FROM QCD TO NUCLEI: ASPECTS OF NUCLEAR THEORY IN FRANCE

Transcription

1 FROM QCD TO NUCLEI: ASPECTS OF NUCLEAR THEORY IN FRANCE Ubirajara van Kolck Institut de Physique Nucléaire 1

2 Outline Hadronic theory in France Nuclear forces from QCD Low-energy nuclear theory in France Structure from nuclear forces 2

3 Goal Why? Derivation of nuclear physics consistent with Standard Model (SM) of particle physics o o correct symmetries systematic Nucleus as the simplest complex system: quarks and gluons interacting strongly, yet exhibiting many regularities QCD at large distances an unsolved part of the SM tools for non-perturbative quantum (field) theories, e.g. cold atoms Nucleus as a laboratory: properties of the SM and beyond nuclear matrix elements for symmetry tests reaction rates for nucleosynthesis equation of state for stellar structure variation of parameters for cosmology 3

4 Q The landscape M ~ m, m, 4π f, QCD N ρ M ~ f, m, nuc ~1 GeV π π ~100 MeV π light-front QCD large-nc expansion lattice chiral perturbation theory unitarity & analyticity Standard Model Hadrons Few-Nucleon Systems QCD perturbative QCD non-relativistic QCD Bira Vittorio non-relativistic/relativistic mean-field methods & beyond Many-Body Systems Nuclear Effective Field Theories ab initio methods SM Tests Neutrino/ Nuclear Astrophysics Cold Atoms 4

5 The Many Facets of Non-Perturbative QCD QCD at high energies and temperatures: gluon saturation, quark-gluon plasma, magnetic fields, CEA-Saclay CPHT-Ecole Polytechnique LMPT-Tours SUBATECH-Nantes Few-nucleon/atom dynamics: energies and cross sections IPHC-Strasbourg IPN-Orsay INL-Nice GANIL Hard probes of hadrons: deep inelastic scattering, PDFs, GPDs, CPHT-Ecole Polytechnique IPN-Orsay LPTHE-Paris Hadron statics and dynamics: rare decays, form factors, CPT-Marseille IPN-Lyon IPN-Orsay LPC-Clermont Ferrand LPT-Orsay LUPT-Montpellier

6 An Emerging Facet: the ab initio approach Lattice QCD CEA-Saclay CPT-Marseille IPN-Orsay LPC-Clermont Ferrand LPT-Orsay in Alpha, ETMC, BMW, quark of mass m q lattice model space gluons path integral solved with Monte Carlo methods, typically for unrealistically large quark masses L b b 6

7 Chiral EFT IPN-Orsay CPT-Marseille nucleon/nuclear observables as expansions in M m q QCD but with unknown coefficients the two scales of QCD M QCD m q m M 2 π QCD 1 M 0.3 fm QCD R 1.2 fm A A mπ 1 m π 1.4 fm 7

8 V = 2N π + LO Weinberg Ordonez + v.k. 92 v.k. 94 Ordonez, Ray + v.k. 94, NLO + + NNLO (circled) dots: unknown coefficients V 3N = NLO NNLO etc. 8

9 Lattice QCD + Chiral EFT b 1 MQCD 1 M 0.3 fm QCD R 1.2 fm L A mπ A A mπ 13 1 m π 1.4 fm 9

10 1) do simulations at smallest possible largest possible m π A Strategy 2) fit EFT to lattice data, extracting coefficients 3) use ab initio methods to solve EFT at decreasing increasing m π A A = 2 =800 MeV m π NPLQCD 13 NLO scattering length Fukugita et al. 95 Beane, Bedaque,Savage + v.k. 02 Barnea, Contessi, Gazit, Pederiva + v.k

11 Still a long way to A 4 =140 MeV m π For now: fit EFT to experimental data Pavón Valderrama 10 A = 2 determined 2N + 3N internucleon forces 11

12 Enter Vittorio Somà CEA-Saclay 12

13 Low-energy nuclear theory in France CEA Bruyères-le-Châtel Mean field + np/nh correlations Family of Gogny interactions Systematics throughout nuclear chart Binding, radii, spectroscopy Reactions (fission, optical potentials) Bordeaux/CEA Saclay/Lyon Multi reference EDF Family of Skyrme interactions Fundaments of EDF theory Systematics throughout nuclear chart Heavy nuclei, deformation, Strasbourg State-of-the-art SM calculations Mean field approaches Binding, excitation spectra, for most of A<100 nuclei Orsay Mean field approaches Towards less-empirical EDFs Transfer reactions Exotic nuclei GANIL Gamov Shell Model Interacting boson model Light/medium nuclei (continuum, pairing, ) Orsay/Lyon Mean field approaches Infinite nuclear matter Astrophysical applications (neutron star crust, EoS, )

14 Status of ab initio many-body theories Ab initio many-body theories Effective structure-less nucleons 2N + 3N inter-nucleon interactions Solve A-body Schroedinger equation Thorough assessment of errors High predictive power Limited applicability domain Input Comp data 56 Ni Inter-nucleon interactions Link to QCD - χeft Soften through RG 16 O 40 Ca 48 Ca 22,24 O CC, SCDyGF, IMSRG Near doubly-magic nuclei A< FY, GFMC, NCSM, LEFT All nuclei A<12 Based on expansion scheme Additional systematic error Cross-benchmarks needed

15 Ab initio methods for open-shell nuclei Keep expansion around a single reference state <-> symmetry breaking Complete isotopic/isotonic chains From a few 10s of nuclei To several 100s of nuclei A Sn Saclay program (since 2009) SCGoGF in place [Somà, Duguet, Barbieri] BCC well on the way [Signoracci, Duguet, Hagen] A O A Ni A Ca CEA-CCRT Others (since 201 0) MR-IMSRG in place [Hergert et al.] Heaviest systems computed so far

16 First results with 2N+3NF [Somà et al., 2013] I. Nuclear structure at/far from β stability Magic numbers and their evolution? Limits of stability beyond Z=8? Mechanisms for nuclear superfluidity? Role and validation of AN forces? II. Observables of interest (near future) Low- lying excitation spectra Spin and (transition) moments Density distribution and radii Two-neutron separation energy near A Ca

17 Microscopic theoretical approaches Ab initio many-body theories Based on elementary interactions Complete and disjointed error estimate Limited reach Controlled extrapolations Test fundamental interactions Do not focus on accuracy at first Interesting potential cross-feeding in the next ten years Extended reach Uncontrolled extrapolations Do not probe fundamental interactions Aims at high accuracy around known data Effective many-body theories Based on effective interactions Partial and composite error estimate