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Strangeness opportunities at the LHC

Strangeness in Collisions. Strangeness opportunities at the LHC. Strangeness at LHC energies Extrapolations / Motivations Strange probes with ALICE Detector and Simulations First p+p Collisions and beyond First measures to target. Boris HIPPOLYTE, STRASBOURG.

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Strangeness opportunities at the LHC

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  1. Strangeness in Collisions Strangeness opportunities at the LHC • Strangeness at LHC energiesExtrapolations / Motivations • Strange probes with ALICEDetector and Simulations • First p+p Collisions and beyondFirst measures to target Boris HIPPOLYTE, STRASBOURG RIKEN BNL Research Center Workshop - BNL - 15/02/06

  2. Wroblewski factor extrapolation to LHC energies Wroblewski factor: Extrapolation at the LHC A+A ~0.45 p+p ~0.25 Data compilation using Becattini et al., PR C64 (2001) 024901, hep-ph/0002267 and references therein Using thermal model description with corresponding system formalism (canonical or grand-canonical), extrapolation is straightforward. RIKEN-BNL Research Center Workshop - BNL

  3. Excitation functions of hyperons yields in A+A dN/dy extrapolations at the LHC for L : 10~30 for X : 3~6 for W : 0.4~0.7 Expected modifications total multiplicity scaling non-equilibrium scenario RIKEN-BNL Research Center Workshop - BNL

  4. Equilibrium vs non−equilibrium scenarii in A+A Eq. [ Oeschler et al., to be published ] [ Andronic et al., nucl-th/0511071 ] Non Eq. [ Rafelski et al., Eur. J. Phys. C45 (2006) 61 ] Calculations from Kraus et al., (Eq.) Rafelski et al., (Non Eq.) Expectations at the LHC energies (eq.): Tch ~170 MeV mB ~1 MeV Scenarii for gs RIKEN-BNL Research Center Workshop - BNL

  5. Blast-Wave parameters <bT> and Tfo extrapolation Compilation from N. Xu Excitation functions of the radial flow velocity and the kinetic freeze-out temperature parameters for central Au+Au or Pb+Pb collisions. Global trend for Blast-Wave parameters (<bT> and Tfo) is clear RIKEN-BNL Research Center Workshop - BNL

  6. Blast-Wave for Multi-Strange Baryons vs √sNN G.E. Bruno J.Phys. G 31 (2005) s127 J. Speltz nucl-ex/0512037 S. Salur nucl-ex/0509036 Evolution of parameters up to LHC energies and systematics study for Tfo RIKEN-BNL Research Center Workshop - BNL

  7. The central detectors of the ALICE experiment Time Projection Chamber -0.9< h < 0.9 azimuth 2p length 5 m active volume 88 m3 RIKEN-BNL Research Center Workshop - BNL

  8. The central detectors of the ALICE experiment Inner Tracking System -0.9< h < 0.9 silicon layers 6 pixel/drift/strip 2/2/2 cells(M) 9.84/23/2.6 area 0.21/1.31/4.77 m3 RIKEN-BNL Research Center Workshop - BNL

  9. The central detectors of the ALICE experiment Transition-Radiation Detector -0.9< h < 0.9 azimuth 2p length ~7 m active area 736 m2 RIKEN-BNL Research Center Workshop - BNL

  10. The central detectors of the ALICE experiment Time Of Flight -0.9< h < 0.9 azimuth 2p length 7.45 m active area 141 m2 RIKEN-BNL Research Center Workshop - BNL

  11. The central detectors of the ALICE experiment High-Momentum Particle Identification Detector -0.6< h < 0.6 azimuth 57.61° active area 10 m2 RIKEN-BNL Research Center Workshop - BNL

  12. The central detectors of the ALICE experiment PHOton Spectrometer -0.12< h < 0.12 azimuth 100° active area 8 m2 RIKEN-BNL Research Center Workshop - BNL

  13. The central detectors of the ALICE experiment Transition-Radiation Detector High-Momentum Particle Identification Detector Inner Tracking System Time Projection Chamber PHOton Spectrometer Time Of Flight RIKEN-BNL Research Center Workshop - BNL

  14. Fiducial volume and reconstruction strategies Standard / extended fiducial volume leading to high purity / efficiency for strange particle reconstruction RIKEN-BNL Research Center Workshop - BNL

  15. Simulation of hyperons in Pb+Pb R. Vernet et al. ALICE Internal Note 2005 - 042 b Expected L invariant mass distribution for 300 central HIJING simulated events. Expected raw spectra extrapolated to 107 central events (first year Pb+Pb data). W L RIKEN-BNL Research Center Workshop - BNL

  16. PID Range of ALICE at mid−rapidity Estimates as in the Physics Performance Report Vol.II for one year of Pb+Pb data-taking (central events) 107 central Pb+Pb events RIKEN-BNL Research Center Workshop - BNL

  17. Hadronization via coalescence at LHC energies Fries and Müller, EJP C34, S279 (2004) Amplitude for mixed ratio is the same at LHC than for RHIC but the limit is pushed to higher pT Calculation implies assumption on transverse radial flow extrapolation But first ALICE data will be elementary collisions a check magnitude of this behaviour then assume coalescence mechanisms if needed. Probing baryon/meson differences at LHC energies implies PID over a large pT range and ALICE is perfectly designed for this. RIKEN-BNL Research Center Workshop - BNL

  18. Simulation of hyperons in p+p L. Gaudichet et al. ALICE Internal Note 2005 - 041 Reconstruction rates for different multiplicity regimes (soft / hard) Expected raw spectra extrapolated to 109 events (first year p+p data). X Baryon over meson ratio in p+p collisions (gluonic baryon junction). RIKEN-BNL Research Center Workshop - BNL

  19. Mixed ratio @ UA1: p+p @ 630 GeV Extracting mixed ratio from 1996 UA1 strange particle data Ratio vs pT already surprisingly high in p+p data at high energies RIKEN-BNL Research Center Workshop - BNL

  20. Hard/soft/min.bias spectra @ CDF: p+p @ 1800 GeV Extrapolation using CDF strange particle publication: PR D72 (2005) 052001  Main difference between preprint and final publication is a comparison with PYTHIA 6.216 After PYTHIA tuning with pions, the bottom line is min. bias L spectra is close but K0s is slightly overestimated RIKEN-BNL Research Center Workshop - BNL

  21. Mixed ratio @ CDF: p+p @ 1800 GeV Extracting mixed ratio from 2005 CDF strange particle data Ratio vs pT slightly lower but compatible within errors RIKEN-BNL Research Center Workshop - BNL

  22. Mixed ratio using PYTHIA: p+p @ 14 TeV Simulation used for PPR analysis by L. Gaudichet Extrapolation of the main behaviours from RHIC, UA1 and CDF data is currently being investigated. • This feature is not observed in default PYTHIA at 14 TeV: • Going from LO to NLO may help getting the magnitude; • 2) Other ingredients may be needed to get the shape. RIKEN-BNL Research Center Workshop - BNL

  23. Conclusion • Using strangeness as a powerfull probe at LHC energies • with the PID capabilities of the ALICE experiment • a) equilibrium vs non-equilibrium scenario • b) kinetic freeze-out of multi-strange particles • c) hadronization and coalescence validity at LHC • a strange particles (specific probes and PID) ! • First measurements of strange particles in p+p to extract: • 1) interesting for baryon creation mechanisms • 2) references for Pb+Pb mandatory • WARNING: minimum bias trigger for p+p ! RIKEN-BNL Research Center Workshop - BNL

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