Interaction of the single-particle and collective degrees of freedom in non-magic nuclei: the role of phonon tadpole terms

A method of a consistent consideration of the phonon contributions to mass and gap operators in non-magic nuclei is developed in the so-called g^2 approximation, where g is the low-lying phonon creation amplitude. It includes simultaneous accounting for both the usual non-local terms and the phonon tadpole ones. The relations which allow the tadpoles to be calculated without any new parameters are derived. As an application of the results, the role of the phonon tadpoles in the single-particle strength distribution and in the single-particle energies and gap values has been considered. Relation to the problem of the surface nature of pairing is discussed.Comment: 22 pages, 7 figure

Neutrino Cooling of Neutron Stars. Medium effects

This review demonstrates that neutrino emission from dense hadronic component in neutron stars is subject of strong modifications due to collective effects in the nuclear matter. With the most important in-medium processes incorporated in the cooling code an overall agreement with available soft X ray data can be easily achieved. With these findings so called "standard" and "non-standard" cooling scenarios are replaced by one general "nuclear medium cooling scenario" which relates slow and rapid neutron star coolings to the star masses (interior densities). In-medium effects take important part also at early hot stage of neutron star evolution decreasing the neutrino opacity for less massive and increasing for more massive neutron stars. A formalism for calculation of neutrino radiation from nuclear matter is presented that treats on equal footing one-nucleon and multiple-nucleon processes as well as reactions with resonance bosons and condensates. Cooling history of neutron stars with quark cores is also discussed.Comment: To be published in "Physics of Neutron Star Interiors", Eds. D. Blaschke, N.K. Glendenning, A. Sedrakian, Springer, Heidelberg (2001

TeV gamma-ray emission from binaries: 2129+47XR and Cygnus X-3

International audienceThe new galactic gamma-source (neutron star) 2129+47XR is detected at energy >0.8 TeV with flux (0.19±0.09)x10^-12 cm^2s^-1 and indices of the integral spectra are kγ=−1.12±0.06, kON=−1.28±0.07 and kOff=−1.73±0.07. The results of ten-year observation of galactic source Cygnus X-3 by SHALON mirror Cherenkov telescope are discussed. The gamma -quantum spectra and images of the sources are presented. The Cygnus X-3 binary, known for more than 20 years as a source with variable intensity have been regularly observed since a 1995. The the increase of gamma-quantum flux was observed in 1997 and 2003 years

Very high energy gamma-quanta 1–65 TeV from the Cygnus X-3 binary

The results of almost ten-year observation of Cygnus X-3 point source by SHALON mirror Cherenkov telescope are presented. The galactic source Cygnus X-3, known for more than 10 years as a source with variable intensity 0.8TeV ) = (6.8 ± 0.7) • 10−13cm−2s−1. The flux in 2003 was (1.79 ± 0.33) • 10−12cm−2s−1. Earlier, in 1997, an increase in the flux was also observed (1.2 ± 0.5) • 10−12cm−2s−1. The limits on gamma-rays from Cygnus X-3, the source that results stimulated the construction of many new detectors are presented. These upper limits and SHALON fluxes are now more than a factor 100 less than the fluxes originally reported