Neutrino-related questions in nuclear and astro-particle physics

Assuming basic familiarity with neutrino physics, I give a telegraphic and panoramic view of the current status and the main open challenges in the field. I also illustrate how the mechanism responsible for neutrino mass generation may shed light upon some of the current puzzles in particle physics as well as cosmology * .

Arxiv preprint physics/0503172, 2005

The review consists of two parts. In the first part the critical points in the past, present and future of neutrino physics (nuclear, particle and astroparticle) are briefly reviewed. In the second part the contributions of Yugoslav physics to the physics of the neutrino are commented upon. The review is meant as a first reading for the newcomers to the field of neutrino physics.

Springer Tracts in Modern Physics, 2000

A review of the problem of neutrino mass, mixing and oscillations is given. Possible phenomenological schemes of neutrino mixing are discussed. The most important consequences of neutrino mixing-neutrino oscillations are considered in some details. The data of atmospheric, solar and LSND experiments are discussed. The results of phenomenological analyses of the data under the assumption of the mixing of three and four massive neutrinos are shortly presented.

2016

The neutrino [1] is an elementary particle that scatters only through the weak interaction, and consequently rarely interacts in matter. Neutrinos are neutral, carry spin-1/2, and are members of the family of elementary particles called leptons. Thus they differ from the quarks of the standard model (spin-1/2 particles which participate in strong and electromagnetic interactions) and from

2003

The discovery of neutrino mass establishes the need for physics beyond the Standard Model. I summarize the status of two-and three-neutrino oscillation parameters from current solar, atmospheric, reactor and accelerator data. Future neutrinoless double beta decay experiments will probe the nature of neutrinos, as well as the absolute scale of neutrino mass, also tested by tritium beta decay spectra and cosmological observations. Sterile neutrinos do not provide a good way to account for the LSND hint, which needs further confirmation. Finally I sketch the main theoretical ideas for generating neutrino mass.

1999

Astrophysical and cosmological consequences of a standard $\nu_{\tau}$ of (15 +- 3) keV/c^{2} mass are discussed in the light of the recent results of the solar, atmospheric and LSND neutrino experiments and theoretical prejudices.

Pramana-journal of Physics, 2004

This is the report of neutrino and astroparticle physics working group at WHEPP-8. We present the discussions carried out during the workshop on selected topics in the above fields and also indicate progress made subsequently. The neutrino physics subgroup studied the possibilities of constraining neutrino masses, mixing and CPT violation in lepton sector from future experiments. Neutrino mass models in the context of Abelian horizontal symmetries, warped extra dimensions and in the presence of triplet Higgs were studied. Effect of threshold corrections on radiative magnification of mixing angles was investigated. The astroparticle physics subgroup focused on how various particle physics inputs affect the CMBR fluctuation spectrum, and on brane cosmology. This report also contains an introduction on how to use the publicly available code CMBFAST to calculate the CMBR fluctuations.

arXiv: High Energy Physics - Phenomenology, 2002

We review the role of massive neutrinos in astrophysics and cosmology, assuming that the oscillation interpretation of solar and atmospheric neutrinos is correct. In particular, we discuss cosmological mass limits, neutrino flavor oscillations in the early universe, leptogenesis, and neutrinos in core-collapse supernovae.

The European Physical Journal Plus

This paper is an introduction to neutrino astronomy, addressed to astronomers and written by astroparticle physicists. The focus is on achievements and goals in neutrino astronomy, rather than on the aspects connected to particle physics, however the particle physics concepts needed to understand the peculiar neutrino features are also introduced. The material is selected-i.e., not all achievements are reviewed-making however efforts to highlight current research issues.

Proceedings of Frontier Research in Astrophysics — PoS(FRAPWS2014), 2016

This article summarises a talk given at the 2014 Palermo workshop on Astrophysics. It covers a short review on the neutrino physics status and the potential physics opportunities of future experiments. During the last year our knowledge on the neutrino oscillation parameter sin 2 θ13 improved dramatically, and the large value opened the way to oscillation experiments sensitive to possible CP-violation. The first high-energetic neutrinos in the TeV range were detected in the IceCube experiment, while the Planck collaboration set further limits on the number of active neutrinos from cosmological constraints. Over the next years the Katrin will investigate the beta decay of Tritium to study the absolute neutrino mass scale, while new experiments will investigate the potential sterile neutrino scenario which could explain the event excess of the MiniBooNE and LSND experiment.

2008

An introduction to various topics in neutrino astrophysics is given for students with little prior exposure to this field. We explain neutrino production and propagation in stars, neutrino oscillations, and experimental searches for this effect. We also touch upon the cosmological role of neutrinos. A number of exercises is also included.

Physics of Atomic Nuclei, 2000

I discuss the implications of the latest data on solar and atmospheric neutrinos which strongly indicate the need for physics beyond the Standard Model. I review the theoretical options for reconciling these data in terms of three-neutrino oscillations. Even though not implied by the data, bi-maximal models of neutrino mixing emerge as an attractive possibility. Supersymmetry with broken R-parity provides a predictive way to incorporate it, opening the possibility of testing neutrino anomalies at high-energy collider experiments such as the LHC or at the upcoming long-baseline or neutrino factory experiments. Reconciling, in addition, the hint provided by the LSND experiment requires a fourth, light sterile neutrino. The simplest theoretical scenarios are the most symmetric ones, in which two of the four neutrinos are maximally-mixed and lie at the LSND scale, while the others are at the solar mass scale. The lightness of the sterile neutrino, the nearly maximal atmospheric neutrino mixing, and the generation of ∆m 2 ⊙ & ∆m 2 atm all follow naturally from the assumed lepton-number symmetry and its breaking. These two basic schemes can be distinguished at neutral-current-sensitive solar & atmospheric neutrino experiments such as the Sudbury Neutrino Observatory. However, underground experiments have not yet proven neutrino masses, since there is a variety of alternative mechanisms. For example, flavour changing interactions can play an important rôle in the explanation of solar and of contained atmospheric data and could be tested through effects such as µ → e + γ, µ − e conversion in nuclei, unaccompanied by neutrino-less double beta decay. Conversely, the room is still open for heavy unstable neutrinos. A short-lived ν µ might play a rôle in the explanation of the atmospheric data. Finally, in the presence of a sterile neutrino ν s , a long-lived ν τ in the MeV range could delay the time at which the matter and radiation contributions to the energy density of the Universe become equal, reducing the density fluctuations on the smaller scales, and rescuing the standard cold dark matter scenario for structure formation. In this case the light ν e , ν µ and ν s would account for the solar & atmospheric data.

1998

An introduction to various topics in neutrino astrophysics is given for students with little prior exposure to this field. We explain neutrino production and propagation in stars, neutrino oscillations, and experimental searches for this effect. We also touch upon the cosmological role of neutrinos. A number of exercises is also included.

1999

I discuss the implications of the latest data on solar and atmospheric neutrinos which strongly indicate the need for physics beyond the Standard Model. I review the theoretical options for reconciling these data in terms of three-neutrino oscillations. Even though not implied by the data, bi-maximal models of neutrino mixing emerge as an attractive possibility. Supersymmetry with broken R-parity provides a predictive way to incorporate it, opening the possibility of testing neutrino anomalies at high-energy collider experiments such as the LHC or at the upcoming long-baseline or neutrino factory experiments. Reconciling, in addition, the hint provided by the LSND experiment requires a fourth, light sterile neutrino. The simplest theoretical scenarios are the most symmetric ones, in which two of the four neutrinos are maximally-mixed and lie at the LSND scale, while the others are at the solar mass scale. The lightness of the sterile neutrino, the nearly maximal atmospheric neutrino mixing, and the generation of ∆m 2 ⊙ & ∆m 2 atm all follow naturally from the assumed lepton-number symmetry and its breaking. These two basic schemes can be distinguished at neutral-current-sensitive solar & atmospheric neutrino experiments such as the Sudbury Neutrino Observatory. However, underground experiments have not yet proven neutrino masses, since there is a variety of alternative mechanisms. For example, flavour changing interactions can play an important rôle in the explanation of solar and of contained atmospheric data and could be tested through effects such as µ → e + γ, µ − e conversion in nuclei, unaccompanied by neutrino-less double beta decay. Conversely, the room is still open for heavy unstable neutrinos. A short-lived ν µ might play a rôle in the explanation of the atmospheric data. Finally, in the presence of a sterile neutrino ν s , a long-lived ν τ in the MeV range could delay the time at which the matter and radiation contributions to the energy density of the Universe become equal, reducing the density fluctuations on the smaller scales, and rescuing the standard cold dark matter scenario for structure formation. In this case the light ν e , ν µ and ν s would account for the solar & atmospheric data.

2018

Even though the combined laboratory, astrophysical and cosmological evidence implies that neutrinos have masses, neutrinos provide only a small cosmic dark matter component. The study of solar neutrinos provides important information on nuclear processes inside the Sun as well as on matter densities. Moreover, supernova neutrinos provide sensitive probes for studying supernova explosions, neutrino properties and stellar collapse mechanisms. Neutrino-nucleus reactions at energies below 100MeV play essential roles in core-collapse supernovae, explosive and r-process nucleosynthesis, as well as observation of solar and supernova neutrinos by earthbound detectors. On the other hand, recent experimental data of high-energy extragalactic neutrinos at 1 PeV open a new window to probe non-standard neutrino properties, such as resonant effects in the oscillation probability.