Microscopic description of nuclear shapes and collective excitations

master's thesis

• Title (croatian): Mikroskopski opis oblika i kolektivnih pobuđenja atomske jezgre
• Author: Luka Lotina
• Mentor: Kosuke Nomura (mentor)
• Committee member: Kosuke Nomura (predsjednik povjerenstva)
• Committee member: Tamara Nikšić (član povjerenstva)
• Committee member: Matko Milin (član povjerenstva)
• Committee member: Nils Paar (član povjerenstva)
• Committee member: Mihael Makek (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2020-07-30, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

In this work, a mean-field model based on relativistic energy density functionals (REDF) was applied to even-even isotopes of krypton, barium and xenon. Quadrupole and octupole deformations of given isotopes in the ground-state were examined using a relativistic Hartree-Bogoliubov (RHB) model and a DD-PC1 functional. It was calculated that one krypton isotope, one xenon isotope and seven barium isotopes are octupole-deformed in the ground-state. A calculation of excitation energies and transition strengths was performed using a quadrupole-octupole collective Hamiltonian (QOCH). The results for the excitation energies and transition strengths were compared with the available experimental data. It is shown that the results for heavier nuclei, like barium and xenon, are in much better agreement with the experimental data than the results for lighter nuclei, like krypton. It is also shown that the calculated excitation energies of states with positive parity are in much better agreement with experimental data than energies of states with negative parity.

Abstract (croatian)

U ovom radu primijenjen je model srednjeg polja baziran na relativističkim energijskim funkcionalima gustoće (REDF) na parno-parne izotope kriptona, barija i ksenona. Pomoću relativističkog Hartree-Bogoliubovljevog (RHB) modela i DD-PC1 funkcionala, ispitane su kvadrupolne i oktupolne deformacije danih izotopa u osnovnom stanju. Oktupolne deformacije u osnovnom stanju izračunate su za jedan izotop kriptona, jedan izotop ksenona i sedam izotopa barija. Za izračun energija pobuđenja i snaga prijelaza korištena je metoda kvadrupolno-oktupolnog kolektivnog Hamiltonijana (QOCH). Izračunate energije pobuđenja i snage prijelaza uspoređene su s dostupnim eksperimentalnim podacima. Utvrđeno je da rezultati za teže jezgre, poput barija i ksenona, pokazuju puno bolje slaganje s eksperimentalnim podacima od rezultata za lakše jezgre kao što je kripton. Također je pokazano da su izračunate energije pobuđenja za stanja s pozitivnim paritetom u puno boljem slaganju s eksperimentalnim podacima od energija za stanja s negativnim paritetom.

• Keywords: quadrupole deformations; octupole deformations; relativistic energy density functional; quadrupole-octupole collective Hamiltonian
• Keywords (croatian): kvadropolne deformacije; oktupolne deformacije; relativistički energijski funkcional gustoće; kvadrupolno-oktupolni kolektivni hamiltonijan
• Language: english
• URN:NBN: urn:nbn:hr:217:579081
• Study programme: Title: Physics; specializations in: Research; Course: Research; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra fizike (magistar/magistra fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-01-05 12:00:22