Particle-core coupling inS37

Abstract

Excited states of the neutron-rich N = 21 37 S nucleus have been studied using binary grazing reactions produced by the interaction of a 215-MeV beam of 36 S ions with a thin 208 Pb target. The magnetic spectrometer, PRISMA, and the γ -ray array, CLARA, were used in the measurements. The level scheme of 37 S was established to an excitation energy of 4196 keV and a number of new transitions were observed, in particular that corresponding to the decay of the proposed J π = (11/2 − ) level at an excitation energy of 2776 keV. The structure of the state is discussed within the context of state-of-the-art shell-model calculations using the SDPF-U effective interaction; the main component of the wave function corresponds to the coupling of the odd 1f 7/2 neutron to the first 2 + state of the 36 S core. The electromagnetic decay properties of the state are discussed within the context of a particle-core coupling model and the shell model. The other members of the multiplet of states are also discussed.

First in-beamγ-ray study of the level structure of neutron-richS39

“…Such a particle-core coupling description has been found to have some validity in earlier work in this region (e.g., see Refs. [4,53,54]). The excitation energy of the first 2 + state of 38 S is 1292 keV [55] and this suggests that a particle-core coupling description is appropriate for the 1517-keV J π = (11/2 − ) state of 39 S. in relation to the odd-A isotopes is rather sparse.…”

Multinucleon transfer reactions in the Ar40+Pb208 system

“…This is the reason why multinucleon transfer reactions have recently been used as a competitive tool for the production of neutron-rich nuclei in the vicinity of the light partner (see for example Refs. [10][11][12][13]). …”

Lifetime measurements of states of S35 , S36 , Grocutt1, Chapman2, Haas3 et al. 2022Phys. Rev. CSelf Cite3000View full textAdd to dashboardCite

“…In the present work, lifetime limits have been established for two states in 37 S, namely, the first-excited state at 646 keV with J π = 3/2 − and the (11/2 − 1 ) state at 2776 keV. These two states were strongly populated in the earlier work of Chapman et al [6] which, as previously noted, used the same beam and target combination.…”

“…The strong 2776-keV transition has previously been assigned to the decay of the 2776-keV excited state to the ground state [6]. There is no previous credible evidence for its population in a direct single-neutron transfer reaction and its strong population here suggests that it is yrast; a tentative J π value of (11/2 − 1 ) has been assigned, based on the population characteristics of binary grazing reactions and on comparison with the results of shell-model calculations [6]. With this proposed assignment, decay to the ground state takes place through an E 2 transition.…”

“…Similarly, most of the 2p 3/2 neutron-transfer strength, (2 j + 1)S = 2.6, is located in the 646-keV J π = 3/2 − first-excited state. The results of shell-model calculations [6] indicate that about 20% of the wave function of the first excited J π = 3/2 − state corresponds to the coupling of a 1 f 7/2 neutron to the first excited J π = 2 + state of the 36 S core, and this component cannot, of course, be populated in a direct one-neutron transfer process. The relatively strong population of the non-yrast 646-keV J π = 3/2 − first-excited state in the present work is consistent with single-neutron transfer playing an important role.…”