Heavy ion physics at LHCb

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1 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ+ c in ppb, 5 ev Heavy flavour with SMOG data Conclusion Heavy ion physics at E milie Maurice on behalf of the collaboration ICFNP 25th August 217, Kolymbari, Creta August 22, 217 1/21

2 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ+ c in ppb, 5 ev detector and the fixed-target system Heavy flavour with SMOG data Conclusion [JINS 3 (38) S85] was designed for heavy flavor physics but is now a general purpose detector Fully instrumented in 2 < y < 5 Excellent performance: X Vertex, IP and decay time resolution X Momentum resolution X Particle identification K K 95%, π K 5% µ µ 97%, π µ 1-3% Heavy ions program: novelty for Reversal of p and Pb beams backward and forward rapidity region Fixed-target mode: unique at LHC! snn [69, 115] GeV backward rapidity region 2/21

3 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 3/21 Selected results 1. J/ψ production in ppb collisions at 8.2 ev, arxiv: D production in ppb collisions at 5 ev, arxiv: Λ + c production in ppb collisions at 5 ev, -CONF J/ψ and D production in par collisions at 11 GeV -CONF-217-1

4 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion ) ) J/ψ production measurement in ppb collisions [arxiv: ] First analysis of ppb collisions at s NN = 8.16 ev, from November 216 Extraction of prompt J/ψ and J/ψ from b-decays Simultaneous fit of mass and pseudo-proper decay time Candidates / ( 6 MeV/c Forward: ppb 6 < p < 7 GeV/c 3.5 < y* < 4. J/ ψ -from-b-hadrons background prompt J/ ψ s NN =8.16 ev: ppb Candidates / ( 6 MeV/c Backward: Pbp 6 < p < 7 GeV/c 4. < y* < 3.5 J/ ψ -from-b-hadrons background prompt J/ ψ s NN =8.16 ev: Pbp t z = (Z J/ψ Z PV ) M J/ψ p z Mass distributions described by: M [MeV/c 2 µ + - µ ] M [MeV/c 2 µ + - µ ] Signal: Crystal Ball Background: Exponential t z distributions described by: Signal: δ(t z ) for prompt, exponential for b-decays Background: empirical function from sideband Candidates / (.15 ps ) s NN =8.16 ev: ppb 6 < p 3.5 < y* < 7 GeV/c < t z [ps] Candidates / (.15 ps ) s NN =8.16 ev: Pbp 6 < p 4. < y* < 7 GeV/c < t z [ps] 4/21

5 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion Prompt J/ψ modification factor [arxiv: ] Nuclear modification factor R ppb (p, y ) 1 d 2 σ ppb (p,y )/dp dy A d 2 σ pp(p,y )/dp dy σ pp at s = 8.16 ev: interpolation of measurements, and extrapolation for bins not covered by pp data Forward: ppb Backward: Pbp RpPb HELAC Onia with EPS9LO HELAC Onia with nceq15 HELAC Onia with EPS9NLO CGC (8.16 ev) RpPb HELAC Onia with EPS9LO HELAC Onia with nceq15 HELAC Onia with EPS9NLO (8.16 ev) heoretical references cf. slides 9, prompt J/ψ, ppb 1.5 < y < p [GeV/c].5. prompt J/ψ, Pbp 5. < y < p [GeV/c] Prompt J/ψ R ppb as a function of p Strong suppression at low p, decreasing with increasing p Collinear factorization including PDF modification in nuclei in agreement with data p dependence at fwd rapidity reproduced by Colour Glass Condensate calculations 5/21

6 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 6/21 Non prompt J/ψ modification factor [arxiv: ] Forward: ppb Backward: Pbp RpPb FONLL with EPS9NLO (8.16 ev) RpPb FONLL with EPS9NLO (8.16 ev) heoretical references cf. slides 9, J/ψ -from-b-hadrons, ppb 1.5 < y < p [GeV/c].5. J/ψ -from-b-hadrons, Pbp 5. < y < p [GeV/c] Non prompt J/ψ R ppb as a function of p Access the production of b hadrons At forward rapidity: small suppression at low p At backward rapidity: compatible with unity pqcd calculations with npdfs in agreement with data

7 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 7/21 Prompt and non prompt J/ψ modification factor [arxiv: ] RpPb HELAC Onia with EPS9LO HELAC Onia with nceq15 HELAC Onia with EPS9NLO Energy Loss CGC (5eV) (8.16eV) RpPb FONLL with EPS9NLO (5eV) (8.16eV) heoretical references cf. slides 9, 1 5eV, arxiv: prompt J/ψ < p < 14GeV/c y.5 J/ψ -from-b-hadrons < p < 14GeV/c y Prompt and non prompt J/ψ R ppb as a function of y At backward rapidity: suppression of prompt J/ψ not well reproduced At forward rapidity: good agreement of CGC and coherent energy loss calculations with the experimental data Large uncertainties on the gluon PDFs at low x

8 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 8/21 D production in ppb collisions at 5 ev [arxiv: ] Update of previous preliminary results with 1 times more statistics Number of inclusive candidates is extracted from a fit to the mass distribution hen separation between prompt D and B-component with the D impact parameter to PV Candidates / (3 MeV/c 2 ) Backward Data Fit Signal Background M(K π ± ) [MeV/c 2 ] ± 2 < p < 3 GeV/c 4. < y* < 3.5 Candidates / (.1) Backward 2 < p < 3 GeV/c 4. < y* < 3.5 Data Fit Prompt D -from-b Background log (χ 2 )) 1 (D IP

9 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 9/21 D cross section at 5 ev [arxiv: ] Cross section integrated over the full range σ forward (p < 1GeV/c, 1.5 < y < 4.) = (23.6 ±.5 ± 13.) mb σ backward (p < 1GeV/c, 5. < y < 2.5) = (252.7 ± 1. ± 2.) mb [mb/(gev/c)] d d p σ Forward Backward (.1) EPS9LO EPS9NLO nceq15 s NN = 5 ev p [GeV/c] [mb] d σ d y* Data EPS9LO EPS9NLO nceq15 s NN = 5 ev 5 5 y* Compared with HELAC-Onia [J.-P. Lansberg, H.-S. Shao, EPJC77 (217) 1] tuned to reproduced pp data with the PDF set C1NLO [H.-L. Lai et al, PRD82 (21) 7424] using nuclear PDFs: EPS9LO or EPS9NLO [K. J. Eskola, H. Paukkunen, C. A. Salgado, JHEP4 (29) 65], nceq15 [K. Kovarik et al, PRD93 (216) 8537]

10 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 1/21 D nuclear modification factor in ppb collisions at 5 ev [arxiv: ] Nuclear modification factor R ppb (p, y ) 1 d 2 σ ppb (p,y )/dp dy A d 2 σ pp(p,y )/dp dy Computed in the kinematic range common to ppb and pp, or Pbp and pp R ppb EPS9LO EPS9NLO nceq15 s NN = 5 ev Backward p [GeV/c] R ppb EPS9LO EPS9NLO nceq15 CGC s NN = 5 ev Forward p [GeV/c] R ppb prompt D prompt J/ψ EPS9LO EPS9NLO nceq15 CGC s NN = 5 ev p < 1 GeV/c y* Compared with HELAC-Onia as for the integrated cross-section Color Glass Condensate [B. Ducloué,. Lappi, H. Mäntysaari, PRD91 (215) 1145] Prompt J/ψ R ppb measured at 5 ev in [JHEP2 (214) 72]

11 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 11/21 Λ + c production in ppb collisions at 5 ev [-CONF-217-5] SAR, arxiv: Λ + c cross section measurements? Baryon to meson production ratio: Comparison to AA collisions Relevant to charmed hadron hadronisation mechanism Λ + c D First charmed baryon measurement in pa Λ + c analysis in ppb collisions at 5 ev Same data sample as D Same strategy: inclusive Λ + c pk π + determine from mass fit, then prompt fraction extracted from IP fit

12 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion Λ + c /D ratio in ppb collisions at 5 ev [-CONF-217-5] R Λ + c /D = σ Λ + c (p,y ) σ D (p,y ) Predictions Similar for EPS9LO and EPS9NLO nceq15 slightly lower At forward rapidity: Λ + c /D is consistent at lower p, but below theories at higher p At backward rapidity: Λ + c /D is consistent for all p nceq15: Eur. Phys. J. C77 (217) 1, EPS9LO: Comput. Phys. Commun. 184 (213) 2562, EPS9NLO: Comput. Phys. Commun. 198 (216) /21

13 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 13/21 Λ + c /D ratio in ppb collisions at 5 ev [-CONF-217-5] R Λ + c /D = σ Λ + c (y ) σ D (y ) At forward rapidity: Λ + c /D is consistent for all y At backward rapidity: Λ + c /D is consistent at lower y but display a rising trend with increasing y nceq15: Eur. Phys. J. C77 (217) 1, EPS9LO: Comput. Phys. Commun. 184 (213) 2562, EPS9NLO: Comput. Phys. Commun. 198 (216) 238 Charmed baryon to meson production ratio in cold nuclear matter measured Results consistent with NLO predictions but display a rising trend with increasing y

14 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 14/21 fixed target: data taking Data recorded with gas pressure in the VELO [arxiv: ] Parasitic to the collider mode Gas spreads in the beam pipe up to ±2m around Use non-colliding bunches First production measurements in fixed-target mode J/ψ and D in par collisions, s NN = 11 GeV, with protons on target p cross section measurement in phe collisions, s NN = 11 GeV, with protons on target [-CONF-217-2]

J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 15/21 Fixed target heavy flavour program at Unique opportunity to perform fixed-target heavy ion physics at

15 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 15/21 Fixed target heavy flavour program at Unique opportunity to perform fixed-target heavy ion physics at LHC: Forward measurement of open and hidden charm production (J/ψ, D...) Measurement down to low p Large rapidity coverage ( 3 rapidity units) at large Bjorken-x Eskola et al. Access to npdf anti-shadowing region Access to intrinsic charm content in the nucleon J. Pumplin et al. Proton-nucleus collisions provide reference for heavy ions studies

16 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 16/21 Charm production analysis in par collisions -CONF Study the J/ψ and D production in par collisions at s NN = 11 GeV Analysis of data collected in 215, with 6.5 ev proton beam on argon gaseous target Reconstructed collision vertices extended over 1m J/ψ and D selected with Z vertex inside the Vertex Detector, [ 2, +2] mm, extracted with Crystal Ball functions c 2 ) Candidates / (1 MeV/ preliminary s NN = 11 GeV par N J/ψ = 482 ± 23 Candidates / (5 MeV/ c 2 ) σ 14 MeV/c 2 σ 8 MeV/c preliminary s NN = 11 GeV par N D = 6451 ± m(µ + µ ) [MeV/c 2 ] m(k 5 J/ψ µ + µ 6 5 D K π ± Split data in 4 rapidity bins: [2, 3], [3, 3.5], [3.5, 4], [4, 4.6] π + ) [MeV/c 2 ] Split data in 4 p bins: [, 6], [6, 12], [12, 18], [18, 8] MeV/c

17 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 17/21 D corrected yields -CONF D traverse momentum and rapidity distributions /dp D dn 25 2 preliminary s NN = 11 GeV par /dy D dn preliminary s NN = 11 GeV par ransverse momentum p [MeV/c] Rapidity y Box: quadratic sum of all uncertainties Red area: Monte Carlo Pythia8-C9MCS Overall MC yields normalized to overall data yields

18 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 18/21 J/ψ corrected yields -CONF J/ψ /dp dn preliminary s NN = 11 GeV par ransverse momentum p [MeV/c] Phenomenological parametrizations based on /dy* J/ψ dn preliminary s NN = 11 GeV par Rapidity in centre-of-mass y* y = y 4.77 Arleo, F. & Peigné, S. J. High Energ. Phys. (213) 213: 122 Arleo, F. et al. J. High Energ. Phys. (213) 213: 155 MC and phenomenological distributions are normalized to data Phenomenological parameters Extracted from linear and logarithmic interpolations between 41.5 GeV and 2 GeV measurements No strong difference observed within uncertainties

19 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 19/21 Comparison between J/ψ and D cross sections -CONF J/ψ/D cross sections ratio vs transverse momentum and rapidity ) σ(j/ψ) / σ(d preliminary s NN = 11 GeV par ) σ(j/ψ) / σ(d preliminary s NN = 11 GeV par ransverse momentum p [MeV/c] Rapidity y Luminosity cancel out in the cross section ratio: σ(j/ψ) σ(d ) ratio increases with transverse momentum No significant dependence of σ(j/ψ) σ(d ) with rapidity Need theoretical predictions σ(j/ψ) σ(d ) = Y (J/ψ) L L Y (D )

20 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 2/21 Bjorken-x distribution -CONF Bjorken-x definition: x 2 = M snn exp( y ), with rapidity in CMS y = y 4.77 /dx 2 J/ψ dn preliminary s NN = 11 GeV par /dx 2 D dn preliminary s NN = 11 GeV par M J/ψ x 2 = exp(-y*) s NN 15 = x 2 M D exp(-y*) s NN Bjorken-x x Bjorken-x x 2 Bjorken-x range covered by the data: J/ψ x 2 [.3,.45] D x 2 [.2,.27] Access intrinsic charm regime Need theoretical predictions

21 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 21/21 Conclusion Recent results of heavy ions program Successful data taking in ppb collisions at s = 8.16 ev in 216 Precise measurement of prompt and non prompt J/ψ production Analysis of ppb collisions at s = 5 ev in 213 Precise measurement of prompt D production First measurement of prompt Λ + c production Demonstration of the feasibility of the heavy-flavor fixed-target program First measurement of J/ψ/D production in par collisions at s = 11 GeV Access npdf anti-shadowing region and intrinsic charm content in the nucleon With future larger data samples: ψ(2s), χ c More results to come!

22 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 22/21 Extra slides

23 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 23/21 D nuclear modification factor in ppb collisions at 5 ev [arxiv: ] Comparison of D suppression with J/ψ and ψ(2s) suppression measured by [HEP2 (214) 72, JHEP3 (216) 133] R R ppb (J/ψ)/R (D ) ppb R ppb (ψ(2s))/r (D ) ppb s NN =5 ev * y

24 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 24/21 R FB for prompt D meson production Forward-backward ratio R FB for prompt D meson production R FB 1 s NN = 5 ev R FB 1 p < 1 GeV/c s NN = 5 ev.5 Data EPS9 LO EPS9 NLO nceq p [GeV/c].5 Data EPS9 LO EPS9 NLO nceq y* see slides 9, 1 for theoretical predictions

25 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 25/21 fixed target: data taking Data recorded with gas pressure in the VELO System Duration snn Protons on target phe 7h 11 GeV pne 12h 11 GeV par 17h 11 GeV par 11h 69 GeV PbAr 1h 69 GeV phe 18h 11 GeV phe 87h 87 GeV

26 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 26/21 Fixed target data for cosmic rays? Fixed target data at 1 GeV provides inputs to MC models describing underlying event: Important for modeling cosmic ray showers in the atmosphere AMS2 measurement of p/p ratio in cosmic rays shows hints of excess at high energies p/p predictions from spallation of primary cosmic rays on interstellar medium (H or He): PRL 117, 9113 (216) Limitation from uncertainties on p production cross-sections No previous measurement in phe Predictions from soft QCD models vary within a factor 2 in fixed-target mode is well suited to measure p production cross section in phe

27 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 27/21 p cross section measurement in phe collisions -CONF Measurement of antiproton production in phe collisions at s NN = 11 GeV Analysis of data collected in May 216, with 6.5 ev proton beam: count antiprotons Minimum bias trigger, fully efficiency on candidate events Exploit excellent PID capabilities In (p, p ) bins within the range: 12 < p < 11 GeV/c, p >.4 GeV/c Background: gas impurity measurement (.6 ±.2)% Residual vaccum in LHC: 1 9 mbar Measurement in data before He injection Normalization: use p e elastic scattering to evaluate the luminosity Cross section very well known Distinct signature with single low-p and very low p electron track, nothing else L =.443 ±.11 ±.27 nb 1

28 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 28/21 p cross section measurement in phe collisions -CONF measured the total inelastic cross section σinel = (14 ± 1) mb he EPOS LHC prediction: 118 mb [. Pierog et al. Phys. Rev. C92 (215), 3496] Ratio is 1.19 ±.8 Result for prompt production compared to EPOS LHC predictions: Excluding weak decays of hyperons Cross section data larger by a factor 1.5 wrt EPOS LHC plans: Measure p from strange decays Analyze phe data, s NN = 87 GeV

29 J/ψ in ppb, 8 ev D in ppb, 5 ev Λ + c in ppb, 5 ev Heavy flavour with SMOG data Conclusion 29/21 Other charmed hadrons in par data -CONF c 2 ) Candidates / (4 MeV/ preliminary s = 11 GeV par + - D K π + π + c 2 ) Candidates / (2.67 MeV/ preliminary s = 11 GeV par *+ D D π m(k π π ) [MeV/c 2 ] m(d π + ) [MeV/c 2 ] c 2 ) Candidates / (6.4 MeV/ preliminary s = 11 GeV par Ds K K π + Candidates / (6.4 MeV/ c 2 ) preliminary s = 11 GeV par + - Λ p K π + c m( K 2 K π 22 + ) [MeV/c 24 2 ] m(p 232 K π + ) 234 [MeV/c ]

New high resolution measurements of open and hidden charm production in proton-nucleus collisions at s = 110 GeV with LHCb

LHCb SMOG par Analysis par Results Conclusion New high resolution measurements of open and hidden charm production in protonnucleus collisions at s = 11 GeV with LHCb E milie Maurice on behalf of the LHCb