Baryonic matter physics at the Nuclotron

Peter Senger (GSI) Outline:  The physics case: - Baryonic matter at neutron star densities - Strange matter: hyperons, hypernuclei, strange dibaryons  Experimental requirements and rate estimates NICA/JINR-FAIR Bilateral Workshop, FIAS, Frankfurt, April 2-4, 2012

Nuclotron beam intensity, particles per cycle Beam 4 d p d He



Current

3  10 10 3  10 10 6  10 8 2  10 8

Ion source type

Duoplasmotron --- ,, -- --- ,, -- ABS (“Polaris”)

Nuclotron-M (2010)

8



10 10 8



10 10 2



10 9 2



10 8

Nuclotron-N (2012)

5



10 11 5



10 11 3



10 10 7



10 10

(SPI) New ion source + booster (2014)

5



10 12 5



10 12 1



10 12 7



10 10

(SPI)

7 10 12 24 14 24 56 Li B C Mg N Ar Fe 84 Kr

2  10 9 1  10 9 2  10 9 2  10 8 1  10 7 4  10 6 1  10 6 1  10 5

Laser --- ,, -- --- ,, -- --- ,, -- ESIS (“Krion-2”) --- ,, -- --- ,, -- --- ,, -- 7



10 9 3



10 9 6



10 9 7



10 8 3



10 7 8



10 6 4



10 6 2



10 5 3



10 10 2



10 9 3



10 10 4



10 9 3



10 8 2



10 9 2



10 9 1



10 8 5



10 11 7



10 10 3



10 11 4



10 10 5



10 10 2



10 10 5



10 10 1



10 9 124 Xe

1  10 4

--- ,, -- 1



10 5 7



10 7 1



10 9 197 Au

-

--- ,, -- 7



10 7 1



10 9

Nuclotron-M (2010): vacuum ( I

 

Nuclotron-N (2012) : new ESIS (KRION 6T: I x2) + Adiabatic RF capture (I x100), new power supply system, orbit correction, automatization;



x2)

G.Trubnikov, NICA RT5 

x20) + Reconstructed LU-20 (new RFQ + H-resonator:

28 Aug 2010

Nuclear matter and strangeness physics at Nuclotron energies

 Nuclear matter equation-of-state, new forms of nuclear matter at high densities?

What are the properties and the degrees-of-freedom of nuclear matter at neutron star core densities?

 Production of single and double hypernuclei Can we establish a third dimension of the nuclear chart?  Strange matter: Does strange matter exist in the form of heavy multi-strange objects?

?

s d u s s u Λ Λ

Dense nuclear matter in heavy ion collisions

Messengers from the dense fireball at Nuclotron beam energies

φ, Ξ , Ω π, K, Λ, ...

p, Λ, Ξ + , Ω + ρ → e + e , μ + μ ρ → e + e , μ + μ resonance decays ρ → e + e , μ + μ -

Available data on strangeness production

AGS Au+Au HADES Ar+KCL 1.76 A GeV 2 A GeV 4 A GeV centr. Au+Au 4 A GeV FOPI Al+Al 1.93 A GeV S

*

(1385)  

+



Au+Au 4 A GeV (statistical model)

AGS

Proton collective flow from AGS (1988-1999)

collective flow driven by pressure E895 Collaboration, C. Pinkenburg et al., Phys. Rev. Lett. 83, 1295 (1999). No conclusion on the nuclear compressibility at high densities (2 – 5 ρ 0 ) P. Danielewicz, R. Lacey, W.G. Lynch, Science 298 (2002) 1592

Probing the nuclear equation-of-state at 2 – 3 ρ

0 Idea:  Subthreshold particle production via multiple collisions is sensitive to nuclear density  K + yield  baryon density ρ  compressibility κ stiff EOS soft EOS Experiment:C. Sturm et al., Phys. Rev. Lett. 86 (2001) 39 Theory: Ch. Fuchs et al., Phys. Rev. Lett. 86 (2001) 1974

(sub)threshold production of K + mesons: soft EOS Neutron star J1614-2230 with M =1.976  0.04 M   stiff EOS?

Exploring the "nuclear" EOS at 3ρ 0 < ρ < 7ρ 0 with (sub)threshold production of multistrange hyperons Direct production: pp  

-

K + K + p (E thr pp  

-

K + K + K 0 p (E thr pp  Λ 0 Λ 0 pp (E thr pp  

+

pp  

+



-

pp (E thr 

-

pp (E thr = 3.7 GeV) = 7.0 GeV) = 7.1 GeV) = 9.0 GeV) = 12.7 GeV)

N

FAIR NICA Production via multiple strangeness exchange reactions: Hyperons (s quarks): 1. pp 2. p Λ 0  3.

4.

 K K + + Λ  

-

 0 Λ 0 Λ 0  

-

p

,

Λ 0 

-

n

-

p

, ,

p, pp  Λ πΛ  0

-

K K 0  K + K pp, K + 

-

π,  

-

 0  

-

 Antihyperons (anti-s quarks): 1. Λ 0 2. 

+

K K + +  

+

 0  

+

 + .

, AGS SPS Measure excitation function for multi-strange hyperons in light and heavy collision systems

Hyperon production in Au+Au collisions at 4 A GeV HYPQGSM calculations Ξ → Λπ Ω →ΛK MB MY BB BY YY Y: hyperon B: Baryon M: meson Multi-strange hyperon production dominantly via ΛΛ collisions

Hypernuclei and metastable multi-strange objects

?

H. Stöcker et al., Nucl. Phys. A 827 (2009) 624c

Double-strange hypernuclei

Double strangeness exchange: K + p  K + + Ξ – Ξ + 12 C  ΛΛ 6 He + 4 He + t ΛΛ 6 He  Λ 5 He + p + π Observed ΛΛ hypernuclei: 1963: ΛΛ 10 Be (Danysz et al.) 1966: ΛΛ 6 He (Prowse et al.) 1991: ΛΛ 10 Be or ΛΛ 10 Be (KEK-E176) 2001: ΛΛ 4 H (BNL-E906) 2001: ΛΛ 6 He (KEK-E373) 2001: ΛΛ 10 Be (KEK-E373)

Multi-strange hypernuclei in A+A collisions Production via coalescence of hyperons and light nuclei Thermal model: A. Andronic, P. Braun-Munzinger, J. Stachel, H. Stöcker, arXiv:1010.2995v1 Λ + Λ + Λ + Ξ Ω – – + + 2 3 4 4 4 H  He He He Ξ – + 4 He  He    Λ 3  H Λ 4 Λ 5 He He Λ Λ 5 Ξ 5 Ω 5 H He ? He ?

Yield of ΛΛ 5 H ≈ 2·10 -6 4 He ΛΛ 5 H ΛΛ 6 He ≈ 4·10 -8 Λ 5 He π Λ p π Nuclotron (√s NN = 3.3 GeV)

Possible experiment layout

tracking chambers Dipole magnet

TOF wall measures Time-of-flight for mass determination.

Time-of-flight wall (RPC) Silicon tracker

Silicon tracker in magnetic dipole field measures tracks (multiplicity) and curvature (particle momentum).

6 m

Tracking chambers may be needed to match tracks in Silicon detector to hits in TOF wall

Strange particle reconstruction without TOF in central Au+Au collisions at 4 A GeV

UrQMD+GEANT+CBMroot (CBM detector model)

I. Vassiliev, Frankfurt

Measured yields in 10000 central collisions of Au+Au at 4.0 A GeV: ~ 11000 Λ ~ 4000 K 0 s ~ 8 Ξ -

10 8 central

Hyperon production in Au+Au collisions at 4 A GeV HYPQGSM calculations

Hypernuclei production in Au+Au collisions at 4 A GeV HYPQGSM calculations: A.Zinchenko et al. (LHEP JINR)

Hyperon yields at the Nuclotron

4 A GeV min. bias Au+Au collisions, Multiplicities from statistical model, Reaction rate 10 5 /s Particle   Anti  +  +  E thr NN GeV 3.7

6.9

7.1

9.0

12.7

M central 1  10 -1 2  10 -3 2  10 -4 6  10 -5 1  10 -5 M m.bias

2.5

 10 -2 5  10 -4 5  10 -5 1.5

 10 -5 2.5

 10 -6 ε % 3 3 15 3 3 Yield/s m. bias 75 1.5

0.15

4.5

 10 -2 7.5

 10 -3 Yield/week m. bias 4.5

 10 7 9  10 5 9  10 4 2.7

 10 4 4.5

 10 3

Hypernuclei yields at the Nuclotron

4 A GeV min. bias Au+Au collisions, Multiplicities from statistical model, Reaction rate 10 5 /s Hyper nucleus Λ 3 H ΛΛ 5 H ΛΛ 5 He M central 2  10 -2 2  10 -6 4  10 -8 M m.bias

5  10 -3 5  10 -7 1  10 -8 ε % 1 1 1 Yield/s m. bias 5 5  10 -4 1  10 -5 Yield/week m. bias 3  10 6 300 6

Conclusions

Promising observables for a fixed-target experiment at the Nuclotron: • Multi-strange hyperons (EOS at neutron star density) • Production of single and double hypernuclei • Multi-strange dibaryons ?

Experimental requirements: • Magnet + tracking detectors with high granularity (track reconstruction, momentum determination) • Time-of-flight detector (particle identification) • Projectile-Spectator Detector (reaction plane) • Fast readout electronics and online event selection • Beam intensities of N B = 10 7 -10 8 ions/sec

Experiments on superdense nuclear matter Experiment STAR@RHIC BNL NA61@SPS CERN MPD@NICA Dubna CBM@FAIR Darmstadt BM@N Dubna Energy range (Au/Pb beams)  s NN E kin = 20 – 160 A GeV  s NN = 6.4 – 17.4 GeV  s NN = 7 – 200 GeV = 4.0 – 11.0 GeV E kin = 2.0 – 35 A GeV  s NN = 2.7 – 8.3 GeV E kin = 2.0 – 4.5 A GeV  s NN = 2.6 – 3.3 GeV Reaction rates 10 5 Hz 1 – 800 (limitation by luminosity) 80 (limitation by detector) ~1000 (design luminosity of 10 27 cm -2 s -1 for heavy ions) – 10 7 (limitation by detector) 10 5 (limitation by DAQ/trigger) Advantage of collider experiments: Uniform phase-space coverage when measuring excitation functions.

 complementary measurements with CBM@FAIR and MPD@NICA