Federico Antinori - LBNL Heavy Quark Workshop - 3 November Heavy Flavour in ALICE Federico Antinori (INFN Padova & CERN) for the ALICE Collaboration

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Contents The LHC, Heavy Flavours and ALICE The LHC, Heavy Flavours and ALICE or “ALICE in Wonderland” or “ALICE in Wonderland” Benchmark channels Benchmark channels D 0  K -  + D 0  K -  + B  e + X B  e + X B  µ + X B  µ + X Additional measurements under investigation Additional measurements under investigation D +  K -  +  + D +  K -  +  + B  J/  + X B  J/  + X v 2 v 2 D s D s b tagged jets b tagged jets Coming up: pp Coming up: pp Conclusion Conclusion

Federico Antinori - LBNL Heavy Quark Workshop - 3 November The LHC, Heavy Flavours and ALICE

Federico Antinori - LBNL Heavy Quark Workshop - 3 November LHC Running conditions: Running conditions: + other ions (Sn, Kr, O) & energies (e.g.: 5.5 TeV) + other ions (Sn, Kr, O) & energies (e.g.: 5.5 TeV) *L max (ALICE) = ** L int (ALICE) ~ 0.5 nb -1 /year Collision system √s NN (TeV) L 0 (cm -2 s -1 ) Run time (s/year)  geom (b) pp * PbPb ** 7.7 pPb ArAr

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Heavy LHC cc and bb rates cc and bb rates ALICE PPR (NTLO + shadowing) ALICE PPR (NTLO + shadowing) 115 / / / 0.2 Pb-Pb 5.5 TeV (5% cent) 0.16 / / / 0.5 pp 14 TeV shadowingsystem NN x-sect (mb) total multiplicity PbPb pp PbPb pp cc bb PbPb/pp

Federico Antinori - LBNL Heavy Quark Workshop - 3 November large cross-sections large cross-sections low-x (a field of its own!) low-x (a field of its own!)  accessible x1, x2 regions in the ALICE experiment central detector muon arm

Federico Antinori - LBNL Heavy Quark Workshop - 3 November study medium with probes of known colour charge and mass study medium with probes of known colour charge and mass  e.g.: energy loss by gluon radiation expected to be: parton-specific: stronger for gluons than quarks (colour charge ratio = 9/4) parton-specific: stronger for gluons than quarks (colour charge ratio = 9/4) flavour-specific: stronger for lighter than for heavier quarks (dead-cone effect) flavour-specific: stronger for lighter than for heavier quarks (dead-cone effect) study effect of medium on fragmentation (no extra production of c, b at hadronization) study effect of medium on fragmentation (no extra production of c, b at hadronization)  independent string fragmentation vs recombination e.g.: D + s /D + e.g.: D + s /D + + measurement important for quarkonium physics + measurement important for quarkonium physics open QQ production natural normalization for quarkonium studies open QQ production natural normalization for quarkonium studies B meson decays non negligible source of non-prompt J/  at LHC B meson decays non negligible source of non-prompt J/  at LHC

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Large suppression at RHIC! yet, region above 3-4 GeV expected to be dominated by beauty... yet, region above 3-4 GeV expected to be dominated by beauty... [Xin n.p. electrons ~ as suppressed as expected for c only (no b) n.p. electrons ~ as suppressed as expected for c only (no b) scaled to M. Cacciari et al., hep-ph/ disentangling c/b is a must! disentangling c/b is a must! e.g. full reconstruction of D vertices e.g. full reconstruction of D vertices non phot. el.

Federico Antinori - LBNL Heavy Quark Workshop - 3 November By the way: the factor 9/4? energy loss should be proportional to: C R = 4/3 for q, = 3 for g energy loss should be proportional to: C R = 4/3 for q, = 3 for g at RHIC, at 6-8 GeV p T : x ~ at RHIC, at 6-8 GeV p T : x ~  large quark contribution also for light flavours? at LHC, at same p T : x ~ a few at LHC, at same p T : x ~ a few  quark contribution negligible

11/2006 PSI J. Schukraft 10 ALICE Set-up HMPID Muon Arm TRD PHOS PMD ITS TOF TPC Size: 16 x 26 meters Weight: 10,000 tons

Federico Antinori - LBNL Heavy Quark Workshop - 3 November ALICE Status Timeline: Timeline: Installation & commissioning ongoing Installation & commissioning ongoing Global commissioning in December & February (cosmics) Global commissioning in December & February (cosmics) April 2008 on: cosmics, then pp run (commissioning  physics) April 2008 on: cosmics, then pp run (commissioning  physics) followed by first Pb-Pb run (√s = 5.5 TeV, L = 5·10 25 cm -2 s -1 ) followed by first Pb-Pb run (√s = 5.5 TeV, L = 5·10 25 cm -2 s -1 ) Startup configuration: Startup configuration: complete: ITS, TPC, TOF, HMPID, muon arm, PMD, trigger dets (V0, T0, ZDC, Acorde) complete: ITS, TPC, TOF, HMPID, muon arm, PMD, trigger dets (V0, T0, ZDC, Acorde) partially complete: PHOS (3/5), TRD (5/18), DAQ/HLT (20-30%) partially complete: PHOS (3/5), TRD (5/18), DAQ/HLT (20-30%)

Federico Antinori - LBNL Heavy Quark Workshop - 3 November |η| < 0.9: B = 0.4 T TRD TPC ITS with: - Si pixel - Si drift - Si strip Tracking

Federico Antinori - LBNL Heavy Quark Workshop - 3 November longitudinal coverage: |  | < 1 (tracking), |  |<2 (multiplicity) Inner Tracking System (ITS)

Federico Antinori - LBNL Heavy Quark Workshop - 3 November ITS Installation

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Silicon Pixel Detector (SPD) PIXEL CELL z: 425  m r  : 50  m Two layers: r = 4 cm r = 7 cm  9.8 M

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Expected resolution on track impact parameter track impact parameter (d 0 ) track impact parameter (d 0 )

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Benchmark channels

Federico Antinori - LBNL Heavy Quark Workshop - 3 November D0  K-+D0  K-+D0  K-+D0  K-+ expected ALICE performance expected ALICE performance S/B ≈ 10 % S/B ≈ 10 % S/  (S+B) ≈ 40 (1 month Pb-Pb running) S/  (S+B) ≈ 40 (1 month Pb-Pb running) statistical. systematic. p T - differential

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Beauty to electrons Expected ALICE performance (1 month Pb-Pb) Expected ALICE performance (1 month Pb-Pb) e ± identification from TRD and dE/dx in TPC e ± identification from TRD and dE/dx in TPC impact parameter from ITS impact parameter from ITS S/(S+B) S per 10 7 central Pb-Pb events

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Electrons (from b) p t spectrum Error composition stat error stat  syst error 11% from overall normalization not included

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Expected performance on D, B R AA m b = 4.8 GeV D 0  K    B  e + X 1 year at nominal luminosity (10 7 central Pb-Pb events, 10 9 pp events) should clarify the heavy flavour quenching story should clarify the heavy flavour quenching story mass dependence colour charge dependence

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Beauty to single muons expected in the muon arm expected in the muon arm  very high statistics and heavy flavour purity expected low mass  high mass 

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Beauty to dimuons Two main sources: Two main sources: Bµ + + D + X µ - + X B B X + µ + “BD SAME ”“BB DIFF ”  Consistency check!

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Additional measurements under investigation

Federico Antinori - LBNL Heavy Quark Workshop - 3 November D+  K-++D+  K-++D+  K-++D+  K-++ Preliminary study: performance comparable to that for D 0  K -  + Preliminary study: performance comparable to that for D 0  K -  + Pb-Pb significance ~ 30 (1 month)

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Ds+Ds+Ds+Ds+ D s + as probe of hadronization? D s + as probe of hadronization? from string fragmentation: cs / cd ~ 1/3 from string fragmentation: cs / cd ~ 1/3 after decays: D s + (cs) / D + (cd) ~ 0.6 after decays: D s + (cs) / D + (cd) ~ 0.6 from recombination: cs / cd ~ N(s) / N(d) from recombination: cs / cd ~ N(s) / N(d)  how large at LHC? experimentally accessible? experimentally accessible? D + (c  ~ 310 µm)  K -  +  + with BR ~ 9.2 % D + (c  ~ 310 µm)  K -  +  + with BR ~ 9.2 % in Alice: expect similar performance as for D 0  K -  + in Alice: expect similar performance as for D 0  K -  + D s + (c  ~ 150 µm)  K - K +  + with BR ~ 4.4 % D s + (c  ~ 150 µm)  K - K +  + with BR ~ 4.4 % but mostly resonant decays:  + or K 0 * K + (non resonant only 20 %) but mostly resonant decays:  + or K 0 * K + (non resonant only 20 %)  favours bkgnd rejection (for D +  K -  +  +, non-resonant ~ 96 %)  may be well visible (expecially if D s + /D + is large!) Under study! Under study!

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Heavy Flavour v 2 v 2 = azimuthal anisotropy  elliptic flow v 2 = azimuthal anisotropy  elliptic flow can get charm v 2 from can get charm v 2 from direct charm elliptic flow direct charm elliptic flow non-flowing c recombining with flowing matter non-flowing c recombining with flowing matter azimuthally dependent energy loss azimuthally dependent energy loss...?...?  in general, v 2  0 if charm “strongly coupled” with azimuthally asymmetric medium...

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Non photonic el. RHIC to what extent can one accommodate small v 2 with large suppression? to what extent can one accommodate small v 2 with large suppression? [Xin

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Reconstructed D v 2 at LHC? Full reconstruction of D decays at LHC Full reconstruction of D decays at LHC qualitatively different measurement from non-photonic electrons! qualitatively different measurement from non-photonic electrons! better correlation with original heavy-quark momentum better correlation with original heavy-quark momentum b vs c b vs c First indications from preliminary studies in ALICE: expected error ~ few % (D v 2 ) First indications from preliminary studies in ALICE: expected error ~ few % (D v 2 )

30 B  J/  + X More “exclusive” than B  e/µ + X More “exclusive” than B  e/µ + X better handle on B momentum distribution better handle on B momentum distribution Preliminary pp study: pseudoproper decay time Preliminary pp study: pseudoproper decay time (à la CDF) CDF (data) ALICE (prelim. simulation) p T >0

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Heavy flavour jets? 2 GeV 20 GeV 100 GeV 200 GeV Mini-Jets 100/event 1/event 100k/month Well visible event-by-event! e.g. 100 GeV jet + underlying event Well visible event-by-event! e.g. 100 GeV jet + underlying event For high energy jets: Nb ~ Nu,d For high energy jets: Nb ~ Nu,d  heavy flavour rich! b-tagged jets? b-tagged jets?  study quenching of b jets!  Preliminary look: impact parameter tagging looks promising (full simulation needed)

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Coming up: pp

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Example: D 0 in pp D 0  K -  + D 0  K -  + 1 year run  ~ 10 9 events 1 year run  ~ 10 9 events ~ 20 shifts, 10 hrs each  a few 10 7 events ~ 20 shifts, 10 hrs each  a few 10 7 events  reach out to 12 GeV or so

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Example: B  e + X in pp electron id in TRD and TPC, electron impact parameter from ITS electron id in TRD and TPC, electron impact parameter from ITS

Federico Antinori - LBNL Heavy Quark Workshop - 3 November Conclusion Heavy flavours kindly provide us with a very promising tool to study the properties of the strongly interacting medium produced in ultra-relativistic nucleus-nucleus collisions Heavy flavours kindly provide us with a very promising tool to study the properties of the strongly interacting medium produced in ultra-relativistic nucleus-nucleus collisions At LHC At LHC  very high rates  very high rates  very extended p T range  very extended p T range  well developed jets  well developed jets ALICE is well equipped for heavy flavour physics ALICE is well equipped for heavy flavour physics