. Mev-<-e-?-<-.4-mev, The flux has been observed by the "Gallium" experiments, GALLEX 69 , SAGE 70 and GNO 71 , via the transition Gallium to Germanium ? e + 71 Ga ? e ? + 71 Ge, with a threshold of .233 MeV. They all show a deficit of ? e 's compared to the model, roughly ? obs (? e )/? mod

,. R. Homestake and . Davis, Phys. Rev. Lett, vol.12, p.302, 1964.

J. N. Bahcall, Phys. Rev. Lett, vol.17, p.398, 1966.

J. N. Bahcall, A. M. Serenelli, and S. Basu, Astrophys.J, vol.621, p.85, 2005.

S. M. Bilenky, B. Pontecorvo, and ;. Hampel, 1977 neutrino oscillations as the most reasonable explanation for the observed ?e deficit, vol.7, p.15807, 1977.

M. Altmann, Phys. Lett, vol.616, p.174, 2005.

F. Gallex-+-gno and . Kaether, Phys. Lett, vol.685, p.47, 2010.

. The, Glashow resonance, i.e. the reaction ?e + e ? ? W ? ? X should affect the ?e flux above E? e > 6.3 10 15 eV. 76, vol.342, p.55, 2013.

, Maurizio Spurio, PoS, vol.2015, p.54, 2015.

A. D. Avrorin, , 2015.

M. G. Aartsen, Astrophys.J, vol.809, 20158.

A. Aguilar, Phys. Rev, vol.64, p.112007, 2001.

A. A. Aguilar-arevalo,

, Phys. Rev. Lett, vol.110, p.161801, 2013.

B. Armbruster, Phys. Rev, vol.65, p.112001, 2002.

G. Mention, Phys. Rev, vol.83, p.73006, 2011.

F. P. An, Phys. Rev. Lett, vol.118, p.251801, 2017.

J. Kopp, JHEP, vol.1305, p.143, 2013.

M. Dentler, JINST, vol.1711, issue.93, p.11011, 2016.

Y. J. Neos-collaboration and . Ko, Phys. Rev. Lett, vol.118, p.121802, 2017.

N. Allemandou,

, Phys. Rev. Lett, vol.121, p.161801, 2018.

L. Bernard,

J. Ashenfelter,

, phenomena and objects such as gamma-ray bursts, supernovae remnants, quasars, blazars, · · · 98 . As an illustration

, Neutrinos may also be a signal of dark matter annihilation in the universe 99

K. N. Abazajian, Astro2020 Science White Paper: Cosmology and Fundamental Physics

M. Chianese,