Σ(85) Ξ(5) Production of and measured by ALICE in pp, ppb and PbPb collisions at the LHC for the ALICE Collaboration Pusan National University, OREA Quark Matter 7 in Chicago 7.. QM7
* suppressed, no suppression observed for Φ.5.4..5.4... pp.76 ev pp 7 ev * / φ/ */ ALICE PbPb.76 ev PbPb.76 ev (PRC 9, 469). EPOS EPOS w/o UrQMD. hermal Model, = 56 MeV 4 6 8 4 6 8 arxiv:7.555 Lifetime(fm/c): τρ(.) < τ*(4.) < τσ*(5.5) < τλ*(.6) < τξ*(.7)<τφ(46.) QM7
.5.4...5.4.. * suppressed, no suppression observed for Φ pp.76 ev pp 7 ev * / φ/ */ ALICE PbPb.76 ev PbPb.76 ev (PRC 9, 469). EPOS EPOS w/o UrQMD. hermal Model, = 56 MeV 4 6 8 4 6 8 arxiv:7.555 * Resonance decay * Regeneration In the hadronic phase * * Rescattering inetic freezeout Chemical freezeout Regeneration: (pseudo) elastic scattering of decay products Rescattering: elastic or (pseudo) elastic scattering through a different resonance Lifetime(fm/c): τρ(.) < τ*(4.) < τσ*(5.5) < τλ*(.6) < τξ*(.7)<τφ(46.) ρ QM7
.5.4...5.4.. * suppressed, no suppression observed for Φ pp.76 ev pp 7 ev * / φ/ */ ALICE PbPb.76 ev PbPb.76 ev (PRC 9, 469). EPOS EPOS w/o UrQMD. hermal Model, = 56 MeV 4 6 8 4 6 8 arxiv:7.555 * Resonance decay * Regeneration In the hadronic phase * * Rescattering inetic freezeout Chemical freezeout Regeneration: (pseudo) elastic scattering of decay products Rescattering: elastic or (pseudo) elastic scattering through a different resonance Lifetime(fm/c): τρ(.) < τ*(4.) < τσ*(5.5) < τλ*(.6) < τξ*(.7)<τφ(46.) Lifetime(fm/c): τρ(.) < τ*(4.) < τσ*(5.5) < τλ*(.6) < τξ*(.7)<τφ(46.) ρ QM7
Production of Σ(85) Counts/(8 MeV/c ) Counts / (8 MeV/c ) 4 4 ALICE, ppb,...4.5.6.7.8.9 (GeV/c ) PbPb,. < p Σ* + Ξ (Ξ ) =.76 ev, % <.7 GeV/c, y <.5 (Σ* ) Λ Σ* Data, eventmix bkg subtracted Combined fit (Λ (Σ* ) Residual background.5 < y <,. < p CMS = 5. ev (6%) ) <.5 GeV/c Mixedevent subtracted Residual background Combined fit + M Λ *+ + Σ Λ ppb ALICE Performance PbPb ] dy) [(GeV/c) N/(dp d /N evt 4 5 6 7 + Σ (85) ALICE, ppb, = 5. ev NSD (x8) % (x) 6% (x/) 6% (x/4) Levysallis fit.5 < y 4 5 6 (GeV/c) p CMS < ppb...4.5.6.7.8.9 ALI PERF 5 M Λ (GeV/c ) arxiv:7.7797 QM7
6.5 / χ / ndf 5. / 55 7.756.47 p 5..9.5 p.5..45.88 p.6. 9.6.6 p4 9. 59.5 67.4.9 p5 9.8.6 4 χ / ndf 6.98 / 7 p.669.65 p.689.88 p 96. QM7 Production of Ξ(5) Counts/( MeV/c ).5.4... / ALICE, ppb,.5 < y <,.8 < p CMS ppb = 5. ev (4%) <. GeV/c + Ξ* (Ξ* ) Ξ + (Ξ ) Mixedevent subtracted Residual background Combined fit.48.5.5.54.56.58.6 (GeV/c ) M Ξ ] ) [(GeV/c) N/(dydp /N evtd 4 5 6 7 8 (Ξ(5) +Ξ(5) ) ALICE, ppb, NSD (x8) % (x) 4% (x/) 46% (x/4) 6% (x/8) Levysallis fit = 5. ev.5 < y 4 5 6 7 8 (GeV/c) p CMS ppb <
χ / ndf.8 / 5 p.4 8. p.5. p..5 p4 p5 6.e+4 4.688e+.98e+4.46e+ 6.5 / χ / ndf 5. / 55 7.756.47 p 5..9.5 p.5..45.88 p.6. 9.6.6 p4 9. 59.5 67.4.9 p5 9.8.6 χ / ndf 6.98 / 7 p.669.65 p.689.88 p 96. Production of Ξ(5) Counts/( MeV/c ) Counts/(6 MeV/c ).5.4... /.48.5.5.54.56.58.6 (GeV/c ) 4 8 6 4 ALICE, ppb,.5 < y <,.8 < p CMS ppb pt bin 6 Ξ* +Ξ* Ξ + + Ξ ALICE Preliminary + = 5. ev (4%) pt bin 4 <. GeV/c + Ξ* (Ξ* ) Ξ + (Ξ ) Mixedevent subtracted Residual background Combined fit M Ξ.48.5.5.54.56.58.6 (GeV/c ) ALI PREL 5767 PbPb,. < p <.5 GeV/c, y <.5 PbPb =.76 ev (%) Mixedevent subtracted Residual background Combined fit M Ξ ] ] ) [(GeV/c) ) [(GeV/c) N/(dydp N/(dydp d /N evtd 4 5 6 4 7 5 8 6 PbPb, y <.5 ALI PREL 5787 4 (Ξ(5) =.76 +Ξ(5) ev ) ALICE Preliminary ALICE, ppb, = 5. ev NSD (x8) % (x) 4% (x/) 46% (x/4) 6% (x/8) Levysallis fit 8% (x6) % (x) 4% (x/4) 48% (x/8) Boltzmann fit EPOS v.7 (Ξ* +Ξ*.5 < y 4 5 6 7 8 p (GeV/c) p CMS PbPbpPb Uncertainties: stat.(bars), syst.(boxes) < 4 5 6 (GeV/c) ) h_xispectrum Entries 7 Mean.67 RMS.78 QM7
Σ* /Λ ratio in pp and ppb )/[(Λ+Λ)] * +Σ GSIHeidelberg model =56 MeV. ALICE, ppb, HERMUS =58 MeV ALICE, pp, s.5 ppb, DPMJE SAR, dau, = 5. ev = 7 ev (INEL) = GeV no multiplicity dependence * (Σ..5..5 pp, Pythia8 SAR, pp, 4 dn /dη s = GeV lab η <.5 lab agreement with QCDinspired model and thermal model predictions Measurement in PbPb is ongoing Lifetime(fm/c): τρ(.) < τ*(4.) <τσ*(5.5)<τλ*(.6)<τξ*(.7)<τφ(46.) 5 QM7
Ratio of resonance yields in PbPb ρ/.8 ALICE Preliminary.6 pp, PbPb =.76 ev ρ +, y <.5.4...8.6.4., pp, PbPb HERMUS EPOS, PRC9 (6), 49 EPOS without UrQMD Uncertainties: stat. (bar), sys. (box), uncorr. sys. (shaded box) ALIPREL77 4 6 8 (dn /dη) Lifetime(fm/c): τρ(.) < τ*(4.) < τσ*(5.5) <τλ*(.6) < τξ*(.7) < τφ(46.) 6 QM7
Ratio of resonance yields in PbPb.5.4..5.4. pp.76 ev pp 7 ev * / ALICE PbPb.76 ev PbPb.76 ev (PRC 9, 469).. φ/ Lifetime(fm/c): τρ(.) < τ*(4.) < τσ*(5.5) <τλ*(.6) < τξ*(.7) < τφ(46.) 6 QM7.. EPOS EPOS w/o UrQMD hermal Model, = 56 MeV 4 6 8 4 6 8
Ratio of resonance yields in PbPb ALIPREL658 Lifetime(fm/c): τρ(.) < τ*(4.) < τσ*(5.5) <τλ*(.6) < τξ*(.7) < τφ(46.) 6 QM7
Ratio of resonance yields in PbPb ) + +Ξ )/(Ξ * +Ξ * (Ξ.8.6 pp, ppb, s = 7 ev ALICE,INEL EPJ. C75(5) PYHIA8 (Monash ) ALICE, VA mult.classes arxiv:7.7797 DPMJE = 5. ev PbPb, =.76 ev ALICE Preliminary GSIHeidelberg =56 MeV HERMUS =58 MeV EPOSv.7.4. ALI PREL 94 Uncertainties: stat. (bars), sys. (boxes) uncorr. sys. (shaded boxes) 4 6 8 4 dn /dη lab η <.5 lab Lifetime(fm/c): τρ(.) < τ*(4.) < τσ*(5.5) <τλ*(.6) < τξ*(.7) < τφ(46.) 6 QM7
Ratio of resonance yields in PbPb Lifetime(fm/c): τρ(.) < τ*(4.) < τσ*(5.5) <τλ*(.6) < τξ*(.7) < τφ(46.) ρ/.8 ALICE Preliminary.6.4...8.6.4. pp, PbPb =.76 ev ρ +, y <.5, pp, PbPb HERMUS EPOS, PRC9 (6), 49 EPOS without UrQMD Uncertainties: stat. (bar), sys. (box), uncorr. sys. (shaded box) 4 6 8 4 6 8 ALIPREL77 (dn /dη) dn.5.4...5.4.. pp.76 ev pp 7 ev * / φ/ ALICE PbPb.76 ev PbPb.76 ev (PRC 9, 469).. EPOS EPOS w/o UrQMD hermal Model, = 56 MeV 4 6 8 dn /dη /dη ALIPREL658 ) + +Ξ )/(Ξ * +Ξ * (Ξ.8.6.4. ALI PREL 94 pp, ppb, s = 7 ev ALICE,INEL EPJ. C75(5) PYHIA8 (Monash ) = 5. ev ALICE, VA mult.classes arxiv:7.7797 DPMJE Uncertainties: stat. (bars), sys. (boxes) uncorr. sys. (shaded boxes) PbPb, =.76 ev ALICE Preliminary 4 6 8 4 dn /dη GSIHeidelberg =56 MeV HERMUS =58 MeV EPOSv.7 lab η <.5 lab Several shortlived resonances exhibit suppression from peripheral to central PbPb collisions with respect to thermal model in central PbPb qualitatively described by EPOSv + UrQMD afterburner for ρ, *, Λ* and Φ favoured explanation is dominance of elastic rescattering in the hadronic phase Also the Ξ*/Ξ exhibits suppression with respect to the thermal model predictions 6 QM7
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ALIPREL9