Multi-Strange Hyperons Triggering at SIS 100 Hamda CHERIF For the CBM

Multi-Strange Hyperons Triggering at SIS 100 Hamda CHERIF For the CBM collaboration DPG Spring meeting Darmstadt, 14-18 March 2016

The Compressed Baryonic Matter (CBM) Experiment at FAIR Explore QCD phase diagram in the region of high net baryon densities Transition Radiation Ring Imaging Detector Cherenkov Micro Vertex Detector Time of Flight Silicon Tracking System Physics program is performed with ions beam delivered by SIS 100/300 accelerator at FAIR 1st phase SIS100 with energies up to 11 AGeV for heavy nuclei, 29 GeV for protons 15/03/2016 Dipole Magnet Muon Detector Projectile Spectator Detector The detector systems of the CBM experiment DPG Spring meeting 2

Experimental challenges Strangeness enhancement is one of the earliest proposed signatures of the formation of a deconfined QGP Multi-strange hyperons are very rare Interaction rates up to 10 MHz High multiplicity of charged Ω decay and Au Au collision at particles produced in heavy ion 10 AGeV collisions Huge data rates up to 1 TB/s CBM experiment requires a Software Trigger to decide what data to save rejection factor of 400 or more 15/03/2016 DPG Spring meeting 3

Selection strategy of Multi-strange hyperons Selection of events containing multistrange hyperons : , Ξ-, , Ω-, and based on simulated data using: *Decay topology in STS *TOF particle identification The selection strategy is developed for Au Au collisions at SIS 100 energies 15/03/2016 DPG Spring meeting 4

Simulation Simulation approach: Events are generated with UrQMD generator Particles are propagated one by one through the CBM detector systems using GEANT3 transport Reconstruction of simulated events Physics analysis Simulation setup: *CbmRoot *Geometry : magnet STS TOF *KF Particle Finder package [M.Zyzak HK 25.5] 15/03/2016 DPG Spring meeting 5

Multiplicity per Au Au central event (UrQMD) High Statistic required 15/03/2016 DPG Spring meeting 6

Hyperons selection cuts, decay topology Selection cuts in KF Particle Finder, to ensure: χ2prim 3 for π, p χ2geo 3 for Λ 10 cm for Λ Charged tracks are secondary χ2prim 3 for π, K χ2prim 5 for Λ χ2geo 3 for Ξ, Ω 5 cm for Ξ, Ω Secondary vertex position is at a certain distance from the Primary vertex 15/03/2016 DPG Spring meeting 7

Reconstruction: Invariant Mass 5 Million Au Au central collisions @ 10 AGeV Efficiency 20% Efficiency 15% Efficiency 8.4% Efficiency 6.1% 8

Selected Events at SIS 100 energies with 5M Au Au central collisions 10 AGeV 2874 8 AGeV 8.1x104 1070 535 5.2x104 283 73 29 3 ΛΞ Ξ ¿ Ω Ω ¿ 3 ΛΞ Ξ ¿¿ ¿ Ω Ω ¿ ¿¿ 4 AGeV 6 AGeV 2.1x104 2704 290 62 14 3 ΛΞ Ξ 15/03/2016 ¿ 0 Ω Ω ¿ ¿¿ 1 0 DPG Spring meeting ΛΞ Ξ ¿ Ω Ω 0 ¿ ¿¿ 9

Rejection Factor at SIS 100 energies 𝑹. 𝑭 𝑮𝒆𝒏𝒆𝒓𝒂𝒕𝒆𝒅 𝒆𝒗𝒆𝒏𝒕𝒔 𝑺𝒆𝒍𝒆𝒄𝒕𝒆𝒅 𝒆𝒗𝒆𝒏𝒕𝒔 R.F 4 AGeV 6AGeV 8AGeV 10AGeV Minimum Bias 19800 1850 700 430 Central 1800 225 95 59 15/03/2016 DPG Spring meeting 10

Summary CBM at FAIR is an experiment to explore QCD phase diagram in the region of high net baryon densities The CBM detector is an excellent device to measure multi-strange hyperons with high statistic at SIS 100 energies in the first phase of FAIR project The rejection factor is calculated and reaches the CBM requirement Thankyou youfor foryour your Thank attention attention 15/03/2016 DPG Spring meeting 11