Strangeness opportunities at the LHC RIKEN BNL Research Center Workshop - BNL - 15/02/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with ALICE Detector and Simulations 3.First p+p Collisions and beyond First measures to target Strangeness in Collisions Boris HIPPOLYTE, STRASBOURG

02/2006 RIKEN-BNL Research Center Workshop - BNL 2 Wroblewski factor extrapolation to LHC energies Extrapolation at the LHC A+A ~0.45 p+p ~0.25 Wroblewski factor: Using thermal model description with corresponding system formalism (canonical or grand-canonical), extrapolation is straightforward. Data compilation using Becattini et al., PR C64 (2001) , hep-ph/ and references therein

02/2006 RIKEN-BNL Research Center Workshop - BNL 3 Excitation functions of hyperons yields in A+A dN/dy extrapolations at the LHC for  :10~30 for  :3~6 for  :0.4~0.7 Expected modifications total multiplicity scaling non-equilibrium scenario

02/2006 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/ ] Non Eq. [ Rafelski et al., Eur. J. Phys. C45 (2006) 61 ] Expectations at the LHC energies (eq.): T ch ~170 MeV  B ~1 MeV Scenarii for  s Calculations from Kraus et al., (Eq.) Rafelski et al., (Non Eq.)

02/2006 RIKEN-BNL Research Center Workshop - BNL 5 Blast-Wave parameters and T fo extrapolation Global trend for Blast-Wave parameters ( and T fo ) is clear Excitation functions of the radial flow velocity and the kinetic freeze-out temperature parameters for central Au+Au or Pb+Pb collisions. Compilation from N. Xu

02/2006 RIKEN-BNL Research Center Workshop - BNL 6 Blast-Wave for Multi-Strange Baryons vs √s NN G.E. Bruno J.Phys. G 31 (2005) s127 J. Speltz nucl-ex/ S. Salur nucl-ex/ Evolution of parameters up to LHC energies and systematics study for T fo

02/2006 RIKEN-BNL Research Center Workshop - BNL 7 The central detectors of the ALICE experiment Time Projection Chamber -0.9<  < 0.9 azimuth 2  length 5 m active volume 88 m 3

02/2006 RIKEN-BNL Research Center Workshop - BNL 8 The central detectors of the ALICE experiment Inner Tracking System -0.9<  < 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 m 3

02/2006 RIKEN-BNL Research Center Workshop - BNL 9 The central detectors of the ALICE experiment Transition-Radiation Detector -0.9<  < 0.9 azimuth 2  length ~7 m active area 736 m 2

02/2006 RIKEN-BNL Research Center Workshop - BNL 10 The central detectors of the ALICE experiment Time Of Flight -0.9<  < 0.9 azimuth 2  length 7.45 m active area 141 m 2

02/2006 RIKEN-BNL Research Center Workshop - BNL 11 The central detectors of the ALICE experiment High-Momentum Particle Identification Detector -0.6<  < 0.6 azimuth 57.61° active area 10 m 2

02/2006 RIKEN-BNL Research Center Workshop - BNL 12 The central detectors of the ALICE experiment PHOton Spectrometer -0.12<  < 0.12 azimuth 100° active area 8 m 2

02/2006 RIKEN-BNL Research Center Workshop - BNL 13 The central detectors of the ALICE experiment High-Momentum Particle Identification Detector PHOton Spectrometer Time Projection Chamber Inner Tracking System Time Of Flight Transition-Radiation Detector

02/2006 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

02/2006 RIKEN-BNL Research Center Workshop - BNL 15 Simulation of hyperons in Pb+Pb  Expected  invariant mass distribution for 300 central HIJING simulated events. R. Vernet et al. ALICE Internal Note   Expected raw spectra extrapolated to 10 7 central events (first year Pb+Pb data).

02/2006 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) 10 7 central Pb+Pb events

02/2006 RIKEN-BNL Research Center Workshop - BNL 17 Hadronization via coalescence at LHC energies Fries and Müller, EJP C34, S279 (2004) Calculation implies assumption on transverse radial flow extrapolation Amplitude for mixed ratio is the same at LHC than for RHIC but the limit is pushed to higher p T Probing baryon/meson differences at LHC energies implies PID over a large p T range and ALICE is perfectly designed for this. But first ALICE data will be elementary collisions  check magnitude of this behaviour then assume coalescence mechanisms if needed.

02/2006 RIKEN-BNL Research Center Workshop - BNL 18 Simulation of hyperons in p+p Reconstruction rates for different multiplicity regimes (soft / hard) L. Gaudichet et al. ALICE Internal Note  Expected raw spectra extrapolated to 10 9 events (first year p+p data). Baryon over meson ratio in p+p collisions (gluonic baryon junction).

02/2006 RIKEN-BNL Research Center Workshop - BNL 19 Mixed UA1: 630 GeV Extracting mixed ratio from 1996 UA1 strange particle data Ratio vs p T already surprisingly high in p+p data at high energies

02/2006 RIKEN-BNL Research Center Workshop - BNL 20 Hard/soft/min.bias CDF: 1800 GeV Extrapolation using CDF strange particle publication: PR D72 (2005) Main difference between preprint and final publication is a comparison with PYTHIA After PYTHIA tuning with pions, the bottom line is min. bias  spectra is close but K0s is slightly overestimated

02/2006 RIKEN-BNL Research Center Workshop - BNL 21 Mixed CDF: 1800 GeV Extracting mixed ratio from 2005 CDF strange particle data Ratio vs p T slightly lower but compatible within errors

02/2006 RIKEN-BNL Research Center Workshop - BNL 22 Mixed ratio using PYTHIA: 14 TeV This feature is not observed in default PYTHIA at 14 TeV: 1)Going from LO to NLO may help getting the magnitude; 2) Other ingredients may be needed to get the shape. Simulation used for PPR analysis by L. Gaudichet Extrapolation of the main behaviours from RHIC, UA1 and CDF data is currently being investigated.

02/2006 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  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 !