scholarly journals Investigating Sterile Neutrino Flux in the Solar Neutrino Data

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Ankush ◽  
Rishu Verma ◽  
Gazal Sharma ◽  
B. C. Chauhan
Keyword(s):  
Solar Neutrino ◽  
Particle Physics ◽  
Sterile Neutrino ◽  
Neutrino Flux ◽  
Solar Neutrinos ◽  
Neutrino Energy ◽  
Fourth Degree ◽  
Solar Neutrino Flux ◽  
Neutrino Experiments ◽  
Solar Phase

There are compelling evidences for the existence of a fourth degree of freedom of neutrinos, i.e., sterile neutrino. In the recent studies the role of sterile component of neutrinos has been found to be crucial, not only in particle physics, but also in astrophysics and cosmology. This has been proposed to be one of the potential candidates of dark matter. In this work we investigate the updated solar neutrino data available from all the relevant experiments including Borexino and KamLAND solar phase in a model independent way and obtain bounds on the sterile neutrino component present in the solar neutrino flux. The mystery of the missing neutrinos is further deepening as subsequent experiments are coming up with their results. The energy spectrum of solar neutrinos, as predicted by Standard Solar Models (SSM), is seen by neutrino experiments at different parts as they are sensitive to various neutrino energy ranges. It is interesting to note that more than 98% of the calculated standard model solar neutrino flux lies below 1 MeV. Therefore, the study of low energy neutrinos can give us better understanding and the possibility of knowing about the presence of antineutrino and sterile neutrino components in solar neutrino flux. As such, this work becomes interesting as we include the data from medium energy (~1 MeV) experiments, i.e., Borexino and KamLAND solar phase. In our study we retrieve the bounds existing in literature and rather provide more stringent limits on sterile neutrino (νs) flux available in solar neutrino data.

ON THE COHERENCE CONDITION FOR RESONANT SPIN-FLAVOR PRECESSION OF MAJORANA SOLAR NEUTRINOS

1992 ◽  
Vol 07 (06) ◽  
pp. 1309-1314
Author(s):  
RAUL HORVAT
Keyword(s):  
Solar Neutrino ◽  
Neutrino Flux ◽  
Majorana Neutrino ◽  
Solar Neutrinos ◽  
Sunspot Activity ◽  
The Sun ◽  
Solar Neutrino Problem ◽  
Mass Eigenstates ◽  
Flavor Changing ◽  
Solar Neutrino Flux

One of the most attractive solutions to the solar-neutrino problem (including an anticorrelation of the solar-neutrino flux with sunspot activity) incorporates a Majorana neutrino having a flavor-changing transition moment as large as (0.1–1)×10−10 Bohr magnetons. This solution is compatible with all known laboratory, astrophysical and cosmological bounds. Here we show the consistency of the solution with the coherence condition for effective-mass eigenstates inside the sun.

Bounds on Sterile Neutrino Component in the Solar Neutrino Flux

2018 ◽  
pp. 713-716
Author(s):  
Govind Singh ◽  
Ashish Sharma ◽  
Gazal Sharma ◽  
Shankita Bhardwaj ◽  
Surender Verma ◽  
...  
Keyword(s):  
Solar Neutrino ◽  
Sterile Neutrino ◽  
Neutrino Flux ◽  
Solar Neutrino Flux

scholarly journals Using Helioseismic Data to Probe the Hydrogen Abundance in the Solar Core

1990 ◽  
Vol 121 ◽  
pp. 327-340 ◽  
Author(s):  
D. O. Gough ◽  
A. G. Kosovichev
Keyword(s):  
Solar Neutrino ◽  
Particle Physics ◽  
Sound Speed ◽  
Main Sequence ◽  
Neutrino Flux ◽  
Sequence Evolution ◽  
The Sun ◽  
Low Degree ◽  
The Standard Model ◽  
Solar Neutrino Flux

AbstractA procedure for inverting helioseismic data to determine the hydrogen abundance in the radiative interior of the sun is briefly described. Using Backus-Gilbert optimal averaging, the variation of sound speed, density and hydrogen abundance in the energy-generating core is estimated from low-degree p-mode frequencies. The result provides some evidence for there having been some redistribution of material during the sun’s main-sequence evolution. The inversion also suggests that the evolutionary age of the sun is perhaps some 10 per cent greater than the generally accepted value, and that the solar neutrino flux, based on standard nuclear and particle physics, is about 75 per cent of the standard-model value.

scholarly journals UPDATED REVIEW OF SOLAR MODELS AND SOLAR NEUTRINO EXPERIMENTS

1992 ◽  
Vol 01 (02) ◽  
pp. 281-302 ◽  
Author(s):  
DOUGLAS R.O. MORRISON
Keyword(s):  
Solar Neutrino ◽  
Neutrino Flux ◽  
Reaction Rates ◽  
New Physics ◽  
Solar Neutrinos ◽  
Sunspot Activity ◽  
Evolutionary Models ◽  
Small Diffusion ◽  
Solar Neutrino Problem ◽  
Solar Neutrino Flux

The Conventional Wisdom that there is a Solar Neutrino Problem and that New Physics is required, is examined. The various solar evolutionary models, (or SSM), are described and in particular the four new 1992 papers. While the evolutionary models are generally robust, there are important assumptions and uncertainties (screening, nuclear reaction rates, etc.) which mean that the errors cannot be small. Diffusion in the Sun is expected to be significant but so far there is no calculation which includes all types of diffusion, especially turbulent diffusion. The new and important helioseismological results are shown to to be in agreement with some of the SSM calculations. The experimental results are beginning to be not inconsistent with the SSM calculations. Kamiokande is consistent with SSM calculations except for one with rather small errors. The new GALLEX result is in agreement with all SSM calculations within 1.3 to 2 standard deviations. The 1990 SAGE I experiment is shown to have no evidence of solar neutrinos and is inconsistent with all SSM calculations and with GALLEX. However the new 1991 SAGE II experiment finds neutrino rates not inconsistent with SSM calculations. The Chlorine experiment is significantly below SSM calculations and is inconsistent with Kamiokande. In particular the Chlorine claim that there is a variation of the solar neutrino flux with the inverse of the sunspot activity, which shows a correlation of five standard deviation significance, is in contradiction with the results of the Kamiokande experiment which finds no variation of the solar neutrino flux with time. The overall conclusion is that there is no compelling evidence for a Solar Neutrino Problem or need for New Physics. However the neutrinos could still have masses and further experiments with higher statistics are essential as they are one of the rare ways of studying this low mass region. Thus the Solar Neutrino Problem is becoming a Neutrino Mass Quest.

IMPLICATIONS OF THE RECENT SOLAR NEUTRINO EXPERIMENT FOR PARTICLE PHYSICS

1991 ◽  
Vol 06 (08) ◽  
pp. 645-657 ◽  
Author(s):  
M. FUKUGITA ◽  
T. YANAGIDA
Keyword(s):  
Time Variation ◽  
Solar Neutrino ◽  
Particle Physics ◽  
Neutrino Flux ◽  
The Other ◽  
Data Sets ◽  
Neutrino Experiment ◽  
Physics Model ◽  
Neutrino Experiments ◽  
Solar Neutrino Experiment

Physical implications of the results of recent solar neutrino experiments from the Homestake, Kamioka and Baksan Laboratories are discussed. We argue that the results from Homestake and Kamioka, if the two data sets are combined, strongly suggest some unusual neutrino properties rather than the modification of astrophysical models of the sun. If the time variation of neutrino captures, as observed at Homestake, is a statistical fluke, the neutrino conversion in matter proposed by Mikheyev and Smirnov among several possibilities yields the most attractive explanation for the neutrino flux deficit. We remark that the solution includes the possibility predicted by simple SO(10) models and it is tested by the gallium experiment. If the time variation at Homestake is true, on the other hand, one must explain why such an effect is not seen at Kamiokande. We stress that it is still possible to make a particle physics model which explains the two apparently contradictory observations.

scholarly journals Solar neutrinos as indicators of the Sun’s activity

2019 ◽  
Vol 34 (33) ◽  
pp. 1950227 ◽  
Author(s):  
O. M. Boyarkin ◽  
I. O. Boyarkina
Keyword(s):  
Solar Flares ◽  
Solar Neutrino ◽  
Neutrino Flux ◽  
Solar Neutrinos ◽  
Anapole Moment ◽  
Electron Neutrinos ◽  
Additional Resonance ◽  
Solar Neutrino Flux ◽  
Neutrino Fluxes ◽  
The Magnetic Field

Opportunity of the solar flares (SFs) prediction observing the solar neutrino fluxes is investigated. In three neutrino generations, the evolution of the neutrino flux traveling the coupled sunspots (CSs) which are the SF source is considered. It is assumed that the neutrinos possess both the dipole magnetic moment and the anapole moment while the magnetic field above the CSs may reach the values [Formula: see text] Gs, display the twisting nature and posses the nonpotential character. The possible resonance conversions of the solar neutrino flux are examined. Since the [Formula: see text] resonance takes place before the convective zone, its existence can in no way be connected with the SF. However, when the solar neutrino flux moves through the CSs in the preflare period, then it may undergo the additional resonance conversions and, as a result, depleting the electron neutrinos flux may be observed.

scholarly journals ON RECONCILING ATMOSPHERIC, LSND, AND SOLAR NEUTRINO-OSCILLATION DATA

1998 ◽  
Vol 13 (28) ◽  
pp. 2249-2264 ◽  
Author(s):  
D. V. AHLUWALIA
Keyword(s):  
Neutrino Oscillation ◽  
Solar Neutrino ◽  
Sterile Neutrino ◽  
Atmospheric Neutrino ◽  
Neutrino Flux ◽  
Cpt Symmetry ◽  
Charge Conjugate ◽  
Mixing Matrix ◽  
Quantum Operators ◽  
Neutrino Experiments

The L/E-flatness of the e-like events observed in the recent atmospheric-neutrino data from super-Kamiokande (SuperK) is interpreted to reflect a new symmetry of the neutrino-oscillation mixing matrix. From that we obtain an analytical set of constraints yielding a class of mixing matrices of the property to simultaneously fit both the SuperK and the LSND data. The resulting mass squared difference relevant for the LSND experiment is found as 0.3 eV2. The discussed symmetry, e.g., carries the nature that expectation values of masses for νμ and ντ are identical. These considerations are purely data dictated. A different framework is then applied to the solar neutrino problem. It is argued that a single sterile neutrino is an unlikely candidate to accommodate the data from the four solar neutrino experiments. A scenario is discussed which violates CPT symmetry, and favors the [Formula: see text] system to belong to the "self"–"anti-self" charge conjugate construct in the (1/2, 0)⊕(0,1/2) representation space, where the needed helicity flipping amplitudes are preferred, rather than the usual Dirac, or Majorana, constructs. In the presented framework the emerging SuperK data on solar neutrino flux is reconciled with the Homestake, GALLEX, and SAGE experiments. This happens because the former detects not only the solar νe but also, at a lower cross-section, the oscillated solar [Formula: see text]; while the latter are sensitive only to the oscillation-diminished solar νe flux. A direct observation of solar [Formula: see text] by SNO will confirm our scenario. Finally, we consider the possibility for flavor-dependent gravitational couplings of neutrinos as emerging out of the noncommutativity of the quantum operators associated with the measurements of energy and flavor.

TIME VARIATION OF SOLAR NEUTRINO FLUX

1993 ◽  
Vol 08 (21) ◽  
pp. 1961-1968 ◽  
Author(s):  
PROBHAS RAYCHAUDHURI
Keyword(s):  
Solar Activity ◽  
Solar Neutrino ◽  
Neutrino Flux ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Neutrino Experiment ◽  
Sunspot Maximum ◽  
Solar Neutrino Flux ◽  
Activity Cycles ◽  
Neutrino Experiments

Considering the solar neutrino data during the period from June, 1989 to April, 1992 within first sunspot maximum (it coincides with the maximum of the sunspot (Wolf numbers) and second sunspot maximum (usually appears 2–3 years after the first sunspot maximum) from the four solar neutrino experiments (37 Cl radiochemical, SAGE I & II, Gallex, Kamiokande II & III) we see that the average solar neutrino flux is much higher at the second sunspot maximum (May, 1991 to April, 1992) than at the first sunspot maximum (June, 1989 to April, 1991). This type of observation is already observed in the previous two solar activity cycles in 37 Cl solar neutrino experiment. It has been known for many years that first sunspot maximum and second sunspot maximum are essential features of the solar activity cycle. The above observation suggests that the solar neutrino flux data from the solar neutrino experiments appear to be varying with the solar activity cycle which suggests that the solar activity cycle is due to the pulsating character of the nuclear energy generation inside the core of the Sun.

Can photoionization effects explain the solar-neutrino problem?

1995 ◽  
Vol 73 (1-2) ◽  
pp. 53-58
Author(s):  
J. G. Hykawy
Keyword(s):  
Solar Neutrino ◽  
Initial Conditions ◽  
Neutrino Flux ◽  
New Physics ◽  
Solar Neutrino Problem ◽  
Solar Neutrino Flux ◽  
Accretion Model ◽  
Neutrino Fluxes ◽  
Neutrino Experiments ◽  
Good Agreement

In a simple accretion model of the Sun, the inclusion of photoionizationlike phenomena leads to a set of initial conditions for solar burning that mimic a combination of the classic low-Z and high-Y models. When such initial conditions are used as input to the standard SunEV code, the predicted neutrino fluxes are in good agreement with those presently being observed in the Kamiokande, SAGE and GALLEX experiments. No new physics is required. It is possible that the combination of a low-Z and high-Y model, which is able to explain the solar neutrino deficit, might also provide good agreement with the presently observed helioseismic data. If data from the planned next generation of solar-neutrino experiments (e.g., SNO, SuperKamiokande) shows that the Mikheyer–Smirnov–Wolfenstein effect is not the solution to the solar-neutrino problem, experiments measuring the low-energy solar neutrino flux might show that a low-Z, high-Y combination model is valid.

SOLAR NEUTRINOS WITH EXOTIC SCATTERING

1993 ◽  
Vol 08 (14) ◽  
pp. 1273-1284 ◽  
Author(s):  
JOÃO PULIDO
Keyword(s):  
Elastic Scattering ◽  
Solar Neutrino ◽  
Solar Neutrinos ◽  
The Sun ◽  
Neutral Currents ◽  
Neutrino Scattering ◽  
Flavor Changing ◽  
Lepton Decays ◽  
Neutrino Experiments ◽  
Vacuum Mixing

The possibility of unconventional neutrino scattering in the Sun via flavor changing neutral currents as a possible source of the solar neutrino deficit is investigated. If the effect is really significant, a resonant process will occur. Taking into account the neutrino deficit reported by the solar neutrino experiments (Kamiokande II, SAGE Gallex), one finds Δ2m21 = (0.6–1.4) × 10−5 eV 2 with no vacuum mixing and 0.16 ≤ fex ≤ 0.34 where fex is the lepton violating coupling. Our understanding of the neutrino phenomenon in the Sun may be improved through accuracy improvements in experiments measuring νee− elastic scattering or others searching for exotic lepton decays.

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