TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhysProc.5.007
TI  - The SINDRUM-I Experiment
PY  - 2021/09/06
UR  - https://www.scipost.org/SciPostPhysProc.5.007
JF  - SciPost Physics Proceedings
JA  - SciPost Phys. Proc.
VL  - 
IS  - 5
SP  - 007
A1  - Eichler, Ralph
AU  - Grab, Christophorus
AB  - SINDRUM-I was the first nearly 4 spectrometer at SIN. It was initially designed to 9 search for the forbidden decay + ! e+e􀀀e+ , but also successfully studied various 10 other processes with high precision. The upper limit obtained for the branching ratio of B!3e = 􀀀 (+ ! e+e􀀀e+ )=􀀀 (+ ! e+e¯ 11  ) < 1.0  10􀀀12(90% CL) from 1988 is still the best. The first statistically significant observation of the rare decay + ! e+e􀀀e+e¯ 12  , achieved in 1985, yielded a branching ratio of B13 !3e2 = (3.40.20.2)10􀀀5. Several 14 othermeasurements of rare decays were undertaken: the first observation of the -decay 15 + !e+ee􀀀e+ resulted in 􀀀 (+ !e+ee􀀀e+ )=􀀀 (+ !+ ) = (3.2  0.5  0.2)  10􀀀9, 16 also still the best measurement; and a determination of the ratio of the weak axial- to 17 vector-form factor FA=FV = (0.7  0.5), resolving an ambiguity. In addition, upper limits 18 for + ! e+ and + ! e+e with subsequent decay ! e+e􀀀 (search for "massless" Goldstone bosons) and 0 !e+e􀀀 19 < 1.3  10􀀀7 were obtained.
ER  -

@Article{10.21468/SciPostPhysProc.5.007,
	title={{The SINDRUM-I Experiment}},
	author={Ralph Eichler and Christoph Grab},
	journal={SciPost Phys. Proc.},
	pages={007},
	year={2021},
	publisher={SciPost},
	doi={10.21468/SciPostPhysProc.5.007},
	url={https://scipost.org/10.21468/SciPostPhysProc.5.007},
}