Determination of Vud from nuclear mirror transitions.pdfVIP

Determination of |Vud | from nuclear mirror transitions O. Naviliat-Cuncic1 and N. Severijns2 1LPC-Caen, ENSICAEN, Universit´e de Caen Basse-Normandie, CNRS/IN2P3-ENSI, Caen, France 2Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven, B-3001 Leuven, Belgium (Dated: September 5, 2008) The Vud element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix has traditionally been determined from the analysis of data in nuclear superallowed 0+ → 0+ transitions, neutron decay and pion beta decay. We show here that this element can independently be determined from nuclear mirror transitions. The extracted value, |Vud | = 0.9719 ± 0.0017, is at 1.2 combined standard deviations from the value obtained in superallowed 0+ → 0+ transitions and has a similar precision than the value obtained from neutron decay experiments. We discuss some prospects to improve its precision through experiments in nuclear mirror transitions. 8 0 PACS numbers: 12.15.Hh; 23.40.-s; 24.80.+y 0 2 p The unitarity conditions of the Cabibbo-Kobayashi- |Vud | using only neutron decay data [8] yielded the value e Maskawa (CKM) quark mixing matrix [1, 2] provide sen- |Vud | = 0.9790(30). The present world average recom- S sitive means to test the consistency of the three genera- mended value for the neutron lifetime, τn = 885.7(8) s 5 tion standard electroweak model and to search for new [9], combined with the world average value for the beta physics beyo