The FARCOS project Collaboration: INFN (CT, LNS, MI, NA; Italy), GANIL (France), Un. Huelva (Spain) Synergies: Fazia, Neutron detectors, Spectrometers, …

Physics case: dynamics and spectroscopy 1.Imaging in heavy-ion collisions 2.Spectroscopy of exotic nuclei: –In heavy-ion collisions MPCS: Multi-Particle Correlation Spectroscopy –Direct reactions

FARCOS : F emtoscope AR ray for CO rrelations and S pectroscopy 300  m 1500  m Double-sided Silicon Strip CsI(Tl) +  D 32 x x 6.4 cm 2 4 cm Angular resolution: ~0.2 o at d=60 cm

Farcos as a modular correlator Event characterization (4  ) Correlations Coupling to 4  detectors for dynamics studies (LNS, GANIL, NSCL-MSU, …)

INFN LNS 1m 1° 30° TARGET 176° Beam 1192 Si-CsI(Tl) Telescopes

Si CsI(Tl) ΔE(Si)-E(CsI) Charge Z for particles punching throught the Si detector PSD in CsI(Tl) Z and A for light charged particles ΔE(Si)-ToF Mass for particles stopping in the Si detector 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 HI p d t 3 He  Li Be ~300 μm 3-12 cm Particle identification (as in Chimera) V(t) t slow fast

Farcos array features High angular resolution (<0.5 o ): Flexibility: allow coupling to –4  detectors, magnetic spectrometers, other correlators –Neutron detectors for n-p correlations (future) Low thresholds for low energy experiments at Spiral2 and Spes –pulse-shape on silicon and digitalization (future, interface to Fazia project)

Density dependence of the asymmetry term in nuclear EoS B.A. Li et al., Phys. Rep. 464, 113 (2008) ??? Many approaches… large uncertainties Microscopic many-body, phenomenological, variational

Symmetry Energy: who cares? GDR & PYGMY RESONANCE skins halos resonances Supernovae, neutron stars MSU Imbalance ratios GSI Elliptic flow LNS Competitiion Inc. Fusion / DIC

Isospin diffusion, fractionation, isoscaling phenomena… … n/p energy spectra and angular distributions p-p, n-n and n-p correlation functions Producing density gradients Large N/Z to enhance effects of E sym (  ) 124 Sn+ 124 Sn (N/Z=1.48), 48 Ca+ 48 Ca (N/Z=1.4), 197 Au+ 197 Au (N/Z=1.49) Radioactive beams… Pre-equilibrium n,p Expansion Multifragmentation Sec. decays! E beam <100 MeV   n p

Heavy-ion collisions: open issues Pre-equilibrium neutron/proton emissions: the most sensitive probes of E sym (  ) –n/p relative energy spectra –p-p, n-p, n-n two-particle correlation functions Space-time characterization: different particles emitted by several sources & over different time scales –Need space-time probes to disentangle sources  t as short as sec  r as small as 1 fm“femtoscopy”

Correlation femtoscopy in HIC Femtoscope 1+R(q) q (MeV/c) proton-protondeuteron-alpha 6 Li Sensitive to space-time properties  rel High angular resolution required! Resonances Low q (  rel ) measurements

Imaging correlations, “Femtoscopy” Fast simultaneous emitting sources (pre-equilibium) Source size Slow sequential emissions (evap.) 14 N+ 197 Au E/A=75 MeV G. Verde et al., PRC65, (2002) qe Space-time images Source function: Spatial distribution of proton emitting source in HIC: “femtoscopy” - measuring sizes  r~1 fm and times  t~ s

Farcos for complex particle correlations r (fm) S(r) Images d-   - 6 Li p-p Different particles emitted by different sources and at different times (hierarchy) Event characterization required ! ==> Coupling to 4  mandatory p-p 1+R(E * ) E * (MeV) d-  6 Li- 

Multi-Particle Correlation Spectroscopy (MPCS) Expansion HIC and correlations as a spectroscopic tool Several unbound species in just one single experiment! 10 C* Not only EoS…

MPCS: 8 B and 12 C Event mixing Modified event mixing 3-alpha correlation function 12 C states: sequential decay C+Mg, E=53 MeV/u F. Grenier et al., NPA 2008 Indra data 12 C   12 C    Be   LASSA data Spin of 8 B states W.Tan, PRC 2004 J=1 + 8 B  p+ 7 Be Accessing spins and branching ratios (sequential decay paths) Multi-  correlations: Hoyle and Boson condensate states

E k (MeV) 1+R(E k ) 2  -2p correlations: states in 10 C* F. Grenier, A. Chbihi, G. Verde et al., Nucl. Phys. A811 (2008) 233 p-p-  four-particle correlations 10 C  6 Be+   (2p+  )  10 C  8 Be+  p   (  +  )  p 10 C  9 B+p   (  +  p)  p Disentangle sequential decay paths 10 C 9B9B 6 Be 8 Be

Symmetry energy and pp, nn and np correlations Asy-stiff Asy-soft Symmetry potential neutron-neutron proton-proton proton-neutron q (MeV/c) 1+R(q) 52 Ca+ 48 Ca E/A=80 MeV pp Sources Asy-stiff: more localized source Imaging Future perspectives: pp, nn, np correlations! Coupling to neutron detectors

Neutron-proton correlation expts neutron-proton Ghetti et al, PRC 69 (2004) Protons Neutrons Emission chronology sensitive to Asy-EOS …difficult experiments

n/p MSU n detectors Liquid scintillators p detectors DE-E (Lassa) M. Famiano et al., PRL97, (2006) M.B. Tsang et al., PRL102, (2009) 112 Sn+ 112 Sn vs 124 Sn+ 124 Sn E/A=50 MeV n/p spectra ==>   0.7

Spectroscopy: “stand-alone” mode Example: 8 He Spiral (GANIL) E/A=15.4 MeV 8 H + p  7 He + d 8 H + p  6 He + t Shell structure close to drip lines Similar experiments at LNS (FRIBS) or at LNL(SPES) Spes: low energies (Pulse shape on 1st Silicon) Must2 expts

Spectroscopy: “coupling” mode FRIBS beams at the LNS of Catania 34 Ar+p  33 Ar+d Correlator ( 33 Ar residue) 33 Ar 34 Ar d Chimera (d) Correlator Heavy core: Magnex at ~ 0 o Scattered d with Correlator Spiral/Spiral2, Spes, … Day-1 experiment at the INFN-LNS

Imaging correlations at low energies Perspectives at Spiral2 and Spes: Imaging in fusion, fission, DIC, N/Z effects on limiting temperatures and reaction mechanisms, particle emission chronology Requires low identification thresholds: pulse-shaping techniques on silicon detectors Chimera solution, Fazia implementation (digitalization of silicon signals) Future issue: Pulse-shape capabilities in integrated electronics (ASIC, etc.)

Workshop in 2011 Catania, probably spring or early fall 2011 –Integrated electronics for silicon detectors, new solutions, pulse-shape in integrated solutions, coupling to different detectors (also neutrons, gammas, spectrometers, …), others You are all very welcome: need to build up synergies