http://arxiv.org/abs/1311.7043
Time modulations at per mil level have been reported to take place in the decay constant of about 15 nuclei with period of one year (most cases) but also of about one month or one day. In this paper we first investigate the possibility of an annual modulation induced by the coupling with a scalar field sourced by the Sun. Then, we give the results of the activity measurement of a 40K source and a 232Th one. The two experiments have been done at the Gran Sasso Laboratory during a period of about 500 days, above ground (40K) and underground (232Th) with a sensitivity of a few parts over 10^-5. Finally, we give the results of the activity measurement at the time of the X-class solar flares which took place in May 2013. Briefly, our measurements do not show any evidence of time dependence in the decay rate of 40K and 232Th.
Thu, 28 Nov 13
36/47
You must be logged in to post a comment.