**Nuclear and Particle Physics Colloquium 135**

**(****核与粒子物理学术报告会****135)**

**Place: Shahe Campus C523**

**Time****：****09:00, July. 05, 2024**

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**Seminar 1 : On Optical Model For Sub-Barrier Heavy-Ion Fusion Reactions**

**Speaker: Sergue Vinitsky ****教授**

**Abstract**:

A new method for solving the inverse scattering problem in the coupled channels method of an optical model (OM) with consistent calculation of unknown coupling constant dependent on collision energy based on the incoming wave boundary condition (IWBC) approach is presented. We performed benchmark calculations with a single-channel approximation for scattering and metastable states ^{16}O+^{144}Sm. TIME6T program for solving the time dependent Schrödinger equation (TDSE) will be briefly presented.

**About the speaker: **

Prof. Sergue Vinitsky, born in 1950, professor, leading researcher of Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna. He was engaged in computer modeling of quantum few-body scattering processes, collective nuclear models and heavy ion reactions, methods, algorithms and software to solve multichannel scattering and eigenvalue problems, published more than 200 articles and achieved a number of important scientific results: 1987 First JINR Prize Methods of solving the quantum mechanics three-body problem and its application in the muon catalysis problem of the nuclear fusion reactions, 2015 Second JINR Prize Problem-oriented complex of programs for solving boundary value problems in the dynamics of few-body quantum systems.

**Seminar 2 : Application of minimax optimization for solving the two-center Dirac equation**

**Speaker: Ochbadrakh Chuluunbaatar ****教授**

**Abstract**:

In this talk we present the variational solution of this two center problem using a basis constructed by linear combinations of relativistic Slater type spinor wave functions with noninteger powers of the radii on the two centers. The solutions are obtained by a minimax procedure, that we have developed with a new iterative scheme. We investigate the behavior of the electron in its 1ss_{g} level of the diatomic homo-nuclear systems A_{2}^{(2Z-1)+}. Our approach has the advantage of needing small basis sets for a relative error of the of 10^{-7}–10^{-8}.

**About the speaker: **

Prof. Chuluunbaatar, born in 1974. Scientific researcher and deputy director of Meshcheryakov Laboratory of Information Technologies, Joint Institute for Nuclear Research, Dubna, Russia and Leading researcher of Institute of Mathematics and Digital Technology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia. Results of the scientific activities have been published in more than 230 articles in the field of computational physics, mathematical modelling, variational and numerical methods in the few-body problem.

**Seminar 3 : Quantum Tunneling of Clusters through Barriers**

**Speaker: Alexander Gusev ****教授**

**Abstract**:

Computational schemes of the finite element method for solving multichannel scattering metastable states problems are presented. The tunnelling problem of clusters consisted of several identical particles connected by pair harmonic oscillator potential through gaussian barriers is analyzed.

**About the speaker: **

Prof. Alexander Alexandrovich Gusev, Born in 1977. Leading Researcher of Meshcheryakov Laboratory of Information Technologies, Joint Institute for Nuclear Research, Dubna, Moscow Region 141980, Russia. The scientific interests is the development of finite element method schemes for solving the bound state, multichannel scattering and metastable state problems in geometric collective models of nucleus, models of subbarier heavy-ion fusion reactions, and other models in nuclear, atomic, molecular physics and physics of semiconductor nanostructures. Results of the scientific activities have been published in more than 120 articles.