Analysis of nuclear properties of symmetry breaking pear-shaped nuclei in relation with CP-violating effects
(2024) FYSK04 20241Mathematical Physics
Department of Physics
- Abstract
- To investigate the non-zero nuclear Schiff moment exhibited by PT-violating nuclei, this paper examines the prediction of shapes and excited states of Radium isotopes by applying different Skyrme-like models. The calculations were conducted by employing computational programs incorporating both the Hartree-Fock-Bogoliubov method and Hartree-Fock + BCS with an effective Skyrme force. A preliminary survey of nuclear properties that contribute to the enhancement of the nuclear Schiff moment is also presented.
- Popular Abstract
- Picture the early universe, beginning with the Big Bang. According to our current understandings, the Big Bang should have produced equal amounts of matter and antimatter. However, we find ourselves in a universe dominated by matter, with antimatter relatively scarce. This asymmetry presents one of the most captivating mysteries in physics:
Why is there more matter than antimatter in our universe today?
The key to unravel this mystery may lie in a phenomenon known as CP-violation. To grasp this concept, we first need to understand the role of symmetry in physics. Symmetries represent the fundamental building blocks of physics, describing how certain properties of a system remain unchanged under specific transformations. CP-violation... (More) - Picture the early universe, beginning with the Big Bang. According to our current understandings, the Big Bang should have produced equal amounts of matter and antimatter. However, we find ourselves in a universe dominated by matter, with antimatter relatively scarce. This asymmetry presents one of the most captivating mysteries in physics:
Why is there more matter than antimatter in our universe today?
The key to unravel this mystery may lie in a phenomenon known as CP-violation. To grasp this concept, we first need to understand the role of symmetry in physics. Symmetries represent the fundamental building blocks of physics, describing how certain properties of a system remain unchanged under specific transformations. CP-violation occurs when the laws of physics do not apply equally to matter and antimatter--- in simpler terms, it is the breakdown of this symmetry under certain conditions. This phenomenon may hence hint at an explanation as to why matter dominates our current universe.
Since the effects of CP-violation tend to be almost negligible, scientists have sought for conditions where these effects are highly amplified. One prominent indicator to CP-violation is the existence of a permanent electric dipole moment, EDM of atoms. This results from an imbalance of charges within an atom, deviating from a perfectly spherical distribution. The permanent EDM arises from the nuclear Schiff moment, a property emerging from CP-violating forces. This Schiff moment is of much interest as it is particularly enhanced in specific deformed nuclei, notably in octupole-deformed nuclei, which resembles a pear shape.
These pear-shaped nuclei serve as notable candidates to
study these phenomena because they break spatial symmetries, significantly enhancing CP-violating effects i.e. the nuclear Schiff moment. Some isotopes, particularly certain radium isotopes which exhibit pear-shaped nuclei, have been found to exhibit these enhanced Schiff moments. This project focuses on the properties of these nuclei, mainly by predicting and comparing their shapes and ground states using computational programs.
The forces between nucleons in the nucleus are taken into account by Skyrme forces in this study. These are effective forces obtained by fitting experimental data of nuclear properties such as mass and binding energies to theoretical models. Skyrme parameterizations refer to different sets of parameters within the Skyrme force model, each fitted to specific experimental data sets. By comparing predictions for these different Skyrme parameterizations, e.g. SLY4 and UNEDF1, we evaluate how different models affect the predictions of nuclear properties of pear-shaped nuclei.
The main objective of our research is the analysis of nuclear properties for well-known Radium isotopes, namely Ra220-228, suggested in previous studies to exhibit highly amplified octupole deformation. The goal? To identify potential candidates for experimental validation by ongoing research groups in this field. This area of research aims to deepen our understanding of nuclear properties and potentially lead to groundbreaking discoveries in fundamental physics, ultimately explaining the matter-antimatter asymmetry of the universe. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9170325
- author
- Lim, Zi Yao LU
- supervisor
- organization
- course
- FYSK04 20241
- year
- 2024
- type
- M2 - Bachelor Degree
- subject
- keywords
- Radium Isotopes, Nuclear Schiff Moment, Electric Dipole Moment (EDM), Octupole Deformation, CP Violation, Symmetry Breaking, Pear-shaped Nuclei, Hartree-Fock-Bogoliubov (HFB), Skyrme Interaction, Quasi-particles, Nilsson Model, Computational Physics, Parity Doublets, Skyrme Parametrizations, Multipole Moments
- language
- English
- id
- 9170325
- date added to LUP
- 2024-08-12 08:23:11
- date last changed
- 2024-08-12 08:23:11
@misc{9170325,
abstract = {{To investigate the non-zero nuclear Schiff moment exhibited by PT-violating nuclei, this paper examines the prediction of shapes and excited states of Radium isotopes by applying different Skyrme-like models. The calculations were conducted by employing computational programs incorporating both the Hartree-Fock-Bogoliubov method and Hartree-Fock + BCS with an effective Skyrme force. A preliminary survey of nuclear properties that contribute to the enhancement of the nuclear Schiff moment is also presented.}},
author = {{Lim, Zi Yao}},
language = {{eng}},
note = {{Student Paper}},
title = {{Analysis of nuclear properties of symmetry breaking pear-shaped nuclei in relation with CP-violating effects}},
year = {{2024}},
}