Modern Theory of Nuclear Structure, Exotic Excitations and Neutrino-Nucleus ReactionsModern Theory of Nuclear Structure, Exotic Excitations and Neutrino-Nucleus Reactions

N. PaarN. Paar

Physics DepartmentPhysics Department

Faculty of ScienceFaculty of Science

University of ZagrebUniversity of Zagreb

CroatiaCroatia

www.phy.hr/~npaarwww.phy.hr/~npaar

Modern Theory of Nuclear Structure, Exotic Excitations and Neutrino-Nucleus ReactionsModern Theory of Nuclear Structure, Exotic Excitations and Neutrino-Nucleus Reactions

Modern Theory of Exotic Nuclear Structure: Excitations, Weak Interaction Rates and

Beyond

Modern Theory of Exotic Nuclear Structure: Excitations, Weak Interaction Rates and

Beyond

NuPECC Meeting, Zagreb, 13.-14.6.2008.

BEYOND THE MEAN FIELD

Transitions between spherical and axiallydeformed shapes

RMF+GCM

DESCRIPTION OF NUCLEAR QUANTUM PHASE TRANSITIONS

COLLECTIVE EXCITATIONS IN NUCLEI: GIANT RESONANCES

IVGDR

ISGMR

Self-consistent description of excitations : relativistic quasiparticle random phase approximation (RQRPA)

EXOTIC MODES OF EXCITATION IN NUCLEI

→ REVIEW: Paar, Vretenar, Khan, Colò, Rep. Prog. Phys. 70, 691 (2007).

exotic nuclei are characterized by weak binding of outermost nucleons, diffuse neutron densities, formation of the neutron skin and halo

effect on multipole response → new exotic modes of excitation

Among the low-lying states, a single state has more distributed structure composed of many transitions from weakly bound neutron orbitals

Among the low-lying states, a single state has more distributed structure composed of many transitions from weakly bound neutron orbitals

PYGMY DIPOLE RESONANCE (PDR)

PYGMY DIPOLE RESONANCES AND NEUTRON SKIN

● Adrich et al., PRL 95, 132501(2005).

Klimkiewicz, Paar, et al. PRC 76, 051603(R) (2007)

Result (averaged 130,132Sn) :

a4 = 32.0 ± 1.8 MeV

...)(18

)(

),(

2

1)(

202

0

002

0

04

02

2

2 |

Kpa

ES

LAND

Sn isotopes

A.Krasznahorkay et al.

PRL 82(1999)3216

PYGMY DIPOLE RESONANCES AND NEUTRON SKIN

Rn – Rp :

130Sn: 0.23 ± 0.04 fm

132Sn: 0.24 ± 0.04 fm

EXOTIC MODES TOWARDS THE PROTON DRIP-LINE

PROTON PYGMY DIPOLE RESONANCE

PROTON PYGMY DIPOLE RESONANCE

Proton PDR is composed from transitions of weakly bound protons including those which are bound only due to the Coulomb barrier

Centroid energy and B(E1) for low-lying states

Centroid energy and B(E1) for low-lying states

Paar, Vretenar, Ring, Phys. Rev. Lett. 94, 182501 (2005)

NEUTRINO-NUCLEUS REACTIONS

ZXN

0+ 1+

1-

2+3-

2-

0+

Z+1XN-1

E

RQRPA amplitudes RHB occupation probabilities

Reduced matrix elements for the neutrino-nucleus cross section:

Possible extrapolations towards exotic nuclei relevant for astrophysics without any adjustments of interaction parameters

RHB+RQRPA

DISTRIBUTION OF CROSS SECTIONS OVER MULTIPOLARITIES

The knowledge onspin-dipole excitations and higher multipolaritiesis essential for reliabledescription of neutrinonucleus cross sections!

Paar, Vretenar, Marketin, Ring Phys. Rev. C 77, 024608 (2008)

e-NUCLEUS CROSS SECTIONS AVERAGED OVER NEUTRINO FLUX

e FLUX

Experimentalflux of neutrinos obtained from + decay at rest

(νμ,μ-)

<σ>(10-40cm2)

RPA(Volpe et al.) 19.23

QRPA(Volpe et al.) 20.29

CRPA(Kolbe et al.) 18.18

PN-RQRPA 10.97

EXP.(LSND) 12±0.3±1.8

MUON NEUTRINO CAPTURE, EXOTIC ATOMS, …

Self-consistent description of muon atom:

FLUX

Supernova neutrino flux:

Cross section averaged over Supernova neutrino flux

CROSS SECTIONS FOR SUPERNOVA NEUTRINOS

2 4 6 8 10 T[MeV]

4

3

2

1

0

5

Unified description of the structure of stable and nuclei far from stability, and reliable extrapolations toward the drip lines

CONCLUDING REMARKS

www.phy.hr/~npaar

When extended to take into account the most important correlations, it describes deformations and shape-coexistence phenomena associated with shell evolution

Insight into dynamics of exotic modes of excitation, neutrino-nucleus reactions, weak interaction rates of relevance for nuclear astrophysics

T. Nikšić, T. Marketin, D. Vretenar, Zhipan-LiUniversity of Zagreb, Croatia

G. A. LalazissisAristotle Universtity of Thessaloniki, Greece

P. RingTechnische Universitaet Muenchen, Germany

G.ColòUniversità degli Studi and INFN, Milano, Italy

E. KhanIN2P3-CNRS/Université Paris-Sud, Orsay, France