Measurement of the β–ν correlation coefficient<i>a</i>_βνin the β decay of trapped⁶He⁺ions

Abstract

Abstract\nWe have measured the ??? angular correlation in the ? decay of 6 He + ions using a transparent Paul trap. The 6 He + ions, produced at GANIL, were first cooled and bunched before being injected in the LPCTrap setup. The angular correlation was inferred from the time of flight of recoil nuclei detected in coincidence with the ? particles. The detection system gives access to the full ? decay kinematics, providing means to check the data reliability and to reject a large fraction of background. We find a ?? = -0.3335(73) stat (75) syst, in agreement with the Standard Model prediction for a pure Gamow-Teller transition.