arXiv subjects

E. Yu. Popov

Publications and source records attributed to E. Yu. Popov.

8 recordsLinked to original sources

arXiv2026

Can Euclidean lattice quantum field theory be analytically continued into Minkowski space?

In this paper, we attempt to test whether Euclidean lattice quantum field theory can be analytically continued into Minkowski space via the inverse Wick rotation. Our discussion indicates that such an analytical continuation is impossible without first taking the lattice theory to the continuum limit. The obstacle is that discretization of spacetime converts local quantum field theory into a theory with a nonlocal form factor, for which the Wick rotation is infeasible.

hep-th↗

arXiv2023

Why is ${\rm Pb}^{208}$ the heaviest stable nuclide?

In an effort to understand nuclei in terms of quarks we develop an effective theory to low-energy quantum chromodynamics in which a single quark contained in a nucleus is driven by a mean field due to other constituents of the nucleus. We analyze the reason why the number of $d$ quarks in light stable nuclei is much the same as that of $u$ quarks, while for heavier nuclei beginning with ${\rm Ca}^{40}$, the number of $d$ quarks is greater than the number of $u$ quarks. To account for the finiteness of the periodic table, we invoke a version of gauge/gravity duality between the dynamical affair in stable nuclei and that in extremal black holes. With the assumption that the end of stability for heavy nuclei is dual to the occurrence of a naked singularity, we find that the maximal number of protons in stable nuclei is $Z_{\max}^{\rm H}\approx 82$.

nucl-th↗

arXiv2021

How to detect the lightest glueball

We suggest a procedure of the lightest glueball detection in a head-on collision of photons whose center-of-mass energy is in the range $1.3-2$ GeV. Recent evidence for the scattering of light by light in experiments at the Large Hadron Collider is used as a phenomenological basis of our suggestion. With this evidence, the cross section of the lightest glueball creation in the $γγ$ collisions is estimated to be $\sim 60\,$nb. The predominant mode of the lightest glueball decay, predicted from the gauge/gravity duality, proves to be the decay into two neutral vector mesons $ρ^0ρ^0$. Because $ρ^0$ decays into $π^+π^-$, a drastic increase in the $π^+π^-π^+π^-$ yield is expected as the center-of-mass energy of the colliding photons approaches the value of the lightest glueball mass. This fact may be regarded as the unique signature of the lightest glueball detection.

hep-ph↗

arXiv2019

Correspondence between the physics of extremal black holes and that of stable heavy atomic nuclei

Extremal black holes are immune of Hawking evaporation. On the other hand, some heavy atomic nuclei feature extraordinary stability to spontaneous transmutations changing their mass numbers. The fact that extremal black holes and stable nuclei share a common trait, that of defying spontaneous ejection of their constituents, suggests that a good part of nuclear physics is modelled on physics of extremal black holes through a simple version of gauge/gravity duality. A general criterion for discriminating between stable and unstable microscopic systems can be formulated to gain a new insight into some imperfectly understood phenomena, such as instability of truly neutral spinless particles (Higgs bosons, $π_0$, quarkonia, glueballs).

hep-th↗

arXiv2015

Cosmic censorship and stationary states of half-spin particles in the field of Reissner-Nordstroem naked singularity

The paper explores quantum mechanics of half-spin particle motion in the field of Reissner-Nordstroem (RN) naked singularity. It is shown that for any quantum mechanical Dirac particle, irrespective of availability and sign of its electrical charge, the RN naked singularity is separated by an infinitely high positive potential barrier. With like charges of a particle and the source of the RN naked singularity, near the origin there exists the second completely impenetrable potential barrier. It has been proved that in the field of the RN naked singularity, bound states of half-spin particles can exist. The conditions for appearance of such states were revealed and computations were performed to find energy eigenvalues and eigenfunctions.

gr-qc↗

arXiv2015

Analysis of half-spin particle motion in Reissner-Nordstroem and Schwarzschild fields by means of the method of effective potentials

The paper presents the analysis of effective potentials of Dirac equations in Schwarzschild and Reissner-Nordstroem fields. It is shown that in the majority of the explored cases the condition of a particle "fall" to appropriate event horizons is fulfilled. The exception is one of the solutions with normalizable wave functions for the Reissner-Nordstroem extreme field, for which the existence of the stationary bound state of half-spin particles is possible inside the event horizon.

gr-qc↗

arXiv2015

Some Aspects of Quantum Mechanics of Particle Motion in Static Centrally Symmetric Gravitational Fields

The domain of wave functions and effective potentials of the Dirac and Klein-Gordon equations for quantum-mechanical particles in static centrally symmetric gravitational fields are analyzed by taking into account the Hilbert causality condition. For all the explored metrics, assuming existence of event horizons, the conditions of a "fall" of a particle to the appropriate event horizons are implemented. The exclusion is one of the solutions for the Reissner-Nordstroem extreme field with the single event horizon. In this case, while fulfilling the condition found by V.I.Dokuchaev, Yu.N.Yeroshenko, the normalization integral is convergent and the wave functions become zero on the event horizon. This corresponds to the Hilbert causality condition. In our paper, due to the analysis of the effective potential for the Reissner-Nordstroem extreme field with real radial wave functions of the Dirac equation, the impossibility is demonstrated for the bound stationary state existence of quantum-mechanical particles, with positive energy, off the event horizon. The analysis of the effective potential of the Dirac equation for the case of the naked singularity of the Reissner-Nordstroem field shown the possible existence of stationary bound states of quantum-mechanical half-spin particles.

gr-qc↗

arXiv2013

Stationary Bound States of Dirac Particles in the Schwarzschild Gravitational Field

Nondecaying bound states of elementary spin-half particles are validated and calculated numerically for the Schwarzschild gravitational field using a self-conjugate Hamiltonian with a flat scalar product for any value of the gravitational coupling constant. Hilbert condition g_{00}>0 leads to a boundary condition such that components of the vector of current density of Dirac particles are zero near the "event horizon". At small values of the coupling constant, the energy spectrum is close to the hydrogen-like spectrum. Based on the results of this study, we can assume that there exists a new type of collapsars, for which the Hawking radiation mechanism is not present. From the standpoint of cosmology, if the value of the gravitational coupling constant is small, alpha<<1, the new type of nonradiating relict collapsars can manifest itself only through gravitation. Thus, they are good candidates for the role of "dark matter" carriers. In the wide range of admissible masses, there can exist collapsars of a new type with the masses of hypothesized WIMP particles, which are treated as representatives of "dark matter" in numerous scenarios of the expansion of the universe. The results of this study can lead to revisiting some concepts of the standard cosmological model related to the evolution of the universe and interaction of collapsars with surrounding matter.

gr-qc↗