出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Flavour symmetries represent a powerful tool in analysing model-independently hadronic matrix
elements. Going beyond isospin symmetry results, however, in a large uncertainty related to
the symmetry breaking due to the relatively large strange quark mass. Considering the U-spin
subgroup of flavour SU(3), its breaking is analysed on a group theoretical basis. Due to the
simple behaviour of the weak effective hamiltonian under U-spin and the unique structure of the
breaking terms, such a group theoretical analysis leads to a manageable number of parameters.
In view of the enormous amount of data expected from LHCb and a possible Super B factory,
this data driven method provides a way of gathering information on hadronic matrix elements in
general and U-spin breaking in particular. As a first application, the pair of decays B− !J/yK−
and B− !J/yp− is discussed.
