arXiv subjects
Publications and source records attributed to B. O. Kerbikov.
The neutron to mirror neutron transitions in neutron stars would possibly result in significant effects. In this work we show that collisional decoherence entails exponential relaxation in lieu of oscillations. Decoherence is a great many orders of magnitude faster than the expected oscillations. The admixture of mirror neutrons at all times remains very small with respect to ordinary neutrons component.
Positronium spectrum and lifetimes are known with high precision. The situation is different for positronium moving across a magnetic field. The total momentum does not commute with the Hamiltonian and is replaced by the conserved pseudomomentum. The internal dynamics is not separated from the motion of the system as a whole. The Coulomb potential well is distorted and a wide outer potential well is created. We analytically determine the energy spectrum for a broad range of magnetic field and pseudomomentum values. The ground state energy is compared with the result obtained by solving the Bethe-Salpeter equation. The gauge independence of the pseudomomentum expectation value is established. On the pseudomomentum-magnetic field plane we locate the region in which the ground state resides in the outer well. The results may play a role in the suppression of pulsars' radio emission (polar cap problem).
Increasingly precise astrophysical observations of the last decade in combination with intense theoretical studies allow for drawing a conclusion about potential Quark Matter presence in Neutron Stars interiors. Quark Matter may form the Neutron Star inner core or be immersed in the form of bubbles, or droplets. We consider the second scenario and demonstrate that even a small fraction of quark matter bubbles can lead to a high nonlinearity of the sound wave. Below the bubble resonant frequency the sound speed is lower than the ambient value. At the resonance it sharply grows. The peak is constrained by viscous dissipation. Above the resonance the speed exceeds the pure neutron star matter value. The dispersion equation for the bubbly neutron star compressibility is derived.
The possibility of neutron swapping between the ordinary and mirror sectors is today a subject of a great many theoretical and experimental studies. In this paper, we investigate the neutron-mirror neutron transitions in different environments from vacuum to neutron star. Our approach is based on the density matrix formalism, Lindblad and Bloch equations and the implication of the seesaw mechanism to the Hamiltonian diagonalization.
We compute the soft real photon emission rate from the QCD matter in the vicinity of the critical line at moderate density and the temperature approaching the critical one from above. The obtained production rate exhibits a steep rise close to $T_c$ due to the formation of the slow fluctuation mode.
The transition of QGP from fluid-dynamical regime to freeze-out is accompanied by the onset of instabilities. In the present paper we investigate the impact of the magnetic field on the Rayleigh instability. We show that extremely strong field generated in peripheral heavy ion collisions has an insignificant influence on the Rayleigh bubble dynamics. Magnetic "friction" turns out to be much weaker than the viscous one.
We show that at finite density pressure-pressure and current-current correlators exhibit divergences at $T_c$ owing to the fluctuations of the diquark field. Specifically, this leads to a significant excess of the soft photon production rate near $T_c$.
We examine the behavior of sound attenuation and bulk viscosity near the 2'nd order QCD phase transition at finite density. A dynamical model is presented describing the coupled evolution of sound mode and a slow mode of fluctuations.
We propose a new approach based on the Lindblad and Bloch equations for the density matrix to the problem of a neutron into an antineutron conversion. We consider three strategies to search for conversion: experiments with trapped neutrons, oscillations in nuclei, and quasi-free propagation. We draw a distinction between $n\bar{n}$ oscillations in which the probability that a neutron transforms into an antineutron depends on time according to the sine-square law and the non-oscillatory overdamped $n\bar{n}$ conversion. We show that in all three cases decoherence due to the interaction with the environment leads to non-oscillatory evolution.
The mass and the wave function of doubly charmed $Ξ^{++}_{cc}$ (ccu) baryon are evaluated using Green Function Monte Carlo method to solve the three-body problem with Cornell potential. The mass of $Ξ^{++}_{cc}$ with spin $1/2$ is in a good agreement with the LHCb value. Simulation of the wave function by random walks resulted in a configuration of the quark-diquark type. The radius of $Ξ^{++}_{cc}$ is much larger than the size needed for a large isospin splitting. The prediction for the $Ω_{cc}$ mass is presented.
Spectra of $q \bar{q}$ hadrons are investigated in the framework of the Hamiltonian obtained from the relativistic path integral in external homogeneous magnetic field. The spectra of all 12 spin-isospin s-wave states, generated by $π$ and $ρ$ mesons with different spin projections, are studied both analytically and numerically on the lattice as functions of (magnetic field) $eB$. Results are in agreement and demonstrate three types of behavior, with characteristic splittings predicted by the theory.
Spectra of $q \bar q$ mesons are investigated in the framework of the Hamiltonian obtained from the relativistic path integral in external homogeneous magnetic field. The spectra of all 12 spin-isospin s-wave states generated by $π$- and $ρ$-mesons with different spin projections, are studied analytically as functions of the field strength. Three types of behavior with characteristic splittings are found. The results are in agreement with recent lattice calculations.
The lecture presents an overview of the quest for the new physics in low energy neutron phenomena. In addition to the traditional topics the quantum damping of $n$ $\bar{n}$ oscillations is discussed.
We investigate the sound absorption in quark matter due to the interaction of the sound wave with the precritical fluctuations of the diquark-pair field above $T_c$. The soft collective mode of the pair field is derived using the time dependent Ginzburg-Landau functional with random Langevin forces. The strong absorption near the phase transition line may be viewed as a manifestation of the Mandelshtam-Leontovich slow relaxation time theory.
An analysis is made of the role played by the gas environment in neutron-mirror-neutron and neutron-antineutron oscillations. In the first process the interaction with the ambient medium induces a refraction energy shift which plays the role of an extra magnetic field. In the second process antineutron annihilation in practice might lead to strong decoherence, which should be taken into account in experiments with free neutrons looking for the neutron to antineutron transformation.
We investigate the electrical conductivity(EC) of dense quark matter in the vicinity of the phase transition line. We show that: (i) At high density the Drude EC does not depend on the magnetic field up to $eB \sim 10^{19} \ G$. (ii) In the precritical region the fluctuation EC (paraconductivity) dominates over the Drude one.
We briefly review the recent studies of the behavior of composite systems in magnetic field. The hydrogen atom is chosen to demonstrate the new results which may be experimentally tested. Possible applications to physics of antihydrogen are mentioned.
Relativistic world-line Hamiltonian for strongly interacting 3q systems in magnetic field is derived from the path integral for the corresponding Green's function. The neutral baryon Hamiltonian in magnetic field obeys the pseudomomentum conservation and allows a factorization of the c.m. and internal motion. The resulting expression for the baryon mass in magnetic field is written explicitly with the account of hyperfine, OPE and OGE (color Coulomb) interaction. The neutron mass is fast decreasing with magnetic field, losing 1/2 of its value at eB~0.25 GeV^2 and is nearly zero at eB~0.5 GeV^2. Possible physical consequences of the calculated mass trajectory of the neutron, M_n(B), are presented and discussed.