Pionic matrix elements in neutrinoless doubleβ decay
Abstract
Physics beyond the standard model of electroweak interactions that violates lepton number will, in general, induce operators involving the quark and lepton fields that violate lepton number. I point out that some matrix elements of particular operators are known. In the limit of exact SU(3) flavor symmetry the operator ūγ_{μ}(1γ_{5})dūγ_{μ}(1γ_{5})d is part of the 27 representation responsible for ΔI=32 strangeness changing decays in the standard model. At leading order in the chiral expansion there is only one coupling constant that describes the weak interactions of the pseudoGoldstone bosons induced by the 27 representation. The observed branching fraction for K^{+}>π^{+}π^{0} determines this coupling constant. Contributions of the form m_{s} ln m_{s} are used to estimate SU(3) breaking corrections to the relation between K^{+}>π^{+}π^{0} and the π^{}>π^{+}e^{}e^{} interaction.
 Publication:

Physical Review C
 Pub Date:
 April 1999
 DOI:
 10.1103/PhysRevC.59.2293
 arXiv:
 arXiv:nuclth/9811087
 Bibcode:
 1999PhRvC..59.2293S
 Keywords:

 24.80.+y;
 23.40.Bw;
 Nuclear tests of fundamental interactions and symmetries;
 Weakinteraction and lepton aspects;
 Nuclear Theory;
 High Energy Physics  Phenomenology
 EPrint:
 6 pages, latex