Perspectives for Heavy Flavour Physics in the ALICE detector

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Perspectives for Heavy Flavour Physics in the
ALICE detector

• CERN Heavy Ion Forum
• Ginés MARTINEZ GARCIA, Subatech
• for the ALICE collaboration
• Geneva, July 19th 2006

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Physics Motivations

• Dissociation and regeneration of quarkonia in hot
  QGP.
• Brownian motion and coalescence of low pT HQ in
  the quark gluon plasma (QGP).
• Energy loss of Heavy Quarks (HQ) in hot and high
  density medium formed in AA central collisions.
• Heavy flavour physics in pp collisions Quarkonia
  production mechanism, small x physics, gluon
  shadowing.

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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)
• Reference for Quarkonia

L.O.
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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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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 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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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 for HQ

• 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

Muon Spectrometer -4.lthlt-2.5
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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 ALICE PPR Vol.2
(to be published in J.Phys. G) 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-
PbPb central 10
Electron Identification (TRD)
sJ/Y 35 MeV s? 80 MeV dNch/dy 3000
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Quarkonia ? 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.

sJ/Y 65 MeV s? 100 MeV dNch/dy 6000
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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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Under-progress

• Measurement of DgtK-pp
• Electron-muon coincidences
• Polarization of the J/Y
• Measurement of beauty J/Y
• Measurement of beauty via tri-muon events
• Measurement of charm in the muon spectrometer
• Measurement of electro-weak bosons

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D gt K-pp

• Low pT under study
• Rebinning
• Additional cuts

Significance
Analysis feasible also without PID, but more time
consuming
pT integrated results
Elena BRUNA et Francesco PRINO, Torino
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J/Y polarization
1lt pT lt 4 GeV/c
4 lt pT lt 7 GeV/c
pT gt 7 GeV/c
Enrico SCOMPARIN et Roberta ARNALDI Torino
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Electro-weak bosons

• W- gt m- n
• Z0 gt m m-
• Cross-checking efficiency, resolution and
  integrated luminosity
• (Unique) shadowing measurements
• Reference for high pT muon suppression.

sres/MZ0 2 sint/MZ0 1.2
Zaida CONESA DEL VALLE et Nicolas BLUSSEAU, Nantes
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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
Electron triggers Bandwidth limitation
NPbPb central 2 .108 collisions
Hadron triggers Npp minb 2 .109 collisions
20 physics events per event
Hadron triggers NPbPb central 2 .107
collisions
????
????
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1st scenario for physics results

• ?Ldt dt 1030 cm-2 s-1 x 7.2x105 s
• 7.2x1035 cm-2(0.72 pb-1) for pp run at 14TeV
• Npp collisions 5x1010 collisions
• Enough for doing Heavy Flavours and electro-weak
  physics
• Spring 2008
• First pp collisions at 0.9 TeV end of 2007

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Conclusions

• D meson physics can be done in the central
  barrel
• Beauty physics can be done via single electron
  (ylt0.9), single muon (-4.ltylt-2.5)
  measurements, and dimuon correlated continuum
• Quarkonia physics can be done via dielectron and
  dimuon channels. Quarkonia polarization can be
  measured
• Beauty J/Y can be studied via di-electrons
• Electro-weak physics (in a unexplored y domain)
  via muon and dimuons quark-shadowing and
  baseline.

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Much more difficult (with the current setup)

• Open B meson measurements
• Open charm measurement in the muon channel.
• Heavy flavored baryon studies
• c quarkonia resonances
• J/Y dimuons from beauty decays
• Bottom-charmed mesons

Brain storming about future ALICE upgrades is
starting
Work done for Physics Performance Report of
ALICE, Vol. 2, and by the members of the Heavy
Flavour Working Group (PWG3).
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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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HI Quarkonia 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