Search for possible neutrino radiative decays during the 2001 total solar eclipse

Abstract

We present the results of the observations performed in the occasion of the June 21 st , 2001 total solar eclipse, looking for visible photons emitted through a possible radiative decay of solar neutrinos. We establish lower limits for the ν 2 or ν 3 proper lifetimes τ 0 /m ≥ 10 3 s/eV, for neutrino masses larger than 10 −2 eV.

New lower limits on the lifetime of heavy neutrino radiative decay

“…The digital video-camera used in occasion of the 2002 TSE was a small backup system. It produced a digital film of the eclipse that could confirm our earlier results [16]. A smaller Celestron C5 telescope equipped with a manually controlled digital camera (Canon D20) was also used.…”

“…We recall that this image is a superposition of 195 selected 16 bit frames recorded during the TSE and aligned with respect to the center of the Sun position behind the Moon. As in the case of the 2002 eclipse [16] we chose the Haar wavelet basis [22]. The n-order term of the decomposition is obtained by dividing the N × N pixels 2 image in squares of N/2 n ×N/2 n pixels 2 and averaging the luminosity in each square; the averages are then subtracted and the resulting image, the n-order residual, can be used to obtain the (n + 1)-order term.…”

“…The analysis of the data obtained by this experiment required a detailed Monte Carlo simulation, including the neutrino production in the solar core, its propagation, decay, and the detection by our telescope on Earth. Such a code was developed for the analysis of the previous data collected during the 2001 eclipse [16] and was adapted to the conditions of the 2006 observations. The model is described in detail in ref.…”

“…We made a search for solar neutrino radiative decays during the June 21, 2002 TSE, in Zambia [16] after a first attempt during the 1999 eclipse in Romania [17]. The proper lower time limits (95% C.L.)…”

Atmospheric ν and Long Baseline ν experiments II

“…Neutrino decay could be another exotic explanation for neutrino disappearence; SK data do not favour ν decay and no radiative decay was observed in specific experiments [18].…”