Search for beta-delayed proton emission from Be

K. Riisager; M. J. G. Borge; J. A. Briz; M. Carmona-Gallardo; O. Forstner; L. M. Fraile; H. O. U. Fynbo; A. Garzon Camacho; J. G. Johansen; B. Jonson; M. V. Lund; J. Lachner; M. Madurga; S. Merchel; E. Nacher; T. Nilsson; P. Steier; O. Tengblad; V. Vedia

doi:10.1140/epja/s10050-020-00110-2

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2023 Impact factor 2.6

Hadrons and Nuclei

Eur. Phys. J. A (2020) 56: 100
https://doi.org/10.1140/epja/s10050-020-00110-2

Regular Article – Experimental Physics

Search for beta-delayed proton emission from $^{11}$ Be

K. Riisager¹^*, M. J. G. Borge²^,3, J. A. Briz³, M. Carmona-Gallardo⁴, O. Forstner⁵, L. M. Fraile⁴, H. O. U. Fynbo¹, A. Garzon Camacho³, J. G. Johansen¹, B. Jonson⁶, M. V. Lund¹, J. Lachner⁵, M. Madurga², S. Merchel⁷, E. Nacher³, T. Nilsson⁶, P. Steier⁵, O. Tengblad³ and V. Vedia⁴

¹ Department of Physics and Astronomy, Aarhus University, 8000, Aarhus C, Denmark
² ISOLDE, EP Department, CERN, 1211, Geneve 23, Switzerland
³ Instituto de Estructura de la Materia, CSIC, 28006, Madrid, Spain
⁴ Grupo de Física Nuclear and IPARCOS, Universidad Complutense de Madrid, CEI Moncloa, 28040, Madrid, Spain
⁵ Faculty of Physics, University of Vienna, Währinger Strasse 17, 1090, Wien, Austria
⁶ Institutionen för Fysik, Chalmers Tekniska Högskola, 41296, Göteborg, Sweden
⁷ Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany

^* e-mail: kvr@phys.au.dk

Received: 9 January 2020
Accepted: 16 February 2020
Published online: 30 March 2020

Abstract

We report on an attempt to reproduce the observation of $\beta ^-$ -delayed proton emission from $^{11}$ Be through detection of the final state nucleus $^{10}$ Be with accelerator mass spectrometry. Twelve samples were collected at the ISOLDE facility at CERN at different separator settings, allowing tests of different sources of contamination to be carried out. The observed amounts of $^{10}$ Be per collected $^{11}$ Be rule out several contamination sources, but do not agree internally. Formation of BeH molecular ions in the ion source may explain our data, in which case an upper limit of the $\beta$ p branching ratio of $2.2 \times 10^{-6}$ can be derived.