The upper limit of the branching ratio for radiative beta-decay of free neutron
M. Beck+, J. Byrne, R. U. Khafizov*, V. Yu. Kozlov+, Yu. A. Mostovoi*, O. V. Rozhnov, N. Severijns+, V. A. Solovei
University of Sussex, Brighton BN1 9RH, Sussex, UK
+Katholieke Universiteit Leuven, B-3001 Leuven, Belgium
*RSC Kurchatov Institute, 127562 Moscow, Russia
Petersburg Nuclear Physics Institute, 188350 Gatchina, Russia
PACS: 13.30.-a, 13.40.-f, 14.20.Dh
We conducted the experiment on radiative neutron beta-decay on a
intensive cold neutron beam at ILL during April and May of 2002. This work is
dedicated to the analysis of the methodology and the results of the study.
The main outcome of this experiment is the branching ratio (BR) for the
rare neutron decay mode in the gamma-quanta energy region from 35 to
100 KeV. The limit obtained is BR < 6.9 • 10-3 (90% C.L.), which
is only a few permilles greater than the theoretical BR value, calculated
within the standard weak interactions model.