The evolution of magnetic dipole strength in ${}^{100-140}$ Sn isotope chain and quenching of nucleon g factors

Abstract

The evolution of electromagnetic transitions along isotope chains is of particular importance for the nuclear structure and dynamics, as well as for the r-process nucleosynthesis. Recent measurement of inelastic proton scattering on even-even ${}^{112-124}$Sn isotopes provides a novel insight into the isotopic dependence of E1 and M1 strength distributions. We investigate M1 transitions in even-even ${}^{100-140}$Sn isotopes from a theoretical perspective, based on relativistic nuclear energy density functional. The M1 transition strength distribution is characterized by an interplay between single and double-peak structures, that can be understood from the evolution of single-particle states, their occupations governed by the pairing correlations, and two-quasiparticle transitions involved. It is shown that discrepancy between model calculations and experiment on B(M1) transition strength is considerably reduced than previously known, and the quenching of the g-factors for the free nucleons needed to reproduce the experimental data on M1 transition strength amounts $g_{eff}/g_{free}$=0.80-0.93. Since some of the B(M1) strength above the neutron threshold may be missing in the inelastic proton scattering measurement, further experimental studies are required to confirm if only small modifications of the bare g-factors are actually needed when applied in finite nuclei.

8 pages, 7 figures, revised version

References in corpus (44)

• Novel features of nuclear forces and shell evolution in exotic nuclei
• Nuclear weak-interaction processes in stars
• Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies
• Theory of neutrinoless double beta decay
• Magnetic dipole excitations in nuclei: elementary modes of nucleonic motion
• DIRHB -- a relativistic self-consistent mean-field framework for atomic nuclei
• Quasiparticle random phase approximation based on the relativistic Hartree-Bogoliubov model
• Nuclear Equation of State from ground and collective excited state properties of nuclei
• Anomalous Behavior of 2+ Excitations around 132Sn
• Isovector Giant Dipole Resonance from the 3D Time-Dependent Density Functional Theory for Superfluid Nuclei
• Supernova Inelastic Neutrino-Nucleus Cross Sections from High-Resolution Electron Scattering Experiments and Shell-Model Calculations
• Novel shape evolution in Sn isotopes from magic numbers 50 to 82
• Effects of Inelastic Neutrino-Nucleus Scattering on Supernova Dynamics and Radiated Neutrino Spectra
• Relativistic RPA in axial symmetry
• Inclusive charged-current neutrino-nucleus reactions calculated with the relativistic quasiparticle random phase approximation
• Optimizing the relativistic energy density functional with nuclear ground state and collective excitation properties
• Systematic investigation of low-lying dipole modes using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory
• Pairing transitions in the finite-temperature relativistic Hartree-Bogoliubov theory
• Quantum Monte Carlo calculations of magnetic moments and M1 transitions in A<=7 nuclei including meson-exchange currents
• The Proton Electric Pygmy Dipole Resonance
• Skyrme-Rpa Description of Spin-Flip M1 Giant Resonance
• Electromagnetic M1 transition strengths from inelastic proton scattering: The cases of 48Ca and 208Pb
• Low-energy multipole response in nuclei at finite temperature
• Electric and magnetic dipole strength in 112,114,116,118,120,124Sn
• Model dependence of the neutron-skin thickness on the symmetry energy
• Neutron star structure and collective excitations of finite nuclei
• Spin-flip M1 giant resonance as a challenge for Skyrme forces
• Low-energy monopole strength in exotic Nickel isotopes
• Testing Skyrme energy-density functionals with the QRPA in low-lying vibrational states of rare-earth nuclei
• Relativistic Hartree-Fock-Bogoliubov model for deformed nuclei
• Neutrino and antineutrino charge-exchange reactions on 12C
• Gamow-Teller excitations at finite temperature: Competition between pairing and temperature effects
• M1 Resonances in Unstable Magic Nuclei
• Elimination of spurious modes within QRPA
• Magnetic dipole excitations based on the relativistic nuclear energy density functional
• Pygmy dipole mode in deformed neutron-rich Mg isotopes close to the drip line
• Experimental status of the nuclear spin scissors mode
• Low-energy M1 excitations in ${}^{208}$Pb and the spin channel of the Skyrme energy-density functional
• Role of residual interaction in the relativistic description of M1 excitation
• Hybrid method to resolve the neutrino mass hierarchy by supernova (anti)neutrino induced reactions
• Magnetic dipole excitation and its sum rule in nuclei with two valence nucleons
• On the importance of using exact pairing in the study of pygmy dipole resonance
• Self-consistent calculation of the reactor antineutrino spectra including forbidden transitions
• Skyrme RPA for nuclear resonances: trouble with magnetic modes

Cited by in corpus (2)

• Benchmark of many-body approaches for magnetic dipole transition strength
• Magnetic quadrupole transitions in the relativistic energy density functional theory