ch
T,jet (= preco,ch
T,jetp
1
10
6-10
5-10
4-10
3-10
2-10
1-10
1
10
]-1
) [(G
eV/c
)je
th
dre
co,c
hT,
jet
/(d p
jets
N2) d
trig
(1/N
Au+Au 200 GeV, 0-15% = 0.2jet RTanti-k
+jet0p
< 11 GeV [SE]Ttrig9 < E
< 15 GeV [SE]Ttrig11 < E
ME
= 0.5jetR
10- 0 10 20 30 A) [GeV/c]× r - raw,ch
T,jet (= preco,ch
T,jetp
1
10
ME
SE
10- 0 10 20 30 A) [GeV/c]× r - raw,ch
T,jet (= preco,ch
T,jetp
1
10
Rjet = 0.2 Rjet = 0.2 Rjet = 0.5Rjet = 0.5
γrich+jet: SE and MEπ0+jet: SE and ME
(1/N
trig)d
2N
jets/(dpreco
,ch
T,jet
d⌘ j
et)[GeV
/c]
<latexit sha1_base64="en/L7D35gxayRQV+ou4JhGeTypE=">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</latexit>
preco,chT,jet (= praw,chT,jet � ⇢.A) [GeV/c]
<latexit sha1_base64="3o5THPyQge35D2UbUG4c86OfncQ=">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</latexit>
STAR Preliminary STAR PreliminarySTAR Preliminary
STAR Preliminary
Caption- The reconstructed jet pT,jetreco distributions forthe same event (SE) and mixed event (ME) for twotriggers (ETtrig) bins: 9-11 GeV and 11-15 GeV. Left andright panels are for Rjet =0.2 and 0.5, respectively.Lower panels shows the ratio between SE andnormalized ME.
2 4 6 8 10 12 14 16 [GeV/c]ch
T,jetp
5-10
4-10
3-10
2-10
1-10
1
-1) [
GeV
/c]
jet
h d
ch T,je
t/(d
pje
ts2
dN
trig
1/N
Au+Au, 0-15%=0.5jet, RTanti-k
< 30 GeV/cconstT
p+jet
dirg
PYTHIA
< 11 GeVtrigT9 < E
< 15 GeVtrigT11 < E
STAR Preliminary
γdir+jet: Recoil jet pT spectra
0 5 10 15 20 25 [GeV/c]ch
T,jetp
4-10
3-10
2-10
1-10
-1) [
GeV
/c]
jet
h d
ch T,je
t/(d
pje
t2
dN
trig
1/N
Au+Au, 0-15%=0.5
jet, RTanti-k
< 30 GeV/cconstT
p+jet0p
PYTHIA < 15 GeVtrig
T11 < E < 11 GeVtrig
T9 < E
STAR Preliminary
π0+jet: Recoil jet pT spectra
Rjet = 0.2 Rjet = 0.5 Rjet = 0.2 Rjet = 0.5
pchT,jet [GeV/c]<latexit sha1_base64="mJP1QSwhujYxwyefnk2BbzIKIG0=">AAACA3icbVDLSgNBEJz1GeNr1ZteBoPgQeJuFPQY9KDHCHlBsobZSScZM7O7zMwKYVnx4q948aCIV3/Cm3/j5HHQxIKGoqqb7i4/4kxpx/m25uYXFpeWMyvZ1bX1jU17a7uqwlhSqNCQh7LuEwWcBVDRTHOoRxKI8DnU/P7l0K/dg1QsDMp6EIEnSDdgHUaJNlLL3m1KgaNWUj66A53eJrSXPjSuoHpMvZadc/LOCHiWuBOSQxOUWvZXsx3SWECgKSdKNVwn0l5CpGaUQ5ptxgoiQvukCw1DAyJAecnohxQfGKWNO6E0FWg8Un9PJEQoNRC+6RRE99S0NxT/8xqx7px7CQuiWENAx4s6Mcc6xMNAcJtJoJoPDCFUMnMrpj0iCdUmtqwJwZ1+eZZUC3n3JF+4Oc0VLyZxZNAe2keHyEVnqIiuUQlVEEWP6Bm9ojfryXqx3q2PceucNZnZQX9gff4AoxuXgw==</latexit>
Au+Au 200 GeV, 0-15% Au+Au 200 GeV, 0-15% Au+Au 200 GeV, 0-15% Au+Au 200 GeV, 0-15%
• First γdir+jet and π0+jet measurement at RHIC within 9 < ETtrig < 15 GeV is presented in central Au+Au collisions atcenter of mass energy 200 GeV
• Recoil jet with jet radius 0.2 is strongly suppressed at high jet pT whereas a noticeable recovery of jet energy loss isobserved at jet radius 0.5 for both the γdir and π
0 trigger cases; consistent with the previous h+jet analysis [5]
• Recoil jet suppression is seen to be independent of ETtrig; whereas γdir+jet and π0+jet show similar level of
suppression
Caption- Fully corrected semi-inclusive recoilcharged jet pT,jetch spectra for the above twoETtrig bins. Dashed lines are PYTHIA8expectation. Left panel (Rjet=0.2) and Rightpanel (Rjet=0.5). Lighter (darker) bandsrepresent systematic (statistical) uncertainties.
