相关论文: Positronium oscillations to Mirror World revisited
We report on a direct search for a three-body decay of the orthopositronium into a photon and two penetrating particles, o-Ps -> gamma + X1 + X2. The existence of this decay could explain the discrepancy between the measured and the…
We address a method of limiting neutron-mirror neutron mixing ($\epsilon_{nn'}$) by analyzing its effect on neutron star (NS) heating. This method employs observational bounds on the surface temperature of NSs to constrain $\epsilon_{nn'}$.…
We briefly review the concept of a parallel `mirror' world which has the same particle physics as the observable world and couples to the latter by gravity and perhaps other very weak forces. The nucleosynthesis bounds demand that the…
We briefly review the concept of a parallel `mirror' world which has the same particle physics as the observable world and couples to the latter by gravity and perhaps other very weak forces. The nucleosynthesis bounds demand that the…
We show that a consequence of isospin symmetry, recently discovered in mirror conjugated one-nucleon decays, can be extended to mirror-conjugated $\alpha$-particles decays, both virtual and real. For virtual $\alpha$-decays of bound mirror…
Positronium decay rates are computed at the one-loop level, using convolution-type factorized amplitudes. The dynamics of this factorization is probed with dispersion relations, showing that unallowed approximations are usually made, and…
We comment on a recently discussed possibility of oscillations between neutrons and degenerate mirror neutrons in the context of mirror models for particles and forces. It has been noted by Bento and Berezhiani that if these oscillations…
The present status of theoretical and experimental investigations of the decay rate of a positronium is considered. The increasing interest to this problem has been caused by the disagreement of the calculated value of $\Gamma_3 (o-Ps)$ and…
The manuscript by Berezhiani (arXiv:1812.11089) proposes a model that has the neutron decaying into a mirror neutron with a branching fraction of 1%, alleviating the tension between neutron lifetime measurements in beam vs bottle…
Interference between different energy eigenstates in a quantum system results in an oscillation with a frequency which is proportional to the difference in energy between the states. Such an oscillation is observable in polarized…
In laser gravitational waves detectors optical loss restricts sensitivity. We discuss polarization scattering as one more possible mechanism of optical losses. Circulated inside interferometer light is polarized and after reflection its…
We construct the three dimensional mirror theory of SO(2k) and SO(2k+1) gauge groups by using O3-planes. An essential ingredient in constructing the mirror is the splitting of a physical brane (NS-brane or D5-brane) on O3-planes. In…
The decay of the para-positronium into two photons is studied in the framework of a composite Quantum Field Theoretical approach. This amounts to the evaluation of the electron-positron dressing together with the Weinberg compositeness…
In this work we study a mirror model with inverse seesaw neutrino masses in which symmetry breaking scales are fixed from bounds in the neutrino sector. The Higgs sector of the model has two doublets and neutral singlets. The mirror model…
We estimate the most important corrections to the branching ratios for the invisible decays of quarkonium states, arising from possible extensions of the standard model. Among the possibilities considered are the presence of extra Z-bosons,…
We study photocurrent of exciton polaritons in inversion broken systems. We use an effective Hamiltonian and Green's function approaches to deduce the formula for polariton photocurrent. The obtained formula shows the polariton photocurrent…
Positronium annihilation amplitudes that are computed by assuming a factorization approximation with on-shell intermediate leptons do not exhibit good analytical behaviour. Using dispersion techniques, we find new contributions that…
We discuss the phenomenological implications of the neutron (n) oscillation into the mirror neutron (n'), a hypothetical particle exactly degenerate in mass with the neutron but sterile to normal matter. We show that the present…
Hyperfine spectroscopy of positronium formed in the presence of a static magnetic field is considered. Generalising the situation hitherto developed in the literature, the magnetic field is not assumed to be parallel to the momentum of…
Positronium atoms (Ps) are widely used as a probe to characterize voids or vacancies in non-metallic materials, where Ps annihilation lifetime is strongly modified by pickoff, depending on the size of the trapping cavity and on the…