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Title: Study of 14O as a test of the unitarity of the CKM matrix and the CVC hypothesis

Abstract

The study of superallowed beta decay in nuclei, in conjunction with other experiments, provide a test of the unitarity of the quark mixing matrix or CKM matrix. Nonunitarity of the CKM matrix could imply the existence of a fourth generation of quarks, right handed currents in the weak interaction, and/or new exotic fermions. Advances in radioactive beam techniques allow the creation of nearly pure samples of nuclei for beta decay studies. The subject of this thesis is the development of a radioactive beam of 14O and the study of the 14O halflife and branching ratio. The radioactive beam is produced by ionizing 12C 14O radioactive gas and then accelerating with an ECR ion source. The 14O nucleus decays via superallowed beta decay with a branching ratio > 99 percent. The low Z of 14O is important for calculating reliable corrections to the beta decay that generally increase in with Z. The > 99 percent branching ratio can be established with modest precision on the complementary branching ratio.When this work began the experimentally determined CKM matrix was nonunitary by 2.5 standard deviations. Recent studies of Kaon, Hyperon, and B meson decays have been used to determine V us and Vmore » ub matrix elements. In this work the halflife and branching ratio of 14O are measured and used to establish V ud. The unitarity of the CKM matrix is then assessed. The halflife of 14O was determined to be 70.683 ± 0.015 s and the GamowTeller branching ratio was found to be 0.643 ± 0.020 percent. Using these results the value of Vud is 0.9738 ± 0.0005. Incorporating the new values for Vus of 0.2272 ± 0.0030 and V ub of 0.0035 ± 0.0015 the squared sum of the first row of the CKM matrix is 0.9999 ± 0.0017 which is consistent with unitarity.« less

Authors:
 [1]
  1. Univ. of California, Berkeley, CA (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
OSTI Identifier:
840334
Report Number(s):
LBNL-56278
R&D Project: 460801; TRN: US0501972
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: TH: Thesis (Ph.D.); Submitted to the University of California Berkeley, Berkeley, CA (US); PBD: 1 Jun 2004
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ACCURACY; B MESONS; BETA DECAY; BRANCHING RATIO; ECR ION SOURCES; FERMIONS; HYPOTHESIS; MATRIX ELEMENTS; NUCLEI; QUARKS; UNITARITY; WEAK INTERACTIONS; SUPERALLOWED BETA DECAY HALF-LIFE OXYGEN 14 RADIOACTIVE ION BEAM

Citation Formats

Burke, Jason Timothy. Study of 14O as a test of the unitarity of the CKM matrix and the CVC hypothesis. United States: N. p., 2004. Web. doi:10.2172/840334.
Burke, Jason Timothy. Study of 14O as a test of the unitarity of the CKM matrix and the CVC hypothesis. United States. doi:10.2172/840334.
Burke, Jason Timothy. Tue . "Study of 14O as a test of the unitarity of the CKM matrix and the CVC hypothesis". United States. doi:10.2172/840334. https://www.osti.gov/servlets/purl/840334.
@article{osti_840334,
title = {Study of 14O as a test of the unitarity of the CKM matrix and the CVC hypothesis},
author = {Burke, Jason Timothy},
abstractNote = {The study of superallowed beta decay in nuclei, in conjunction with other experiments, provide a test of the unitarity of the quark mixing matrix or CKM matrix. Nonunitarity of the CKM matrix could imply the existence of a fourth generation of quarks, right handed currents in the weak interaction, and/or new exotic fermions. Advances in radioactive beam techniques allow the creation of nearly pure samples of nuclei for beta decay studies. The subject of this thesis is the development of a radioactive beam of 14O and the study of the 14O halflife and branching ratio. The radioactive beam is produced by ionizing 12C14O radioactive gas and then accelerating with an ECR ion source. The 14O nucleus decays via superallowed beta decay with a branching ratio > 99 percent. The low Z of 14O is important for calculating reliable corrections to the beta decay that generally increase in with Z. The > 99 percent branching ratio can be established with modest precision on the complementary branching ratio.When this work began the experimentally determined CKM matrix was nonunitary by 2.5 standard deviations. Recent studies of Kaon, Hyperon, and B meson decays have been used to determine Vus and Vub matrix elements. In this work the halflife and branching ratio of 14O are measured and used to establish Vud. The unitarity of the CKM matrix is then assessed. The halflife of 14O was determined to be 70.683 ± 0.015 s and the GamowTeller branching ratio was found to be 0.643 ± 0.020 percent. Using these results the value of Vud is 0.9738 ± 0.0005. Incorporating the new values for Vus of 0.2272 ± 0.0030 and Vub of 0.0035 ± 0.0015 the squared sum of the first row of the CKM matrix is 0.9999 ± 0.0017 which is consistent with unitarity.},
doi = {10.2172/840334},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2004},
month = {6}
}

Thesis/Dissertation:
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