HAD_01:

Measurements of Jets andPhotons in Heavy Ion Collisions
at the Highest Beam Energy
during the LHC-Run 2 by ALICE
Tatsuya Chujo (Univ. of Tsukuba)2015 Joint Workshop of TYL/FJPPL and FKPPL(Particle Physics Laboratories) @OISTMay20, 2015
OIST, Okinawa, Japan

Outline
1. Introduction
2. Project report (2014-2015)
3. Project proposal (2015-2016)
4. Summary2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

21.Introduction2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

Quark Gluon Plasma (QGP)
Wuppertal-­‐Budapest’s	
  LQCD	
  EOS
JHEP	
  1011	
  (2010)77

gluon
quark

state of quarks and gluon inside hadrons under the• De-confined
extremely high temperature and energy density• Lattice QCD calculations:• Critical temperature: T = 150-200 MeV• Crossover phase transition from hadronic phase to parton phase.
• A primordial state of universe, after few micro second of Big Bang.
c2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)Experimental study on QGP by
Relativistic Heavy Ion collisions

LHC-ALICE experiment:
CERN-LHC (2009-)
36 countries, 129 institutions,√sNN = 2.76 (5.5 design) TeV Pb-Pb~1,000 collaborators.
2.76, 7.0, 8.0 TeV p-p
The dedicated experiment to HI program
5.02 TeV p-Pb
and QGP study at LHC
T. Chujo, 2013 Joint Workshop of FJPPL (TYL) and FKPPL, Yonsei Univ. Seoul, Korea, June 4, 2013

Probing QGP by Higher harmonics
FFlluuccttuuaattiioonnss  ooff  tthhee  UUnniivveerrssee

FFlluuccttuuaattiioonnss  ooff  LLiittttllee  bbaanngg

Plank (2013)
Determination of cosmologicalparameters

AALLIICCEE,,  SSeepp,,22001111

Power spectrum

8th !

Heavy Ion Collisions
Initial condition, QGP property (e.g. η/s)

6

LHC Heavy Ion Physics Highlights (Run-1: 2009-2013)•

Initial temperature: Tint ~ 304 ± 51 MeV-

Thermal photon radiation~1.4 x Tint (RHIC).

•

Denser (~x2) and longer lifetime w.r.t RHIC•

Strong collective flow, jet quenching.

•

Disappearance of excited Υ states, evidence forcreation of high temperature matter•

Recombination of c-cbar pairs (J/ψ)•

Collectivity in small system p-Pb, p-p (high multip.)•…

Y family melting
Jet quenching2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

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Energy balance by low pT particle at large angle
Slide from Y. Tachibana (ATHIC 2014)2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

8

QGP fluid + jet model

Y. Tachibana, ATHIC 20142015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

9Mach cone; EOS dep.
Y. Tachibana, T. Hirano,
PRC 90, 021902(R) (2014)•Diﬀerent cS for Ideal and lattice, diﬀerent angle.
•Possibility to measure cs (EOS) by soft hadron angle.
2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

10Keys to understand dE/dx in QCD plasma
1. Control path length (parton scattering point)
2. Energy calibration (e.g. γ-jet)
3. Detection of medium response by jet (parton)
propagation
5-1C$+(&/8%&V%4$A#&_8%+&41%.&/8%&./-1+()0&<1AI)%4&CA)9&D)1S%-&#1#%+/6#&I/-"+.$61+&/1&"&G%"9)0&<1AI)%4&I-1C%&D=$(=%-&#1#%+/6#&*
2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

11

Our project goals:• To perform high precision measurements and to develop
original physics data analysis during the LHC Run-2(2015-2018) for the quantitative determination of QPG
properties at the highest temperature.
• Particular emphasis on jets and photons measurements,
Japan and France in ALICE, by EMCal/DCal detectors,
which has been built within the framework of France-Japan
collaboration.
• Participation of Japan in the French lead upgrade project
MFT (Muon Forward Tracker) NEW
2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

12

2. Project report(2014-2015)

2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

ALICE jet results (1)RAA =Pb-Pb 2.76 TeV

dnAA /dpT dy”hot/dense QCDmedium”=”QCD vacuum”
Nbinary · dnpp /dpT dy

p-Pb 5.02 TeV• Observed jet suppression in Pb-Pb, un-modified in p-Pb.
2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

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Path length “control” experiment
π0-jet correlations
From TDR ALCE-DCal(work done by H.Yokoyama, M. Sano)•

Hard scattering point (in x-y plane) oftrigger π0 with associate recoil jet.
• The higher ET π0, the stronger surface
bias.
•<q-hat> = 20 & 50 GeV2/fm• small difference.
à can be used as geometry measureof emission point, without knowing thequench parameters.
2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

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ALICE jet results (2)D. Watanabe

π0-jet correlations in pp (7TeV)• Provide an important baseline data for Pb-Pb.
• Clear back-to-back jet peak is seen, andnarrower width with increasing jet pT andtrigger π0 pT.
• Now analyzing Pb-Pb data.

2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

16

DCal (Di-jet Calorimeter) in ALICE• Jet measurement including neutral particles, Electromagnetic Calorimeter for jet
trigger, DCal.
• Japan-France-US-Italy-China collaboration in ALICE• 2009: ALICE approval. supported by FJPPL.
• 2011: Finished all module production in Tsukuba and shipped them to France• 2013/2014: all SM tested at CERN (D. Watanabe, N. Tanaka, et al.)
• 2013-2015: EMCal/DCal/PHOS L1 jet trigger development (H. Yokoyama, R. Hosokawa,
R. Guernane)• Tsukuba-Grenoble collaboration for jet trigger.
• 2014 Nov.: Installation completed in ALICE P2• EMCal/ DCal detector, deputy project leader: T. Chujo (2013.11-)

DCal
EMCal

DCal / PHOS

PHOS

DCal detector modules before installation(Sep. 2013 @ CERN, ALICE assembly area)DCal detector modules after installation(Nov. 2014 @ CERN, ALICE)We ARE HERE

EMCal/ DCal/ PHOS Jet L1 trigger
Jet trigger efficiency（w/ BG subtraction from DCal side）

Rejection factor（w/ BG subtraction from DCal side）↑ DCal + PHOS trigger patch (H. Yokoyama)

H.Yokoyama, R. Hosokawa, R. Guernane, J. Kral, T. Chujo• Grenoble LPSC - Tsukuba- Jyvaskyla team for L0/L1 trigger• Tsukuba: EMCal/ DCal /PHOS Level-1 jet & photon
trigger, FPGA firmware development.
• Reasonable turn-on curve on jet trigger.
• Rejection factor 104 at 30 GeV jet.
2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

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Frist workshop in Tsukuba (March 3-7, 2014)
within the framework of France-Japan ALICE collaboration.
@ Univ. of Tsukuba, ~80 participants [FJPPL supported]2nd workshop in Sante-Maxime (March 15-16, 2015)“ALICE physics analysis workshop”~30 participants [FJPPL supported]

22

Dual	
  Degree	
  Program	
  (Ph.D)	
  Grenoble	
  U.	
  -­‐	  U.	
  of	
  Tsukuba• Grenoble	
  University	
  (Joseph	
  Fourier)	
  and	
  University	
  of	
  Tsukuba,	
  agreed	
  to	
  start	  the	
  joint	
  double	
  degree	
  program	
  (Ph.D)	
  in	
  2015.	
  • Supervised	
  by	
  two	
  insHtutes	
  (Grenoble	
  and	
  Tsukuba)	
  on	
  same	  thesis	
  topics.	
  • Ph.D	  degrees	
  will	  be	
  obtained	
  from	  both	  Grenoble	
  and	
  Tsukuba	
  aJer	  successful	  defense.	
  • Hiroki	
  Yokoyama	
  (U.	
  Tsukuba):	
  started	  April	
  2015.	
  • “pi0-­‐jet	
  correlaHons	
  in	  p-­‐Pb”,	
  jet	
  trigger	  • Ritsuya	
  Hosokawa	
  (U.	
  Tsukuba):	
  will	  start	  Sep.	
  2015.	
  • “Full	
  jet	  pT	  spectra	
  in	
  13	
  TeV	  p-­‐p	
  and	
  5.1	
  TeV	
  Pb-­‐Pb”,	
  jet	
  trigger	  • They	  are	  the	
  ﬁrst	  students	
  for	
  this	  program,	
  both	  worked	
  on	
  ALICE.

23

Muon Forward Tracker (MFT) Project
MFT: Muon Forward Tracker, proposed in ALICE (-4.0 < η < -2.5)• Silicon pixel tracker in Muon Spectrometer• Separation of charm/beauty down to very low p• Precise ψ(2s) measurement even in central Pb-Pb• Prompt and non-prompt J/ψ separation• Improve S/B ratio and mass resolution for Low Mass di-muons
T

The MFT project has been approved by the ALICE Collaboration to be part of the
ALICE upgrade planned for the LHC LS 2017/2018
Hiroshima G. joined for this project in 2014.

MUON
+ MFT

2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

24

3. Project Proposal(2015-2016)2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

ALICE	
  Run-­‐2	
  (2015-­‐2018)	
  and	  DCal,	
  jet	
  physics• 	  Highest	
  beam	  energy	  ever	
  at	
  LHC	  in	
  Run-­‐2	
  (2015-­‐2018)	
  
– pp	
  (	
  √s	
  =	
  13	
  TeV)	
  – Pb-­‐Pb	  (	  √sNN	
  =	
  5.1	
  TeV)	
  – p-­‐Pb	
  (	  √sNN	
  =	
  5.1	
  TeV?)	
  • Longest,	
  hoQest,	
  and	
  largest	
  QGP	
  creaSon	
  at	
  LHC	  • 2015	
  plan:	  – Run-­‐2	
  start	
  in	
  pp	
  (13	
  TeV)	
  in	
  June,	
  PbPb	  (Nov.)	
  2015.
Proton-proton collision at 900 GeV as determined by the innersilicon trackers in the ALICE detector (Image: ALICE/CERN)
http://home.web.cern.ch/about/updates/2015/05/low-energy-collisions-tune-lhc-experiments

26

Our proposal (2015-2016)• Run-2 start-up, and first physics data taking by DCal.
• Successful operation of EMCal/ DCal operation, jet trigger• Physics outputs from EMCal/DCal.
• Data analysis in Run-1 and new Run-2, will be presented at Quark
Matter 2015 international conference, Kobe, Sep-Oct, 2015, Japan(French collaborators will be invited).
• H. Hamagaki (chair)• Double degree PhD program for two students.
• Further involvement of MFT project.

qm2015.riken.jp

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2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)27

HAD_01: Project Members2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)28

HAD_01: Funding request (2015-2016)

FranceJapan* In addition to a support from France, we would like to ask a support from KEK forto conduct PhD double degree program for 2 students (Grenoble-Tsukuba)2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

29

4. Summary✓ 2014-2015:- ALICE DCal has been finally installed to ALICE experimental area
successfully.
- Jet Level 1 trigger development has been completed within the
FJPPL framework.
- Ready for the physics data taking in Run-2.
- Grenoble-Tsukuba PhD double degree program has been newly
launched in 2015.
- Newly involved in the MFT project in 2014 (Hiroshima).
✓ 2015-2016:– DCal first data, physics outputs on jet from ALICE w/ DCal.
(1) Develop double degree program(2) QM 2015 international conference in Kobe, Sep-Oct, 2015,
French collaborators will be invited.
- Asked TYL-FJPPL support for both (1) and (2).
2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

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Backup slides

2015 Joint Workshop of TYL/FJPPL and FKPPL @ OIST, May 20, T. Chujo (U. Tsukuba)

LHC schedule beyond LS1Only EYETS (19 weeks) (no Linac4 connection during Run2)
LS2
starting in 2018 (July)
18 months + 3months BC (Beam Commissioning)
LS3
LHC: starting in 2023 => 30 months + 3 BC
injectors: in 2024=> 13 months + 3 BC
2015

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LHC schedule approved by CERN management and LHC experiments spokespersons and technical coordinators
Monday 2nd December 201332

ment non-perturbatively into a set of final-state hadrons. The characteristic colli10
mated spray of hadrons resulting from the fragmentation of an outgoing parton 10
isalled a “jet”.
10

-10

10-8

-11

10-9

Jet quenching (energy loss of parton in QGP)
0

2

4

6

8

10

12

14

16

18

20

0

2

4

6

8

10

12

p (GeV/c)

14

16

18

20

p (GeV/c)

T

T

dnAA
”hot/dense
QCDmedium”/dpandFig. 15. Invariant+0 yields measured
by PHENIX in peripheral(left)
T dycentral (right)=
R=
0 + X cross section (cirAA
AuAu collisions (squares)[89],
comparedtothe(T-scaled)pp→+
AA”QCD vacuum”
Nbinary · dnpp /dpT dycles) [134] and to a NLO pQCD calculation (curves and yellow band) [119].
RAA

Au+Au - 200 GeV (central collisions):
Direct 2 , 2 * [PHENIX]
Inclusive h± [STAR]+0 [PHENIX]. [PHENIX]g
GLV energy loss (dN /dy = 1400)

10Ncoll scaling

1

10-1

Npart scaling

Fig. 2. “Jet quenching” in a head-on nucleus-nucleus collision. Two quarks suffer a hard scat0
2
4
6
8
10
12
14
16
18
20
p
(GeV/
c
)
１）DDeeccrreeaassee  ooff  hhiigghh  mmoommeennttuumm  ppaarrttiiccllee  
ering: one goesout directly to the vacuum, radiates a few gluons and hadronises, the otherT
oes through the dense plasma created (characterised by transport coefficient q̂, gluon density
Fig. 16. RAA (pT ) measured in central AuAu at 200 GeV for +0 [89] and . [135] mesons,yyiieellddss

N g /dy and temperature T ), suffers energy loss due to medium-induced gluonstrahlung andcharged hadrons [114], and direct photons [136, 137] compared to theoretical predictions fornally fragments outside into a (quenched) jet.
parton energy loss in a dense medium with dN g /dy = 1400 (yellow curve) [138].

✓•･

NNoo  oobbsseerrvvaattiioonn  aatt  lloowweerr  ccoolllliiddiinngg  
bbeeaamm  eenneerrggyy  ((ee..gg..  SSPPSS))

One of the first proposed “smoking guns” of QGP formation was “jet quench-

top RHIC energies is very close to the “participant scaling”, (N part /2)/Ncoll ≈ 0.17,ng” [6] i.e. the attenuation or disappearance of the spray of hadrons resulting fromexpected in the strong quenching limit where only hadrons coming from partons
２）DDiissaappppeeaarraannccee  ooff  bbaacckk--ttoo--bbaacckk  jjeettss  

produced at the surface of the medium show no final-state modifications in their
he fragmentation of a parton having suffered energy loss in the dense plasma prospectra [141]. From the RAA one can approximately obtain the fraction of energy
uced in the reaction (Fig. 2). The energy lost by a particle in a medium, &E, proEEnneerrggyy  lloossss  〜  ffeeww  GGeeVV//ffmm

lost, !loss = &pT /pT , via
ides fundamental information on its properties. In a general way, &E depends both1/(n−2)!loss ≈ 1 − RAA,(36)n the characteristics of the particle traversing it (energy E, mass m, and charge) and

✓
✓

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CCaannnnoott  eexxppllaaiinneedd  bbyy  hhaaddrroonn  ggaass..

n the plasma properties (temperature T , particle-medium interaction coupling1when', the AuAu and pp invariant spectra are both a power-law with exponent n, i.e.
nd thickness L),→  OOnnee  ooff  tthhee  eevviiddeenncceess  ooff  QQGGPP  
i.e. &E(E, m, T, ', L). The following (closely related) variables1/p
areT dN/d pT # p−n [142].
pedestal
and flow
At RHIC(n ≈ 8, RAA ≈ 0.2), one finds !loss ≈ 0.2.
T
xtremely useful to characterise the interactions of a particle inside a medium:
The high-pT AuAu suppression can be well reproduced by parton energy loss

ffoorrmmaattiioonn

models that assume the formation of a very dense system with initial gluon ra-

T. Chujo,2013)Jointof FJPPL()(TYL)
Yonsei Univ.
Seoul, Korea, June 4, 2013
the mean free path ( = 1/()*),
whereis theWorkshop
medium density# T 3andfor FKPPL,
ang