Two- and multi-particle correlation studies Correlations as probes for spectroscopy and dynamics [dynamics]  [spectroscopy] Nuclear equation of state; Symmetry energy Resonance decay/Invariant mass spectroscopy Spectroscopic properties of unbound states Collaboration: INFN, CNRS (France), TAMU (USA)

Plans Shorter term project: – Correlation femtoscopy experiments with stable beams at GANIL and stable and exotic beams at LNS Physics (high priority on light particle detection, High statistics!) Observables Detector needs Typical experiments Possible proposals for campaigns in (?) Longer term projects: – Inclusion of neutron correlations – Decay spectroscopy with magnetic spectrometers + correlators – Low energy reactions: CN decay  femtoscopy and multi- particle invariant mass spectroscopy in CN decay

Projectile Target Pre-equilibrium, stopping, compression Expansion Fragmentation Unbound states Secondary decays and Spectroscopy tools Equation of State Dynamics: Femtoscopy (HBT) Correlation functions Spectroscopic tools: Primordial source reconstruction Resonance decays A - Physical systems: HIC collision, particle emitting sources B - Techniques and observables C – Detector needs! Correlators (MUST2, FARCOS) + 4π event characterizer (Chimera, Indra) TIME

“interdisciplinary research topic” From low to relativistic energies: sharing of analysis techniques and ideas WPCF-2013, Workshop on Particle Correlations and Femtoscopy, Catania, Nov 2013: large participation and exchanges with LHC and RHIC, – Interactions in three particle correlation studies Alice Vs Chimera, Birmingham, …) – Exchanges in projectile/target cluster structure effects on elliptic flow – Femtoscopy: energy-scan and studies over widely varying systems – 3D Vs. 1D imaging studies – Effects of collective motion on correlations – Resonance decays: in-medium effects on spectroscopy, recombination and rescattering, … Relevance to multi-particle correlations in halo nuclei (exotic beam studies at Isol and In-Flight facilities

Building correlations Final-state interactions Coulomb anti-correlation (repulsion) Resonances Detection needs/ requirements:  Shape of resonances: high angular and energy resolution  Low q-regions: high granularity and angular resolution 1+R(q) q (MeV/c) deuteron-alpha 6 Li …can be extended to three- and multi- particle correlation functions…

r (fm) S(r) Source function “Size” Source funnction S(r): “Space-time” profile of decaying system  Need high resolution in measuring the shape of peak! q (MeV/c) 1+R(q) p-p Data Shape measurements of pp correlations Input Output G. Verde et al., PRC65, (2002)

Present challenge: symmetry energy Asymmetry term Brown, Phys. Rev. Lett. 85, 5296 (2001) Many approaches… large uncertainties…. Microscopic many-body, phenomenological, variational, … ZH Li, U. Lombardo, PRC (2006) Fuchs and Wolter, EPJA 30, 5 (2006) B.A. Li et al., Phys. Rep. 464, 113 (2008) E sym (MeV) Stiff Soft Need HIC at intermediate energies + Ranges of N/Z (δ 2 )  enhance E sym effects

Symmetry energy and correlation functions IBUU simulations 52 Ca+ 48 Ca E/A=80 MeVCentral collisions Proton-proton correlation sensitive to Esym nn and np also… but difficult… (later projects)  …meanwhile use: t- 3 He, t-t and 3 He- 3 He Correlation functions neutron-neutron proton-proton q (MeV/c) 1+R(q) proton-neutron Lie-Wen Chen et al., PRL (2003), PRC(2005) Stiff Soft

First results from MSU on Ca+Ca – 80 MeV/u MSU: HiRA + 4pi Correlations + 4pi array 40 Ca+ 40 Ca Vs. 48 Ca+ 48 Ca E/A = 80 MeV 1.Size effect or N/Z effect? 2.What is the role of space-time ambiguities?  Need new experiments and better 4π characterization event-by event

Isolating particle at the early dynamical stage 112 Sn+ 124 Sn E/A=50 MeV b red =0-0.4 time (fm/c) dN/dt P T /m > 0.2 P T /m > 0.3 Early Late Sn+SnE/A=50 MeVb red =0-0.4 B. Barker et al.

Experimental data (preliminary) Xe+AuE/A=50 MeV MCP=36 (~b red <0.3) Proton energy spectra with p T > 0.15 pp correlations No P T gate P T /m > 0.2 Moving source fit: single-particle emitting source moving with v ~ v NN E.V. Pagano T. Minniti, G. Verde, et al., to be submitted Source functions

Effects of p T gates on pp correlations Xe+Au E/A=50 MeVb red <0.3 (p T /m) min Fraction of dynamically emitted protons (%) - f dynamical Source function size – r 1/2 Source size f dynamical Consistent with increasing importance of dynamical sources at high P T Trend at high P T of source size need more understanding… Work in progress Preliminary T. Minniti, G. Verde, et al., in progress Increasing relevance of dynamical emissions

Typical experimental setup Correlators (FARCOS + MUST2) 4π det Needs: 4π for characterization of collision events: b, reaction plane, flow! Correlators: High resolution in (Theta, Phi, E) Large solid angle coverage: statistics AND changing kinematics with E beam + other physics cases in same experiment: Campaigns “a-la-indra” Example: G. Verde and J. Natowitz –> comparisons femtoscopic radii vs coalescence radii (discussed briefly during last IWNDT meeting in College Station)

Must2: Mur à Strip Mostly used for direct reactions with exotic beams (GANIL, RIKEN) Optimized for high energy and angular resolution detection of light particles: p, d, t, 3He, 4He, 6He, …, Li isotopes… (dynamic range limited) ASIC electronicsby the same team that develops GET electronics (similar ASIC concepts, no digitalization, …) In our project: best suited at large angles in the lab frame, dominated by light particle emissions Very flexible

Symmetry energy at very low densities? (TAMU) Pre-equilibrium emission Flow Multifragmentation Central  ρ ≈ 0.01∙ρ 0 Clustering (~alphas) at small densities affects E sym C.J. Horowitz et al., NPA776, 55 (2006), G. Wanatabe et al., PRL103, (2009) E sym (ρ) not vanishing at very low ρ 64 Zn+ 92 Mo, 197 Au 40 Ar, 64 Zn+ 112,124 Sn E/A=35 MeV Emission volumes and densities from coalescence analyses of energy spectra ! TAMU E sym (MeV) Density ρ(fm -3 ) Symmetry Energy at very low densities J.B. Natowitz et al, PRL 104 (2010) R. Wada et al., PRC85, (2012) Coalescence Vs. Femtoscopy? statisctial Vs. dynamical

Invariant mass spectroscopy: “gratuit” in the same experiment! HIC and correlations as a spectroscopic tool Cluster states, Hoyle states, BEC, … Same experiment Access to invariant masses, spin, branching ratios for simultaneous and sequential decays Compare direct reactions to HIC and in-medium decay Expansion Not only EoS… Several unbound species in just one single experiment! 10 C*

Spectroscopy  Dynamics p-p- 16 O correlation function 1+R 8 Be  p- 7 Li 8 B  p- 7 Be 10 B  α- 6 Li 12 C  α+α+α 9 B  p+α+α 18 Ne  p+p+ 16 O Xe+AuE/A=50 MeV

Example: 8 B unbound states in central HIC States of 8 B  p+ 7 Be p+ 7 Be (?) B8B p- 7 Be correlations W.P. Tan et al. Phys. Rev. C69, (2004) Xe+AuE/A50 MeV Central collisions Relative height of resonances constraints the spin of states

Example: 2α-2p correlations : states in 10 C* E k (MeV) 10 C  6 Be+α  (2p+α)  α 10 C  8 Be+p+p  (α+α)+  p 10 C  9 B+p  (p+α  α)  p F. Grenier et al., Nucl. Phys. A811 (2008) 233 Constraining branching ratios for sequential vs simultaneous decays 4-particle correlation functions: p-p-α-α

Direct and fragmentation reactions with exotic beams 12 Be + p, 12 CE/A = 50 MeV 10 5 pps MSU Several new states studied R.J. Charity et al., PRC76, (2007)

Projectile fragmentation beams Opportunity: fast exotic LNS Ex: Primary beam: 20 Ne E/A=45 MeV/A Production target: 9 Be (500  m) Fragments transported and tagged event-by-event by  E-ToF DSSD Tagging detector T (ns) 10 B e 16 C 13 B 12 Be 9 Li 6 He 17 C 7 Li ΔE (MeV) Bρ=2.71 Tm 11 Be Light and medium mass isotopes for direct reactions in inverse kinematics: multi-particle correlations

Interplays dynamics-spectroscopy Femtoscopy (dynamics) with light particles (strongly interacting!) needs spectroscopy information: resonances, quantum statistical symmetries, etc. Spectroscopy information may be extracted from correlations with light complex particles (example: 10 C  p+p+α+α)

Invariant mass spectroscopy: Direct (FRIBS) Vs. Multifragmentation Multifragmtation reactions: -Good: high statistics, “clean” stable beams -Bad: not clean states produced, distortions in medium (low density nuclear matter), effects of reaction/production mechanism Direct reactions with exotic beams: -Good: clean states and analysis methods -Bad: low statistics, low beam quality (tracking required with resolution and rate limitations, …) Comparisons would be of mutual benefit: -Effects of reaction mechanism on extraction of spectroscopic properties (important for exotic beam studies, structure  reaction mechanism!) -In-medium effects on resonance formation and decay -Search for clusters in low density matter (Symmetry energy) -…

Experiments: scanning over widely varying systems Energy scan (E-scan): “wide” range of beam energies (intermediate) – understand space-time ambiguity in emitting source profiles – E/A<35 LNS, TAMU(?) – E/A>35 GANIL Mass scan Vs. Isospin scan (A-scan, N/Z-scan) – understand ambiguity in size effects Vs. symmetry energy effects – 40,48Ca+40,48Ca – 58,64Ni+58,64Ni – 112,124Sn+112,124Sn – …and inverse kinematics combinations (ex.: Sn+Ni, etc.), better for coalescence studies

Shorter term campaigns –Fermi energies Reaction systems at GANIL (> 2016?) N/Z-scan and A-scan: 40Ca + 40Ca, 48Ca + 48Ca 58Ni + 58NiCa, 64Ni + 64Ni E/A= MeV 112Sn + 112Sn, 124Sn + 124Sn 58Ni + 40Ca, 64Ni + 48Ca(coalescence vs femtoscopy) N/Z-scan: 48Ca + 48Ca, 48Ti + 48TiE/A=40 – 80MeV 96Zr + 96Zr, 96Ru + 96RuE/A= MeV Reaction systems at LNS (<2017) N/Z-scan and A-scan: 40Ca + 40Ca, 48Ca + 48Ca 58Ni + 58NiCa, 64Ni + 64Ni E/A= MeV 112Sn+112Sn, 124Sn+124Sn 58Ni + 40Ca, 64Ni + 48Ca(coalescence vs femtoscopy) FRIBS beams: direct reactions and invariant mass spectroscopy

Spokesperson of Mus2 project Group Leader

Longer term challenges: neutron-proton correlations nn, np and pp correlation functions  Symmetry energy Correlators Protons EDEN Neutrons Measuring pp, np, nn correlations: LNS: EDEN + MUST2/FARCOS GANIL: DEMON + MUST2/FARCOS neutron-proton correlations G. Verde, Must2 meeting – 14 Nov 2013

Correlations at low energies 16 O+ 27 E/A=8.8 MeV 1+R(q) q (MeV/c) Correlation femtoscopy: volumes, emission times, prompt vs evaporative decays, light particle emission chronology, etc. Multi-particle decay spectroscopy: emission of exotic nuclear systems (p- rich and n-rich)  exploratory plans for SPES and Spiral2 Evaporative scenario Explosive scenario  Start with stable beam experiments at LNS and GANIL: test experimental techniques in CN reactions ( ?)

Documents under construction Scientific program Logistics and Technical details Manpower organization: students for data analysis, organization of calibration tasks (“Indra-like” organization), technical tasks Letter of Agreement with international partners Milestones

Backup slides

Resonance decay (invariant mass) spectroscopy: direct and fragmentation reactions New state in 8 Be at E*~23 MeV --> sequential: 8 Be  7 Li + p 7 Li  t + α R.J. Charity et al., PRC78, (2008)