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S. M. Bilenky

Publications and source records attributed to S. M. Bilenky.

136 records · Page 8Linked to original sources
arXiv1994

A Model Independent Approach to Future Solar Neutrino Experiments

We discuss here what model independent information about properties of neutrinos and of the sun can be obtained from future solar neutrino experiments (SNO, Super-Kamiokande). It is shown that in the general case of transitions of solar $ν_e$'s into $ν_μ$ and/or $ν_τ$ the initial $^8\mathrm{B}$ neutrino flux can be measured by the observation of NC events. From the CC measurements the $ν_e$ survival probability can be determined as a function of neutrino energy. The general case of transitions of solar $ν_e$'s into active as well as sterile neutrinos is considered. A number of relations between measurable quantities the test of which will allow to answer the question whether there are sterile neutrinos in the solar neutrino flux on the earth are derived. Transitions of solar $ν_e$'s into active and sterile states due to neutrino mixing and Dirac magnetic moments or into active left-handed neutrinos and active right-handed antineutrinos due to neutrino mixing and Majorana transition magnetic moments are also considered. It is shown that future solar neutrino experiments will allow to distinguish between the cases of Dirac and Majorana magnetic moments.

hep-ph↗
arXiv1994

Neutrino Magnetic Moment and the Process $νe \rightarrow νe γ$

The contribution of a neutrino magnetic moment $μ_ν$ to the cross section of the process $νe^{-}\rightarrow νe^{-} γ$ has been calculated and compared with the Standard Electroweak one. The radiative process allows to reach low enough values of $Q^2$ without the need to operate at very small energies of recoil electrons. Regions in the phase space which are more favourable to set bounds on $μ_ν$ are suggested.

hep-ph↗
arXiv1993

Future Solar Neutrino Experiments and Neutrino Spin-Flavour Precession

The main features of the observables in the SNO and Super-Kamiokande solar neutrino experiments in the case of neutrino spin and/or spin-flavour precession in the magnetic field of the sun are discussed. It is shown without any model dependent assumption that in the case of Majorana transition magnetic moments the NC event rate $N^{\mathrm{NC}}$ does not depend on time and a measurement of $N^{\mathrm{NC}}$ will allow to determine the initial flux of $^8\mathrm{B}$ neutrinos with a theoretical uncertainty of a few \%. In the case of Dirac magnetic moments the NC event rate will depend on time and we obtain a model independent lower bound for the transition probability of initial $ν_e$'s into right-handed sterile neutrinos.

hep-ph↗
arXiv1993

Neutrino Mixing and Future Solar Neutrino Experiments

Possibilities of a model independent treatment of the data from future real-time solar neutrino experiments (SNO, Super-Kamiokande and others) are discussed. It is shown that in the general case of transitions of the initial solar $ν_e$'s into $ν_μ$ and/or $ν_τ$ the total flux of initial 8B neutrinos and the $ν_e$ survival probability can be determined directly from the experimental data. Lower bounds for the probability of transition of solar $ν_e$'s into all possible sterile states are derived and expressed through measurable quantities.

hep-ph↗
arXiv1993

Sterile Neutrinos and Future Solar Neutrino Experiments

It is shown that future solar neutrino experiments (SNO, Super-Kamiokande and others), in which high energy neutrinos will be detected (mostly from 8B decay), may allow to answer in a model independent way the question whether there are transitions of solar $ν_e$'s into sterile states. No assumptions about the initial flux of 8B neutrinos are done. Lower bounds for the probability of transition of solar $ν_e$'s into all possible sterile states are derived and expressed through measurable quantities.

hep-ph↗
arXiv1993

On the Proton Form Factors in the Time-Like Region

The process $ \bar{p} p \rightarrow e^{-} e^{+} $ is considered in the general case of polarized initial particles. A relation between the difference of the phases of the electromagnetic form factors $G_M$ and $G_E$ in the time-like region and measurable asymmetries is derived. It is shown that the moduli of the form factors can be determined from measurements of the total unpolarized cross section and of the integral asymmetry for longitudinally polarized (or transversely polarized) $\bar{p}$ and $p$. The behaviour of the proton form factors at high $q^2$ in the time-like region is also discussed. From the Phragmén-Lindelöf's theorem it follows that the asymptotical behaviour of the form factors in the space-like and time-like regions must be the same. An analysis of experimental data in both regions based on perturbative QCD is presented.

hep-ph↗
arXiv1993

Towards a Model Independent Treatment of Future Solar Neutrino Data

Possibilities of a model independent treatment of the data from future real-time solar neutrino experiments (SNO, Super-Kamiokande and others) are discussed. It is shown that in the general case of transitions of the initial solar $ν_e$'s into $ν_μ$ and/or $ν_τ$ the total flux of initial $^8\mathrm{B}$ neutrinos and the $ν_e$ survival probability can be determined directly from the experimental data. Relations between observable quantities are derived, which, if confronted with the experimental data, would allow to reveal the presence of sterile neutrinos in the solar neutrino flux on the earth. Neutrino transitions due to spin and resonant spin-flavour precession in the magnetic field of the sun are shortly discussed.

hep-ph↗
arXiv1992

Neutrino Mixing

In the first part of these lectures the neutrino mixing hypothesis will be considered in detail. We will discuss the possible schemes of neutrino mixing and present the data of the recent experiments searching for effects due to nonvanishing neutrino masses and mixing angles.In the second part of these lectures the physics of solar neutrinos will be considered.We will discuss the MSW resonance solution of the equation of evolution of a neutrino in matter and present data of solar neutrino experiments.

hep-ph↗
arXiv1992

See-Saw Type Mixing and $ ν_μ \to ν_τ $ Oscillations

We consider $ ν_μ \to ν_τ $ oscillations under the assumption that there is a see-saw type mixing of the light neutrinos with heavy Majorana particles. It is shown that the existing data, including the recent LEP data, do not exclude the possibility that the additional terms in the transition probability due to this mixing could be of the same order of magnitude as the usual oscillating term. Detail investigations of $ ν_μ \to ν_τ $ transitions in future CERN and Fermilab experiments could allow to get informations not only about the neutrino masses and mixing but also about the mixing of neutrinos with heavy Majorana particles.

hep-ph↗