Analysis of nuclear properties of symmetry breaking pearshaped nuclei in relation with CPviolating effects
(2024) FYSK04 20241Mathematical Physics
Department of Physics
 Abstract
 To investigate the nonzero nuclear Schiff moment exhibited by PTviolating nuclei, this paper examines the prediction of shapes and excited states of Radium isotopes by applying different Skyrmelike models. The calculations were conducted by employing computational programs incorporating both the HartreeFockBogoliubov method and HartreeFock + 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 CPviolation. 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. CPviolation... (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 CPviolation. 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. CPviolation 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 CPviolation tend to be almost negligible, scientists have sought for conditions where these effects are highly amplified. One prominent indicator to CPviolation 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 CPviolating forces. This Schiff moment is of much interest as it is particularly enhanced in specific deformed nuclei, notably in octupoledeformed nuclei, which resembles a pear shape.
These pearshaped nuclei serve as notable candidates to
study these phenomena because they break spatial symmetries, significantly enhancing CPviolating effects i.e. the nuclear Schiff moment. Some isotopes, particularly certain radium isotopes which exhibit pearshaped 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 pearshaped nuclei.
The main objective of our research is the analysis of nuclear properties for wellknown Radium isotopes, namely Ra220228, 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 matterantimatter asymmetry of the universe. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/studentpapers/record/9170325
 author
 Lim, Zi Yao ^{LU}
 supervisor

 Gillis Carlsson ^{LU}
 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, Pearshaped Nuclei, HartreeFockBogoliubov (HFB), Skyrme Interaction, Quasiparticles, Nilsson Model, Computational Physics, Parity Doublets, Skyrme Parametrizations, Multipole Moments
 language
 English
 id
 9170325
 date added to LUP
 20240812 08:23:11
 date last changed
 20240812 08:23:11
@misc{9170325, abstract = {{To investigate the nonzero nuclear Schiff moment exhibited by PTviolating nuclei, this paper examines the prediction of shapes and excited states of Radium isotopes by applying different Skyrmelike models. The calculations were conducted by employing computational programs incorporating both the HartreeFockBogoliubov method and HartreeFock + 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 pearshaped nuclei in relation with CPviolating effects}}, year = {{2024}}, }