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J-Cal Overview. Extension of EM-Cal for B-to-b jet capabilities. Yasuo MIAKE Univ. of Tsukuba. S. Esumi, T. Horaguchi H. Yokoyama, M. Sano T. Chujo. Y. Miake, April.,7, 2009 @ LBNL. What is J-Cal. (ΔΦ,Δη) ~ (0.025,0.025). J-Cal consists of 3 super modules of the EMCAL - PowerPoint PPT Presentation
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1Y. Miake, April.,7, 2009 @ LBNL
J-Cal OverviewJ-Cal Overview
Yasuo MIAKEUniv. of Tsukuba
Extension of EM-Cal forB-to-b jet capabilities
S. Esumi, T. HoraguchiH. Yokoyama, M. SanoT. Chujo
2
What is J-CalWhat is J-Cal✓J-Cal consists of 3 super modules of
the EMCAL
• Same design, same material, same
electronics as the ALICE EMCAL
✓J-Cal sits on the other side of ALICE
EMCAL detecting Back-to back jet
J-Cal, extension of EM-Cal coverage
for Jets !!
J as Jet, Japanese,,,
2
module
(ΔΦ,Δη) ~ (0.025,0.025)
3 Super Module36 x 24 =864 modules
(ΔΦ,Δη)~(1.0, 0.7)
J-Cal
5
Where is J-Cal Where is J-Cal Where is J-Cal Where is J-Cal
✓In φ, it is on the other side
of ALICE EMCAL
✓In η, it is next to the PHOS
eta view of ALICE & J-CAL
J-Cal
ALICE EMCAL
eta view of ALICE & J-CAL
3 super module(ΔΦ,Δη) ~(1.0, 0.7)
6
Physics MotivationsPhysics Motivations
✓Study of jets hopefully with PID (Parton ID)
•Jet quench
•Mach cone
•Tomography
pedestal and flow subtracted
PHENIX, arXiv:0705.3238 [nucl-ex]PHENIX, arXiv:0705.3238 [nucl-ex]
J-Cal improve Back-to back jets performance in ALICE
Define B-to-B jets Trigger B-to-B jets
7
Our wishOur wish
✓ We want to see mach cone with away side jet Ejet > ~ 50 GeV
at LHC.
V.S. Pantuev, arXiv:hep-ph/0701.1882v1V.S. Pantuev, arXiv:hep-ph/0701.1882v1
RHIC LHC
8
Jets; Gamma-Jet & DiJetJets; Gamma-Jet & DiJet
✓Gamma-Jet
• Quark Jet
• Easier analysis
(no energy loss for gamma)
• Smaller rate
• Inclusive meas.
• Reaction plane dependence
✓Di-Jet•Mostly Gluon Jets
•x1000 higher rate, thus higher statistics
•Semi-exclusive meas. can be done w.r.t. reaction plane, centrality & pt of jets
Partonic Energy Loss
9
Key issues; resolutionsKey issues; resolutions
✓Good characteristics of
Back-to back jets
•Origins clean
•Kinematically clean Energy balance
back-to back in phi
✓Need to have better
resolutions RMS of (φ1-φ2)
RMS of (Ejet1-Ejet
2)
φ1
φ2
Ejet1
Ejet2
Rcone < 0.2
ΦJET1-ΦJET2PYTHIA8
pt = 40 GeV/c 80 120
10
Energy resolutionEnergy resolution
✓Statistical fluctuation in
neutrals determines the
resolution.
✓J-Cal improves the
resolution from ~45%
to ~35%
✓Imbalance in energies
provides information on
the partonic energy
loss. Dijet Intrinsic
TPC - TPC
Rcone = 0.2
γ-Jet: J-Cal - EMC
J-Cal - EMC
TPC - EMC
PYTHIA8, detector resolution included
See talk by H. Yokoyama
11
Δφ B-to-b balance in φΔφ B-to-b balance in φ
✓Better phi
resolution helps a
lot finding jets in
heavy ion
environment
Rcone = 0.2
γ-Jet: J-Cal - EMC
TPC - TPC
J-Cal - EMC
TPC - EMC
Dijet Intrinsic
PYTHIA8, detector resolution included
12
Effect of the energy lossEffect of the energy loss
✓Jet energy reduces from 100 GeV to 80 GeV in central Pb+Pb at
pThat =100 GeV event
PYQUEN; detector resolution not included
Pb+Pb central(5%), pThat = 100 GeV
13
Effects on energy and φ Effects on energy and φ balancebalancePYQUEN, detector resolution not included
See talk by H. Yokoyama
14
RatesRates
✓1 month running/year
✓104 events/year
✓Using Day-1 ALICE with J-
Cal
•Establish Dijets Axis
up to100~150 GeV
✓3 orders of magnitude
larger than gamma-Jet
See talk by S. EsumiThanks – Peter Jacobs
From slides shown by J. Harris at Tamura Symposium, Nov. 2008
Full Dijets reconstruction by EMCAL+JCAL
15YMiake, Mar.,24, 2009 @ CERN
J-Cal doubles γ-Jet yield J-Cal doubles γ-Jet yield
• γin PHOS and J-cal, jet in
EM-Cal.
• Thanks to Peter Jacobs
✓J-Cal doubles rate of γ-Jet
✓leading pi0 may be
improved by a factor of
10!
• Need simulations
Thanks to Peter Jacobs
J-X
16
Jet trigger in Pb+PbJet trigger in Pb+Pb
✓With Rcone = 0.2, triggering jet of < 50 GeV becomes
difficult.
✓Back-to back
Backgrounds
Fig.8.4 of TDR
Ejet = 100 GeV
50 GeV
Rcone = 0.2
Rcone
17
SummarySummary✓J-Cal (EM) for back-to back jet performance
Improve
Resolutions ; ~45% to ~35 %
Acceptances ; 3 x γ-jets
Trigger ; (to be done)
✓Funding
•At least 1 SM EMC is already granted at Tsukuba.
•The rest of the money in negotiation.
✓Full collaboration (asking help) with US-EMCal • Dec, 2008, T.Chujo w. 2 students @ Wayne State
• Arp, 2009, 2 students (M. Sano, H. Yokoyama) stay 2 months @LBNL
• J-Cal proposal at the next ALICE week (June, 2009), see talk by Y. Miake.
• Preparation for the analysis tool at Tsukuba, see talk by T. Horaguchi.
18
F. A. Q.F. A. Q.
✓Why not with PHOS?
•For jets, eta coverage of PHOS is too narrow.
•Cone radius of >0.2 needed
•J-Cal + Phos works better
✓Why not with γ-Jet?
•Rates.
• DiJets & γ-Jet will play complimental role
19
Fluctuation with limitationFluctuation with limitation
✓Statistical fluctuation with total energy limitation
•Total jet energy is fixed.
fluctuation of neutral play significant role
CDF, PRL94(2005)171802 EJET=ECHARGED+ENEUTRAL
EJET
Charged(2/3)
~15@100Gev
Frag
men
tatio
n
Neutral(1/3)
~7@100Gev
dECHARGED = -dENEUTRAL
22
Control variables requiredControl variables requiredfor Heavy Ion Exp.for Heavy Ion Exp.
✓Since heavy ion collisions is so complicated, while
there is no ‘standard model’, we need to measure
heavy ion collisions w. many control variables.
•Centrality / impact parameter of collisions
•Reaction Plane Angle
•Yet, another control variable for the next generation
experiments ;
→ Jet Axis
23YMiake, Mar.,24, 2009 @ CERN
Budget (Grant in Aid,JSPS)Budget (Grant in Aid,JSPS)
✓Total of ≲1 M$ in 5 yrs is granted.
2008 2009 2010 2011 2012
開発・試験
検出器製作
陽子・陽子衝突における測定と研究
鉛・鉛衝突における測定と研究
設計計算
成果発表
テスト実験
搬入
測定器完成
D1 渡邊健悟M2 佐野正人M2 坂田洞察M1 横山広樹M1 浜田英太郎M1 梶谷緑M1 轟木M1 木村瑞希
2008.4.1現在
トリガー導入
最終製作図面
個別要素試験
システムテスト
第1モジュール
第2モジュール
第3モジュール
第4モジュール
解析プログラム開発
GEANT4開発
トリガープログラム開発
トリガープログラム試験
pp物理解析・評価
PbPb物理解析・評価 Tomography解析
27
Possibility of Parton IDPossibility of Parton ID
✓As a new generation exp.,
from Particle ID to Parton
ID !
•According to CDF exp.,
charged/neutral works
✓Might be very difficult in
heavy ion environment
✓Nevertheless, challenge!
✓It becomes feasible for
higher pt jet 27
CDF, PRL94(2005)171802
gluon jet
quark jet
28
STAR, arXiv:nucl-ex/0701074STAR, arXiv:nucl-ex/0701074
Scenario at RHICScenario at RHIC
✓Claims• Stopped parton is the source of
ridge as well as Mach cone.
• This happens only at the surface
• There should be velocity boost at the ridge region (pi,K,p)
• v3 components independent of R.P.
V.S. Pantuev, arXiv:hep-ph/0701.1882v1V.S. Pantuev, arXiv:hep-ph/0701.1882v1
29
At higher energies, At higher energies,
✓Dijets with energy un
✓Mach cone with away
side jet.
✓Higher, the better;
•Clear separation in
momentum and φ
V.S. Pantuev, arXiv:hep-ph/0701.1882v1V.S. Pantuev, arXiv:hep-ph/0701.1882v1
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