The experiments to determine the electron capture and β-decay of 8B into the highly excited states of 8Be

S Víñals ,L M Fraile ,J D Ovejas ,A Gad ,Jørgen Arendt Jensen ,M Münch ,J Benito ,R Lică ,P Figuera ,K Riisager ,María José García Borge ,O Tengblad ,S Smain ,Á Perea ,E Nácher ,B Jonson ,H O U Fynbo ,I Marroquín ,T Nilsson ,Ch Sotty

doi:10.1088/1742-6596/1643/1/012130

Abstract

The main goal of this work is to study the structure of the highest energy states in 8Be populated following the β+-decay and the electron capture (EC) of 8B. With this aim, two experiments were performed at ISOLDE-CERN in 2017 and 2018. The first experiment had the aim to resolve the 2+ doublet at 16.6 and 16.9 MeV, in order to study their isospin mixing. The second experiment aimed to determine a value or give an experimental upper limit to the branching ratio of the exotic EC-p decay.In this paper, we present the experimental setups and we discuss the analysis and present the preliminary results obtained so far.

Highlights

The 8B nucleus is interesting both from astrophysics and nuclear structure point of view
The β+-decay of the 8B is the main source of solar neutrinos above 2 MeV, the shape of the β+/electron capture (EC)-decay α-spectrum has been studied in detail in numerous occasions
The interest of the present study focuses on the 8B nuclear structure and the study of the population to high excited states in the daughter 8Be

Summary

Introduction

The 8B nucleus is interesting both from astrophysics and nuclear structure point of view. As far as is known the 8B decay by allowed transitions to the 2+ states in 8Be that break into two alphas (see figure 1). The β+-decay of the 8B is the main source of solar neutrinos above 2 MeV, the shape of the β+/EC-decay α-spectrum has been studied in detail in numerous occasions (see reference in [1] and reference therein).

Objectives

Results

Conclusion