Quarkonia Measurements with ALICE at the LHC Frederick Kramer for the ALICE Collaboration IKF, Goethe-Universit¨ at Frankfurt Hadron 2011 Conference, Munich, June 16th, 2011 H-QM Quark Matter Studies IKF Helmholtz Research School Institut für Kernphysik Frankfurt
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Introduction J /ψ in pp Collisions Differential Cross Sections Multiplicity Dependence J /ψ in Pb-Pb Collisions Nuclear Modification Factors Frederick Kramer Quarkonia Measurements with ALICE at the LHC 1 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Introduction Frederick Kramer Quarkonia Measurements with ALICE at the LHC 1 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Physics Motivation: J /ψ in Heavy-Ion Collisions Quark-Gluon Plasma (QGP): Deconfined state of strongly interacting matter QGP induced effects: → AA c c ◮ Melting due to Debye screening � c c ◮ Recombination of uncorr. Q¯ Q ⇈ c c c c c c ◮ Thermal production (at LHC) ⇈ c c Frederick Kramer Quarkonia Measurements with ALICE at the LHC 2 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Physics Motivation: J /ψ in Heavy-Ion Collisions Quark-Gluon Plasma (QGP): Deconfined state of strongly interacting matter QGP induced effects: → AA c c c ◮ Melting due to Debye screening � c c ◮ Recombination of uncorr. Q¯ Q ⇈ c c c ◮ Thermal production (at LHC) ⇈ c c c c Frederick Kramer Quarkonia Measurements with ALICE at the LHC 2 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Physics Motivation: J /ψ in Heavy-Ion Collisions Quark-Gluon Plasma (QGP): Deconfined state of strongly interacting matter QGP induced effects: → AA J/ ψ D c c c D c ◮ Melting due to Debye screening � D c D c ◮ Recombination of uncorr. Q¯ D Q ⇈ J/ ψ c c c c ◮ Thermal production (at LHC) ⇈ D c D c D Frederick Kramer Quarkonia Measurements with ALICE at the LHC 2 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Physics Motivation: J /ψ in Heavy-Ion Collisions Quark-Gluon Plasma (QGP): Deconfined state of strongly interacting matter QGP induced effects: → AA J/ ψ D c c c D c ◮ Melting due to Debye screening � D c D c ◮ Recombination of uncorr. Q¯ D Q ⇈ J/ ψ c c c c ◮ Thermal production (at LHC) ⇈ D c D c D ◮ Cold nuclear matter effects: → pA ◮ Nuclear absorption (small at LHC) � ◮ Shadowing (depending on x ) �⇈ ◮ Direct Quarkonia production + feed down (J /ψ ) → pp Quarkonia in heavy-ion collisions - probe of deconfinement Frederick Kramer Quarkonia Measurements with ALICE at the LHC 2 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Physics Motivation: J /ψ in pp Collisions 1 0.8 0.6 CSM- CSM- 0.4 CDF Data NRQCD 0.2 0 α -0.2 -0.4 -0.6 -0.8 -1 5 10 15 20 25 30 p (GeV/c) T [J.P.Lansberg: Phys. Lett. B 695 (2011) 149] [A.Abulencia: Phys. Rev. Lett. 99(13) (2007) 132001] Competing models: ◮ Polarization ◮ Colour Singlet Model (CSM) parameter ◮ Non-Relativistic QCD approach (NRQCD) α = σ T − 2 σ L σ T +2 σ L ◮ Colour Evaporation Model (CEM) Elementary production mechanisms not well understood pp: crucial baseline for Pb-Pb Frederick Kramer Quarkonia Measurements with ALICE at the LHC 3 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook The ALICE Experiment ∼ 1000 members 116 institutes, 33 countries J /ψ → e + e − | y | < 0 . 9 p t > 0 TPC, ITS J /ψ → µ + µ − 2 . 5 < y < 4 . 0 p t > 0 Muon Spectrometer Frederick Kramer Quarkonia Measurements with ALICE at the LHC 4 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook J /ψ in pp Collisions Frederick Kramer Quarkonia Measurements with ALICE at the LHC 4 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook J /ψ in pp Collisions - Invariant Mass Spectra at 7 TeV J /ψ → e + e − J /ψ → µ + µ − μμ 4000 2 Counts per 40 MeV/c dN/dM OS ALICE pp s =7 TeV pp, s =7TeV 120 LS*1.25 ALICE Performance 3500 100 20/5/2011 80 3000 60 N = 15090 ± 278 J/ ψ = 85.6 1.0 MeV 40 2500 σ ± J/ ψ S/B (3 σ )= 2.5 20 2000 100 OS-1.25*LS 80 1500 2 MC ( χ /dof=1.1) 60 1000 40 20 500 0 -20 2 2.5 3 3.5 4 4.5 5 1.5 2 2.5 3 3.5 4 4.5 5 2 M (GeV/c ) 2 m (GeV/c ) μμ ee [ALICE: arXiv:1105.0380] ◮ Background: Subtraction of ◮ Fit of Crystal-Ball function like-sign spectrum (signal) + 2 exponentials ◮ Signal: Bin counting (background) Frederick Kramer Quarkonia Measurements with ALICE at the LHC 5 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Differential Cross Sections - 7 TeV d 2 σ /d p t d y d σ /d y b/GeV/c) 10 b) + - ALICE, e e pp s =7 TeV µ pp s =7 TeV + - /dy ( 9 ALICE, µ µ 1 CMS 8 LHCb ψ µ J/ dy ( σ 7 d T 6 /dp -1 5 10 ψ J/ σ 4 2 d 3 + - ALICE e e , |y|<0.9 + - ALICE , 2.5<y<4.0 µ µ 2 CMS, |y|<1.2 -2 10 ATLAS, |y|<0.75 1 open: reflected LHCb, 2.5<|y|<4.0 0 -5 -4 -3 -2 -1 0 1 2 3 4 5 0 2 4 6 8 10 12 y p (GeV/c) T [ALICE: arXiv:1105.0380], [CMS: arXiv:1011.4193], [ATLAS: arXiv:1104.3038], [LHCb: arXiv:1103.0423] p t spectra in good agreement with other LHC experiments Frederick Kramer Quarkonia Measurements with ALICE at the LHC 6 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Differential Cross Sections - 2.76 & 7 TeV d 2 σ /d p t d y d σ /d y b) b / GeV/c) ALICE preliminary µ /dy ( 9 inclusive J/ production ψ + - -1 1 e e , pp s =7 TeV, L=3.9 nb (arXiv:1105.0380) + - -1 ψ µ µ , pp s =7 TeV, L=13.3 nb (arXiv:1105.0380) 8 J/ - -1 e + e , pp s =2.76 TeV, L=1.1 nb σ µ d + - -1 ( , pp s =2.76 TeV, L=20.2 nb µ µ T 7 /dydp 6 ψ J/ σ 5 2 d -1 10 4 ALICE preliminary pp, 2.5<y<4 3 s =7 TeV, L=13.3 nb -1 (arXiv:1105.0380) s =2.76 TeV, L=20.2 nb -1 2 s =7 TeV, CS+CO NLO (M. Butenschoen et al., arXiv:1105.0820) 1 s =2.76 TeV, CS+CO NLO open: reflected (M. Butenschoen et al., priv. comm.) 0 -2 10 -5 -4 -3 -2 -1 0 1 2 3 4 5 0 1 2 3 4 5 6 7 8 y p (GeV/c) T Good agreement of d 2 σ /d p t d y with NLO NRQCD calculations Frederick Kramer Quarkonia Measurements with ALICE at the LHC 7 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Inclusive J /ψ Production vs. Collision Energy 12 b) 2 > (GeV/c) Inclusive J/ production ψ µ ALICE, |y|<0.9 ( preliminary ) ALICE 2.5<y<4, p <8 GeV/c /dy ( T CDF, |y|<0.6 PHENIX 1.2<|y|<2.2 10 10 PHENIX |y|<0.35 PHENIX, |y|<0.35 ψ T 2 J/ <p HERAB σ E866 d 8 NA50 NA3 NA60 6 4 1 2 line: d /dy, scaled to CDF data point σ c c NLO (MNR), m =1.2 GeV, = = 2m µ µ c F R c ALICE Preliminary 0 2 3 4 1 10 10 10 10 1/2 s s (TeV) [M.L.Mangano: Nucl. Phys. B373 (1992) 295] p 2 ◮ � � extracted from fits to the t ◮ ALICE mid-rapidity data follows p t differential distributions trend of cross section vs. √ s ◮ Approximately logarithmic increase with √ s ◮ NLO pQCD d σ c¯ c /d y prediction scaled to match CDF data Frederick Kramer Quarkonia Measurements with ALICE at the LHC 8 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook Multiplicity Dependence Y R J /ψ : Yield in multiplicity bin over yield per inelastic pp collision yield ALICE Preliminary 9 ψ yield over inclusive J/ pp at s = 7 TeV 8 J/ ee (|y| < 0.9) 7 ψ → 6 J/ (2.5 < y < 4.0) ψ → µ µ 5 4 ψ = J/ 3 ψ R J/ 2 Y Global systematic error : 8% 1 0 0 1 2 3 4 5 6 dN /d | η ch R =0 dN /d = η η ch <dN /d | > η ch =0 η Approximately linear increase with charged particle density Indication for multiple parton interactions Frederick Kramer Quarkonia Measurements with ALICE at the LHC 9 / 14
Introduction J /ψ in pp Collisions J /ψ in Pb-Pb Collisions Summary & Outlook J /ψ in Pb-Pb Collisions Frederick Kramer Quarkonia Measurements with ALICE at the LHC 9 / 14
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