Baryonic matter physics at the Nuclotron Peter Senger

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 Current Ion source type Nuclotron-M (2010) Nuclotron-N (2012) New ion source + booster (2014) p 3 1010 Duoplasmotron 8 1010 5 1011 5 1012 d 3 1010 --- , , --- 8 1010 5 1011 5 1012 4 He 6 108 --- , , --- 2 109 3 1010 1 1012 d 2 108 ABS (“Polaris”) 2 108 7 1010 (SPI) 7 Li 2 109 Laser 7 109 3 1010 5 1011 10 B 1 109 --- , , --- 3 109 2 109 7 1010 12 C 2 109 --- , , --- 6 109 3 1010 3 1011 24 Mg 2 108 --- , , --- 7 108 4 109 4 1010 14 N 1 107 ESIS (“Krion-2”) 3 107 3 108 5 1010 24 Ar 4 106 --- , , --- 8 106 2 109 2 1010 56 Fe 1 106 --- , , --- 4 106 2 109 5 1010 84 Kr 1 105 --- , , --- 2 105 1 108 1 109 124 Xe 1 104 --- , , --- 1 105 7 107 1 109 197 Au - --- , , --- 7 107 1 109 Nuclotron-M (2010): vacuum ( x 100), new power supply system, orbit correction, automatization; Nuclotron-N (2012): new ESIS (KRION 6 T: I x 20) + Reconstructed LU-20 (new RFQ + H-resonator: I x 2) + Adiabatic RF capture (I x 2) G. Trubnikov, NICA RT 5 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 s d u us Λ Λ

Dense nuclear matter in heavy ion collisions

Messengers from the dense fireball at Nuclotron beam energies p, Λ, Ξ+, Ω+ ρ→ e + e -, μ + μ - φ, Ξ-, Ω- ρ → e + e -, μ + μ - π, K, Λ, . . . resonance decays ρ → e + e -, μ + μ -

Available data on strangeness production AGS Au+Au HADES Ar+KCL 1. 76 A Ge. V 2 A Ge. V 4 A Ge. V FOPI Al+Al 1. 93 A Ge. V centr. Au+Au 4 A Ge. V S*(1385) +

Au+Au 4 A Ge. V (statistical model) AGS

Proton collective flow from AGS (1988 -1999) collective flow driven by pressure E 895 Collaboration, C. Pinkenburg et al. , Phys. Rev. Lett. 83, 1295 (1999). No conclusion on the nuclear compressibility at high densities (2 – 5 ρ0) P. Danielewicz, R. Lacey, W. G. Lynch, Science 298 (2002) 1592

Probing the nuclear equation-of-state at 2 – 3 ρ0 Idea: Subthreshold particle production via multiple collisions is sensitive to nuclear density K+ yield baryon density ρ compressibility κ soft EOS stiff EOS Experiment: C. Sturm et al. , Phys. Rev. Lett. 86 (2001) 39 Theory: Ch. Fuchs et al. , Phys. Rev. Lett. 86 (2001) 1974

Neutron star J 1614 -2230 with M =1. 976 0. 04 M stiff EOS? (sub)threshold production of K+ mesons: soft EOS

Exploring the "nuclear" EOS at 3ρ0 < ρ < 7ρ0 with (sub)threshold production of multistrange hyperons Direct production: pp - K+K+p pp - K+K+K 0 p pp Λ 0Λ 0 pp pp + - pp (Ethr = 3. 7 Ge. V) (Ethr = 7. 0 Ge. V) (Ethr = 7. 1 Ge. V) (Ethr = 9. 0 Ge. V) (Ethr = 12. 7 Ge. V) FAIR NICA N Production via multiple strangeness exchange reactions: Hyperons (s quarks): 1. pp K+Λ 0 p, pp K+K-pp, 2. pΛ 0 K+ - p, πΛ 0 K+ - π, 3. Λ 0Λ 0 - p, Λ 0 K - - 0 4. Λ 0 - - n, -K- - Antihyperons (anti-s quarks): 1. Λ 0 K+ + 0 , 2. + K+Measure + +. excitation AGS SPS function for multi-strange hyperons in light and heavy collision systems

Hyperon production in Au+Au collisions at 4 A Ge. V 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) 624 c

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: 1966: 1991: 2001: (Danysz et al. ) 6 ΛΛ He (Prowse et al. ) 10 10 ΛΛ Be or ΛΛ Be (KEK-E 176) 4 ΛΛ H (BNL-E 906) 6 ΛΛ He (KEK-E 373) 10 ΛΛ Be (KEK-E 373) ΛΛ 10 Be

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, ar. Xiv: 1010. 2995 v 1 Λ + 2 H Λ 3 H Λ + 3 He Λ 4 He Λ + 4 He Λ 5 He Ξ–+ 4 He Λ Λ 5 H Ξ–+ 4 He Ξ 5 He ? Ω–+ 4 He Ω 5 He ? Yield of ΛΛ 5 H ≈ 2· 10 -6 Measure: Yield of ΛΛ 6 He ≈ 4· 10 -8 Λ ΛΛ 5 H 4 He 5 He πNuclotron Λ p π- (√s. NN = 3. 3 Ge. V)

Possible experiment layout TOF wall measures Time-of-flight for mass determination. tracking chambers Dipole magnet Silicon tracker in magnetic dipole field measures tracks (multiplicity) and curvature (particle momentum). Time-of-flight wall (RPC) Tracking chambers may be needed to match tracks in Silicon detector to hits in TOF wall 6 m

Strange particle reconstruction without TOF in central Au+Au collisions at 4 A Ge. V Ur. QMD+GEANT+CBMroot (CBM detector model) Measured yields in 10000 central collisions of Au+Au at 4. 0 A Ge. V: ~ 11000 Λ ~ 4000 K 0 s ~ 8 Ξ- I. Vassiliev, Frankfurt 108 central

Hyperon production in Au+Au collisions at 4 A Ge. V HYPQGSM calculations

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

Hyperon yields at the Nuclotron 4 A Ge. V min. bias Au+Au collisions, Multiplicities from statistical model, Reaction rate 105/s Particle Ethr. NN Ge. V M central M m. bias ε % Yield/s m. bias Yield/week m. bias - 3. 7 1 10 -1 2. 5 10 -2 3 75 4. 5 107 - 6. 9 2 10 -3 5 10 -4 3 1. 5 9 105 Anti- 7. 1 2 10 -4 5 10 -5 15 0. 15 9 104 + 9. 0 6 10 -5 1. 5 10 -5 3 4. 5 10 -2 2. 7 104 + 12. 7 1 10 -5 2. 5 10 -6 3 7. 5 10 -3 4. 5 103

Hypernuclei yields at the Nuclotron 4 A Ge. V min. bias Au+Au collisions, Multiplicities from statistical model, Reaction rate 105/s Hypernucleus Λ 3 H 5 ΛΛ He M central M m. bias ε % Yield/s m. bias Yield/week m. bias 2 10 -2 5 10 -3 1 5 3 106 2 10 -6 5 10 -7 1 5 10 -4 300 4 10 -8 1 1 10 -5 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 NB = 107 -108 ions/sec

Experiments on superdense nuclear matter Experiment Energy range (Au/Pb beams) Reaction rates Hz STAR@RHIC BNL s. NN = 7 – 200 Ge. V NA 61@SPS CERN Ekin= 20 – 160 A Ge. V s. NN= 6. 4 – 17. 4 Ge. V (limitation by detector) MPD@NICA Dubna s. NN= 4. 0 – 11. 0 Ge. V ~1000 CBM@FAIR Darmstadt Ekin= 2. 0 – 35 A Ge. V s. NN= 2. 7 – 8. 3 Ge. V BM@N Dubna Ekin= 2. 0 – 4. 5 A Ge. V s. NN= 2. 6 – 3. 3 Ge. V 1 – 800 (limitation by luminosity) 80 (design luminosity of 1027 cm-2 s-1 for heavy ions) 105 – 107 (limitation by detector) 105 (limitation by DAQ/trigger) Advantage of collider experiments: Uniform phase-space coverage when measuring excitation functions. complementary measurements with CBM@FAIR and MPD@NICA