Multiple physical elements to determine the gravitational-wave signatures of core-collapse supernovae

We review recent progress in the theoretical predictions of gravitational waves (GWs) of core-collapse supernovae. Following a brief summary of the methods in the numerical modeling, we summarize multiple physical elements that determine the GW signatures which have been considered to be important in extracting the information of the long-veiled explosion mechanism from the observation of the GWs. We conclude with a summary of the most urgent tasks to make the dream come true.     

Neutrinos,axions and conformal symmetry

We demonstrate that radiative breaking of conformal symmetry (and simultaneously electroweak symmetry) in the standard model with right-chiral neutrinos and a minimally enlarged scalar sector induces spontaneous breaking of lepton number symmetry, which naturally gives rise to an axion-like particle with some unusual features. The couplings of this ‘axion’ to standard model particles, in particular photons and gluons, are entirely determined (and computable) via the conformal anomaly, and their smallness turns out to be directly related to the smallness of the masses of the light neutrinos.     

Nuclear Responses for Neutrinos and Mo Observatory of Neutrinos

Nuclear responses for neutrinos and neutrino studies in Mo nuclei are briefly reported. Nuclear spin-isospin responses for neutrinos are crucial for neutrino studies in nuclei. Spin-isospin responses for solar neutrinos, supernova neutrinos and neutrinos involved in double-beta decays are discussed. It is of great interest to study neutrino masses and low energy solar neutrinos. It is shown that it is possible to carry out with ¹⁰⁰Mo both spectroscopic studies of double-beta decays with the sensitivity of the order of m 0.03eV and real-time exclusive studies of the low energy solar neutrinos.     

Neutrinos, their partners, and unification

Efforts to unify group-theoretically the standard-model gauge interactions with the generation structure of fermions and their mirror partners should be accompanied by the unification of the corresponding gauge couplings. In this paper, the possibility of such a unification is studied, and conclusions on possible symmetry-breaking channels and scales as well as on the fermion content of the theory are drawn. The breaking of some of the symmetries allows various Majorana masses for neutrinos and their mirror partners, so these are studied next. Implications for neutrino mixings and mass hierarchies in connection with recent experimental results, as well as for electroweak precision tests, are then discussed. Received: 11 May 1999 / Published online: 28 September 1999     

Singletons and Neutrinos

The first half is a rapid review of 30 years of work on physics in anti-de Sitter space, with heavy emphasis on singletons. Principal topics are the kinematical basis for regarding singletons as the constituents of massless particles, and the effect of (negative) curvature in the infrared domain. Ideas that lead to an alternative to Big Bang cosmology are merely sketched. The second half presents new ideas inspired by experimental results on neutrino oscillations. Since leptons are massless before symmetry breaking it is natural to view them as composite states consisting of one Bose singleton (the Rac) and one Fermi singleton (the Di). This gives rise to a particular formulation of the phenomenology of electroweak physics, and strong suggestions for an expansion of the Standard Model. An expansion of the Higgs sector seems inevitable, and flavor changing symmetry, complete with a new set of heavy vector mesons, is a very attractive possibility.     

On the origin of the heavy nuclei

Nuclear formation processes and the conditions of their physical environment are investigated on the basis of the empirical abundance distribution of the nuclei. Three different abundance components of the heavy nuclei require very different physical conditions for their formation but appear genetically correlated. The component formed in a slow neutron capture chain indicates the pre-existence of the neutron-rich component, and of an iron abundance peak considerably smaller than found in the solar system. The neutron-rich and the proton-rich components seem to have been formed byβ-decay from progenitors which were produced at conditions of matter densityρ≈2×10¹⁰g/cm³ and of temperaturekT≈500keV, respectively.     

Neutrinos and the Weak Interactions

We show that neutrinos and electrons share the same theoretical structure and satisfy parallel relations particularly of the Large Number kind. We then argue that the neutrino can be described as a “cold” electron in a sense that is detailed, and thereby the weak interactions are indeed a weak form of electromagnetism.     

Dirac Neutrinos in the Seesaw Mechanism: Violation of the Number of Dirac Neutrinos

Physics of Atomic Nuclei - The seesaw mechanism, which explains the smallness of the neutrino masses by the involvement of high Majorana masses, leads to particles of the same Majorana nature and...     

Photo-protons from heavy elements

Preliminary values of the cross sections for the emission of high-energy photo-protons from targets of copper, silver and gold irradiated with 400 MeV bremsstrahlung are reported.     

Nucleosynthesis of heavy elements in the r-process

The current state of the problem of heavy-element production in the astrophysical r-process is surveyed. The nucleosynthesis process in the neutron-star-merger scenario, within which the problem of free-neutron source is solved, is considered most comprehensively. A model that describes well the observed abundances of heavy elements is examined. Theoretical approaches used in this model to calculate a number of features of short-lived neutron-rich nuclei are described. The contributions of various fission processes to the production of heavy elements are assessed. The possibility of superheavy-element production in the r-process is demonstrated.     

Neutrinos and explosive nucleosynthesis

Core-collapse supernovae produce a hot protoneutron star that cools emitting huge amounts of neutrinos of all flavors. The interaction of these neutrinos with the outer layers of the protoneutron star produces an outflow of matter whose composition is determined by the luminosities and energies of the emitted neutrinos and antineutrinos. The presence of light nuclei like deuterons and tritons can have a big impact in the average energies of the emitted antineutrinos and consequently in the neutron-richness of the ejected matter. Recent hydrodynamical models show that the ejected matter is in fact proton-rich and constitutes the site of the νp-process where antineutrino absorption reactions catalyze the nucleosynthesis of nuclei with A>64.     

Production and study of new heavy elements

The last results of search for spontaneously fissioning nuclei in the Allende meteorite, investigations of the mechanisms and productions of light Cf isotopes and 110 element using different dielectric detector types and methods of their development have presented.     

SNO and supernovae

The Sudbury Neutrino Observatory (SNO) has unique capabilities as a supernova detector. In the event of a galactic supernova there are opportunities, with the data that SNO would collect, to constrain certain intrinsic neutrino properties significantly, to test details of the various models of supernova dynamics, and to provide prompt notification to the astronomical community through the Supernova Early Warning System (SNEWS). This paper consists of a discussion of these opportunities illustrated by some preliminary Monte Carlo results.     

On the widths ofK levels of heavy elements

The ratios of the widths ofK levels of heavy elements with atomic number 70 to 92 have been calculated with relativistic wave functions, retardation, screening and field theoretical corrections to relativistic energy. The calculated values have been compared with the available observed data and good agreement has been obtained.     

Neutrinos in the time of Higgs

In this paper, the recent progress in the determination of neutrino oscillation parameters and future prospects have been discussed. The tiny neutrino masses as inferred from oscillation data and cosmology cannot be explained naturally by the Higgs mechanism and warrant some new physics. The latter can be connected to the Majorana nature of the neutrinos which can be probed by neutrinoless double beta decay (0 νββ). The paper also summarizes the latest experimental results in 0 νββ and discusses some implications for the left–right symmetric model which could be a plausible new physics scenario for the generation of neutrino masses.     

Neutrinos from earth and heavens

We present here the session devoted to Neutrinos from Earth and Heavens. It covers in fact three topics : double beta decay, high energy neutrino astronomy and the role of neutrinos in cosmology.