scholarly journals Measurement of the Solar Neutrino Energy Spectrum Using Neutrino-Electron Scattering

1999 ◽  
Vol 82 (12) ◽  
pp. 2430-2434 ◽  
Author(s):  
Y. Fukuda ◽  
T. Hayakawa ◽  
E. Ichihara ◽  
K. Inoue ◽  
K. Ishihara ◽  
...  
1998 ◽  
Vol 436 (3-4) ◽  
pp. 243-250 ◽  
Author(s):  
John N. Bahcall ◽  
Plamen I. Krastev

2019 ◽  
Vol 627 ◽  
pp. A39 ◽  
Author(s):  
Tuomo Salmi ◽  
Valery F. Suleimanov ◽  
Juri Poutanen

The aim of this work is to study the possible effects and biases on the radius constraints for rotation-powered millisecond pulsars when using Thomson approximation to describe electron scattering in the atmosphere models, instead of using exact formulation for Compton scattering. We compare the differences between the two models in the energy spectrum and angular distribution of the emitted radiation. We also analyse a self-generated, synthetic, phase-resolved energy spectrum, based on Compton atmosphere and the most X-ray luminous, rotation-powered millisecond pulsars observed by the Neutron star Interior Composition ExploreR (NICER). We derive constraints for the neutron star parameters using both the Compton and Thomson models. The results show that the method works by reproducing the correct parameters with the Compton model. However, biases are found in both the size and the temperature of the emitting hotspot, when using the Thomson model. The constraints on the radius are still not significantly changed, and therefore the Thomson model seems to be adequate if we are interested only in the radius measurements using NICER.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Ankush ◽  
Rishu Verma ◽  
Gazal Sharma ◽  
B. C. Chauhan

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.


1968 ◽  
Vol 46 (10) ◽  
pp. S491-S493
Author(s):  
V. A. Dergachov ◽  
G. E. Kocharov

We consider the possibilities of investigating the internal structure of the sun using the energy spectrum and the intensity of its neutrino radiation. The experimental determination of the solar neutrino flux will permit us to obtain values for some parameters which are important for the theory of the internal structure of the sun (e.g. the time for evolution and the concentrations of various isotopes in the interior). It is also possible to decide whether or not the gravitational constant varies with time.


2005 ◽  
Vol 20 (14) ◽  
pp. 3055-3058
Author(s):  
◽  
RICHARD GRAN

The K2K long-baseline neutrino oscillation experiment has analyzed all data including the period ending in February 2004. The total data sample is from 8.9 × 1019 protons on target. We observe 108 events at the far detector, Super-Kamiokande, when 150.9 + 11.6 - 10.0 were expected. Further, we observe a distortion of the neutrino energy spectrum which is consistent with νμ to ντ oscillation. The probability that we would observe these results if there is no neutrino oscillation is 0.011%, a 3.9 σ significance.


2005 ◽  
Vol 20 (14) ◽  
pp. 3110-3112 ◽  
Author(s):  
◽  
D. W. Liu

Existence of non-zero neutrino magnetic moment would mean new physics beyond the standard model. A search for the neutrino magnetic moment has been conducted using the high statistic solar neutrino data from Super-Kamiokande-I. This is done by looking for the distortion to the observed energy spectrum of recoil electrons. A non-zero neutrino magnetic moment would cause an increase of event rates at lower energies. The search found no clear signal of neutrino magnetic moment. A limit on the neutrino magnetic moment has been obtained at 3.6 × 10-10μB at 90% C.L. by fitting to the Super-Kamiokande day-night spectra. The effects of neutrino oscillation have been included in the analysis. Including results from other neutrino experiments limiting the oscillation region, a limit of 1.1 × 10-10μB at 90% C.L. was obtained.


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