Author/Authors :
Simson، نويسنده , , M. and Ayala Guardia، نويسنده , , F. and Baeكler، نويسنده , , S. F. Borg، نويسنده , , M. and Glück، نويسنده , , F. and Heil، نويسنده , , W. and Konorov، نويسنده , , I. and Konrad، نويسنده , , G. and Muٌoz Horta، نويسنده , , R. and Leung، نويسنده , , K.K.H. and Sobolev، نويسنده , , Yu. and Soldner، نويسنده , , T. and Wirth، نويسنده , , H.-F. and Zimmer، نويسنده , , O.، نويسنده ,
Abstract :
The retardation spectrometer aSPECT was built to measure the shape of the proton spectrum in free neutron decay with high precision. This allows us to determine the antineutrino electron angular correlation coefficient a. We aim for a precision more than one order of magnitude better than the present best value, which is Δ a / a = 5 % .
ecent beam time performed at the Institut Laue-Langevin during April/May 2008 we reached a statistical accuracy of about 2% per 24 h measurement time. Several systematic effects were investigated experimentally. We expect the total relative uncertainty to be well below 5%.
