Small systems Resonances hadronic phase partonic phase?

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1 Christina Markert University of Texas at Austin Small systems Resonances hadronic phase partonic phase? NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 1

2 Phase diagram of nuclear matter (QCD) NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 2

2T(time and temperature) of hadronic medium central A+A collision peripheral A+A collision

Hadronisation Hadronisation chem. Freeze-out chem. Freeze-out kinetic Freeze-out chem.

Temperature [MeV] 2 15 1 T ch 155 ± 2 MeV T ch non-equi, Phys.Rev.

3 2T(time and temperature) of hadronic medium central A+A collision peripheral A+A collision high multiplicity p-a collisions low multiplicity p-a collisions Hadronisation Hadronisation Hadronisation Hadronisation chem. Freeze-out chem. Freeze-out kinetic Freeze-out chem. Freeze-out kinetic Freeze-out chem. Freeze-out kinetic Freeze-out kinetic Freeze-out? Temperature [MeV] T ch 155 ± 2 MeV T ch non-equi, Phys.Rev. C88 (213) 3497 T kin from BW (p,k,π) Phys.Rev. C88 (213) dn /dη ch NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 3

4 Resonance interaction in hadronic medium central A+A collision Hadronisation chem. Freeze-out re-scattering - loss K* re-generation - gain K* kinetic Freeze-out Life-time [fm/c] ρ(77) = 1.3 Δ (1232) = 1.7 K(892) = 4 Σ(1385) = 5.7 Λ(152) = 13 φ (12) = 44 NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 4

5 Count resonances: Resonances in EPOS (+UrQMD) AG Knospe, CM, K Werner, J Steinheimer, M Bleicher: PRC93 (216) 1, ) EPOS + UrQMD OFF (~ 168 MeV) from core + corona contribution core ~ thermal distribution 2.) EPOS + UrQMD ON follow decay particles in hadronic medium count resonance when all decay particles do not interact (elastic or pseudo-elastic) Temperature [MeV] T ch 155 ± 2 MeV T ch non-equi, Phys.Rev. C88 (213) 3497 T kin from BW (p,k,π) Phys.Rev. C88 (213) dn /dη ch NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 5

6 Resonance ratios (EPOS+UrQMD) AG Knospe, CM, K Werner, J Steinheimer, M Bleicher - )/2K +K* (K* φ/k UrQMD OFF UrQMD ON EPOS v (dn ch /d ) PRC91 (215) UrQMD OFF UrQMD ON EPOS v (dn ch /dη) NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 6

7 ρ(77) meson suppression in Pb-Pb Ratio EPOS prediction ++ (1232) /p.5 Λ(152)/Λ Life-time [fm/c] ρ(77) = 1.3 Δ (1232) = 1.7 K(892) = 4 Σ(1385) = 5.7 Λ(152) = 13 φ (12) = ρ(77) /π ± Preliminary: p+p, Pb+Pb 1 1 dn /dη ch Trend of ρ resonance suppression with increasing centrality in agreement with EPOS model predictions. à Confirms extended hadronic medium NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 7

8 K(892) in PHSD at RHIC energies A. Ilner, D. Cabrera, CM, E. Bratkovskaya arxiv: submitted to Physical Review C PHSD describes K(892) suppression in A+A collisions à Reconstructed K(892) from later time. NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 8

9 Medium in p-pb collisions? NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 9

10 Medium in p-pb collisions? ]/K + K *(892) [K *(892) p+p p+pb EPOS EPOS v3.17 Pb+Pb EPOS 1 1 dn Data: Eur.Phys.J. C76 (216) no.5, 245 /dη ch φ(12)/k p+p p+pb EPOS EPOS v3.17 Pb+Pb EPOS 1 1 dn /dη ch K*/K in p-pb shows similar behavior compared to low multiplicity Pb-Pb collisions This is mainly a hadronic effect due to hadronic interactions (re-scattering) à Extended hadronic medium. NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 1

11 Medium in p-pb collisions? ]/K + K *(892) [K *(892) p+p p+pb EPOS EPOS v3.17 Pb+Pb EPOS 1 1 dn /dη ch φ(12)/k (fm/c) τ Hadr 1.18EPOS v π + K + N p+p + N p+pb EPOS EPOS v3.17 Pb+Pb EPOS Pb+Pb p+pb dn ch/dη ch K*/K in p-pb shows similar behavior compared to low multiplicity Pb-Pb collisions This is mainly a hadronic effect due to hadronic interactions (re-scattering) à Extended hadronic medium. à Hadronic lifetime is about 1.5 fm/c in -5% p-pb collisions NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

12 Core corona contribution Ratio p-pb Corona/All Core/All 1 1 Pb-Pb 2 1 dn /dη ch 3 1 ( η <.5) Continues transition from p-pb to pp (corona =1) and Pb-Pb collisions. However with K*/K and phi/k we are not sensitive to partonic phase. à Same ratios independent of centrality and collisions system - )/2K +K* - (K* φ/k UrQMD OFF UrQMD ON EPOS v3.17 UrQMD OFF UrQMD ON EPOS v3.17 (dn ch /d ) (dn ch /dη) NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216

13 Strangeness production in p-pb (pp) Collisions Bellini SQM216 A. Tounsi and K. Redlich, B. J. Phys. G 28 (22) 295 p-pb ratios fit into the transition from a canonical (pp) to a grand canonical system (Pb-Pb) (Ξ is a little off). Volume effect of strangeness suppression in small systems. Only hadronic effect. Don t forget that we don t have evidence for strangeness enhancement in central Pb-Pb collisions NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

14 Do we have same hadronic medium in -5% p-pb and 6-8% Pb-Pb collisions? NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

15 Mean p T in small system size (GeV/c) p T p+pb EPOS v Pb+Pb K *(892) p φ(12) 1 1 dn /dη ch Larger mean p T in p-pb at same Pb-Pb multiplicity: More head on quark-quark scatterings? More radial flow? à Hadronic phases are different NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

Mean p T in small system size (GeV/c) p T 1.5 1.4 1.3 1.2 p+pb EPOS v3.17 Pb-Pb p-pb 1.1 1 Pb+Pb.9.8.

16 Mean p T in small system size (GeV/c) p T p+pb EPOS v3.17 Pb-Pb p-pb Pb+Pb K *(892) p φ(12) 1 1 dn /dη ch Same kinetic freeze-out temperature, different expansion velocity (from p,k,π) à Different hadronic medium? NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

17 Do we have evidence for partonic medium in high multiplicity p-pb collisions? NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

18 Nuclear modification factor (p-pb) ch jets R ppb p-pb s NN = 5.2 TeV Charged jets, anti-k T, η <.5 lab Reference: Scaled pp jets 7 TeV Global normalization uncertainty Resolution parameter R = p (GeV/c) T, ch jet ALI PUB Phys. Lett. B749 (25) R_AA 6-8% Pb-Pb shows suppression. Binary collisions in p-pb not easy to determine No high pt jet R_pPb suppression in p-pb (minbias) à Need jet R_pPb for -5% p-pb collisions à No direct comparison à room for possible low pt suppression NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

19 p-pb collisions (correlations) (-2%) (6-1%), PLB 719 (213) 29-2% 6-1% ATLAS, PRL 11 (213) NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

20 Extended hadronic medium in pp collisions NeD-216, Phuket, Thailand, 31 Oct - 5 Nov 216 2

Suppression of resonances in p-pb à hadronic phase Increase of strangeness production in events with increasing multiplicity -> canonical to grand canonical system.

21 Suppression of resonances in p-pb à hadronic phase Increase of strangeness production in events with increasing multiplicity -> canonical to grand canonical system. Hadronic phase in different There are no signatures of partonic phase Maybe small hint from v2 of partonic phase Difficult to get R_pPb -5% (not sensitive right now) NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

22 P- Pb prompt D Q ppb p-pb, s NN = 5.2 TeV Average D, D, D* -.96 < y <.4 cms + + ZN Energy Classes -2% 2-4% 4-6% 6-1% p (GeV/c) T arxiv: NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

23 P- Pb prompt D Q ppb p-pb, s NN = 5.2 TeV Average D, D, D* -.96 < y <.4 cms + + ZN Energy Classes -2% 2-4% 4-6% 6-1% p (GeV/c) T R AA % Pb Pb, = 2.76 TeV s NN + + Average D, D, D*, y <.5 Charged pions, η < (GeV/c) p T arxiv: arxiv: arxiv: NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

24 P- Pb Phys. Lett. B 727 (213) CR = color reconnection NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

25 K(892) in PHSD at RHIC energies A. Ilner, D. Cabrera, CM, E. Bratkovskaya arxiv: submitted to Physical Review C NeD-216, Phuket, Thailand, 31 Oct - 5 Nov

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