Summary of recent(heavy ion) resultsfrom LHC

Tatsuya Chujo
2013 RHIC & AGS Annual Usersʼ Meeting
June 27, 2013, BNL, USAOutline✦ Introduction✦ First three years of LHC heavy ion runs
✦ Highlights from p-Pb results (2013)✦ SummaryT. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)2

13 yeas ago..., at BNL

June 12, 2000 @ PHENIXFirst collisions at RHIC at √sNN = 56 GeV Au+Au

about 9.5 years after...

2009.11.23 at the CERN-ALICE control room

First proton-proton collisions
p+p √s= 900 GeV

4

First proton-proton collisions
p+p √s= 900 GeV in ALICE (2009.11.23)

5

First ALICE
publication
submitted to EPJC 28 Nov 2009arXiv:0911.5430v2

Mar. 30, 2010
First p-p collisionsat √s = 7 TeV

Nov. 8, 2010
First Pb-Pb collisions at LHC,
the opening new era ofheavy ion program at LHC

LHC run history••

2009: Commissioning and first data p-p (900 GeV)•2011: Long p-p (7 TeV) and one month Pb-Pb(2.76 TeV) = x10 luminosity than that in 2010.
first p-p (2.76 TeV).

•2012: Long p-p (8 TeV), one day p-Pb (5.02 TeV)
pilot run•

2013: 1.5 month p-Pb and Pb-p run (5.02 TeV), (32nb-1 in ALICE)•

2013.02 - 2014 winter: LHC Long Shutdown 1(LS1) ← We are here now

2010: First p-p run (7 TeV) and first Pb-Pb run(2.76 TeV)

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)9

First three years of
LHC heavy ion runs

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)10

Initial temperature
Direct photon pT
spectra at LHC•Observed an excess overp-p baseline at low pT (< 2GeV/c).

T = 304

51 MeV•~30% higher than RHIC
RHIC (200 GeV Au+Au):
T = 221 ±19 ± 19 MeV
PHENIX, PRL 104, 132301 (2010)

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)11

Dissociation temperature
CMS, PRL 109(2012) 222301

Melting excited ϒ states• Suppression of ground state Y(1s), and excited states Y(2S) and Y(3S).
• Consistent with the sequential melting scenario, Y(3S) > Y (2S) > Y (1S).
T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)12

Freeze-out Tkin and <βT>

LHC
RHIC

Blast-wave fits
ALICE, PRL, 109 252301 (2012)
ALICE, arXiv:1303.0737• Tkin= 95 ± 10MeV

Signiﬁcant	  changes	  in	  slope	  compared	  to	  RHIC,	  especially	  for	  protons.
T. Chujo (U. Tsukuba)→ comparable with RHIC
• <βT>= 0.65 ± 0.02
→ 10% higher than RHIC

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)13

Tch and μb•

Measured dN/dy of PID
hadrons at mid-rapidity at LHC.

•

Data: feed-down corrected.

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)14

Tch and μb•

Measured dN/dy of PID
hadrons at mid-rapidity at LHC.

•

Data: feed-down corrected.

•Thermal statistical model with
Tch = 164 MeV, μb = 1 MeV➡

does not reproduce the datawell, especially p, Λ, φ, K*

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)15

Tch and μb•

Measured dN/dy of PID
hadrons at mid-rapidity at LHC.

•Data: feed-down corrected.

•Thermal statistical model with
Tch = 164 MeV, μb = 1 MeV➡

•

does not reproduce the datawell, especially p, Λ, φ, K*

Tch = 152 MeV, μb = 1 MeV w/oφ, K*, improving the fit, but
multi-strangeness (Ξ, Ω) does
not get right.
Indicating the importance of re-scattering at hadronic phase?

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)16Energy density

Multiplicity density:
2.1x Central Au-Au at 200 GeV

Energy density:~ 3 x RHIC (larger <mT>)

B.Mueller et al., Ann.Rev.Nucl.Part.Sci.62 (2012) 361
ALICE: PRL 106 (2011) 032301
CMS: JHEP 1108 (2011) 141
ATLAS: PLB 710 (2012) 363
T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)17

Freeze-out volume and lifetime• Freeze-out volume: 300 fm3 ~ 2 x RHIC.
• Lifetime: 10 fm/c ~ 40% longer than that at RHIC.

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)18

Elliptic flow v2 at LHC

ATLAS-CONF-2012-117

ALICE; PRL 105 (2010) 252302• 30 % increase compared to RHIC data, due to <p > increase.
• p dependence holds from RHIC to LHC.
• Suggesting similar η/s at LHC as RHIC produced.
TTT. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)19

vn and initial conditions, η/sCMS-HIN-12-011• v measurements byntwo particle
correlations, |Δη| >2, at very central
collisions (0-0.2%).

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)20

vn and initial conditions, η/s←Glauber with different η/s• Power spectrum of v .
• disentangle initial
ncondition and η/s.

←Glauber and CGS with η/s
VISH2+1 Hydro

CMS-HIN-12-011
T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)21

Further constraint on η/s; E-by-E vn
ATLAS-CONF-2012-114•Direct measurements ofv2, v3, v4 (only v2 shown).

•Model comparison:•••both work in 0-1%

•Glauber works in40-45%

MC-KLM (CGC)
works in 5-10%

Additional constrains byevent-plane correlations(ATLAS-CONF-2012-049).

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)22

Quark number scaling of v2
LHCRHIC

Pb-Pb events at sNN = 2.76 TeV

0.14

Centrality 20-40%

0.12

v2/nq

0.1
0.08
0.06/KpU
10.04
0.02
000.5

11.5

ALICE preliminary(m -m0)/nq [GeV]

22.5

TALI−PREL−12345

PHENIX, PRL 98, 162301 (2007)• K /n scaling at LHC does not work well like those at RHIC.
• Affected by a strong radial flow for protons (hadronic re-scatterings)?
ETq

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)23

Jets in LHC heavy ion collisions

Energy loss, single hadron RAA
RAA for EM probes, hadrons

Baryonenhancement(pT < 8 GeV/c)→
recombination+ radial flow

RAA for π, K, p
Equallysuppressed→Fragmentation•••

EM probes: RAA~1.
Hadrons: strong suppression RAA ~0.1 at ~7 GeV/c, and a rise at higher pT (RAA ~0.5).
Baryon enhancement is observed at intermediate pT.

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)25

Energy loss, jet RAA
ALICE (30-120 GeV)
Full jets (0-10%)

CMS (30-120 GeV)
Full (q/g) jets (0-5%)• a wide kinematic reach for jets at LHC.
• Jet R ~ 0.5 above 100 GeV/c, consistent with hadron’s R .
AA

T. Chujo (U. Tsukuba)

AA

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)26

Energy loss, jet RAA
ALICE (30-120 GeV)
Full jets (0-10%)

CMS (30-120 GeV)
Full (q/g) jets (0-5%)• Jet R from p = 30 - 300 GeV, consistent withAAT

hadron’s RAA.

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)27

Di-jet energy imbalance
CMS, PRC 84, 024906 (2011)

Large energy imbalance isobserved in central Pb-Pb.

ATLAS, PRL, 105 (2010) 252303

pT,1: leading jet
pT,2: sub-leading jetLarge AJ : low momentum
particle (< 4 GeV/c) emitted
at large angle on away side.

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)28

γ-jet: jet tomography
RJγ : fraction of photons with jet
partner

CMS, Phys. Lett. B 718 (2013) 773• γ as a calibrated probe of jet energy.
• significant change in R , <x > compared to PYTHIA and pp. 29
Jγ

T. Chujo (U. Tsukuba)

Jγ

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)

Heavy quark RAA• D mesons are also strongly suppressed.
• A hit of R > R (not yet conclusive). 30
AAT. Chujo (U. Tsukuba)

DAAπ

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)

Charm vs. Bottom• R for charmed
AAmeson (D) vs.
bottom meson(J/ψ from B
decay).

• First indicationof a massdependence ofRAA.

•RAA

B > RAAD* Note: not same kinematic range.
T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)31

J/ψ (color screening vs. regeneration)
mid-rapidity RAA for J/ψ

• J/ψ measured at

mid-rapidity |y|<0.9, by e+e- atLHC.

• Compared to
RHIC midrapidity data.

• Significantlarger RAA thanthose at RHIC.

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)32

J/ψ (color screening vs. regeneration)
forward-rapidity RAA for J/ψ

• J/ψ measured atforward-rapidity
2.5 < y < 4, by μ+μat LHC.

• Compared to

RHIC forwarddata.

• Significant larger

RAA than those atRHIC.

• Suppression isT. Chujo (U. Tsukuba)

stronger than thatat mid-rap.
33
RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)

J/ψ (color screening vs. regeneration)
Low pT: RAA at forward y, J/ψ→μ+μ-High pT: RAA at forward y, J/ψ→μ+μ-• J/ψ R is enhanced at low p .
• Compatible with models including
AAvs.

T

regeneration.

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)34

Charmonia flow (Inclusive J/ψ v2)
ALICE: arXiv:1303.5880• J/ψ produced via

regeneration ofthermal de-confinedc-quarks should
show a non zero v2.

• First hint of non‐zero v2.

• Consistent with thetransport model withregeneration.

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)35

Highlights fromp-Pb results (2013)

Sep. 13, 2012 (ALICE)
p+Pb test run

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)36

dN/dη, RAA in p-Pb
ALICE, PRL 110 (2013) 032301

ALICE, PRL 110 (2013) 082302• dN/dη: most models reproduce data <20%. CGC: steeper rise on shape.
• R ~ 1 in pPb: suppression in Pb-Pb central is a final state effect.
AAT. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)37

Di-Hadron Correlations in p-p & p-Pb
p-p (N ≧110)

p-Pb (N ≧110)• First observation ofridge structure inhigh multiplicity p-p(CMS).

• Also confirmed in p-Pb
high multiplicity
events.

• Alway side ridgestructure is observed inhigh multiplicity p-Pb.

p-Pb (ΣET Pb) < 20 GeVT. Chujo (U. Tsukuba)

p-Pb (ΣET Pb) > 80 GeV

CMS, JHEP 1009 (2010) 91
CMS, PLB 718 (2012) 795
ATLAS, PRL 110, 182302 (2013)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)38

Double ridge structure in p-Pb
ALICE, PLB 719 (2013) 29

0-20%

60-100%•Extract double ridge structure by subtracting p-p jet like
distribution in p-Pb (60-100%) from central p-Pb (0-20%).

•Confirmed that near and away side ridges are almost samestructure.

• Strong correlation between near and away sideyields, suggesting the same origin.

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)39

J/ψ RpPb

Comparison between prompt and inclusive J/ψ:• Measurements are consistent within uncertainties, although prompt is ~ 30%
lower overall.
• Provides further constraints on CGC model.
T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)40

Summary• Hottest, largest, longer lived QGP is produced at LHC
heavy ion collisions.

• There are similarities, differences compared to RHIC, andnewly discovered properties on QGP at LHC.

• We enter an era of determination of QGP properties byjets, photons, c/b quarks, quarkonium with bulk particles.

• Future• Run with full energy √s

NN = 5.5 TeV Pb-Pb in 2015-2017(Run-2), with upgraded detectors (LS1, ALICE).

• Preparing the detector upgrade for higher luminosity LHC run
during LS2 (2018) for Run-3 (2019-2022).

T. Chujo (U. Tsukuba)

RHIC & AGS 2013 annual users‘ meeting, BNL ( Jun. 27, 2013)41

Thank you for yourattentions!