Solar neutrinos and solar oscillations

1994 ◽  
Vol 346 (1678) ◽  
pp. 37-49 ◽  
Keyword(s):  
Solar Neutrino ◽  
Particle Physics ◽  
Sound Speed ◽  
Solar Neutrinos ◽  
Diagnostic Information ◽  
The Sun ◽  
Solar Oscillations ◽  
Thermonuclear Reactions ◽  
Neutrino Production ◽  
Classical Models

For solar neutrino measurements to contribute directly to particle physics it is essential that we know the structure of the Sun. Only then can we be sure both of the conditions under which the neutrinos are produced and of the state of the material through which they must pass before arriving at the detectors on Earth. Solar oscillations play at least one, and possibly two important roles: firstly, as passive carriers of information about density and sound speed, they provide important diagnostic information which has been used to set quite stringent constraints on the structure of the Sun’s interior; secondly, as active participants in the dynamics of the solar core, it is not out of the question that they induce motion that influences substantially the rates of the various thermonuclear reactions that em it the neutrinos. The basic processes of seismic inference will be discussed briefly, followed by a summary of those inferences that have a bearing on neutrino production. Finally, some of the uncertainties in our understanding of the Sun’s interior will be aired, to restrain the temptation to accept too hastily the details of the simple hydrostatic classical models of the Sun.

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.

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.

scholarly journals Solar Opacities Constrained by Solar Neutrinos and Solar Oscillations

1990 ◽  
Vol 121 ◽  
pp. 61-80
Author(s):  
Arthur N. Cox
Keyword(s):  
Electric Fields ◽  
Oscillation Frequency ◽  
Convection Zone ◽  
Solar Surface ◽  
Solar Neutrinos ◽  
Photon Absorption ◽  
Solar Oscillations ◽  
Percent Reduction ◽  
Neutrino Production ◽  
Oscillation Frequencies

AbstractThis review discusses the current situation for opacities at the solar center, the solar surface, and for the few million kelvin temperatures that occur below the convection zone. The solar center conditions are important because they are crucial for the neutrino production, which continues to be predicted about 4 times that observed. The main extinction effects there are free-free photon absorption in the electric fields of the hydrogen, helium and the CNO atoms, free electron scattering of photons, and the bound-free and bound-bound absorption of photons by iron atoms with two electrons in the 1s bound level. An assumption that the iron is condensed-out below the convection zone, and the opacity in the central regions is thereby reduced, results in about a 25 percent reduction in the central opacity but only a 5 percent reduction at the base of the convection zone. Furthermore, the p-mode solar oscillations are changed with this assumption, and do not fit the observed ones as well as for standard models. A discussion of the large effective opacity reduction by weakly interacting massive particles (WIMPs or Cosmions) also results in poor agreement with observed p-mode oscillation frequencies. The much larger opacities for the solar surface layers from the Los Alamos Astrophysical Opacity Library instead of the widely used Cox and Tabor values show small improvements in oscillation frequency predictions, but the largest effect is in the discussion of p-mode stability. Solar oscillation frequencies can serve as an opacity experiment for the temperatures and densities, respectively, of a few million kelvin and between 0.1 and 10 g/cm3. Current oscillation frequency calculations indicate that possibly the Opacity Library values need an increase of typically 15 percent just at the bottom of the convection zone at 3×106K. Opacities have uncertainties at the photosphere and deeper than the convection zone ranging from 10 to 25 percent. The equation of state that supplies data for the opacity calculations fortunately has pressure uncertainties of only about 1 percent, but opacity uncertainties will always be much larger. A discussion is given about opacity experiments that the stars provide. Opacities in the envelopes of the Hyades G stars, the Cepheids, δ Scuti variables, and the β Cephei variables indicate that significantly larger opacities, possibly caused by iron lines, seem to be required.

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.

scholarly journals Brief Review of Solar Models and Solar Neutrino Experiments

1993 ◽  
Vol 137 ◽  
pp. 100-107
Author(s):  
Douglas R.O. Morrison
Keyword(s):  
Solar Neutrino ◽  
Input Data ◽  
New Physics ◽  
Solar Neutrinos ◽  
High Variability ◽  
Neutrino Masses ◽  
The Sun ◽  
Evolutionary Models ◽  
Solar Neutrino Problem ◽  
Neutrino Experiments

AbstractSolar Evolutionary Models are briefly reviewed and while the models are robust, there are uncertainties in the input data which justify rather larger errors. The 1992 experimental results from GALLEX, SAGE II and Kamiokande are shown to be consistent with calculated fluxes of solar neutrinos whereas the Chlorine results continue to be significantly low though this experiment has a problem with the high variability with time of its results in contradiction to Kamiokande. It is concluded that the evidence for a solar neutrino problem is not compelling and New Physics are not demanded. Further experiments are essential to search for neutrino masses and to study the Sun.

scholarly journals Introduction

1995 ◽  
Vol 10 ◽  
pp. 319-320
Author(s):  
W. Däppen
Keyword(s):  
Spherical Harmonics ◽  
Solar Rotation ◽  
Solar Neutrinos ◽  
The Sun ◽  
Solar Oscillations ◽  
Good Information ◽  
Solar Neutrino Problem ◽  
Oscillation Frequencies ◽  
Very High ◽  
Better Than

Since the early 1960s the surface of the Sun has been know to be in a regular pulsating motion with periods of about 5 minutes. While at the beginning various explanations were offered, only in the 1970s it was recognized that these so-called solar oscillations are manifestations of global motions of the Sun about its equilibrium. Helioseismology is the name of the branch of astrophysics that deals with deciphering these data, that cover the whole range of spherical harmonics from l = 0 (radial) to very high angular order (above l = 1000). Thanks to observational data of superb quality (each of the oscillation frequencies is measured accurately to better than one part in ten thousand), our knowledge of the Sun has leap-frogged in the last 20 years. For instance, we now know the run of temperature inside the Sun, or have good information about the internal solar rotation. In the solar neutrino problem the data from solar oscillations have become a compulsory testing stone for any model proposed to explain the discrepancy between observed and theoretically predicted solar neutrinos.

scholarly journals PARTICLE PHYSICS CONFRONTS THE SOLAR NEUTRINO PROBLEM

1992 ◽  
Vol 07 (22) ◽  
pp. 5387-5459 ◽  
Author(s):  
PALASH B. PAL
Keyword(s):  
Magnetic Moment ◽  
Time Variation ◽  
Solar Neutrino ◽  
Particle Physics ◽  
Magnetic Moments ◽  
Neutrino Flux ◽  
The Sun ◽  
Solar Neutrino Problem ◽  
The Earth ◽  
Near Future

This review has four parts. In Part I, we describe the reactions that produce neutrinos in the sun and the expected flux of those neutrinos on the earth. We then discuss the detection of these neutrinos, and how the results obtained differ from the theoretical expectations, leading to what is known as the solar neutrino problem. In Part II, we show how neutrino oscillations can provide a solution to the solar neutrino problem. This includes vacuum oscillations, as well as matter enhanced oscillations. In Part III, we discuss the possibility of time variation of the neutrino flux and how a magnetic moment of the neutrino can explain the phenomenon. We also discuss particle physics models which can give rise to the required values of magnetic moments. In Part IV, we present some concluding remarks and outlook for the near future.

scholarly journals The Internal Structure of the Sun and Solar Type Stars

1976 ◽  
Vol 71 ◽  
pp. 453-466 ◽  
Author(s):  
IAN W. Roxburgh
Keyword(s):  
Internal Structure ◽  
Solar Neutrino ◽  
Convective Zone ◽  
The Sun ◽  
Solar Oscillations ◽  
Solar Constant ◽  
Solar Neutrino Problem ◽  
Solar Type

Our understanding of the internal structure of the Sun and solar type stars has been undermined by recent observations. In this paper we consider some of the puzzles and possible resolutions; the solar neutrino problem, lithium and beryllium abundance, rotation and calcium emission, variation of the solar constant, solar oscillations and the solar convective zone. The picture that emerges is one of confusion, and so it should be since we have no idea of what is going on inside the Sun and a fortiori of what is going on inside other stars.

scholarly journals Excitation of the Solar Oscillations by Objects Consisting of y-Matter

1983 ◽  
Vol 66 ◽  
pp. 383-385
Author(s):  
S. I. Blinnikov ◽  
M. Yu. Khlopov
Keyword(s):  
Particle Physics ◽  
The Sun ◽  
Solar Oscillations ◽  
Ordinary Matter ◽  
Modern Development

AbstractModern development of particle physics makes it probable that new, still undiscovered, particles exist interacting with the ordinary matter by means of gravitation only. Okun suggested to call such particles the y-particles and to call the matter consisting of them the y-matter. We show that planet-like object orbiting inside the Sun and consisting of y-matter may explain 160 min nonradial solar oscillations.

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