Penning trap mass measurements to test three-body forces in atomic nuclei
department or school: Science, Faculty of
department or school: Physics and Astronomy, Department of
data provider: DSpace
degree campus: UBCV
creator: Gallant, Aaron T.
issued: 2015-11-30T19:16:03Z
issued: 2015
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Recent theoretical studies have shown that three-nucleon forces are important for understand- ing neutron-rich nuclei, and for the formation of nuclear shell structure. In particular, theory can not reproduce the N = 28 magic number in â´â¸Ca using two-body interactions. This magic number is only reproduced with the inclusion of three-nucleon forces. Further along the calcium isotopic chain, the three-nucleon interaction predicts new magic numbers at N = 32 and 34, while calculations with phenomenological interactions predict a magic number at N = 32, but disagree on the magicity of N = 34. An other theoretical tool that has been under significant pressure since the advent of precision mass measurements is the isobaric multiplet mass equation, in which the binding energies of states in an isobaric multiplet should vary quadratically with the z-projection of the isospin. This is a consequence of the isospin dependent component of the nuclear Hamiltonian and Coulomb interactions. We test the predictions of phenomenological and three-nucleon interactions through mass measurements of Â²â°'Â²¹Mg, âµÂ¹'âµÂ²Ca, and âµÂ¹K with the TITAN Penning trap mass spectrometer. The measured mass excesses were ME(Â²â°Mg) = 17477.7(18) keV, ME(Â²¹Mg) = 10903.85(74) keV, ME(âµÂ¹Ca) = 36339(23) keV, ME(âµÂ²Ca) = 34245(61) keV, and ME(âµÂ¹K) = 22516(13) keV. With the calcium and potassium mass measurements, we show that the calculations with three-nucleon forces are able to correctly predict the two-neutron separation energies. In the A = 20 and 21 isobaric multiplets, neither the phenomenological nor the three-nucleon based interactions are able to reproduce the measured behaviour.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/55610
note: Penning trap mass measurements to test three-body forces inatomic nucleibyAaron T. GallantB.Sc., Saint Maryâs University, 2008A THESIS SUBMITTED IN PARTIAL FULFILLMENTOF THE REQUIREMENTS FOR THE DEGREE OFDoctor of PhilosophyinTHE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES(Physics)The University of British Columbia(Vancouver)November 2015c© Aaron T. Gallant, 2015AbstractRecent theoretical studies have shown that three-nucleon forces are important for understand-ing neutron-rich nuclei, and for the formation of nuclear shell structure. In particular, theorycan not reproduce the N = 28 magic number in 48Ca using two-body interactions. This magicnumber is only reproduced with the inclusion of three-nucleon forces. Further along the cal-cium isotopic chain, the three-nucleon interaction predicts new magic numbers at N = 32 and34, while calculations with phenomenological interactions predict a magic number at N = 32,but disagree on the magicity of N = 34. An other theoretical tool that has been under significantpressure since the advent of precision mass measurements is the isobaric multiplet mass equa-tion, in which the binding energies of states in an isobaric multiplet should vary quadraticallywith the z-projection of the isospin. This is a consequence of the isospin dependent com-ponent of the nuclear Hamiltonian and Coulomb interactions. We test the predictions of phe-nomenological and three-nucleon interactions through mass measurements of 20,21Mg, 51,52Ca,and 51K with the TITAN Penning trap mass spectrometer. The measured mass excesses wereME(20Mg)= 17477.7(18) keV, ME(21Mg)= 10903.85(74) keV, ME(51Ca)= 36339(23) keV,ME(52Ca) = 34245(61) keV, and ME(51K) = 22516(13) keV. With the calcium and potassiummass measurements, we show that the calculations with three-nucleon forces are able to cor-rectly predict the two-neutron separation energies. In the A = 20 and 21 isobaric multiplets,neither the phenomenological nor the three-nucleon based interactions are able to …
has type: Thesis/Dissertation
date issued: 2016-02
is shown at: 10.14288/1.0220519
language: eng
degree discipline: Physics
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivs 2.5 Canada
rights URI: http://creativecommons.org/licenses/by-nc-nd/2.5/ca/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/55610