Quarkonium production in pp at LHC

Transcription

1 Quarkonium production in pp at LHC CMS ψ χc J/ψ γ LHCb ϒ χc1 χc0 Quarkonia in Deconfined MaEer 8 30 Sept. 011, Acitrezza, Italy CMS χc Hermine K. Wöhri CERN

2 J/ψ fraction from B decays Prompt and non- prompt J/ψ mesons are separated through the lifewme dimension l J/ψ [mm] l J/! = L xy! m J/! p [pseudo- proper decay length]

3 J/ψ fraction from B decays vs. p and y (005) 3 At the beginning there was CDF : the B fracwon increases with p, at mid- rapidity Fraction of J/! from b hadrons CDF s = 1.96 ev y < 0.6 PRD 71 (005) J/! p [GeV/c]

4 J/ψ fraction from B decays vs. p and y (0) 4 At ICHEP, in July 0, CMS and LHCb and ALAS presented early measurements fraction of J/ from B-hadrons CMS CMS 0 nb 0 nb LHCb 14. nb ALAS 17.5 nb LHC s = 7 ev Preliminary 1.4 < y <.4 y < < y < 4.0 y < CDF J/ p [GeV/c] No significant change visible between sqrt(s) = and 7 ev A first result ager only 3 months of LHC running! s = 1.96 ev y < 0.6 PRD 71 (005) 03001

5 J/ψ fraction from B decays vs. p and y (011) 5 In March 011 LHCb presented very detailed measurements, in 5 rapidity bins Fraction of J/! from b hadrons LHCb s = 7 ev 5. nb pb < y <.5.5 < y < < y < < y < < y < J/! p [GeV/c] he B fracwon, for a given p, increases from forward to central rapidity [EPJC711 (011) 1645]

6 J/ψ fraction from B decays vs. p and y (011) 6 LHCb also provided measurements in 5 rapidity bins, integrated in p J/ψ from B J/ψ from B + prompt J/ψ here is a larger B fracwon at mid- rapidity than at forward rapidity! Fraction of J/! from b hadrons y

7 J/ψ fraction from B decays vs. p and y (011) 7 Also ALAS presented very detailed measurements [arxiv: ] Fraction of J/! from b hadrons ALAS ALAS pb nb nb < y < < y y <.0.0 s = 7 ev J/! p [GeV/c] he ALAS mid- rapidity data nicely follows the trend of the LHCb data We see that at high p the fracwon tends to saturate (as expected) LHCb 5. pb nb < y < < y < < y < 4.5

8 J/ψ fraction from B decays vs. p and y (011) 8 What about CMS? Fraction of J/ψ from b hadrons CDF p [GeV/c] he mid- rapidity data points seem to show a similar behaviour for s = 1.96 and 7 ev but the (very precise!) CMS measurements sit systemawcally higher than those of CDF ALAS.3 pb 0.0 < y < 0.8 s = 1.96 ev y < 0.6 PRD 71 (005) s = 7 ev J/ψ CMS 36.7 pb 0.0 < y < 0.9

9 J/ψ fraction from B decays vs. p and y (011) 9 What about CMS? Fraction of J/ψ from b hadrons s = 7 ev CMS 36.7 pb 0.0 < y < < y < p he CMS measurements also show a slight change with rapidity J/ψ [GeV/c]

10 J/ψ fraction from B decays vs. p and y (011) What about CMS? Fraction of J/ψ from b hadrons CMS s = 7 ev 314 nb 1. < y < 1.6 CMS 36.7 pb 0.0 < y < < y < < y < p he CMS measurements also show a slight change with rapidity J/ψ [GeV/c]

11 J/ψ fraction from B decays vs. p and y (011) 11 What about CMS? Fraction of J/ψ from b hadrons CMS s = 7 ev 314 nb 1. < y < < y <.4 CMS 36.7 pb 0.0 < y < < y < < y < p he CMS measurements also show a slight change with rapidity.1 < y <.4 J/ψ [GeV/c]

12 J/ψ fraction from B decays vs. p and y (011) 1 What about CMS? Fraction of J/ψ from b hadrons CMS 314 nb p For a given p, the most mid- rapidity CMS data show a rather different B- fracwon than the most forward LHCb data LHCb 5. pb.0 < y <.5.5 < y < < y < < y < < y < 4.5 s = 7 ev J/ψ 1. < y < < y <.4 CMS 36.7 pb 0.0 < y < < y < < y < < y <.4 [GeV/c]

13 Prompt J/ψ p distributions from LHCb 13 LHCb presented very high quality measurements, in 5 rapidity bins, up to p ~ 15 GeV [nb / GeV/c] d" / dydp BR(J/! $ µµ) # s = 7 ev Prompt J/! 5. pb - 1 LHCb 5. nb.0 < y <.5.5 < y < < y < < y < < y < 4.5 he shape of the p distribuwons can be reproduced by the funcwon dn % " p dp ' 1+ &' LHCb: EPJ C71 (011) (# $ ) p p ( * )* $# ! J/! p [GeV/c]

14 Prompt J/ψ p distributions from LHCb and ALAS 14 LHCb presented very high quality measurements, in 5 rapidity bins, up to p ~ 15 GeV [nb / GeV/c] d" / dydp BR(J/! $ µµ) # s = 7 ev Prompt J/! ALAS.3.7 pb pb nb LHCb 5. pb nb < y < < y < < y < < y < < y < < y < < y < < y < < y < 4.5 LHCb: EPJ C71 (011) 1645 ALAS: arxiv: he shape of the p distribuwons can be reproduced by the funcwon dn % " p dp ' 1+ &' 1 (# $ ) p p ( * )* $# ! J/! p [GeV/c] Also ALAS presented very detailed measurements, extending to higher p values

15 Prompt J/ψ p shape vs. rapidity 15 <p > clearly increases from forward to central rapidity o keep in mind when comparing ALICE J/ψ in dimuons and dielectrons ] [(GeV/c)! p " Prompt J/# s = 7 ev LHCb CMS β = 3.69 ALAS y or y

16 Prompt J/ψ p distributions from ALAS, CMS and LHCb 16 hanks to the high luminosity at LHC the current prompt J/ψ spectra extend from p = 0 already up to 70 GeV/c, spanning 6 orders of magnitude he ALAS and recent CMS data agree extremely well over the full p range [nb / GeV/c] s = 7 ev Prompt J/ψ dσ / dydp BR(J/ψ µµ) CMS 36.7 pb 0.0 < y < < y < < y < 1.6 ALAS.3 pb 0.0 < y < < y < p J/ψ [GeV/c] ALAS: arxiv: CMS: CMS- BPH

17 Prompt J/ψ p distributions from ALAS, CMS and LHCb 17 hanks to the high luminosity at LHC the current prompt J/ψ spectra extend from p = 0 already up to 70 GeV/c, spanning 6 orders of magnitude he ALAS and recent CMS data agree extremely well over the full p range [nb / GeV/c] s = 7 ev Prompt J/ψ dσ / dydp BR(J/ψ µµ) CMS 36.7 pb ALAS.3 pb < y < < y <.0 1 p J/ψ [GeV/c] ALAS: arxiv: CMS: CMS- BPH

18 Prompt J/ψ p distributions from ALAS, CMS and LHCb 18 hanks to the high luminosity at LHC the current prompt J/ψ spectra extend from p = 0 already up to 70 GeV/c, spanning 6 orders of magnitude he ALAS and recent CMS data agree extremely well over the full p range [nb / GeV/c] s = 7 ev Prompt J/ψ dσ / dydp BR(J/ψ µµ) CMS 314 nb 1.6 < y <.4 CMS 36.7 pb ALAS.3 pb -4.1 < y <.4.0 < y <.4 1 p J/ψ [GeV/c] ALAS: arxiv: CMS: CMS- BPH

19 Prompt J/ψ p distributions from ALAS, CMS and LHCb 19 hanks to the high luminosity at LHC the current prompt J/ψ spectra extend from p = 0 already up to 70 GeV/c, spanning 6 orders of magnitude he ALAS and recent CMS data agree extremely well over the full p range Good agreement also with the forward ALAS, CMS and LHCb data [nb / GeV/c] s = 7 ev Prompt J/ψ LHCb 5. pb.0 < y <.5 dσ / dydp BR(J/ψ µµ) CMS 314 nb 1.6 < y <.4 CMS 36.7 pb ALAS.3 pb -4.1 < y <.4.0 < y <.4 1 p J/ψ [GeV/c] LHCb: EPJ C71 (011) 1645 ALAS: arxiv: CMS: CMS- BPH

20 Prompt J/ψ p distributions from ALAS, CMS and LHCb 0 hanks to the high luminosity at LHC the current prompt J/ψ spectra extend from p = 0 already up to 70 GeV/c, spanning 6 orders of magnitude he ALAS and recent CMS data agree extremely well over the full p range Good agreement also with the forward ALAS, CMS and LHCb data [nb / GeV/c] dσ / dydp BR(J/ψ µµ) CMS 314 nb 1.6 < y <.4 CMS 36.7 pb 0.0 < y < < y < < y < < y <.1.1 < y <.4 ALAS.3 pb 0.0 < y < < y < < y <.0.0 < y <.4 1 LHCb 5. pb.0 < y <.5.5 < y < 3.0 p J/ψ s = 7 ev Prompt J/ψ 3.0 < y < < y < < y < 4.5 [GeV/c] LHCb: EPJ C71 (011) 1645 ALAS: arxiv: CMS: CMS- BPH

21 Inclusive ψ from LHCb 1 LHCb measured the p differenwal inclusive ψ cross secwon in two decay channels: ψ µµ ψ J/ψ ππ 11k in ψ J/ψ ππ 90k in ψ µµ LHCb- CONF

22 Prompt ψ from CMS CMS measured the ψ inclusive, non- prompt and prompt p differenwal cross- secwon Prompt producwon cross- secwon allows for direct comparison with theory (no feed- down) B- fracwon as large for ψ as for J/ψ: for p > 0 GeV/c, more than 50% come from B decays Fraction of ψ(s) from b hadrons CMS preliminary 0.0 < y < < y <.4 s = 7 ev 36.7 pb p ψ(s) [GeV/c] CMS- PAS- BPH

23 ϒ(1S) p distributions from CMS and LHCb 3 Also the boeomonium states are now available from more than one LHC experiment [nb / GeV/c] d" / dydp BR(!(1S) $ µµ) # - -3 s = 7 ev!(1s) CMS 3.1 pb pb 0.0 < y < < y <.0 LHCb 3.4 pb.0 < y <.5.5 < y < < y < < y < < y < !(1S) p [GeV/c] CMS: PRD 83 (011) LHCb: CMS- CONF

24 ϒ(1S): p vs. rapidity 4 he <p > decreases with forward rapidiwes It is much larger than for the J/ψ and shows a stronger rapidity dependence ]! [(GeV/c) " p s = 7 ev #(1S) LHCb CMS β = y or y

25 ϒ(1S) rapidity 5 Good compawbility between LHCb and CMS for the dσ/dy 1S producwon cross secwon

26 ϒ(S) and ϒ(3S) 6 Heavier S and 3S states have flaeer dσ/dp

27 ϒ(1S): fiducial cross section measurement from ALAS 7 he dσ/dp differenwal cross secwon in two rapidity intervals was measured in a fiducial phase space domain: η µ <.5, p µ > 4 GeV/c [arxiv:16.535] result is independent on theorewcal assumpwons (including the unknown polarizawon) Neither Pythia nor CSM NLO (w/o χ b feed- down) can sawsfactorily describe the current data

28 8 ϒ: data-theory comparison LHCb: Y(1S) fdir=0.5 F. Maltoni CMS: Y(1S) CMS: Y(S) CMS: Y(3S)

29 he χ c through ECAL or tracking of photon conversions 9 CMS has a very good mass resoluwon ( MeV) thanks to a (very challenging) photon conversion measurement χ c J/ψ γ Larger event samples can be acquired by measuring the photon in the calorimeters (ALAS and LHCb) χ c1 χ c ALAS LHCb χ c0 CMS

30 χ c / χ c1 cross-section ratio 30 LHCb reported a first measurement of the χ c / χ c1 cross- secwon rawo [LHCb- CONF ] and it disagrees with NLO NRQCD

31 he χ b already made a first appearance! 31 CDF measured large feed- down contribuwons from the χ b states to the Y(1S): χ b (1P) Y(1S) = 7.1 ± 6.9 ± 4.4 % [PRL 84 (000) 094] χ b (P) Y(1S) =.5 ± 4.4 ± 1.4 % for Y(1S) with y < 0.7 and p > 8 GeV/c LHCb χ b (1P) χ b (P)? M(χ b (1P)) M(Y(1S)) = 0.44 GeV M(χ b (P)) M(Y(1S)) = 0.80 GeV

32 Exotic charmonium X(387) Ø LHCb measured its mass: M = ± 0.46 ± 0. GeV [LHCb- CONF ] and cross secwon: σ BR = 4.74 ± 1. ± 1.01 nb for.5 < y < 4.5 and 5 < p < 0 GeV/c [LHCb- CONF ] Candidates / 5 MeV/c J/"! +! invariant mass [GeV/c ] J/"! +! - invariant mass [GeV/c ] Candidates / 5 MeV/c N X(387) = 548 ± 4 (stat.)! N!(S) = 7346 ± 155(stat.)! s = 7 ev CMS Preliminary! L dt = 40 pb 3 L int ~ 35 pb - 1 N X(387) = 585 ± 74 (stat.) Ø CMS measured its relawve cross secwon w.r.t. the ψ(s): σ BR(X) / σ BR(ψ S ) = ± ± for y <. and p > 8 GeV/c [CMS- PAS- BPH- - 18]

33 Double J/ψ production 33 Possible producwon mechanisms: gg J/ψ J/ψ double parton scaeering tetraquark ( c and cbar diquarks ) other opwons? LHCb measured σ(j/ψj/ψ) = 5.1 ± 1.0 ± 1.1 nb for < y J/ψ < 4.5 and p < GeV/c [arxiv: ] Possible tetraquark should manifest itself as a spike in the (low) mass di- J/ψ spectrum FiEed yield of J/ψ 1 in slices of M(µµ)

34 Prospects for 011 data analysis 34 So far, the available results were based on the 0 data taking but by now large event samples have been acquired which open the door for many more measurements to be done more potenwal physics analyses than available people

35 Quarkonium production at the LHC 35 the fun has started! and the best is s0ll to come J

36 Further slides 36

37 J/ψ fraction from B decays vs. p and y (011) 37 Fraction of J/ψ from b hadrons s = 7 ev CMS 36.7 pb 0.0 < y < CDF s = 1.96 ev y < 0.6 PRD 71 (005) p J/ψ [GeV/c] even though the (more precise) CMS measurements sit systemawcally higher than CDF

38 Prompt J/ψ p distributions from ALAS, CMS and LHCb 38 hanks to the high luminosity at LHC the current prompt J/ψ spectra extend from p = 0 already up to 70 GeV/c, spanning 6 orders of magnitude [nb / GeV/c] s = 7 ev Prompt J/ψ dσ / dydp BR(J/ψ µµ) CMS 314 nb 0.0 < y < 1. CMS 36.7 pb 0.0 < y < < y < p J/ψ [GeV/c] CMS: CMS- BPH

39 Prompt J/ψ p distributions from ALAS, CMS and LHCb 39 hanks to the high luminosity at LHC the current prompt J/ψ spectra extend from p = 0 already up to 70 GeV/c, spanning 6 orders of magnitude [nb / GeV/c] s = 7 ev Prompt J/ψ dσ / dydp BR(J/ψ µµ) CMS 314 nb 1. < y < 1.6 CMS 36.7 pb 1. < y < p J/ψ [GeV/c] CMS: CMS- BPH

40 Prompt J/ψ p distributions from ALAS, CMS and LHCb 40 hanks to the high luminosity at LHC the current prompt J/ψ spectra extend from p = 0 already up to 70 GeV/c, spanning 6 orders of magnitude [nb / GeV/c] s = 7 ev Prompt J/ψ dσ / dydp BR(J/ψ µµ) CMS 314 nb 1.6 < y <.4 CMS 36.7 pb < y <.1.1 < y <.4 1 p J/ψ [GeV/c] CMS: CMS- BPH

41 Prompt J/ψ p distributions from ALAS and CMS 41 hanks to the high luminosity at LHC the current prompt J/ψ spectra extend from p = 0 already up to 70 GeV/c, spanning 6 orders of magnitude he ALAS and recent CMS data agree extremely well over the full p range ALAS: arxiv: CMS: CMS- BPH

42 (Unsuccessful) search for exotic charmonium X(4140) 4 1.) CDF observed a structure in B + (J/ψ φ) K + decays on basis of 115±1 B +, 6-1 [arxiv: ] m(y) = ± 0.6 MeV and Γ Y = ±.5 MeV 3.) LHCb inveswgated 381± B + decays on the basis of [LHCb- CONF ] 19±5 events CDF LHCb does not see a peak and, hence, does not confirm the state set an upper limit for σ BR(X).) BELLE could not confirm / exclude this state set an upper limit for σ BR(X) new mystery in exowc charmonium producwon?

43 Prompt J/ψ p shape vs. rapidity 43 he two parameters are strongly correlated: 30 73% depending on the y bin <p > shows a clear trend; β seems to fluctuate around a single value We can fix β to a constant value and look at the y- dependence of <p > Helps extracwng <p > from the less accurate ALAS and CMS data dn % " p dp ' 1+ &' 1 (# $ ) p p ( * )* $# ]! [(GeV/c) " p Prompt J/# s = 7 ev β LHCb LHCb LHCb rapidity y rapidity