相关论文: Z boson emission by a neutrino in de Sitter expand…
We present a covariant framework to compute scattering amplitudes and potentials in a de Sitter background. In this setting, we compute the potential of a graviton-mediated scattering process involving two very massive scalars at tree…
The timing data of the binary pulsar PSR1913+16, are used to establish an upper limit on the rate of continuous neutrino emission from neutron stars. Neutrino emission from each of the neutron stars of the binary system, increases the star…
We calculate neutrino emissivities from self-annihilating dark matter ($\chi$) in the dense and hot stellar interior of a (proto)neutron star. Using a model where dark matter interacts with nucleons in the stellar core through a…
Neutrino emissions from electron/positron capture on the deuteron and the nucleon-nucleon fusion processes in the surface region of a supernova core are studied. These weak processes are evaluated in the standard nuclear physics approach,…
Non-unitarity of the neutrino mixing matrix is expected in many scenarios with physics beyond the Standard Model. Motivated by the search for deviations from unitary, we study two neutrino counting observables: the neutrino-antineutrino…
The origin of highest energy cosmic rays is yet unknown. An appealing possibility is the so-called Z-burst scenario, in which a large fraction of these cosmic rays are decay products of Z bosons produced in the scattering of ultrahigh…
Arbitrarily large ground state population is a general property of any ideal bose gas when conditions of degeneracy are satisfied; it occurs at any dimension D. For $D = 1$, the condensation is diffuse, at $D = 2$ it is a sort of…
In the framework of the standard, hot big bang cosmological model the dynamics of the early evolution of the universe is controlled by the energy density of relativistic particles, among which neutrinos play an important role. In…
Position-dependent property of the neutrino produced in high-energy pion decay is studied theoretically using a wave packet formalism. It is found that the neutrino probability has a universal finite-distance correction if the pion has a…
In this letter we study the problem of scalar particle production in external electric field in de Sitter geometry. The total probability is calculated using the previously obtained result in Ref.\cite{6} for transition amplitude in…
Recently, Madsen has argued that relativistic decays of massive neutrinos into lighter fermions and bosons may lead, via thermalization, to the formation of a Bose condensate. If correct, this could generate mixed hot and cold dark matter,…
We consider the possibility that a large fraction of the ultrahigh energy cosmic rays are decay products of Z bosons which were produced in the scattering of ultrahigh energy cosmic neutrinos on cosmological relic neutrinos. We compare the…
In this paper we investigate the Bose-Einstein condensation of massive spin-1 particles in an Einstein universe. The system is considered under relativistic conditions taking into consideration the possibility of particle-antiparticle pair…
If neutrinos have a small but non-zero mass, time-of-flight effects for neutrino bursts from distant sources can yield information on the large-scale geometry of the universe, the effects being proportional to the integral over time of the…
Recently the possibility was widely discussed that a large fraction of the highest energy cosmic rays may be decay products of Z bosons which were produced in the resonant annihilation of ultrahigh energy cosmic neutrinos on cosmological…
In terms of proposed by authors general-relativistic kinetic model of baryon production in expanding primordially symmetrical hot Universe calculates distribution function of extra-massive bosons and concerned with it variables.
Motivated by the observation of tiny neutrino mass can not be explained within the framework of Standard Model (SM), we consider extra gauge extended scenarios in which tiny neutrino masses are generated through seesaw mechanism. These…
Neutrino emissivities in a neutron star are computed for the neutrino bremsstrahlung process. In the first part the electro-weak nucleon-nucleon bremsstrahlung is calculated in free space in terms of a on-shell $T$-matrix using a…
We study the diffusive transport of neutrinos in a newly born neutron star to explore its sensitivity to dense matter properties. Energy and lepton number which are trapped during the catastrophic implosion diffuse out on the time scale of…
By numerically solving the appropriate Boltzmann equations, we study the production of sterile neutrinos in models with low reheating temperatures. We take into account the production in oscillations as well as in direct decays and compute…