111 citations · 766 across the 23 of their papers we have counts for
21 papers · 1 filter
Accounting for the Heisenberg and Pauli principles in the kinetic approach to neutrino oscillations
A. Kartavtsev
While oscillations of solar neutrinos are usually studied using the single-particle quantum-mechanical approach, flavor conversions of supernovae neutrinos are typically analyzed u…
Helicity oscillations of Dirac and Majorana neutrinos
Alexandra Dobrynina, Alexander Kartavtsev, Georg Raffelt
The helicity of a Dirac neutrino with mass evolves under the influence of a -field because it has a magnetic dipole moment proportional to . Moreover, it was recently sho…
Lepton asymmetry from mixing and oscillations
Alexander Kartavtsev, Peter Millington, Hendrik Vogel
We show how the two physically-distinct sources of CP-asymmetry relevant to scenarios of leptogenesis: (i) resonant mixing and (ii) oscillations between different flavours can be u…
Neutrino propagation in media: Flavor-, helicity-, and pair correlations
A. Kartavtsev, G. Raffelt, H. Vogel
Neutrinos propagating in media (matter and electromagnetic fields) undergo flavor and helicity oscillations, where helicity transitions are instigated both by electromagnetic field…
Wave functionals of free real and complex scalar fields on a 1+1 dimensional lattice
Alexander Kartavtsev
We obtain wave functionals of free real and complex scalar fields on a 1+1 dimensional lattice by explicitly calculating the path integral for transition from one field configurati…
Relating quantum mechanics and kinetics of neutrino oscillations
Alexander Kartavtsev
Simultaneous treatment of neutrino oscillations and collisions in astrophysical environments requires the use of (quantum) kinetic equations. Despite major advances in the field of…
Goldstone theorem revisited
Alexander Kartavtsev
According to the Goldstone theorem a scalar theory with a spontaneously broken global symmetry contains strictly massless states. In this letter we identify a loophole in the curre…
Leptogenesis in crossing and runaway regimes
A. Hohenegger, A. Kartavtsev
We study the impact of effective thermal masses and widths on resonant leptogenesis. We identify two distinct possibilities which we refer to as crossing and runaway regimes. In th…
Systematic approach to Delta L=1 processes in thermal leptogenesis
T. Frossard, A. Kartavtsev, D. Mitrouskas
In this work we study the contribution to leptogenesis from Delta L=1 decay and scattering processes mediated by the Higgs with quarks in the initial and final states using the for…
Improving Electro-Weak Fits with TeV-scale Sterile Neutrinos
Evgeny Akhmedov, Alexander Kartavtsev, Manfred Lindner +2
We study the impact of TeV-scale sterile neutrinos on electro-weak precision observables and lepton number and flavour violating decays in the framework of a type-I see-saw extensi…
Systematic approach to thermal leptogenesis
T. Frossard, M. Garny, A. Hohenegger +2
In this work we study thermal leptogenesis using non-equilibrium quantum field theory. Starting from fundamental equations for correlators of the quantum fields we describe the ste…
Leptogenesis in models with keV sterile neutrino dark matter
F. Bezrukov, A. Kartavtsev, M. Lindner
We analyze leptogenesis in gauge extensions of the Standard Model with keV sterile neutrino dark matter. We find that both the observed dark matter abundance and the correct baryon…
Leptogenesis from first principles in the resonant regime
Mathias Garny, Alexander Kartavtsev, Andreas Hohenegger
The lepton asymmetry generated by the out-of-equilibrium decays of heavy Majorana neutrinos with a quasi-degenerate mass spectrum is resonantly enhanced. In this work, we study thi…
A remark on the Koide relation for quarks
A. Kartavtsev
The charged lepton masses obey to high precision the so-called Koide relation. We propose a generalization of this relation to quarks. It includes up and down quarks of the three g…
Medium corrections to the CP-violating parameter in leptogenesis
M. Garny, A. Hohenegger, A. Kartavtsev
In two recent papers, arXiv:0909.1559 and arXiv:0911.4122, it has been demonstrated that one can obtain quantum corrected Boltzmann kinetic equations for leptogenesis using a top-d…
Systematic approach to leptogenesis in nonequilibrium QFT: self-energy contribution to the CP-violating parameter
M. Garny, A. Hohenegger, A. Kartavtsev +1
In the baryogenesis via leptogenesis scenario the self-energy contribution to the CP-violating parameter plays a very important role. Here, we calculate it in a simple toy model of…
Systematic approach to leptogenesis in nonequilibrium QFT: vertex contribution to the CP-violating parameter
M. Garny, A. Hohenegger, A. Kartavtsev +1
The generation of a baryon asymmetry via leptogenesis is usually studied by means of classical kinetic equations whose applicability to processes in the hot and expanding early uni…
Baryogenesis via Leptogenesis in an inhomogeneous universe
A. Kartavtsev, D. Besak
We investigate the influence of primordial perturbations of the energy density and space--time metric on the generation of the lepton and baryon asymmetries. In the weak and strong…
Coherent pion production by neutrinos on nuclei
E. A. Paschos, A. Kartavtsev, G. J. Gounaris
The main part of coherent pion production by neutrinos on nuclei is essentially determined by PCAC, provided that the leptonic momentum transferred square Q^2 remains sufficiently…
Baryon and lepton numbers in two scenarios of leptogenesis
A. Kartavtsev
Baryon and lepton numbers of the Universe in leptogenesis with Dirac neutrino and leptogenesis with Majorana neutrino scenarios are considered. It is shown that despite quite diffe…
Coherent Neutrino-Nucleus Scattering
E. A. Paschos, A. V. Kartavtsev
We review coherent scattering of neutrinos on nuclei by coupling the weak currents to vector and axial-vector meson states. The couplings are obtained from known reactions, like $τ…