Lower bounds on Δms,d from constrained minimal flavour violation

Monika Blanke, Andrzej J. Buras

Research output: Contribution to journalArticlepeer-review

28 Scopus citations


We demonstrate that in the class of models with Constrained Minimal Flavour Violation (CMFV), in which the CKM matrix is the only source of CP violation and B0q-0q mixings (q ≤ d,s) are described by a single operator (q)V-A(q)V-A, the lower bounds on the mass differences ΔMs,d are simply given by their Standard Model values (ΔMs,d)SM with two possible exceptions that we identify. Our proof involves all possible charged gauge boson, Goldstone boson and physical charged and neutral scalar exchanges and assumes that the masses of new charge +2/3 singlet heavy fermions Ti that mix with the top quark have all to be larger than mt, which is chosen by nature. Similarly, the additional charged gauge bosons have to satisfy Mi>MW, while no such bound needs to be set on the charged and neutral scalar masses. The two possible exceptions arise in the presence of U(1) neutral gauge bosons and Majorana fermions in box diagrams with flavour violating couplings. However in the case of the MSSM with CMFV and low tan β our bound is satisfied in spite of gluino and neutralino contributions.

Original languageEnglish
Article number061
JournalJournal of High Energy Physics
Issue number5
StatePublished - 1 May 2007


  • B-physics
  • Beyond standard model


Dive into the research topics of 'Lower bounds on Δms,d from constrained minimal flavour violation'. Together they form a unique fingerprint.

Cite this