The prototype of the Borexino detector Counting Test Facility, located in the Gran-Sasso laboratory, has been used to obtain a bound on the stability of the electron. The new lower limit on the mean lifetime defined on 32.1 days of data set is τ(e−→νe+γ)⩾4.6×1026 yr (90% c.l.).
Response to the critics of Borexino results in “A New experimental limit for the stability of the electron” by H.V. Klapdor-Kleingrothaus, I.V. Krivosheina and I.V. Titkova.”
By Borexino Collaboration (H.O. Back et al.),
e-Print: hep-ex/0703044 (Mar 2007)