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Acknowledgements. Exochim & Farcos collaboration :
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Acknowledgements Exochim& Farcoscollaboration: L. Acosta, F. Amorini, A. Anzalone, L. Auditore, G. Cardella, A. Chbihi, E. De Filippo, L. Francalanza, E. Geraci, C. Guazzoni, E. La Guidara, G. Lanzalone, I. Lombardo, S. Lo Nigro, D. Loria, I. Martel, T. Minniti, E.V. Pagano, A. Pagano, M. Papa, S. Pirrone, G. Politi, F. Porto, F. Rizzo, P. Russotto, S. Santoro, A. Trifirò, M. Trimachi, G. Verde, M. Venhart, M. Veselsky, M. Vigilante NSCL-Michigan State University Z. Chajecki, P. Danielewicz and B. Barker
Dynamics and correlation studies @ INFN-Catania G. Verde & Exochimcoll., INFN-CT, INFN-LNS, Univ. of Catania, LNS LNS Catania K800 Tandem (15 MV) EA ≤ 10 MeV Superconducting Cyclotron
Beam TARGET 30° 176° 1° 1m Chimera… our “Alice” for intermediate energies… 1192 Si-CsI(Tl) Telescopes 18 rings in the range 1° ≤ θ ≤ 30° 17 rings in the range 30° ≤ θ ≤ 176° (sphere) High granularity and efficiency up to 94% 4π • Z identification up to beam charge (ΔE-E) • Z and A identification by ΔE-E up to Z≤ 9 • Z and A identification in CsI up to Z ≤ 4 • Mass identification with low energy threshold (< 0.3 MeV/u) by ToF • Z identification for particles stopping in Si (pulse shape)
Be Li HI a 3He t d p CsI (Tl) Si Particle identification in Chimera PSD in CsI(Tl) Z and A for light charged particles ΔE(Si)-E(CsI) Charge Z for particles punching throught the Si detector t V(t) slow fast ΔE(Si)-ToF Mass for particles stopping in the Si detector gate 3-12 cm ~300 μm E(Si)-Rise time Charge Z for particle stopping in Si detectors (NEW) ΔE(Si)-E(CsI) Charge Z and A for light ions (Z<9) punching throught the Si detector
Farcos project: femtoscopy capabilities Stay tuned! Talk by T. Minniti, INFN-CT and University of Messina
What do you mean by “low energies”? Intermediate energies: E/A=30-100 MeV Medium (GSI) energies: E/A=200-1500 MeV Dynamics/Thermodynamics EoS, Asy-EoS Space-time probes required (Two-particle correlations, Femtoscopy, emission chronology, time-scales, etc.)
High energy Vs. “low” energies • Different interpretations, different models, different physics goals (not always, i.e. elliptic flow etc.), … • Similar space- and time-scales involved: • R ~ 2-10 fm • τ ~ 2-104fm/c Share analysis techniques, ideas, detection technologies…
B.A. Li et al., Phys. Rep. 464, 113 (2008) ??? Many approaches… large uncertainties…. Microscopic many-body, phenomenological, variational, … The EoS of asymmetric nuclear matter Infinite nuclear matter: how does E depend on density?
Intermediate energies: E/A=20-100 MeV High energies: E/A>200 MeV CSR, GSI/Fair, NSCL/FRIB, Riken, … Ganil, Eurisol, Frib, Lns, Nscl, Spiral2, Tamu, … SMF - Baran, Colonna, Di Toro, Greco Asy-Stiff Asy-Soft Producing density gradients in HIC Neutron Stars • Radii • Frequencies of crustal vibrations • Composition, thickness of inner crust • URCA processes • Phases within the star Densities ~ 0.01ρ0 - 6ρ0 – Large Gradients!!!
Probes of the symmetry energy • Probes at Intermediate energies: sub-saturation density Asy-EoS(ρ<ρ0) • Isospin diffusion and drift • Neutron-proton pre-equilibrium emission • nn, np, pp correlation functions • Probes at GSI energies: supra-saturation density Asy-EoS (ρ>ρ0) • π+/π- and K+/K0 emission ratios • n/p elliptic flow • n/p pre-equilibrium emission ρ0~ 0.17 fm-3
Effects of the Esym at high density B.A. Li et al., PRC71 (2005) • N/Z of high density regions sensitive to Esym(ρ) • High ρ>ρ0: asy-stiff more repulsive on neutrons - opposite of sub-saturation trend ≈(ρ/ρ0)γ stiffness stiffness
High densities: flows z x V2 y Y = rapiditypt = transversemomentum UrQMD vs. FOPI data: Au+Au @ 400 A MeV 5.5<b<7.5 fm Elliptic flow: competitionbetween in plane (V2>0) and out-of-planeejection (V2<0) Qingfeng Li, J. Phys. G31 1359-1374 (2005) P.Russotto et al., Phys. Lett. B 697 (2011)
ASY-EOS S394 experiment @ GSI Darmstadt (Germany) Au+Au @ 400 AMeV 96Zr+96Zr @ 400 AMeV 96Ru+96Ru@ 400 AMeV ~ 5x107 Events for each system TofWall Beam Line ASY-EOS experiment(May 2011) “possible“ 1st phasetoward FAIR ??? (e.g. 132Sn,106Sn beams) Krakow array Chimera target Shadow Bar MicroBall Land (notsplitted) P. Russotto, INFN-CT
Chimera for event shape: reaction plane, impact parameter P. Russotto, INFN-CT LAND: neutrons and protons elliptic flow
KinematicsCentralitydependence sortedusingtransverseenergyof LCP (Z≤2) Au+Au @ 400 AMeV preliminary proj mid P. Russotto, INFN-CT g32new
ImQMD: superstiff Zhao-Qing Feng, Gen-Ming Jin, Phys.Lett.B683, 2010 IBUU04: Supersoft Zhigang Xiao et al.PRL 102 (2009) IBUU04 Pion ratios: controversial results…. ????
High ρ/ρ0 Pion and Kaon freeze-out in HIC Low ρ/ρ0 π+, π- K+,K0 RBUU, Ferini et al., PRL97, 202301 • Warning with pions: • Strongly interacting in medium • Freeze-out at late times (low ρ/ρ0) • Difficult to isolate π+ and π- produced in the high density stage • Kaons: more sensitive probes? • Higher thresholds • Weakly interacting in medium • Freeze-out already at 20 fm/c: real high density region probes
Multifragmentation Expansion Pre-equilibrium emission b=central 1 2 b=mid-peripheral Neck, low ρ, isospin drift Neck fragments PLF 3 TLF b=peripheral Isospin diffusion & drift PLF 4 TLF HIC at Fermi energies: Esym(ρ) at ρ<ρ0
Isospin equilibration Long τint Esymvsρ Asy-Stiff Short τint Asy-Soft Isospin translucency Isospin drift Isospin diffusion ρ/ρ0 1 n drift N/Z Proj Targ TLF Neck PLF n/p diffusion TLF Neck PLF Isospin drift & diffusion ρ~ρ0 PLF PLF PLF Targ Proj ρ~1/8ρ0 ρ~ρ0 TLF TLF TLF Low ρ<ρ0 Colonna et al.; Danielewicz et al.
Event characterization 124Sn+64Ni @ 35 MeV/u 7Mc12 0.2<*bred<0.6 Mc>12 *bred<0.2 3Mc6 *bred>0.6 TLF IMF PLF TLF IMF PLF TLF ~ IMF ~ PLF Characterize IMF emission IMF times
Time-scales from three-fragment correlations PLF seq. emission TLF PLF IMF IMF intermediate Vrel (IMF-TLF) / VViola TLF Prompt emission from neck PLF Vrel (IMF-PLF) / VViola 1 TLF seq. emission
1 40 fm/c 2 80 fm/c 3 120 fm/c Emission time-scales and chronology Simultaneous 3 2 1 E. De Filippo, P. Russotto, A. Pagano Phys. Rev. C (2012) Light fragments are produced earlier than heavier ones ~40 fm/cvs~120 fm/c Sequential
Li 124Sn + 64Ni 35 A.MeV Be <N/Z> C B Isospin chronology Prompt emissions more neutron rich neutron-enrichment in neck emissions E. De Filippo, P. Russotto PRC (2012)
Isospin chronology and symmetry energy “Quasi”-Asy-Stiff (γ~0.8) more consistent with experimental results E. De Filippo, A. Pagano, P. Russotto et al., Phys. Rev. C (2012)
Femtoscopy in HIC Hodo56 @ NSCL EDEN @ LNS MEDEA@ GANIL n-n γ-γ FOPI@ GSI 1.2 p-p 1+R(q) 0.6 HODOCT/Aladin @ GSI p-p 0 Lassa @ NSCL 200 100 0 q (MeV/c) p-α INDRA @ GANIL Chimera @ LNS d-α IMF-IMF LCP-IMF
neutron-neutron 7 5 3 1 1.5 1+R(q) 1.0 proton-proton 0.5 0.0 4 3 proton-neutron 2 1 q (MeV/c) NN correlations and symmetry energy Correlation functions IBUU simulations 52Ca+48Ca E/A=80 MeV Central collisions Asy-soft Asy-stiff Lie-Wen Chen et al., PRL (2003), PRC(2005) Proton/neutron emission times sensitive to density dependence of the symmetry energy
Neutron-proton emission chronology Time delay between emissions Δt≠0 - Example: p emitted first Vp < Vn Vp > Vn p p p p n n Interaction attenuated Stronger interaction “particle catch-up”
Lednicky recipe: p-n correlations p first -100 fm/c n first +50 fm/c n first +100 fm/c 1+R+(q) Nuclear FSI 1+R−(q) R. Lednicky et al., Phys. Lett. B373, 30 (1996) Ratio +/- p-n p-n p-n q (MeV/c) q (MeV/c) q (MeV/c) Ratio R+/R- tells us which is emitted first
Isospin effects on p-p 48Ca+48Ca vs40Ca+40Ca E/A=80 MeV - Central R 48Ca+ 48Ca > R 40Ca+ 40Ca Correlations Emitting sources Larger size for more n-rich system: N/Z effect? Size effect? Asy-EoS? σNN Z. Chajecki, et al. Phys. Rev. C (2012)
10C* Multi-Particle Correlation Spectroscopy (MPCS) – “non-femtoscopic” stuff… Not only EoS… Several unbound species in just one single experiment! Expansion • HIC and correlations as a spectroscopic tool • Cluster states in stable and exotic nuclei • BEC, Hoyle
7Be 2.32 3+ 1.4 (?) 0.774 1+ p+7Be 8B 8B unbound state: spin determination Xe+Au E/A50 MeV Central collisions p-7Be correlations p 8B States of 8B p+7Be W.P. Tan et al. Phys. Rev. C69, 061304 (2004)
direct direct 2α+2p α + 8Be α + α + α α+6Be 2p+8Be p+9B α + α α+α α+2p α+ α+p Sequential decay modes: multi-particle correlation functions • Peripheral projectile fragmentation 12C+24Mg E/A=53, 95 MeV (Indra@GANIL) Decay of 12C and 10C quasi projectiles (QP*) 12C* α + α + α10C*α + α + p + p Hoyle states? Boson condensate?
10C 6Be+α (2p+α)+α 10C 8Be+p+p (α+α)+p+p Ek(MeV) 10C 9B+p (p+α+α)+p 2α-2p correlations : states in 10C* F. Grenieret al., Nucl. Phys. A811 (2008) 233
Search for Hoyle states in Nα nuclei J. Manfredi, R.C. Charity et al., PRC 2012 A. Raduta et al., Phys. Lett. B705, 65, 2011 Three-alpha correlations 12C* α + α + α 40Ca+12C, E/A=25 MeV @ Chimera 12C 3 alpha Gated 8Be* α + α No direct three-body decay of Hoyle state in 12C Γ~ 7.5% direct three-body decay (BC?)
Conclusions • Probes of symmetry energy at high density: • GSI energies: n/p flow Chimera-LAND@GSI • π+/π- and K+/K0 emission ratios • Understand where and when π’s and K’s are produced… correlation techniques (?) • Probes of symmetry energy at low density: • Intermediate energies: Isospin diffusion and drift; moderately soft symmetry energy (γ~0.6-0.9) • Still missing probes from femtoscopy future projects • “non-femtoscopic” correlations to learn about new phenomena and exotic nuclear systems