The Solar Neutrino Problem

Haxton, W. C.

doi:10.1146/annurev.aa.33.090195.002331

Cited by 96 publications

(65 citation statements)

References 86 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Vacuum oscillations can reconcile the SSM with the observed rates of all three kinds of solar neutrino experiments (for reviews see [11][12][13][14]). A recent detailed study [15][16][17][18][19] of VO solutions shows that global fits to the data result in oscillation parameters within the ranges 5 · 10 −11 eV 2 ≤ ∆m 2 ≤ 1 · 10 −10 eV 2 and 0.7 ≤ sin 2 2θ ≤ 1 for oscillations between active neutrinos.…”

Section: Introductionmentioning

confidence: 93%

“…Another possible explanation of this excess [6,7] is that the Hep neutrino flux might be significantly larger (about a factor [10][11][12][13][14][15][16][17][18][19][20] than the SSM prediction. The Hep flux depends on solar properties, such as the 3 He abundance and the temperature, and on S 13 , the zeroenergy astrophysical S-factor of the p + 3 He → 4 He + e + + ν reaction.…”

Section: Introductionmentioning

confidence: 99%

“…In this paper we shall further elaborate upon this specific vacuum oscillation solution. For the sake of conciseness, we shall refer to this solution (∆m 2 = 4.2 · 10 −10 eV 2 and sin 2 2θ = 0.93) as HEE (High-Energy Excess) VO.We shall start with a short description of relevant features of those vacuum oscillation solutions, whose parameters fit all global rates; these solutions will be indicated altogether as VO.Vacuum oscillations can reconcile the SSM with the observed rates of all three kinds of solar neutrino experiments (for reviews see [11][12][13][14]). A recent detailed study [15][16][17][18][19] of VO solutions shows that global fits to the data result in oscillation parameters within the ranges 5 · 10 −11 eV 2 ≤ ∆m 2 ≤ 1 · 10 −10 eV 2 and 0.7 ≤ sin 2 2θ ≤ 1 for oscillations between active neutrinos.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Vacuum oscillations and excess of high energy solar neutrino events observed in Superkamiokande

Berezinsky

Fiorentini

Lissia

2000

Astroparticle Physics

View full text Add to dashboard Cite

The excess of solar-neutrino events above 13 MeV that has been recently observed by Superkamiokande can be explained by the vacuum oscillation solution to the Solar Neutrino Problem (SNP). If the boron neutrino flux is 20% smaller than the standard solar model (SSM) prediction and the chlorine signal is assumed 30% (or 3.4σ) higher than the measured one, there exists a vacuum oscillation solution to SNP that reproduces both the observed spectrum of the recoil electrons, including the high energy distortion, and the other measured neutrino rates. The most distinct signature of this solution is a semi-annual seasonal variation of the 7 Be neutrino flux with maximal amplitude. While the temporal series of the GALLEX and Homestake signals suggest that such a seasonal variation could be present, future detectors (BOREXINO, LENS and probably GNO) will be able to test it.Superkamiokande [1][2][3] has recently observed an excess of solar-neutrino events at electron energies higher than 13 MeV. This excess cannot be interpreted as a distortion of the boron neutrino spectrum due to neutrino oscillations [1][2][3][4], if one restricts oneself to those oscillation solutions that explain the observed gallium, chlorine and water-cerenkov neutrino rates.It is tempting to think that this excess is the result of low statistics or small systematic errors at the end of the boron neutrino spectrum. For example, because of very steep end of the electron spectrum, even small systematic error in electron energy (e.g., due to calibration) could enhance the number of events in the highest energy bins. One should 1 wait for future Superkamiokande data, where such possible systematic effects will be further elaborated. The data from the SNO detector, which will come in the operation soon, e.g., see Ref.[5], can shed light on this excess.Another possible explanation of this excess [6,7] is that the Hep neutrino flux might be significantly larger (about a factor 10-20) than the SSM prediction. The Hep flux depends on solar properties, such as the 3 He abundance and the temperature, and on S 13 , the zeroenergy astrophysical S-factor of the p + 3 He → 4 He + e + + ν reaction. Both SSM based [7] and model-independent [8] approaches give a robust prediction for the ratio Φ ν (Hep)/S 13 . Therefore, this scenario implies a cross-section larger by a factor 10-20 than the present calculations (for reviews see [7,9]). Such a large correction to the calculation does not seem likely, though it is not excluded. A large Hep neutrino flux remains a possible explanation of the excess. The signature of Hep neutrinos, the presence of electrons above the maximum boron neutrino energy, can be tested by the SNO experiment.The Superkamiokande collaboration noticed [1] that vacuum oscillations with large ∆m 2 explain the observed high-energy excess. However, the same Ref.[1] emphasizes that those oscillation parameters that reproduce the excess do not solve the Solar Neutrino Problem (SNP), i.e., they do not explain the global rates observed by the fou...

show abstract

Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Vacuum oscillations and excess of high energy solar neutrino events observed in Superkamiokande

Berezinsky

Fiorentini

Lissia

2000

Astroparticle Physics

View full text Add to dashboard Cite

show abstract

“…For adiabatic variation of the magnetic field 2 and electron density, the conversion probability is [34,35] P νeL→νµR = 1 2 (1 − cos 2θ cos 2θ) , (II.11) and at the resonance (θ = π/4) it assumes the maximum value…”

Section: Spin Flavor Oscillations In Amu Theorymentioning

confidence: 99%

Spin-flavour conversion of neutrinos in loop quantum gravity

Lambiase

2003

Class. Quantum Grav.

View full text Add to dashboard Cite

show abstract

“…(13a) -(13c) are determined by the Cl-Ar data (1) and therefore exhibit a certain, although weak, dependence on f Be . The value of f B is constrained 3 In July 1995 the GALLEX collaboration updated their results adding new data from 9 runs of measurements to the previously existing data from 30 runs [13].…”

Section: Msw ν E → ν S Transition Solutions: General Propertiesmentioning

confidence: 99%