J/ψ and ψ(2s) production in pp and PbPb collisions at 5.02 TeV with ATLAS

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1 J/ψ and ψ(s) roduction in and PbPb collisions at 5. ev with ALAS Sebastian aia Araya, for the ALAS Collaboration 8th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions

2 Why measure the Quarkonia: Charmonia bound states of c and c quarks, could be a unique robe to study the hot, dense system created in nucleus-nucleus (A+A) collisions.. Matsui and H. Satz PLB 78 (986) 46 However, the full icture is much more comlicated - Color-Screening: melting - Color-exchange: absortion - Medium induced energy loss - Regeneration via statistical recombination - Feed-Down of excited charmonium states and B-hadrons

3 Method Reconstructed dimuons in Invariant Mass.6 < Mμμ < 4. GeV rigger PbPb - L rigger: Single MU4 (PbPb) - High Level rigger: muons, > 4 GeV rigger - L rigger: Double MU4 - High Level rigger: muons, > 4 GeV Measurements of romt and non-romt J/ψ and ψ(s) Kinematic Range: 9 < < 4 GeV and y <, centrality -8% Perform weighted D unbinned maximum likelihood fit - dimuon Invariant mass and lifetime - Per-dimuon weight: trigger and reconstruction efficiency; accetance - Parametrize signal, background and non-romt fraction 3

4 Simultaneous Fit Method rojections seudo-roer decay time Entries / ( MeV) < y <.5 < 6. GeV ALAS Preliminary s = 5. ev, Ldt Data Fit Promt ψ(ns) = 5 b Non-romt ψ(ns) Bkg = L xym µµ µµ LXY = rojection of decay length on the transverse lane m µµ Entries / (. s) < y <.5 < 6. GeV ALAS Preliminary s = 5. ev, Ldt Data Fit Promt ψ(ns) = 5 b Non-romt ψ(ns) Bkg τ [s]

5 Simultaneous Fit Method PbPb rojections Invariant dimuon Entries / ( MeV) 5 3 < < 7 GeV ALAS Preliminary 4 3 < y -8% <.5 PbPb = 5. ev,.49 nb s NN Data Fit Promt ψ(ns) Non-romt ψ(ns) Bkg m µµ mass and lifetime Entries / (. s) < < 7 GeV < y <.5-8% ALAS Preliminary PbPb s NN Data Fit = 5. ev,.49 nb Promt ψ(ns) Non-romt ψ(ns) Bkg Weights: Accetance, trigger and reconstruction efficiency τ [s] 5

6 Differential roduction Cross Section Promt J/ψ and ψ(s) 5. ev [nb/gev] σ dy d d ) - Br(J/ψ µ + µ 3 3 NRQCD ALAS Preliminary s = 5. ev, Ldt Promt J/ψ Data,.5 < y <. Data,.75 < y <.5 Data,. < y <.75 = 5 b [nb/gev] σ dy d d ) - µ + Br(ψ(S) µ NRQCD ALAS Preliminary Data,.5 < y <. Data,.75 < y <.5 Data,. < y <.75 s = 5. ev, Ldt Promt ψ(s) = 5 b As can be seen, the data are in very good agreement with the theoretical rediction within the uncertainties. 6

7 Differential roduction Cross Section non-promt J/ψ and ψ(s) 5. ev [nb/gev] σ dy d d ) - Br(J/ψ µ + µ 3 3 FONLL ALAS Preliminary Data,.5 < y <. Data,.75 < y <.5 Data,. < y <.75 s = 5. ev, Ldt Non-Promt J/ψ = 5 b [nb/gev] σ dy d d ) - µ + Br(ψ(S) µ FONLL ALAS Preliminary Data,.5 < y <. Data,.75 < y <.5 Data,. < y <.75 s = 5. ev, Ldt Non-Promt ψ(s) = 5 b As can be seen, the data are in very good agreement with the theoretical rediction within the uncertainties. 7

8 Non-romt fraction of J/ψ in 5. ev vs. for y slices f (ns) NP = N (ns) NP N (ns) NP + N (ns) P Non-Promt Fraction.8.6 ALAS Premilinary s = 5. ev, Ldt J/ψ Non-Promt Fraction. < y < < y <.5.5 < y <. = 5 b.4. Strong deendence No significant y deendence

9 Non-romt fraction of J/ψ in 5. ev, 3 ev and.96 ev Non-Promt Fraction ALAS Premilinary J/ψ Non-Promt Fraction ALAS 3 ev, 6.4 b, y <.75 ALAS 5. ev, 5 b, y <.75 CDF ().96 ev, 39.7 b, y <.6. Good agreement between the different energies

10 RAA vs. Integrated y and centrality R AA = N AA h AA i Promt non-promt R AA.4. ALAS Preliminary PbPb, s NN = 5. ev,.49 nb, s = 5. ev, 5 b Promt J/ψ, y < -8% centrality R AA.4. ALAS Preliminary PbPb, s NN = 5. ev,.49 nb, s = 5. ev, 5 b non-promt J/ψ, y < -8% centrality Increasing RAA as a function of Flat along the range

11 RAA vs. y Integrated and centrality Promt non-promt R AA.4. ALAS Preliminary PbPb, s NN = 5. ev,.49 nb, s = 5. ev, 5 b Promt J/ψ, 9 < < 4 GeV -8% centrality R AA.4. ALAS Preliminary PbPb, s NN = 5. ev,.49 nb, s = 5. ev, 5 b non-promt J/ψ, 9 < < 4 GeV -8% centrality y y No significant y deendence

12 RAA vs. Nart Integrated and y Promt Nart: mean number of articiant non-promt R AA.4. ALAS Preliminary PbPb,, s NN = 5. ev,.49 nb s = 5. ev, 5 b Promt J/ψ, y <., 9 < < 4 GeV R AA.4. ALAS Preliminary PbPb,, s NN = 5. ev,.49 nb s = 5. ev, 5 b non-promt J/ψ, y <., 9 < < 4 GeV N Part N Part J/ψ is strongly suressed in most central collisions

13 Suression of ψ(s) to J/ψ vs Nart Promt non-promt J/ψ /R AA ψ(s) R AA.5 ALAS Preliminary PbPb,, = 5. ev,.49 nb s NN s = 5. ev, 5 b J/ψ /R AA ψ(s) R AA.5 ALAS Preliminary PbPb,, = 5. ev,.49 nb s NN s = 5. ev, 5 b.5 Promt, y <., 9 < < 4 GeV.5 non-promt, y <., 9 < < 4 GeV N Part N Part Stronger suression of ψ(s) with resected to the J/ψ 3 Consistent with

14 Conclusions collision - Measurement of the J/ψ and ψ(s) roduction Cross Section for romt and non-romt comonent. - Measurement of non-romt fraction. First measurement of quarkonia roduction in PbPb with ALAS - Per-event Yields of romt and non-romt roduction of J/ψ for different centrality classes. - non-romt fraction for different centrality classes. - J/ψ RAA as a function of, y and NPart. For romt and nonromt comonent. - ψ(s) to J/ψ double ratio as a function of NPart. For romt and non-romt comonent.

15 Additional Slides

16 Centrality vs. Fcal

17 Per-event-yields romt and non-romt J/ψ J/ψ [/GeV] y ALAS Preliminary PbPb s NN = 5. ev,.49 nb Promt J/ψ, y <. J/ψ [/GeV] y ALAS Preliminary PbPb s NN = 5. ev,.49 nb Non-romt J/ψ, y <. N evt N N evt N 3 -% -4% 4-6% 6-8% % -4% 4-6% 6-8% Non-Promt Fraction % -4% 4-6% 6-8% ALAS Preliminary PbPb s NN = 5. ev,.49 nb J/ψ, y <. Poster by Jorge

18 Simultaneous Fit Method