1. Heavy flavours & quarkonia @ LHC
motivations
selected physics channels
quarkonia, B-hadron x-section, « hadronic » charm, heavy flavour quenching

2. Heavy-flavour x-sections @ LHC
c(LHC) = c(RHIC) × 10
b(LHC) = b(RHIC) × 100
W(LHC) = (RHIC) × 10
Z(LHC) = (RHIC)
K. Safarik

3. LHC
world data on total x-section of e+e-  hadrons (PDG06)
 (pb)
s (GeV)
a similar plot is accessible in LHC within a few weeks
typical number of reconstructed resonances in min-bias 5.5 TeV (1 month)   
J/
(1S) Z0
350·103
700·103
300·103
500·103
25·103
11·103

4. expected number of measured muons in min-bias PbPb @ 5.5 TeV (1 month)
Single LHC
14 TeV
charm
bottom W±
expected number of measured muons in min-bias 5.5 TeV (1 month)
charm
bottom W±
4·108
4·105
11·103
simulation by Z. Conesa del Valle

5. A closer look at heavy-quark cross-section
charm
14 TeV
bottom
(14 TeV) / (5.5 TeV)
5.5 TeV
charm thermal production ~ 25%
(assumes large medium temperature)
NLO predictions for LHC: a factor ~ 2 uncertainty
(14 TeV) / (5.5 TeV) ~ 10%
 measuring (c,b) in 14TeV is top priority
hep-ph/ , J. Phys. G 32 (2006) 1295, J. Phys. G 35 (2008)

6. Quarkonia suppression @ LHC
quarkonium dissociation temperatures
A. Mocsy & P. Petreczky, Phys. Rev. Lett. 99 (2007)
RHIC
LHC
hard gluon induced quarkonium breakup hep-ph/
whether J/ melts or RHIC it will be strongly either suppressed or LHC
use (2S) to unravel J/ sup. vs. reco  reco. is small: L. Grandchamp et al., PRC 73 (2006)
(1S) melts significantly only at LHC
additional suppression by hard gluons
relevance of quarkonium ratios vs. pt R. Vogt in J. Phys. G 35 (2008)
5.5 TeV

7. Charmonium regeneration @ LHC1. 2. 3.
peculiar centrality dependence
predictions strongly depend on cc
(re-)dissociation by comovers
regeneration  smaller <p2t>
note: N(B  J/) / N(direct J/) ~ 20% in 4 4.
A. Andronic et al., Phys. Lett. B 652 (2007) 259, J. Phys. G 35 (2008) , A. Capella et al., arXiv: [hep-ph], R. Thews et al., J. Phys. G 35 (2008)

8. Heavy quark quenching @ LHC: new ratios available
isolate mass dep. of E
sensitivity disappears at large pt
lower sensitivity to qhat
RD/h probes color charge dep. of E
RB/h probes mass dep. of E
N. Armesto et al., Phys. Rev. D 71 (2005) , J. Phys. G 35 (2008)

9. Heavy quark quenching @ LHC: new reference available
heavy quark energy loss:
shifts down the (c,b)/W crossing point by ~ 5-7 GeV/c
suppresses muon yield by a factor 2-5 for 2 < pt < 20 GeV/c
W affected by shadowing only
Z. Conesa del Valle et al., Phys. Lett. B 663 (2008) 202, J. Phys. G 35 (2008)

10. Heavy flavour flow @ LHC
resonance interactions increase v2
v2 quantitatively similar at RHIC & LHC
H. van Hess et al., Phys. Rev. C 73 (2006) , J. Phys. G 35 (2008)
more details in “Heavy Ion Collisions at the LHC, Last Call for Predictions”, May-June 2007, CERN proceedings: J. Phys. G 35 (2008)

11. Heavy LHC
CMS
ATLAS
ALICE

12. Heavy flavours with ALICE
electron-muon coincidences: open charm & bottom
ITS, TPC, TRD, ToF (||<0.9)
(di-)electrons: J/, ’, , ’,’’, open charm, open bottom, W±,Z0
muon spectrometer (-2.5<<-4)
(di-)muons: J/, ’, , ’,’’, open charm, open bottom, W±, Z0
hadrons: D0, D±,…

13. Heavy flavours with CMS & ATLAS
muon spectrometer & silicon tracker in central barrel & end-caps (||<2.5)
studies limited to J/, ’, , ’,’’ reconstruction & b-jet tagging
J/, ’, , ’,’’, open bottom, Z0

14. Acceptance for heavy flavour measurements
complementarity between the 3 experiments
ATLAS & CMS acceptance is large in  & limited to high pt
ALICE combines hadrons, electrons, muons & covers low pt & high 
ATLAS, CMS & ALICE-electrons/hadrons have inner tracking
ATLAS & CMS electron/hadron channels not yet investigated

15. Selected physics channels
Quarkonia
B from secondary J/
B from dileptons
B from single leptons
D0  K
Heavy flavour quenching
only “published” results

16. Quarkonia

17. Expected performances for quarkonia
WARNING: different simulation frameworks & different assumptions
bkg assumes dN/d = , S & S/S+B: one month min-bias PbPb (CC for ALICE e+e-)
ALICE +-
ALICE e+e-
CMS +-
ATLAS +-
acceptance
-4<<-2.5
||<0.9
||<2.4
||<2.5
charmonia
(J/) (MeV) 74 30
35 (w/o bkg) 68
S (×103)
677
120
146
8-216 (pt)
S/S+B
413
245
234
(pt)
bottomonia
() (MeV)
109 90
68-90 (bkg level)
145 (||<2)
S , ’, ’’
6800,1800,100
900,350,-
20300,5900,3500
S/S+B , ’, ’’
67,30,21
21,8
36,-,-
45-46
J/, : first detailed studies within one month
’: difficult (small S/B), ’, ’’: need 2-3 runs
From A. HP2006, updated according to ALICE: J. Phys. G 32 (2006) 1295, W. Sommer et al. @ QM2006, CMS: J. Phys. G 34 (2007) 2307, CMS/note-2006/089, ATLAS: L. HEP2007

18. Normalization for suppression studies
normalisation
pros.
cons.
open heavy flavours
most natural
quenching, thermal (charm) production
excited states
sensitivity to medium size & temperature
hard partons, exp. reach (e.g. ’)
Z0, W±
statistics, no hot medium effects
 prod. mechanisms (gg vs. qqbar),  Q2
RAA, Rcp
“easy”
mix cold & hot nuclear effects (i.e. need pA)
there is no golden normalization

19. Observables with bottomonia
suppression 1: TC = 270 MeV, TD/TC = 4.0 (1.4) for ϒ(ϒ’)
suppression 2: TC = 190 MeV, TD/TC = 2.9 (1.1) for ϒ(ϒ’)
statistics: one month 5.5 TeV
large sensitivity to dissociation temperatures and medium size
ALICE: J. Phys. G 32 (2006) 1295, CMS: J. Phys. G 34 (2007) 2307

20. (gen - rec) vs. pt pp @ 14 TeV
More with quarkonia
polarization
dN/dy in pp
pp: test production mechanisms
AA: probe QGP formation
probe gluon distribution at low x
(gen - rec) vs. pt 14 TeV
14 TeV: J/ &  pol. vs. pt
5.5TeV: J/  pol. vs. centrality,  pol. needs 2-3 runs
R. Analdi, E. Scomparin, D. Stocco

21. Open charm & bottom: accessible channels
charm: exclusive hadronic channels
D0  K (tested in pp & PbPb)
D+  K (tested in pp & PbPb)
D±s  KK (under study)
D*  D0 (under study)
D0  K (under study)
c  pK (under study)
charm & bottom: semi-inclusive leptonic channels
c  l + X (à la CDF & D0)
b  l + X (à la CDF & D0)
b  J/ + X (à la CDF & D0)
b  J/ + l (under study)
bbbar  3 (should work in pp)
bbbar  l+l-,l-l+ (Bchain & BBdiff)
bbbar  l-l-,l+l+ (Bchain & B osc.)
more exotic (and more challenging): QQbar  e, b  > 5 prongs, b  J/ + X, etc

22. Selected physics channels
Quarkonia
B from secondary J/
B from dileptons
B from single leptons
D0  K
Heavy flavour quenching
only “published” results

23. Secondary J/ from B hadron decay
N(B  J/) / N(direct J/) ~ 20% in LHC
(d0) < 50 µm for pt > 1.5/2/3 GeV/c in ALICE/CMS/ATLAS
disentangle primary & secondary J/
measure inclusive b cross-section
probe b quark in-medium energy loss
ALICE: CERN/LHC , CERN/LHCC 99-13, ATLAS: EPJC 33 (2004) s1023, CMS: CMS NOTE 2006/031, 2001/008

24. Using secondary J/ from B decay to probe b quark energy loss
secondary J/ from B decay in CMS, pt > 5 GeV/c
energy loss is included in 2 scenarios:
collisional energy loss
collisional + radiative energy loss
with energy loss:
yield reduced by a factor ~ 4
 distribution gets significantly narrower
I.P. Lokhtin & A.M. Snigirev, Eur. Phys. J. C 21(2001)155

25. B signal from high-mass dimuons with vertexing
 from BBbar
 from Drell-Yan
min-bias PbPb one month
r > 50 m suppresses Drell-Yan rate by 2 orders of magnitude with ~ 30% loss of signal
J. Phys. G 34 (2007) 2307

26. B signal from dimuons w/o vertexing
unlike-sign total
unlike-sign from bottom
unlike-sign from charm
like-sign from bottom
unfold mass continuum
large statistics is expected
systematics to be estimated
central PbPb (5%), one month
Mass (GeV/c2)
0-5
5-20
N from bb
41461793
6983130
R. Guernane et al., ALICE-INT , J. Phys. G 32 (2006) 1295

27. B hadron cross-section from single leptons
14 TeV B  +X
First step: extract Nl  B
w/o 2nd vertex: unfold lepton dN/dpt via combined fit
large statistics constrains fit
107 PbPb (5%) evts (1 month)
pt > 2 GeV/c, 200 < d0 < 600 m
80000 e from B, S/(S+B) = 80%
2.1·1012 pp evts (1 year)
pt > 2 GeV/c ·108  from B
with 2nd vertex: cut on dca & subtract remaining background
large purity of lepton sample
5.5 TeV B  e+X
J. Phys. G 32 (2006) 1295, DIMUONnet

28. B hadron cross-section from single leptons
Second step: correct for efficiency, acceptance & decay kinematics
total number of lB
integrated luminosity
lepton global detection efficiency
J. Phys. G 32 (2006) 1295, DIMUONnet

29. B hadron cross-section from single leptons
Third step: the B-hadron inclusive differential cross-section
w/o 2nd vertex
with 2nd vertex
B semi-muonic decays
pp, s = 14 TeV
method widely used (UA1, CDF, D0)
large pt reach, (very) small statistical errors, systematics ~ 10-15%
allows to get B RAA(pt), should work for charm as well
similar performances to be expected in ATLAS & CMS
J. Phys. G 32 (2006) 1295, DIMUONnet

30. background assumes dN/d = 6000 @  = 0
Hadronic charm
cos(pointing) > d0K  d0 < m2 increase S/B by 103
D0  K  (3.8%) c = 123 m
107 central PbPb (5%)
S ~ 13000
S/B ~ 10 %
S/(S+B) ~ 40
background assumes dN/d =  = 0
J. Phys. G 32 (2006) 1295

31. Hadronic charm differential x-section
system pp
pPb
PbPb
s (TeV) 14
8.8
5.5
trig MB CC
Nevt
109
108
107
time (months) 8 1
pt min (GeV/c)
0.5
Estat (%) 3 2 7
Esyst (%) 16 17
the most precise measurement of the total charm x-section in pp LHC
J. Phys. G 32 (2006) 1295

32. Testing QCD with hadronic charm in pp collisions @ 14 TeV
mc, F/0, R/0, PDF
bars: quadratic sum of statistical & systematic errors
expected experimental errors are much smaller than theoretical uncertainties
J. Phys. G 32 (2006) 1295

33. Heavy quark quenching: traditional ratios
1 nominal year: 107 central Pb-Pb events, 109 pp events statistics: bars, systematics: bands
sensitivity to shadowing for pt <~ 7 GeV/c & to energy loss for pt >~ 7GeV/c
J. Phys. G 32 (2006) 1295

34. Heavy quark quenching: more ratios
1 nominal year: 107 central Pb-Pb events, 109 pp events statistics: bars, systematics: bands
sensitivity to color charge dependence
sensitivity to mass dependence
J. Phys. G 32 (2006) 1295

35. Heavy flavours at the LHC provide a rich physics program
more analyses (not discussed here) are under study: heavy flavour flow, charm baryons, e- coincidences, b-tagged jets, Z0, W±,…
first collisions in one month!