Neutrino Solar Flare detection for a saving alert system of satellites and astronauts

During largest solar flare, of a few minutes duration, the particle flux escaping the corona eruption and hitting later on the Earth, is 3-4 order of magnitude above the common atmospheric CR background . If the flare particle interactions on the Sun corona is taking place as efficiently as in terrestrial atmosphere, than their secondaries by charged pions and muons decays, are leading to a neutrinos fluency on Earth comparable to one day terrestrial atmospheric neutrino activity (upper Bound). One therefore may expect a prompt increase of neutrino signals of the order of one day integral events made by atmospheric neutrinos [1]. In present neutrino detectors the signal is just on the edge, but as long as the authors know, it has been never revealed [2], [5]. Sun density at the flare corona might be diluted and pion production maybe consequently suppressed (by a factor (0.1-0.05)) respect to terrestrial atmosphere, leading to a signal at few percent the expected one under the above considerations. This may be the reason for the SK null detection. Indeed the low Gamma signals recently reported [3] confirm this suppressed signal, but just at the detection edge (See Fig. 1,2). Unfortunately the neutrino signal at hundred MeV energies is rare while the one at ten MeV or below is polluted by Solar Hep neutrinos. The expected signal is dominated by 10 -30 MeV neutrinos, that might be greatly improved by anti-neutrino component via Gadolinium presence in next SK detectors [2]. Our earliest (2006) upper limit estimate for October -November 2003 solar flares [1] and the recent January 20th 2005 [2] exceptional flare were leading to signal near unity for Super-Kamiokande and to a few events above unity for few Mega-ton detectors (See Fig. 1,2). Indeed large size neutrino detectors (5 -10 Megaton) at ten GeV (Deep Core) are just recording data; ten GeV is a little high energy but hard solar flare have been observed up to tens GeV gamma. Moreover even GeV (PINGU) detectors, may soon be born. Our recent estimate based on a lower (gamma) bound of neutrino signal, while below the upper ones, still confirms the order of magnitude and the near edge discovery (See Fig. 1,2). The recent peculiar solar flares as the October-November 2003 and January 2005 [3] were source of high energetic charged particles: large fraction of these primary particles, became a source of both neutrons [2] and secondary kaons, K ± , pions, π ± by their particle-particle spallation on the Sun surface [1]. Consequently, µ ± , final secondaries muonic and electronic neutrinos and anti-neutrinos, ν µ , νµ , ν e , νe , γ rays, are released by the chain reactions

occurring on the sun atmosphere. There are two different sites for these decays (see [1]): A brief and sharp solar flare, originated within the solar corona itself and a diluted and delayed terrestrial neutrino flux, produced by late flare particles hitting the Earth’s atmosphere. This latter delayed signal is of poor physical interest, like an inverse missing signal during the E. Forbush phase. The main and first solar flare neutrinos reach the Earth with a well defined directionality and within a narrow time range. The corresponding average energies < E νe >, < E νµ > ( since low solar corona densities) suffer negligible energy loss: < E νe > ≃ 50M eV , < E νµ >≃ 100 ÷ 200 MeV. The opposite occur to downward flare. In the simplest approach, the main source of pion production is

ց p+n+π + at the center of mass of the resonance ∆ (whose mass value is m ∆ = 1232 MeV). As a first approximation and as a useful simplification after the needed boost of the secondaries energies one may assume that the total pion π + energy is equally distributed, in average, in all its final remnants: (ν µ , e + , ν e , ν µ ):E νµ ≥ E νµ ≃ E νe ≃ 1 4 E π + . Similar nuclear reactions (at lower probability) may also occur by proton-alfa scattering leading to:

Here we neglect the π -additional role due to the flavor mixing and the dominance of previous reactions π + . To a first approximation the flavor oscillation will lead to a decrease in the muon component and it will make the electron neutrino component a bit harder. Indeed the oscillation length (at the energy considered) is small with respect to the Earth-Sun distance: L νµ-ντ = 2.48 •

While at the birth place the neutrino fluxes by positive charged pions π + are Φ νe :Φ νµ :Φ ντ = 1 : 1 : 0, after the mixing assuming a democratic number redistribution we expect Φ νe :Φ νµ :Φ ντ = ( 23 ) : ( 23 ) : ( 23 ). Naturally in a more detailed balance the role of the most subtle and hidden parameter (the very recent, possibly detected, neutrino mixing Θ 13 [6]) may be deforming the present averaged flavor balance. On the other side for the anti-neutrino fluxes we expect at the birth place: Φ νe :Φ νµ :Φ ντ = 0 : 1 : 0 while at their arrival (within a similar democratic redistribution): Φ νe :Φ νµ :Φ ντ = ( 13 ) : ( 13 ) : ( 13 ). This neutrino flux, derived by gamma o

…(Full text truncated)…

This content is AI-processed based on ArXiv data.