motivationshq @lhcalice open flavours conclusionsquarkoniaelectroweak 1 alice potential for heavy...
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1Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
ALICE potential for Heavy Flavour
PhysicsGines MARTINEZ-GARCIA
for the ALICE collaborationSubatech, Nantes, France
2Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Physics Motivations
• Probing and characterizing the quark gluon plasma (QGP) in Heavy-Ion collisions;
• Energy loss of Heavy Quarks (HQ) in hot and high density medium formed in AA central collisions: quark coupling and dead-cone effect;
• Brownian motion and coalescence of low pT HQ in the QGP;
• Dissociation (and regeneration) of quarkonia in hot QGP;
• Heavy flavour physics in pp collisions: small x physics, pQCD, HQ fragmentation functions, gluon shadowing, Quarkonia production mechanism;
Motivations
3Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Heavy Quarks in HIC at LHC
• Small xBj (10-3 –10-5);
• Q ~ 0.04 –0.15 fm/c;
• Q QGP <<Q;
• Shadowing / Saturation;
• HQ energy loss in QGP;
• HQ thermalization (low pT);
L.O.
SPSPbP
bCent
RHIC
AuAu
Cent
LHCpp
LHC
pPb
LHCPbPb
Cent
Ncc/evt
0.2 10 0.2 1 115
Nbb/evt
- 0.05 0.007
0.03
5HQ @LHC
4Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Charmonia in HIC at LHC
PLB571 36 (2003)
• Melting of ’ and at SPS and RHIC, and melting of J/ at LHC?
• Magic cancellation between J/ suppression and J/ regeneration? 22 (39)% of J/ (’) from open beauty meson
decays.
SPS RHIC LHC
PLB637 75 (2006) J/ melting
J/ regeneration
HQ @LHC
5Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Bottomonia in HIC at LHC
(2S) (1S)
(3S)b(1P)b(2P)
SPS RHIC LHC
PRD64,094015
• First measurement of Bottomonia.
• Regeneration is expected to be small at LHC.
(1S) melts only at LHC.
(2S)/(1S) as a function of centrality and pT.
m(3S-2S) = 332 MeV/c2
45 (30)% of feed-down from higher resonances for (1S) ((2S))
CUSB Detector(Cornell)
HQ @LHC
6Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
ALICE Capabilities
• ALICE combines electronic, muonic and hadronic channels;
• ALICE covers down to pT ~ 0 for quarkonia and open charm;
• ALICE covers central (||<0.9) and forward (-4.0<<-2.5) regions;
• High precision vertexing in the central barrel;
ALICE
7Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Physics Analysis
• Hadronic decays:– D0K-, D+-K-+, DsK K*, Ds , …
• Leptonic decays:– Single lepton analysis:
– Open charm, open beauty, electro-weak bosons;
– Invariant mass analysis of lepton pairs: – BB, DD, BDsame, J/, ’, family, B J/ +
anything;– Multi-lepton analysis :
– BB J/ ;ALICE
8Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
D0 K-+ channel• High precision
vertexing, better than 100 m (ITS);
• High precision tracking (ITS+TPC);
• K and/or identification (TOF).
107 central
PbPb
1<pT<2 GeV/c
109 pp108 pPb107 PbPb
D K
Open Flavours
F. ANTINORI, A. DAINESE et al.
9Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
D+- K-++ channel
Open Flavours
QM06 Poster: E. BRUNA, F. PRINO et al.• Building K triplets from K pairs (as in D0 analysis);
• Secondary vertex quality: <180m, pointing angle: >0.995 and dist to primary vertex: >1900 m;
PbPb central Significance
for dNch/dy=6000 ~ 40 for dNch/dy=2000 ~ 90
Scaled to 107central PbPb
10Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Open Beauty from single e• Electron Identification
(TRD+TPC);• High precision
vertexing (ITS);• Subtraction of the open
charm contribution. 107 central
PbPb
Open Flavours
F. ANTINORI, M. LUNARDON, R. TURRISI et al.
11Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Open Beauty from and
BB
low mass
high mass
BDsame
5% central
PbPb
Single Muons
QM06 Poster: N. BASTID, Ph. CROCHET, R. GUERNANE et al.
Open Flavours
12Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Energy Loss PhysicsCharm Production:
Quark versus gluon Energy Loss
Lower quark coupling
Beauty production:Mass dependence of Energy
LossDead cone effect
Open Flavours
ALICE PPR Vol.2. J. Phys. G: Nucl. Part. Phys. 32 1295
13Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Quarkonia in ALICE
Quarkonia
J/
||<0.9
||<0.9
-4.0<<-2.5
-4.0<<2.5
J/
Di-electronchannel
Di-muonchannel
Until pT = 0
14Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Quarkonia in the electron channel
• Electron Identification (TRD+TPC);
• Tracking : ITS+TPC+TRD;• 2x108 central PbPb events (no
e-trigger).
QM06 Poster: W. SOMMER, C. BLUME et al.
Quarkonia
10% central PbPb dNch/dy = 3000
13x104 J/pT=0-10 GeV/c
900 (1S)
15Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Quarkonia in the muon channel
Quarkonia
• (1S) & (2S) : 0-8 GeV/c• J/ high statistics: 0-20 GeV/c• ’ poor significance • (3S) ok, but 2-3 run needed.
Yields for baseline
State
S[103
]B[103
]S/B S/
(S+B)1/2
J/ 130 680 0.20
150
’ 3.7 300 0.01
6.7
(1S)
1.3 0.8 1.7 29
(2S)
0.35 0.54 0.65
12
(3S)
0.20 0.42 0.48
8.1
PbPb cent, 0 fm<b<3 fmF. GUERIN, S. GRIGORYAN et al.
16Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
J/ (polarization) in pp
Quarkonia
R.. ARNALDI, D. STOCCO, E. SCOMPARIN, E. VERCELLIN et al.
p+p at 14 TeV
Nominal run 3x106 J/ ()pT 0-20 GeV/c
θ cos α 1cosθ ddσ2
>0 Transverse =0<0 Longitudinal
Possible with >50000 J/ ;Error below 10%; Bgk contribution small;Systematics in the J/ acceptance due to polarization ignorance bellow 10%.
17Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Suppression Scenarii
Quarkonia
• Suppression-1 Tc =270 MeV D/Tc=1.7 for J/ D/Tc= 4.0 for .
• Suppression-2 Tc=190 MeV D/Tc=1.21 for J/ D/Tc= 2.9 for .PRC72 034906(2005)
Hep-ph/0507084(2005)
Good sensitivity J/, (1S) & (2S)
Ph. CROCHET, F, GUERIN, R. GUERNANE, S. GRIGORYAN et al.
18Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Electroweak Boson Detection
ElectroWeak
Z. CONESA, L. APHECETCHE, Ch. FINCK and G. MARTINEZ
• Well known from SM (better than 10%);
• In principle no-interaction with QGP;
• Non explored region: • (M, x) = (80-90 GeV/c2, 10-3 -
10-4); • Luminosity and detector
efficiency cross-check;• Reference of quark (b) energy
loss;
b W
PbPb MB 14400 muons from
W
N+/N ~ 0.4
Di-muons from Z0 240 Z0 in MB
PbPb2400 Z0 in MB
ArAr
19Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Conclusions
• Heavy Flavour production will be measured by ALICE in A+A collisions at LHC energies;
• Exclusive open charm (D0, D+) combined to single-lepton and di-lepton continuum measurements of beauty;
• Huge statistics on charmonia: v2, polarization;– Regeneration: Centrality and pT dependance
• Bottomonia measurement: (2S)/(1S);• Electro-weak boson can be measured in AA:
reference for beauty energy loss;• Ds, c, J/ from B, multi-muon events, etc. have not
been addressed in this talk but should be accessible with ALICE.
Conclusions
20Motivations HQ @LHC ALICE Open Flavours ConclusionsQuarkoniaElectroWeak
Acknowledgements
Special thanks to R. Arnaldi, F. Antinori, L. Aphecetche, N. Bastid, Ch. Blume, E. Bruna, Z. Conesa del Valle, Ph. Crochet, A. Dainese, Ch. Finck, S. Grigoryan, F. Guerin, M. Lunardon, F. Prino, K. Safarik,
E. Scomparin, R. Turrisi, J. Schukraft, W. Sommer, D. Stocco and E. Vercellin for fruitful discussions and the preparation of this talk.
Caminante, son tus huellas el camino, y nada mas;
caminante no hay camino, se hace el camino al andar
Antonio Machado (H. S. QM2002, Nantes)
ALICE will begin to walk next year!