1. Hypernuclei program at the CBM experiment
HYP2015, Sendai, Japan
Vassiliev Iouri , CBM Collaboration
TOF
ECAL
TRD
RICH
STS
PSD
Outline
CBM physics
Motivation for HYP program
CBM tracking and particles ID
Multi-strange hyperons and
Hypernuclei simulation
Conclusion 1 1 1 1 1

2. Physics case: Exploring the QCD phase diagram
The equation-of-state at high B
collective flow of hadrons and HYPERnuclei
particle production at threshold
energies (open charm)
LHC
RHIC
Deconfinement phase transition at high B
excitation function and flow of strangeness (K, , , , ) and HYPERnuclei
excitation function and flow of charm
(J/ψ, ψ', D0, Ds, D, c)
charmonium suppression, for J/ψ and ψ'
SPS-CERN
CBM
QCD critical endpoint
excitation function of event-by-event fluctuations (K/π,  π,  π)
Onset of chiral symmetry restoration at high B
in-medium modifications of hadrons (,, e+e-(μ+μ-))
Projects to explore the QCD phase diagram at large μB:
RHIC energy-scan, bulk observables
bulk and rare observables, high statistic! 2 2 2 2

3. Motivation:  Hypernuclei ? CBM T. Bressani (2009) challenges:
How far can we extend the chart of nuclei towards
the third (strange) dimension by producing single
and double hypernuclei?
Does strange matter exist
in the form of heavy multi-strange objects? 
Hypernuclei ?
CBM
Au+Au -3
T. Bressani (2009)
new physics items:
search for H particle
neutron star composition
are there S=-2 deeply bound K(bar) states?
challenges:
(abundant) production of ΛΛ-hypernuclei is very difficult (CBM!)
identification of produced hypersystems is problematic (CBM!)
complex topology (is good for CBM!)

4. CBM physics program III (P.Senger)
Motivation:
No data at FAIR energies
Strange matter
Hypernuclei, strange dibaryons and massive strange objects
Production of hypernuclei via coalescence
of hyperons and light nuclei
CBM
A. Andronic et al., Phys. Lett. B697 (2011) 203
H. Stöcker et al., Nucl. Phys. A 827 (2009) 624c

5. collisions: Thermal production vs. Coalescence
Motivation:
Hypernuclei, dibaryon and antinuclei production in high energy heavy ion
collisions: Thermal production vs. Coalescence
J. Steinheimer, K. Gudima, A. Botvina, I. Mishustin, M. Bleicher, H. Stöcker
Phys. Lett. B714, 85, (2012)
Lines: UrQMD + thermal hydrodynamics, symbols: DCM + coalescence

6. Why CBM?  up to 107 Au+Au reactions/sec (J/ψ) I.Vassiliev, CBM
FAIR will provide heavy-ion beam energies from (14) A GeV for Q = 0.4 A (0.5 A) nuclei with the SIS100 synchrotron, and (45) A GeV with the SIS300 synchrotron.
 up to 107 Au+Au reactions/sec (J/ψ)
 determination of (displaced) vertices
with high resolution ( 50 m)
 identification of leptons and hadrons
 fast and radiation hard detectors
 self-triggered readout electronics
 high speed data acquisition and
online event selection
powerful computing farm 4-d tracking*
software triggers
I.Vassiliev, CBM

7. SIMDized tracking + KFParticle
CBM tracking:
central 25AGeV
UrQMD
8 DS-strip
Stations
Low material
budget (0.3-1 X0)
High acceptance
~700 
160 p
53 K
32 
KS
0.44 -
0.018 -
reconstruction
CA track finder
~700 
174 p
42 K
30 
4KS
2.4 -
0.005 -
low p tracks !
SIMDized tracking + KFParticle
648 reconstructed tracks
Ref. prim. eff = 96%
All set eff = 87%
dp/p = 1.2%
central: 82 (TF) + 16 (PF) ms/core
mbias : 10 (TF) (PF) ms/core
up to 80 cores/CPU 7 7

8. CBM First Level Event Selection (FLES)
The FLES package is
vectorized, parallelized, portable and scalable up to 3200 cores
Example:
Full track reconstruction including KF particle analysis of multi-strange
(anti) hyperons for min. bias Au+Au collisions at 25 A GeV.
100 nodes with 32 cores each
Single node with up to 80 cores
220 k events/s !
FAIR-Russia
HPC cluster at
ITEP Moscow 8

9. KF Particle Finder with ToF particle ID: Au+Au @ 10AGeV SIS100
165 
170 p
26 K
15 
20KS
0.3 -
central: 40 (TF) + 8 (PF) ms/core
mbias : 5 (TF) + 1 (PF) ms/core, up to 80 cores/CPU

10. KF Particle Finder for the CBM Experiment (development)

11. KF Particle Finder with ToF track ID: Au+Au @ 10AGeV SIS100
165 
170 p
26 K
15 
20KS
0.3 - pv

12. Au+Au 10 AGeV 5M central events
UrQMD
Au+Au 10 AGeV 5M central events
eff =2.3% 12

13. QGP signatures at FAIR energies: Multi-strange antibaryons
E.Bratkovskaya
fias.uni-frankfurt.de/~brat/PHSD/index1.html
V. Vovchenko
QGP
5M events/point GSI Farm
5M events/point GSI Farm
Most of the + produced by QGP @ FAIR energy!?

14. Au+Au 10 AGeV 5M central events
UrQMD
Au+Au 10 AGeV 5M central events
Extended KFParticle Finder 3H
5 second of data taking!
STAR 2010
eff = 19.2%
= 1.7 MeV
S/B ~ 1.5
BR from H. Kamada et al., Phys. Rev., Ser. C 57, 1595 (1998)
M from J. Steinheimer et al., Phys. Lett. B714, 85, (2012) 14

15. Au+Au 10 AGeV 5M central events
UrQMD
Au+Au 10 AGeV 5M central events
Extended KFParticle Finder (,N)bound
5 second of data taking!
eff = 28.9%
= 1.6 MeV
BR ~ 0.2
M from J. Steinheimer et al., Phys. Lett. B714, 85, (2012)
UrQMD output do not contain deuterons
~ 5.6 d/event expected (no secondary d’s)! 15

16. Au+Au 10 AGeV 5M central events
UrQMD
Au+Au 10 AGeV 5M central events
Extended KFParticle Finder 4He
~ 1 min. of data taking!
STS
MVD
eff = 14.7%
= 1.6 MeV
S/B ~ 50
BR ~ 0.2
3 prong detached vertex is good signature of 4He decay
M from J. Steinheimer et al., Phys. Lett. B714, 85, (2012) 16

17. New horizons: ± reconstruction
Σ+ and Σ− have only channels with at least one neutral daughter.
A lifetime is sufficient to be registered by the tracking system: cτ = 2.4 cm for Σ+ and cτ = 4.4 cm for Σ−.
Can not to be identified by the PID detectors.
Identification is possible by the decay topology:
2. Reconstruct a neutral daughter from the mother and the charged daughter
1. Find tracks of Σ and its daughter in STS and MVD
3. Reconstruct Σ mass spectrum from the charged and obtained neutral daughters n π- Σ-
I.Vassiliev, CBM

18. ? Λ Strange and Hyper matter in the Lab s d u
Does strange matter exist in the form of heavy multi-strange objects?

19. Summary: Plans: CBM detector is an excellent device to measure
not only bulk observables, but strangeness, Hypernuclei and other rare probes with high statistic.
Plans:
6He and neutral fragment decay channels. 19 19

20. Thank you very much! Join CBM! どうもありがとうございました
I.Vassiliev, CBM