458 Views

Download Presentation
##### Acknowledgements

**An Image/Link below is provided (as is) to download presentation**

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**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