The XXIII International Scientific Conference of Young Scientists and Specialists (AYSS-2019)

Session

Theoretical Physics

15 Apr 2019, 15:00

LIT, JINR

Conveners

Theoretical Physics: Section 1 Part 1

• Yaroslav Klopot (BLTP JINR)
• Vsevolod Katkov (BLTP JINR)
• Andrey Pikelner (BLTP JINR)

Theoretical Physics: Section 1 Part 2

• Yaroslav Klopot (BLTP JINR)
• Andrey Pikelner (BLTP JINR)
• Vsevolod Katkov (BLTP JINR)

Theoretical Physics: Section 2

• David Edwin Alvarez Castillo (Joint Institute for Nuclear Research)
• Anastasia Golubtsova (Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research)

457. Variational calculations of the H^+_2 and HD^+ rovibrational energies

Mr Askhat Bekbaev (JINR)

15/04/2019, 15:00

Theoretical Physics

Oral

We use the exponential explicitly correlated variational basis set of the type exp(−α_n*R−β_n*r_1−γ_n*r_2) to calculate systematically the nonrelativistic bound-state energies for the hydrogen molecular ion H^+_2 and HD^+.We perform calculations for the states of the total orbital angular momentum L=0-4 with the complete set of vibrational quantum numbers v=0–10.

443. Short-range-Induced Resonances in Two-dimensional Dipolar Scattering

Mr Eugene Koval (BLTP, JINR)

15/04/2019, 15:15

Theoretical Physics

Oral

We investigate the two-dimensional dipole-dipole scattering problem at low energies, which simulates the polar molecules collisions in the optical traps. The resonances induced by short-range interactions are revealed in the scattering cross section dependence on the short-range interaction radius.

327. Tunneling of two interacting atoms from excited states

Mr Ilyas Ishmukhamedov (Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research)

15/04/2019, 15:30

Theoretical Physics

Oral

We consider a tunneling problem of two interacting cold atoms, with the even spatial symmetry, subject to an anharmonic optical trap and linear magnetic-field gradient. The atoms are initially prepared in the two lowest excited states with respect to relative and center-of-mass motions. We calculate the energy spectrum for a wide range of the interatomic coupling strength g. In the limit of...

469. Resonance features of the Josephson junction with ferroelectrical barrier

Dr Ilhom Rahmonov (BLTP, Joint Institute for Nuclear Research)

15/04/2019, 15:45

Theoretical Physics

Oral

The phase dynamics of Josephson junction with ferroelectric barrier is investigated. The Josephson junction dynamics is described in the framework of RCSJ-model and for description of the ferroelectricity is used Landau-Devonshir theory. The IV-characteristic of Josephson junction with ferroelectric barrier is calculated. Its shown that, due to the resonance between Josephson and...

459. How to assemble polydisperse nanoparticles into clusters with predefined fractal dimension?

Mr Oleksandr Tomchuk (Physics Department, National Taras Shevchenko University of Kyiv)

15/04/2019, 16:00

Theoretical Physics

Oral

A generalized non-kinetic off-lattice algorithm to construct stochastic fractal clusters of polydisperse particles with tunable cluster parameters including dimension, is presented. The model is based on a hierarchical procedure and makes it possible to cover the full range of natural mass fractal dimensions between one and three. A morphological study of numerically generated clusters based...

480. Influence of stationary charge imbalance on Shapiro step features

Mr Kirill Kulikov (RF)

15/04/2019, 16:15

Theoretical Physics

Oral

The nonequilibrium phenomena in the coupled system of Josephson junctions, taking into account the charge imbalance of the elementary excitations spectrum branches has been studied. We investigate the influence of stationary charge imbalance on the Shapiro step properties on the current-voltage characteristics of coupled system of Josephson junctions. It has been found that Shapiro step...

379. CPT study of the Fermi-surface reconstruction in the t-J model

Mr Ilya Ivantsov (BLTP JINR.)

15/04/2019, 17:00

Theoretical Physics

Oral

A number of recent experiments have highlighted a remarkable transformation of a large cuprate Fermi surface into small pockets in the underdoped region signaling a breakdown of a conventional Fermi liquid theory in the PG phase. The qualitatively agreement of the experimental data with Fermi surface calculations within phenomenological models based on the measured parameters of the CDW order,...

320. CORRECT USAGE OF THE VLASOV EQUATION

Mr Denis Suchkov (Lomonosov Moscow State University)

15/04/2019, 17:15

Theoretical Physics

Oral

This work is devoted to the study of the properties of the Vlasov equation, as well as the study of the limits of its applicability in the description of physical phenomena. In this paper were shown, that the well-known Vlasov equation [1], widely used in the scientific literature, is only an approximation obtained from the original chain of Vlaosv equations by introducing assumptions [2]....

429. Role of non-abelian anomaly in transition form factors of ${\pi }^0,\eta ,{\eta }^{\prime }$, generalization for the case of any photon virtuality

Mr Sergei Khlebtsov (ITEP, Moscow)

15/04/2019, 17:30

Theoretical Physics

Oral

In the framework of the anomaly sum rules approach, based on the dispersion representation of the axial anomaly and the global quark-hadron duality hypothesis, expressions of Transition Form Factors(TFF) for the pseudoscalar mesons are derived. The obtained solutions are taking into account the mixing between ${\pi }^0-\eta -{\eta }^{\prime }$ and the gluon anomaly term. Within TFF for ${\pi }^0-\eta -{\eta }^{\prime }$...

354. Kinetic description of the electron-positron plasma created from vacuum under the action of a strong laser field

Mr Stanislav Pirogov (Olegovich)

15/04/2019, 17:45

Theoretical Physics

Oral

We consider a self-consistent kinetic description of a electron-positron-gamma plasma, generated from the vacuum in a focal spot of two counterpropagating laser pulses. At the moment in our model includes purely time-dependent external (laser) field, but properly takes into account the semiclassical internal (plasma) field. While nonperturbative kinetic description of electron-positron pair...

308. Form factors of three-nucleon nuclei in the relativistic case

Mr Sergey Yurev (JOINT INSTITUTE FOR NUCLEAR RESEARCH)

15/04/2019, 18:00

Theoretical Physics

Oral

A relativistic generalization of formulas for form factors of three-nucleon nuclei was obtained.The formulas for the form factors took into account the orbital moments of the nucleons inside the nuclei from 0 to 2, that is, the S P and D states.The form factors were calculated as functions of the transmitted momentum of the scattered electron up to 2 GeV.Moreover, for form factors nucleons...

462. Field confinement in infrared effective QCD and thermal field dynamics

Mr Deependra Singh RAWAT (Kumaun University, Nainital, India)

15/04/2019, 18:15

Theoretical Physics

Oral

Keeping in view the dominance of non-perturbative phenomenas in low energy regime of QCD, an infrared effective dual QCD, based on topologically viable homogeneous fibre bundle approach, has been analysed for exploring the dynamics of confined fields in its dynamically broken phase which has been shown to lead an unique multi-flux tube configuration and a typical glueball spectrum intimately...

332. De Sitter space and Entanglement

Mr Felipe Diaz (Universidad Andres Bello)

16/04/2019, 14:00

Theoretical Physics

Oral

De Sitter space, unlike its negatively curved relative, consists of two disconnected boundaries and a causally disconnected interior. In this paper, we argue that the connectedness properties of de Sitter space naturally encode the notion entanglement. We propose an holographic description of an inertial observer in terms of a thermofield double state in the tensor product of the past and...

454. Vacuum fluctuations for a charged scalar field in de Sitter spacetime with compact dimensions

Mr Davit Simonyan (Yerevan State University)

16/04/2019, 14:15

Theoretical Physics

Oral

We investigate the vacuum expectation values of physical observables for a charged scalar field in de Sitter spacetime with an arbitrary number of toroidally compact spatial dimension and in the presence of a brane. Quasiperiodicity conditions with arbitrary phases are imposed along compact dimensions and on the brane the field obeys Robin boundary condition. It has been shown that the vacuum...

370. Bimetric gravity from the spectral point of view

Mr Arkadiusz Bochniak (Institute of Physics, Jagiellonian University)

16/04/2019, 14:30

Theoretical Physics

Oral

Bimetric gravity models originated from the ghost-free Hassan-Rosen theory are known as a possible extensions of the standard cosmological model. These models are characterized by an action that contains few free coefficients which combinations can be used to define parameters that characterize cosmological scenarios.Since even slight change in these parameters may have a huge impact on the...

470. Chameleon mechanism in inhomogeneous astrophysical objects

Ms Noshad Khosravi Largani (Alzahra university)

16/04/2019, 14:45

Theoretical Physics

Oral

Observational evidence implying the accelerated expansion of the universe has been the motivation to develop various classes of modified gravity theories. One of them uses the so-called "screening mechanism", which is successful in reproducing the observed gravitational behavior in large scales as well as being in agreement with tests of general relativity in the solar system. In this work, we...

374. Cylindrical curves and classical paths of irreducible massive spinning particles in 4D Minkowsky space

Mr Ivan Retuntsev (Tomsk State University)

16/04/2019, 15:00

Theoretical Physics

Oral

We study the dynamics of classical spinning particles such that quantization of classical model leads to an irreducible massive representation of the Poincare group from the viewpoint of recently proposed world sheet concept [1]. The class of gauge equivalent classical particle paths is shown to form a cylindrical surface in Minkowski space, irrespectively to any specifics of the classical...

348. Green’s function technique for precise calculation of false vacuum decay rate.

Mr Maxim Bezuglov (JINR)

16/04/2019, 15:15

Theoretical Physics

Oral

False vacuum decay is an interesting physical process that recently attracted a lot of attention due to the possible metastability of the electroweak vacuum in the Standart Model at large energies. If it is true than the universe will eventually tunnel in some other energy state with other particle masses and possibly other laws of physics. In this regard, it is useful to study in detail...

373. Stable interactions between higher derivative extended Chern-Simons and charged scalar field

Ms Victoria Abakumova (Tomsk State University)

16/04/2019, 15:30

Theoretical Physics

Oral

We consider inclusion of interactions between two different derived field theories. One of them is supposed to be gauge invariant. At free level, the wave operator of derived-type theory is the polynomial of the primary operator that is of the lower order. Every symmetry of the primary operator results in series of higher order symmetries of the field equations of the derived model that, in...