Decay of Erg+m149 by positron and delayed proton emission and by electron capture

R. B. Firestone, J. M. Nitschke, P. A. Wilmarth, K. Vierinen, J. Gilat, K. S. Toth, Y. A. Akovali

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

In this study the decay of Erg+m149 by positron emission, electron capture, and β-delayed proton emission was investigated. Gamma rays associated with Erm149 decay were placed in a decay scheme on the basis of γγ and xγ coincidences and half-life. We assigned 120 γ rays deexciting 91 levels in Ho149 to 8.9±0.2 s Erm149 decay. The πs1/2 single-particle state in Ho149 was observed to occur at 49.0 keV above the πh11/2 ground state. A (3.5±0.7) % isomeric transition decay branch and a (0.18±0.07) % β-delayed proton decay branch were determined for Erm149 decay. Three additional γ rays were assigned to 4±2 s Erg149 decay and a (7±2) % β-delayed proton decay branch was determined. Measured EC/β+ ratios to proton emitting states in Ho149 resulted in a (QEC-Sp)=7.0-0.4+5.0 MeV for ER8149 decay and a Sp=1.4-0.6+10 MeV for Ho. The β-delayed proton spectrum from Erg149 consisted of a highly structured component corresponding to the deexcitation of levels between 4 and 5 MeV in Ho149 and a structureless component corresponding to decay from higher levels. The β-strength function for Erg+m149 decay is discussed in terms of single-particle shell-model structure, weak coupling to the Dy148 core, and decay of πh11/2 protons across the shell closure to the νh9/2 neutron orbital.

Original languageEnglish (US)
Pages (from-to)219-232
Number of pages14
JournalPhysical Review C
Volume39
Issue number1
DOIs
StatePublished - 1989
Externally publishedYes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Fingerprint Dive into the research topics of 'Decay of Erg+m149 by positron and delayed proton emission and by electron capture'. Together they form a unique fingerprint.

Cite this