Formation of strangeness-nuclei at PANDA

Transcription

1 Formation of strangeness-nuclei at PANDA T. Gaitanos Introduction Theoretical background RBUU+SMM hybrid model Testing strangeness & fragmentation Strangeness production & fragment yields/spectra for p+x, p+x & X+X Results for PANDA primary target: p+x ΞX, secondary target: Ξ+X AX Final remarks together with A.B. Larionov, H. Lenske, U. Mosel supported by DFG and in part by I3HP SPHERE

2 Introduction HypHI: Heavy-Ion collisions antiproton-nucleus reactions Λ,Σ,π,Κ,... Λ,Σ,π,Κ,... hyperon-baryon explore hyperon-hyperon crucial to understand the strangeness sector of the hadronic EoS direct implications for nuclear astrophysics (max. mass of neutron stars)

3 Relativistic hypernuclei Κ Λ π Λ π Λ Κ Primary : BB->BΛK, BBKK Secondary: πb->λk, BKK Λ p Κ,Kπ ΞΞ Ξ 1. target: pp->, ΞΞ, KKπ...(annih.) πb->λk, BKK (s=0) KB-> KΞ (s=-1) 2. target: ΞB->ΞB, (s=-2) Theoretical framework Phase-Space evolution transport approaches (INC,BUU,RBUU,VUU,(Ur)QMD,HSD, ) Description of fragment formation statistical picture, e.g., SMM, Botvina & Mishustin Description of hypernuclei formation? Phase-Space coalescence (in coordinate and) in momentum space (SMM+H: Botvina & Pochodzalla, PR C76 ('07) , PL B697 ('11) 222) See also: Botvina, et al., Phys. Rev. C86 ('12) , Nucl. Phys. A881 ('12) 228, Phys. Lett. B714 ('12) 85, Phys. Rev. C84 ('11)

4 Non-Equilibrium stage GiBUU-group: Buss, et al., Phys. Rep. 512 (2012) 1 Standard Relativistic Mean-Field (RMF) Non-linear Walecka model (soft EoS) gων=-ξgων, gσν=ξgσν (ξ~ ) Larionov, et al., PR C80,021601(R) Lalazissis, et al., PL B good description of p-nucleus (but not for p-nucleus) opt. Potentials Uopt Consistent description of both, in-medium p and p Uopt: Non-Linear Derivative (NLD) model: Gaitanos/Kaskulov, arxiv: Collision term: primary: BB mesons Golubeva, Pshenichnov, et al., NP A BB, ΞΞ (data) Secondary: ΞΒ (Nijmegen-calc.), KB ΞK (data), ΛΒ ΣB (data,nijmegen-calc.) Formation of single-λ & double- hypernuclei Fragments: SMM, Botvina/Mishustin, Phys. Rep Hyperfragments: phase-space coalescence Gaitanos, et al., NP A

5 Non-Equilibrium stage GiBUU-group: Buss, et al., Phys. Rep. 512 (2012) 1 Standard Relativistic Mean-Field (RMF) Non-linear Walecka model (soft EoS) gων=-ξgων, gσν=ξgσν (ξ~ ) Larionov, et al., PR C80,021601(R) Lalazissis, et al., PL B good description of p-nucleus (but not for p-nucleus) opt. Potentials Uopt Consistent description of both, in-medium p and p Uopt: Non-Linear Derivative (NLD) model: Gaitanos/Kaskulov, arxiv: Collision term: primary: BB mesons Golubeva, Pshenichnov, et al., NP A BB, ΞΞ (data) Secondary: ΞΒ (Nijmegen-calc.), KB ΞK (data), ΛΒ ΣB (data,nijmegen-calc.) Formation of single-λ & double- hypernuclei Fragments: SMM, Botvina/Mishustin, Phys. Rep Hyperfragments: phase-space coalescence Gaitanos, et al., NP A

6 Non-Equilibrium stage GiBUU-group: Buss, et al., Phys. Rep. 512 (2012) 1 Standard Relativistic Mean-Field (RMF) Non-linear Walecka model (soft EoS) gων=-ξgων, gσν=ξgσν (ξ~ ) Larionov, et al., PR C80,021601(R) Lalazissis, et al., PL B good description of p-nucleus (but not for p-nucleus) opt. Potentials Uopt Consistent description of both, in-medium p and p Uopt: Non-Linear Derivative (NLD) model: Gaitanos/Kaskulov, arxiv: Collision term: primary: BB mesons Golubeva, Pshenichnov, et al., NP A BB, ΞΞ (data) Secondary: ΞΒ (Nijmegen-calc.), KB ΞK (data), ΛΒ ΣB (data,nijmegen-calc.) Formation of single-λ & double- hypernuclei Fragments: SMM, Botvina/Mishustin, Phys. Rep Hyperfragments: phase-space coalescence Gaitanos, et al., NP A

7 Non-Equilibrium stage GiBUU-group: Buss, et al., Phys. Rep. 512 (2012) 1 Standard Relativistic Mean-Field (RMF) Non-linear Walecka model (soft EoS) gων=-ξgων, gσν=ξgσν (ξ~ ) Larionov, et al., PR C80,021601(R) Lalazissis, et al., PL B good description of p-nucleus (but not for p-nucleus) opt. Potentials Uopt Consistent description of both, in-medium p and p Uopt: Non-Linear Derivative (NLD) model: Gaitanos/Kaskulov, arxiv: Collision term: primary: BB mesons Golubeva, Pshenichnov, et al., NP A BB, ΞΞ (data) Secondary: ΞΒ (Nijmegen-calc.), KB ΞK (data), ΛΒ ΣB (data,nijmegen-calc.) Formation of single-λ & double- hypernuclei (GiBUU+SMM) Fragments: SMM, Botvina/Mishustin, Phys. Rep Hyperfragments: phase-space coalescence Gaitanos, et al., NP A

8 Collision term: pp-> X (primary elementary channels) Statistical annihilation model (pp-> mesons) up to 6-particles final states (π,η,ω,ρ,k,k,k*,k*) Other channels (pp-> BB) Golubeva, Pshenichnov, et al., NP A537 ('92) 393 Larionov, T.G., Lenske, Mosel, arxiv:

9 Collision term: secondary elementary channels Hyperon-Nucleon rescattering (ΣΝ ΛΝ) T.G., Larionov, Lenske, Mosel, NP A Antikaon-Nucleon rescattering (KΝ ΞΚ), similar situation Cascade-Nucleon rescattering (ΞΝ ), Extended-Soft-Core (ESC), Rijken et al.

10 PANDA: p+x (primary target)... p Κ,Kπ ΞΞ Ξ Good description of strangeness data Secondary channels important! y Larionov, T.G.,Mosel, ArXiv: , Phys. Rev. C85, rapidity spectra

11 PANDA: p+x (primary target)... p Κ,Kπ ΞΞ Ξ Low energy Ξ production due to secondary channels! PΞ ~ 1 GeV/c ==> Ekin ~ 0.3 GeV Larionov, T.G.,Mosel, ArXiv: , Phys. Rev. C85,Hyp2012,

12 PANDA: p+x (primary target)... p Κ,Kπ ΞΞ Ξ E* = Ep+(Mtarg-Btarg)Atarg-(Mres-Bres)Ares-Eem-Erec data: PRC63, Good description of excitation energy spectrum T.G., Larionov,Lenske,Mosel, NP A

13 PANDA: p+x (primary target)... data: PRC63, p Κ,Kπ ΞΞ Ξ Overal good description of different fragment multiplicities T.G., Larionov,Lenske,Mosel, NP A

14 PANDA: p+x (primary target)... p Κ,Kπ ΞΞ Ξ...rapidity spectra Coalescence with stopped Λ's possible No coalescence with Ξ's (in 2th target) T.G., Larionov,Lenske,Mosel, NP A

15 PANDA: Ξ+X (secondary target)... p GiBUU+SMM+momentum coalescence with captured Ξ & ΞΝ GiBUU+SMM+ Κ,Kπ ΞΞ Ξ fragments -fragments Copious production of hypernuclei via Ξ-capture in 2th target... Process strongly dependent on Ξ-energy (ΞΝ )

16 PANDA: p+cu ΞX & Ξ+Cu... T.G., Larionov,Lenske,Mosel, NP A emitted Ξ's from primary target produced fragments from secondary target Total yield Depends also on exp. (material in between, etc.)

17 Final remarks Theoretical studies: Giessen GiBUU+SMM: NE-dynamics + statistical process of fragmentation suitable tool for HypHI- & PANDA-reactions Predictions on single-λ hypernuclei (HypHI) σ ~ µb for ΛH & ΛHe in spectator/target fragmentation in HIC consistency with HypHI-experiment?... (T. Saito) Predictions on double-λ hypernuclei (PANDA) production of Λ-nuclei in first target with very low Prob., Ξ's escape Ξ+X (secondary target) A+X, production of A, energy dependent To do/on work... Collision term: primary & secondary elementary channels under control? in-medium hyperon-nucleon scattering Drift term: Momentum dependent mean-field dynamics

18 Backup slides

19 p+x-reactions: switch from BUU SMM... SMM SMM SMM Def. Of residual spurce particles with ρ>ρsat/100

20 NLD: p & p opt. potentials T.G., Kaskulov & Lenske, PL B703 (2011) 193 antiproton-nucleus RHD proton-nucleus T. G., M. Kaskulov, arxiv: [nucl-th]

21 PANDA: p Κ,Kπ ΞΞ Ξ Ξ-capture in 2th target strongly energy dependent In preparation... Repulsive RMF fields at high energies & ΞΝ

22 Numerical realization (Test-Particle Ansatz): Initialization Propagation (Vlasov, collisions) Initialization: test particles initialized according to empirical density distributions Problem: density profiles not consistent with mean-field used in propagation Solution: Use the same energy density functional ε[ρp,ρn] for initialization & propagation Relativistic Thomas Fermi (RTF) for spherical nuclei New initialization Important in calculating Eexc Old initialization Old initialization New initialization PR C81, (2010), Important in calculating A,Z

23 X+X-Reactions, spectators: BUU SMM... SMM Λ Λ πσ π π π Λ ΛΚ Def. ofspectators Y(0)>0.75 +ρ>ρsat/100 Spectators Well defined conditions after onset of instability Spectators and onset of equilibration PL B663, 197 (08) & PL B675 (09) 297

24 GiBUU+SMM: spectator fragmentation in X+X... absolute yields from spectator fragmentation in (ALADIN-data) fragment velocity spectra in data: Henzlova, PRC78, PL B663, 197 (08) & PL B675 (09) 297

25 HypHI: BUU: BUU fragmenting sources & strangeness (consistent with FOPI/KaoS) SMM: SMM spectator fragmentation (consistent with ALADIN) C-fragmentation 12 6 Λ Λ πσ π π π Λ ΛΚ Li-fragmentation Λ & AX coalescence possible

26 HypHI: Λ Λ πσ π Coal.: Coal. momentum coalescence for Λ close to spectators Estimate: Estimate projectile/target fragmentation: σ(3hλ, In PL preparation... B675 (09) 297 π π Λ ΛΚ 4,5 HeΛ) ~ (6-10)µb