Shell-model studies of the proton drip line nucleus106Sb

Abstract

We present results of shell model calculations for the proton drip line nucleus 106 Sb. The shell model calculations were performed based on an effective interaction for the 2s1d0g 7/2 0h11 11/2 shells employing modern models for the nucleon-nucleon interaction. The results are compared with the recently proposed experimental yrast states. A good agreement with experiment is found lending support to the experimental spin assignements. PACS number(s): 21.60.Cs, 27.60.+j Considerable attention is at present being devoted to the experimental and theoretical study of nuclei close to the limits of stability. Recently, heavy neutron deficient nuclei in the mass regions of A = 100 have been studied, and nuclei like 100 Sn and neighboring isotopes have been identified [1][2][3]. Moreover, the proton drip line has been established in the A = 100 and A = 150 regions [4] and nuclei like 105 Sb and 109 I have recently been established as ground-state proton emitters [5,6]. The next to drip line nucleus for the antimony isotopes,106 Sb with a proton separation energy of ∼ 400 keV, was studied recently in two experiments and a level scheme for the yrast states was proposed in Ref. [7].The aim of this work is thus to see whether shell-model calculations, which employ realistic effective interactions based on state of the art models for the nucleon-nucleon interaction, are capable of reproducing the experimental results for systems close to the stability line. Before we present our results, we will briefly review our theoretical framework. In addition, we present results for effective proton and neutron charges based on perturbative manybody methods. These effective charges will in turn be used in a shell-model analysis of E2 transitions.The aim of microscopic nuclear structure calculations is to derive various properties of finite nuclei from the underlying hamiltonian describing the interaction between nucleons. We derive an appropriate effective two-body interaction for valence neutrons and protons in the singleparticle orbits 2s 1/2 , 1d 5/2 , 1d 3/2 , 0g 7/2 and 0h 11/2 . As closed shell core we use 100 Sn. This effective two-particle interaction is in turn used in the shell model model study of 106 Sb. The shell model problem requires the solution of a real symmetric n × n matrix eigenvalue equatioñwith k = 1, . . . , K. At present our basic approach to finding solutions to Eq. (1) is the Lanczos algorithm, an iterative method which gives the solution of the lowest eigenstates. The technique is described in detail in Ref.[8], see also Ref. [9]. To derive the effective interaction, we employ a perturbative many-body scheme starting with the free nucleonnucleon interaction. This interaction is in turn renormalized taking into account the specific nuclear medium.The medium renormalized potential, the so-called Gmatrix, is then employed in a perturbative many-body scheme, as detailed in Ref.[10] and reviewed briefly below. The bare nucleon-nucleon interaction we use is the charge-dependent meson-exchange model of Machleid...

Electromagnetic transition strengths in52109Te

“…Within this approach the B(E2) values for the 15/2 − and 19/2 − decays are calculated to be 1681 and 1708 e 2 fm 4 , respectively, giving much closer agreement to the experimentally measured values in this work. However, the exact nature of the behavior of effective charges as the proton drip line is approached is not very well understood [11,49]. Despite this, the magnitude of the experimental and theoretical B(E2) values points to a significant amount of collectivity within the band, as shown in Table IV.…”

Observation of a core-excitedE4isomer inCd98

“…A pulsed beam of 58 Ni served as projectile and as a time reference for the 46 Ti͑ 58 Ni, ␣2n͒ 98 Cd reaction. The pulse repetition time was ⌬t = 330 ns.…”

Erratum: Effective Lagrangian approach to structure of selected nuclei far from stability [Phys. Rev. C66,024318 (2002)]

“…level spacing which is apparent in Sb nuclei [19]. Some of the methods that have been tested on these nuclei with various degrees of success are the density dependent relativistic Hartree (DDRH) [16,20], relativistic continuum Hartree Bogoliubov (RCHB) [17], relativistic Hartree Bogoliubov (RHB) [15], Hartree-Fock-Bogoliubov [21] and relativistic Dirac-Hartree-Bogoliubov (DHB) [22].…”