Nuclear magnetic transitions in the relativistic energy density functional approach

Nils Paar,Goran Kružić,Tomohiro Oishi,A Pakou,G Lalazissis,G Souliotis,D Bonatsos

doi:10.1051/epjconf/202125202002

Nils Paar, Goran Kružić + Show 5 more

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https://doi.org/10.1051/epjconf/202125202002

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Abstract

Recently a novel theory framework has been established for description of magnetic dipole (M1) transitions in finite nuclei, based on relativistic nuclear energy density functional with point coupling interactions. The properties of M1 transitions have been studied, including the sum rules, spin, orbital, isoscalar and isovector M1 transition strengths in magic and open shell nuclei. It is shown that pairing correlations and spinorbit interaction plays an important role in the description of M1 transition strength distributions. The analysis of the evolution of M1 transition properties in the isotope chain100-140Sn shows the interplay between single and double-peak structures, determined by the evolution of single-particle states, their occupations governed by the pairing correlations, and two-quasiparticle transitions involved. Comparison of the calculated B(M1) transition strength with recent data from inelastic proton scattering on112-124Sn, shows that quenching of thegfactorsgeff/gfree=0.80-0.93 is required to reproduce the experimental data. Further experimental investigations are needed to determine accurately the quenching factor.

Highlights

Magnetic dipole (M1) transitions represent fundamental excitation phenomena in finite nuclei
Since the resulting photoabsorption cross sections derived from the E1 and M1 strength distributions showed significant differences when compared to those from previous (γ, xn) experiments [27, 28], it is interesting to explore how the new experimental data compare to the model calculations based on the relativistic nuclear energy density functional
It has been shown that 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 twoquasiparticle transitions involved [23]

Summary

Introduction

Magnetic dipole (M1) transitions represent fundamental excitation phenomena in finite nuclei. To respond to some of the open challenges, recently a novel theory framework has been established for studies of M1 excitations, based on the relativistic nuclear energy density functional [21, 22]. The spin, orbital, isoscalar and isovector M1 transition strengths have been studied in detail in magic nuclei 48Ca and 208Pb, and open shell nuclei 42Ca and 50Ti [21].

Results

Conclusion