OMEG Special Seminar and 78th OMEG –SSANP Workshop

Tuesday Nov 12, 2024, 12:00 AM → 7:00 PM Asia/Seoul

Dasom Hall, Computer Science Institute Building, (Soongsil University)

Jubin Park (OMEG & Soongsil University), Myung-Ki Cheoun (Soongsil University and OMEG institute), admin omeg (Soongsil University and OMEG institute)

OMEG Special Seminar and 78th OMEG –SSANP Workshop

“Machine Learning and Quantum Computing”

Date and Time: November 12 2024, 11:00-18:00
Venue: Dasom Hall, Computer Science Institute Building, Soongsil University 369 Sangdo-Ro, Dongjak-Gu, Seoul, Korea (06978)

OMEG Special Seminar

1 Analysis of Radiative capture and stellar weak rates for the astrophysical important nuclei (via ZOOM)

Radiative capture and stellar weak rates are important for the nucleosynthesis of low, intermediate, and heavy mass nuclei. The fundamentals of our work are to analyze the radiative capture of the neutron, proton, and heavy mass projectile by the target nuclei within the framework of the potential model, R-matrix approach, or statistical framework. We aim to analyze the resonant, non-resonant capture cross-section, reaction rates, and destructive half-lives for the list of astrophysical nuclei involved in the p-. s- or r-processes of nucleosynthesis.

Our study covers the nuclear ground state properties via the potential model for low-mass nuclei and the relativistic mean field (RMF) framework for heavy-mass nuclei. The nuclear ground state properties include nuclear radii; neutron skin thickness, neutron and proton separation energies, analysis of the nuclear deformation, nuclear shape evolution, and shape transition. Along with this, we employed a proton-neutron quasi-particles random phase approximation model (pn-QRPA) to study the impact of the nuclear shapes on the stellar beta decay rates for the list of astrophysical important nuclei.

In some environments the beta decay rates and the proton or neutron capture rates are the same at a certain temperature therefore, we aim to determine the temperature at which both rates are separate from each other or the competition of radiative capture and beta decay rates. Furthermore, we aim to calculate the effective thermal transition rates between the ground and isomeric states along with estimates of their thermal decay-decay rates in a suite of nucleosynthesis computations to assess the consequences of the isomer on isotopic abundances.

Speaker: Prof. Abdul Kabir Khan (Institute of Space Technology, Islamabad Pakistan)

Lunch

78th OMEG-SSANP Workshop

Machine Learning and Quantum Computing

2 Wang-Landau Monte Carlo Simulation Method and Spin Model

I will explain the Wang-Landau (WL) Monte Carlo method, comparing it with the traditional Metropolis algorithm. The WL method is particularly useful for calculating the density of states, from which we can derive important thermodynamic quantities like energy, entropy, specific heat, and free energy.

As a demonstration, I’ll examine the Ising model with both nearest-neighbor (J₁) and next-nearest-neighbor (J₂) interactions. For parameters J1=−2 and J2=−1, the system exhibits frustration due to the infinitely degenerate ground states.

Using the WL Monte Carlo method, we calculate the density of states, which allows us to determine the specific heat. Notably, as the system size L increases, the temperature at which a sharp peak in the specific heat occurs shifts toward zero, and the peak’s maximum height grows logarithmically.

Speaker: Prof. Jin Min Kim (Soongsil University)

3 The Full Event Interpretation and Machine Learning at Belle II

We introduce the Full Event Interpretation (FEI) at Belle II experiment. This method
is developed for the research based on SuperKEKB accelerator and Belle II
detector. The analyses with Belle II detector are to precisely measure the Standard
Model (SM) and to find the evidence of the New Physics beyond the SM are in
progress. Since the center-of-mass energy (√s) of SuperKEKB accelerator is
specified to 10.58 GeV to generate Υ(4S) that decays to the pair of B meson with
96% probability, the analyses with Belle II detector are generally focused on B
meson. One of the B meson is regarded and reconstructed as signal, while the
other B is not reconstructed. FEI is to reconstruct particles in the event
automatically to construct ‘other’ B meson, with boosted decision trees (BDT)
method. Since this method allows access of additional information calculated from
‘other’ B, it is possible to improve the quality of events, though in a situation that
complete reconstruction of signal B is forbidden due to invisible particles are
included in the decay mode. To take the advantage of FEI, a ‘tagging’ method has
been used in B meson analyses. We introduce the tagging algorithm of B meson
using BDT. We have applied FEI and tested the effect with one of
lepton-flavor-violating decay modes with simulated samples.

Speaker: Dr Kyoung Ho Kim (KISTI)

4 Machine learning for nuclear masses in deformed relativistic Hartree-Bogoliubov theory in continuum

Most nuclei are deformed and deformations play an important role in various nuclear and astro-physical phenomena. Modern microscopic nuclear mass models have been/are being developed based on the covariant density functional theory to explore exotic nuclear properties. Among them we adopt the mass models based on the relativistic continuum Hartree-Bogoliubov theory (RCHB) with spherical symmetry and deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) with axial symmetry to study possible effects of deformation on the rapid neutron-capture process
abundances. Since the DRHBc mass table is so far finished only for even-Z nuclei, we first study if a Deep Neutral Network (DNN) can be of use to complete the DRHBc mass table focusing on nuclear binding energies. To include information about odd-odd and odd-even isotopes to the DNN we also use the binding energies in AME2020 as a training set in addition to those of even-Z nuclei from the DRHBc mass table. After we obtain a reasonable mass table through a DNN study, we perform a sample sensitivity study of r-abundances to deformation or masses by using the RCHB⋆ and DRHBc⋆ mass tables. Here, ⋆ means the mass table is obtained by the DNN study. To see if such effects persist in various astrophysical sites of the r-process, we use the magnetohydrodynamic jets, collapsars and neutron star mergers. We find that the r-process abundances are highly sensitive to nuclear deformation, particularly in the mass region A= 80− 120.

Speaker: Dr Soonchul Choi (IBS)

5 Coffee Break

6 Optimization of 13C-Substituted Fullerene Configurations Using Quantum Annealing for Infrared Spectral Analysis

Fullerene, primarily known as C₆₀, presents intriguing spectral properties when ^12C atoms are substituted with ^13C isotopes. This study focuses on the specific configurations of ^13C substitution in C₆₀, particularly cases where one ^12C atom is replaced by ^13C at either a pentagonal or hexagonal position. While isolated substitutions offer limited configurations, increasing the number of ^13C atoms introduces a complex combinatorial challenge in determining the lowest-energy configurations. Here, we utilize D-Wave's quantum annealer to optimize these configurations, leveraging quantum computing's advantages in combinatorial optimization over classical methods. The resulting stable configurations of ^13C-substituted C₆₀ are then analyzed to produce their corresponding infrared spectra. This approach offers insights into the spectral signatures of fullerene isotopologues and demonstrates the potential of quantum computing in advancing spectral analysis methodologies.

Speaker: Dr Jubin Park (Soongsil University and OMEG institute)

7 Quantum Eigensolver on D-Wave Advantage 2 and Its Application on Molecular Structure

I will introduce the recently developed quantum eigensolver algorithm based on optimized binary configurations measured by quantum annealing of D-Wave Advantage. The approach provides all energy specrum of L by L matrix with the computational cost of a linear increase in L, unlike exact diagonalization with L^3 iterations on classic computer. Using the method, I examined the energy dispersion of tight-binding Hamiltonian with two cases of metal and insulator. I wil show the comparasion between exact and
our results. I will also discuss the novel algorithm for optimized molecular structure based on classic optimizer and quantum annealing optimizer. Finally, I will show the detailed optimized structure on the H2 molecule

Speaker: Prof. Hunpyo Lee (Kangwon Univ.)

8 Deuteron Model Study Using Quantum Annealing

We study the deuteron model, consisting of a proton and a neutron, by employing a Quantum Annealer to compute the binding energy. Quantum Annealing, as performed by D-wave's quantum computers, is an advanced quantum computing technique designed to solve complex optimization problems. It leverages quantum fluctuations to efficiently identify the global minimum of a specific function. In our research, we translate the Hamiltonian of the deuteron model into a QUBO (Quadratic Unconstrained Binary Optimization) problem. This formulation enables us to fully exploit the quantum annealer's capabilities in accurately determining the ground state energy configurations. By adopting this innovative approach, we aim to highlight the significant potential that quantum computing holds in addressing and solving intricate many-body systems. This work not only advances the application of quantum computing in nuclear physics but also contributes to the broader exploration of quantum techniques for solving fundamental physical problems.

Speaker: Ms Chae-Hyun Yoon (Soongsil University)