Theory for nuclear physics and astrophysics in France Elias Khan NuPECC, October 9, 2015, Ganil 5 IPNO CEA/DAM SPhN LUTH LPC GANIL Subatech CENBG IPNL IPHC

Nuclear structure Age Needs for hiring young researchers within the next 5 years (CNRS-CEA-Universities)

The nucleus Nucleus = specific manybody system: i) All 4 interactions involved ii) Non elementary constituents iii) Finite size iv) Involved in history of matter One of the most challenging/richest system to study Trend: from [era of models] to [era of theories (DFT, EFT)]

1) Theory for nuclear astrophysics 2) Fundamentals of the nuclear interaction 3) Nuclear structure 3 main axis

Theory for nuclear astrophysics Neutron stars: eq. of state, structure (Ganil, LPC, LUTH, IPNL, IPNO, Subatech) Supernovae: electron capture, modelisation (Ganil, LPC, LUTH, IPNL, IPNO)

Time line of core collapse SN Collapse From T. Janka

Nuclear abundances during the initial phase of collapse From R. Hix

Nuclear abundances during the neutrino trapping phase e capture produces neutron rich nuclei, and with fusion of n,p, one gets heavier neutron rich nuclei

F.Gulminelli – LPC CAEN with A.Fantina, J.Margueron, M.Oertel + foreign collaborations (IFIN, LNS, Florianopolis, Coimbra) Modelling stellar matter for applications to Neutron Stars and Core Collapse Supernova New phase transitions at zero and finite temperature Density functional description of matter below and above saturation Unified equation of state for neutron stars and supernova Superfluidity in neutron star cooling Hyperons in dense matter within relativistic mean field Connection with nuclear structure and nuclear reactions Here: the quenching of N=50 towards the dripline modifies the electron capture rate during supernova core collapse up to a factor ~ 3 Color: distribution of nuclei during core collapse is peaked at magic numbers; full line: limits of experimentally known nuclear mass Relative modification of the electon capture rate during collapse for two different initial stellar masses, and for different hypothesis on the quenching factors for magicity at N=50 in the unknown neutron rich region defined by the parameter deltaZ.

Fundamentals of the nuclear interaction Ab initio, few bodies, EFT (IPHC, IPNO, SPhN) Tensor term (CENBG, IPNO, IPNL, SPhN)

Theory IRFU/SPhN  Good overall description  3N forces essential  Agreement between different methods  Points to limitations of current Chiral-EFT interactions [Somà, Duguet et al. Phys. Rev. C (2014)] Two-neutron separation energies  Prediction of the drip line sensitive to 3N Development of ab initio methods for nuclear structure ➢ Direct calculation of the A-body system (all nucleons are active) ➢ Only input: 2- and 3-nucleons, e.g. Chiral-EFT, interactions ➢ No intrinsic limitation in mass: current limits set by computational resources ➢ Open-shell nuclei = Frontier => Gorkov scheme Saclay) Example: ab initio Gorkov Green’s function calculations Short- and long-term future ➢ Extension to doubly open-shells and to additional observables (radii, dipole moments…) ➢ Apply Ab initio theories with symmetry restoration recently Saclay ➢ Computational breakthroughs in the treatment of 3N forces ➢ Ab-initio driven energy-density functionals ➢ Bridging to ab initio description of reactions

Tensor effect in n-rich Ca isotopes PRC (2013)

Nuclear structure Pairing, quarteting, clustering and symmetries: (CENBG, Ganil, IPHC, IPNO) Excitation in nuclei and matter (CENBG, DAM, Ganil, IPHC, IPNL, IPNO) Exotic nuclei : structure far from stability (all) Link with reactions : fission, data oriented, dynamics (DAM, Ganil, IPNO) Decays and radioactivity (Ganil, CENBG)

The physics of N=Z nuclei Isovector and isoscalar pairing. Aligned np pairs? Quarteting? Enhanced deuteron transfer? Coulomb displacement energies. Isospin mixing. Isacker et al.

EDF Ikeda’s diagram E* Nature (Letter)

Conclusions Variety of methods : EDF (Skyrme, Gogny, Relat.), ab initio, shell-model, IBM, few-body, LD Large internationnal impact in each of these fields Age : peak at mid-career Nucl. theo struct.: increase the collaborations among the group and the methods Nucle theo astro: ~ 4 collaborating physicists ; increase the collaboration with exp.

Symmetry-based calculations Ganil end: Gamow Shell model Reaction for SHE

Thèmes Symmetry-based calculations in the shell model and the interacting boson model. The physics of N=Z nuclei. Partial dynamical symmetries in nuclei and other mesoscopic systems. Nuclear-structure calculations for double beta decay.

CENBG Shell model Beyond mean field, correlations Isospin symmetry DAM Reaction model for data Fission modelisation : SPY Collective vibrations in deformed nuclei Mixed SM and MF approaches

IPN Rigiorous EFT applied to the NN interaction Semi classical methods for neutrons stars and fermi gases Beyond mean fild and hihger corr in nucle interaction Pairing effects in/and nuclear dynamics EDM of light nuclei Lattice QCD for nuclei Nuclear incompressibility Clusters in nuclei

IPHC

CURRENT STATUS  EC and  decays crucial in late-stage stellar evolution  core-collapse supernova (CCSN), neutron-star cooling, nucleosynthesis, EC SNe  up to now  no self-consistent models for EC in SN simulations 24 Electron capture (EC) and astrophysics PROJECT  New EC cross-section and rates in finite T self-consistent Skyrme HF + RPA calculations for selected nuclei PERSPECTIVES  New tables of EC rates for an ensemble of nuclei  application to SN simulations Fuller et al., Bruenn (IPM) Langanke et al. (shell model + RPA) Fantina et al. PRC