Heavy Flavour Physics in ALICE Experiment

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Heavy Flavour Physics in ALICE Experiment

• Physics Performance Report
• CERN/LHCC 2005-030
• Ginés MARTINEZ GARCIA, Nantes
• for the ALICE collaboration
• Meeting of the LHC Committee February 15th 2006

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Physics Motivations

• Energy loss of Heavy Quarks (HQ) in hot and high
  density medium formed in AA central collisions.
• Brownian motion and coalescence of low pT HQ in
  the quark gluon plasma (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.
  

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Heavy Quarks in AA coll.

• Small xBj (10-3 10-5)
• DtQ 0.04 0.15 fm/c
• DtQ ltlt tQGP ltlt tQ
• Shadowing / Saturation
• HQ energy loss in QGP
• HQ coalescence (low pT)

L.O.
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Charmonia in AA collisions
SPS
RHIC
LHC
J/Y regeneration
J/Y melting
H. Satz, CERN Heavy Ion Forum, 09/06/05

• Melting of Y and c at SPS and RHIC, and melting
  of J/Y at LHC?
• Magic cancellation between J/Y suppression and
  J/Y regeneration?

22 (39) of J/Y (Y) from open beauty meson
decays.
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Bottomonia in AA collisions
CUSB Detector(Cornell)

• First measurement of Bottomonia.
• Regeneration is expected to be small at LHC.
• ?(2S) behaves as J/y TD?(2S) TDJ/y
• ?(1S) melts only at LHC.
• ?(2S)/?(1S) as a function of pT.

Dm(3S-2S) 332 MeV/c2
45 (30) of feed-down from higher resonances for
?(1S) (?(2S))
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ALICE capabilities

• ALICE combines electronic, muonic and hadronic
  channels
• ALICE covers down to pT 0 for quarkonia and
  open charm
• ALICE covers central (hlt0.9) and forward
  (2.5lthlt4.0) regions
• High precision vertexing in the central barrel

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Physics Analysis

• Hadronic decays
• D0?K p, D-?K p p, Ds?K K, Ds?f p,
• Leptonic decays
• B? l (e or m) anything.
• Invariant mass analysis of lepton pairs BB, DD,
  BDsame, J/Y, Y, ? family, B ?J/Y anything.
• BB ?m m m (J/Y m).
• e-m correlations.
• W- ? l- n, Z0?ll-.

In red channels studied in the PPR In black
under study
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D0?Kp channel

• High precision vertexing, better than 100 mm
  (ITS)
• High precision tracking (ITSTPC)
• K and/or p identification (TOF)

109 pp 108 pPb 107 PbPb
107 central PbPb
D ?Kp
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High Precision charm measurement
Central PbPb Shadowing kT energy loss
pp at 14 TeV Sensitivity to PDFs
Shadowing region
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Open Beauty from single electrons

• Electron Identification (TRDTPC)
• High precision vertexing (ITS)
• Subtraction of the open charm contribution.

107 central PbPb
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mm- correlations
Single Muons
BDsame
BB
5 central PbPb
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Energy loss physics
Charm Production Quark versus gluon Energy
Loss Higher gluon coupling
Beauty production Mass dependence of Energy
Loss Dead cone effect
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Quarkonia ? ee-, mm-
PbPb cent, 0 fmltblt3 fm
Yields for baseline

• ?(1S) ?(2S) 0-8 GeV/c
• J/Y high statistics 0-20 GeV/c
• Y poor significance
• ? ok, but 2-3 run will be needed.

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Suppression scenario

• Suppression-1
• Tc 270 MeV
• TD/Tc1.7 for J/Y
• TD/Tc 4.0 for ?.
• Suppression-2
• Tc190 MeV
• TD/Tc1.21 for J/Y
• TD/Tc 2.9 for ?.

PRC72 034906(2005)
Hep-ph/0507084(2005)
Good sensitivity J/Y, ?(1S) ?(2S)
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Slides for questions
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Quarkonia Acceptances
J/Y
J/Y
Di-electron channel
hlt0.9
2.5lthlt4.0
?
?
Di-muon channel
hlt0.9
2.5lthlt4.0
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mm- Minv in pp _at_ 14 TeV
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ee- Invariant Masses
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Running conditions
Lead-lead nominal run
Proton proton nominal run
?Ldt dt 3.1030 cm-2 s-1 x 107 s 5.1037 cm-2
for pp run, 14 TeV Npp collisions 2 .1012
collisions
?Ldt 5.1026 cm-2 s-1 x 106 s 5.1032 cm-2
PbPb run, 5.5 TeV NPbPb collisions 2 .109
collisions
????
????
Muon triggers 100 efficiency, lt 1kHz
Muon triggers 100 efficiency, 1kHz
Electron triggers 50 efficiency of TRD
L1 20 physics events per event
Electron triggers Bandwidth limitation
NPbPb central 2 .108 collisions
Hadron triggers Npp minb 2 .109 collisions

Hadron triggers NPbPb central 2 .107
collisions
????
????
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Charmonia spectroscopy
J/Y?mm-, ee- (BR 5.9)
y(2S) or y'
pp _at_ 14 TeV sJ/y 70 mb
1 J/y per 1000 pp collisions
27 from cc decay 22 from B decay 5.6 from y(2S)
y(2S) ? mm-, ee-(BR0.8)
60 direct y(2S) 39 from B decay
????
J/y
y(2S) / J/Y direct 1.7
y(2S) / J/y from B 5.2
????
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Bottomonia spectroscopy
?(1S)? mm-, ee- (BR 2.4)
pp _at_ 14 TeV s?(1S) 0.77 mb
1 ?(1S) per 105 pp collisions
?(3S)
29.0 from cb(1P) decay 9.5 from ?(2S) decay
4.5 from cb(2P) decay 1.5 from ?(3S) decay
?(2S)
?(2S)? mm-, ee- (BR 1.3)
25.0 from cb(2P) decay 4.5 from ?(3S) decay
?(3S)? mm-, ee- (BR 1.8)
????
?(1S)
Dm(3S-2S) 332 MeV/c2
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Acceptances
ATLAS CMS present a large lepton acceptance
hlt2.4
ALICE combines muonic and electronic channels
ALICE covers the low pT region ( pT0 for
quarkonia)
ALICE covers the forward region 2.5lthlt4.0
ATLAS, CMS ALICE-electron with high precision
vertexing
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Phenix Factor
T. Frawley