15,346 research outputs found
Flavor changing nucleon decay
Recent discovery of neutrino large mixings implies the large mixings in the
diagonalizing matrices of fields in grand unified theory
(GUT), while the diagonalizing matrices of fields of are
expected to have small mixings like Cabibbo-Kobayashi-Maskawa matrix. We
calculate the predictions of flavor changing nucleon decays (FCND) in ,
, and GUT models which have the above features for mixings. We
found that FCND can be the main decay mode especially for GUT with higher rank
unification group. Recent report for process implies
or GUT if the signal is from the nucleon decay.Comment: 5 pages, 4 figures v2:references are added v3:references, figures and
texts are improved v4:final version to be published in PL
Symmetry breaking boundaries II. More structures; examples
Various structural properties of the space of symmetry breaking boundary
conditions that preserve an orbifold subalgebra are established. To each such
boundary condition we associate its automorphism type. It is shown that
correlation functions in the presence of such boundary conditions are
expressible in terms of twisted boundary blocks which obey twisted Ward
identities. The subset of boundary conditions that share the same automorphism
type is controlled by a classifying algebra, whose structure constants are
shown to be traces on spaces of chiral blocks. T-duality on boundary conditions
is not a one-to-one map in general. These structures are illustrated in a
number of examples. Several applications, including the construction of non-BPS
boundary conditions in string theory, are exhibited.Comment: 51 pages, LaTeX2
- …