exotic nuclei structure and reaction noyaux exotiques ... - IPN - IN2P3

More documents

Recommendations

Info

Low-energy excitations in nuclear systems: from exotic nuclei to the crust of neutron stars IPNO Participation: M. Grasso, E. Khan, J. Margueron, N. Van Giai, Nous étudions l’évolution des modes quadrupolaires de basse énergie en fonction de l’excès de neutrons, en allant des noyaux riches en neutrons jusqu’aux systèmes nucléaires très exotiques situés dans l’écorce d’une étoile à neutrons. L’analyse microscopique est effectuée avec l’approche Hartree-Fock-Bogoliubov + quasiparticle random-phase approximation. L’approximation de Wigner-Seitz est adoptée pour décrire le réseau coulombien d’agrégats nucléaires dans l’écorce des étoiles à neutrons. L’analyse systématique des systèmes nucléaires Z = 50, réalisée en augmentant l’asymétrie d’isospin, montre qu’un mode de basse énergie 2+ est prédit dans tous les systèmes. Cependant, la nature des configurations qui composent ce mode change drastiquement quand la drip line est traversée. Ce résultat est confirmé par l’étude de la densité de transition associée à ce mode dans le système Z = 40 situé dans l’écorce interne d’une étoile. We study [1] the evolution of low-lying quadrupole modes as a function of the neutron excess, from neutron-rich nuclei to the nuclear systems located in the crust of a neutron star. The microscopic analysis is performed within the Hartree-Fock-Bogoliubov + quasiparticle randomphase approximation framework. The Wigner-Seitz approximation is adopted to describe the lattice of nuclear clusters embedded in neutron star crusts. A systematic analysis of Z = 50 nuclear systems, performed by increasing the isospin asymmetry, reveals that a low-energy 2 + mode is found in all the systems (Fig. 1). Fig 2. Transition density (see text) However, the nature of the relevant configurations that construct this mode drastically changes when the drip line is crossed. This result is confirmed by the study of the transition density associated to the mode in the inner crust system with Z = 40 and N = 1460. In Fig. 2 it is shown that the transition density profile is different with respect to typical profiles found for 2+ low-lying modes in nuclei: the excitation is mostly constructed with neutrons belonging to the cluster surface and the external free gas. Fig 1. Analysis of the 2 + response References: [1] M. Grasso, et al., Nucl. Phys. A 807, 1 (2008) 63
Collective excitations with SKYRME second RPA IPNO Participation: M. Grasso Collaboration : University of Catania and INFN, Sezione di Catania Des applications de la Seconde RPA avec l’interaction de Skyrme sont effectuées pour décrire les modes d’excitations du noyau 16 O. Le couplage entre les configurations 1 particule-1 trou et 2 particule-2 trou et celui entre les configurations 2 particule-2 trou sont pris en compte de manière complète. Une caractéristique des résultats de la Seconde RPA est que le spectre est déplacé de plusieurs MeV vers des énergies plus basse par rapport au spectre correspondant obtenu avec la RPA ordinaire. Une fragmentation plus importante de la réponse est aussi obtenue avec la Seconde RPA grâce au nombre très élevé de configurations 2 particule– 2 trou. Une meilleure description des états de basse énergie 0 + et 2 + est réalisée avec la Seconde RPA. In Ref. [1] Second RPA calculations with a Skyrme force are performed to describe nuclear collective and low-lying excited states in 16 O. The coupling between 1 particle-1 hole and 2 particle-2 hole as well as that between 2 particle-2 hole configurations among themselves are fully taken into account and the residual interaction is never neglected,not resorting therefore to a generally used approximate scheme where only the first kind of coupling is considered. The issue of the rearrangement terms inthe matrix elements beyond standard RPA is addressed and discussed. As a general feature of second RPA results, a several-MeV shift of the strength distribution to lower energies is systematically found with respect to A much more important fragmentation of the strength is also naturally provided by second RPA due to the huge number of 2 particle-2 hole configurations. A better description of the excitation energies of the low-lying 0 + and 2 + states is obtained with second RPA with respect to RPA because 2 particle- 2 hole configurations are also included (see Ref. [1]). References: [1] D. Gambacurta, M. Grasso, and F. Catara, [nucl-th] arXiv1002.3563 A b a x Fig 1. Quadrupole response RPA distributions (see for instance Fig. 1 for the quadrupole strength distributions). 64
Page 1 and 2:
EXOTIC NUCLEI STRUCTURE AND REACTIO
Page 3 and 4: in the spectra by analyzing their t
Page 5 and 6: were taken from ref. [5]. Concernin
Page 7 and 8: keV -ray with the particles and the
Page 9 and 10: the 605.9 keV line of the 74 Zn 2+
Page 11 and 12: Figure 2 a n d analysis. Figure 2 s
Page 13 and 14: ing particles was thus obtained by
Page 15 and 16: First p-p p collisions in the ALICE
Page 17 and 18: Quarkonia physics with ALICE IPNO P
Page 19 and 20: NA50 updated puzzle IPNO Participat
Page 21 and 22: Status of the HADES experiment (I):
Page 23 and 24: Status of the HADES experiments (II
Page 25 and 26: Status of the HADES experiment (III
Page 27 and 28: Hadron physics in pbar-p p annihila
Page 29 and 30: Hadron Electrodynamics IPNO Partici
Page 31 and 32: G0 experiment at Jefferson Lab. IPN
Page 33 and 34: GEp-III and GEp-2 at Jefferson Lab
Page 35 and 36: Exotic low mass narrow baryons from
Page 37 and 38: The PVA4 parity violation experimen
Page 39 and 40: Etude des Distributions de Partons
Page 41 and 42: Latest Results from GRAAL IPNO Part
Page 43 and 44: Persistence of the Polarization in
Page 45 and 46: The northern site of the Pierre Aug
Page 47 and 48: The Pierre Auger southern Observato
Page 49 and 50: In figure 4 we plot the differentia
Page 51 and 52: THEORETICAL PHYSICS Research in the
Page 53: transfer reaction, the 34 Si(d, 3 H
Page 57 and 58: Pairing and nuclear incompressibili
Page 59 and 60: Pairing properties in nuclei and in
Page 61 and 62: Evaporation-residue residue cross s
Page 63 and 64: Extending the VMI model: normal and
Page 65 and 66: Alpha particle condensation in nucl
Page 67 and 68: Collective Modes in Ultracold Trapp
Page 69 and 70: Exploring key unknown neutrino prop
Page 71 and 72: Relic astrophysical and cosmologica
Page 73 and 74: After a term by term Borel resummat
Page 75 and 76: Chiral expansions of the π 0 lifet
Page 77 and 78: IPNO Participation: H. Sazdjian Eff
Page 79 and 80: fer is used to extract f + (0). We
Page 81 and 82: cleon. The spectrum becomes strongl
Page 83 and 84: A pseudo Coulombian potential in D=
Page 85 and 86: The many-body problem with an energ
Page 87 and 88: The rotational spectrum and the att
Page 89 and 90: Z-identification of very heavy nucl
Page 91 and 92: The Pegase project, a new solid sur
Page 93 and 94: But at 80 keV total energy ( 200 eV
Page 95 and 96: Isospin effects on fragment and par
Page 97 and 98: Radial collective energy and fragme
Page 99 and 100: Latent heat of the phase transition
Page 101 and 102: Alpha-particle particle condensatio
Page 103 and 104: Fluo X: Deexcitation time measureme
Page 105 and 106:
ENERGY AND ENVIRONMENT The increasi
Page 107 and 108:
toe/cap/y which energy access inequ
Page 109 and 110:
nides. A global comparison can be p
Page 111 and 112:
3D coupling of Monte-Carlo neutroni
Page 113 and 114:
Fission cross sections of actinides
Page 115 and 116:
Studies and synthesis of specific m
Page 117 and 118:
Chemistry and Electrochemistry of T
Page 119 and 120:
function of temperature. The recent
Page 121 and 122:
global electron number of the redox
Page 123:
(D 0 /D)-1 ln complexes of Pa(V). I
show all

exotic nuclei structure and reaction noyaux exotiques ... - IPN - IN2P3

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?