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Andreas Crivellin ITP Bern. Radiative Flavour Violation in the MSSM. in collaboration with Lars Hofer, Ulrich Nierste and Dominik Scherer. Outline:. Why radiative mass generation? The SUSY flavor (CP) problem and the trilinear A-terms Radiative flavour violation in the MSSM
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Andreas Crivellin ITP Bern Radiative Flavour Violation in the MSSM in collaboration with Lars Hofer, Ulrich Nierste and Dominik Scherer
Outline: • Why radiative mass generation? • The SUSY flavor (CP) problem and the trilinear A-terms • Radiative flavour violation in the MSSM • Phenomenological consequences: • B→sγ • Kaon mixing • K →πνν • Bs mixing and Bs→μ+μ-
Radiative mass generation • The smallness of the Yukawa couplings of the first two generations (and the small off-diagonal CKM elements) suggest the idea that these quantities are loop-induced corrections. • SM: Weinberg, 1972; • SUSY: • Buchmüller, Wyler, 1983; • Banks 1988; • Borzumati, Farrar, Polonsky, Thomas 1998/1999; • Ferrandis, Haba 2004
SUSY flavor (CP) problem • The squark mass matrices are not necessarily diagonal (and real) in the same basis as the quark mass matrices. • Especially the trilinear A-terms can induce dangerously large flavor-mixing (and complex phases) because they are also chirality flipping. Possible solutions: • Flavor symmetries • Minimal flavor-violation • Radiative flavor-violation
Chirality-flipping self-energy: Chirally-enhanced part: non-decoupling
Finite renormalization • Corrections to the mass: • Corrections to the CKM matrix: important two-loop corrections A.C.; J. Girrbach 2010
The model SU(2)³ flavor-symmetry in the MSSM superpotential: • CKM matrix is the unit matrix. • Only the third generation Yukawa coupling is different from zero. All other elements are generated via loops using the trilinear A-terms!
Features of the model • Additional flavor symmetries in the superpotential. • Explains small masses and mixing angles via a loop-suppression. • Minimally flavor-violating with respect to the first two generations (renormalization group invariant). • Deviations from MFV if the third generation is involved. • Solves the SUSY CP problem via a mandatory phase alignment between the masses and the A-terms. (Phase of μ enters only at two loops)Borzumati, Farrar, Polonsky, Thomas 1999. • The SUSY flavor problem reduces to the elements which are less constrained.
CKM generation in the up-sector: • Parameter regions compatible with Kaon mixing
Effects in K→πνν • Verifiable predictions for NA62
CKM generation in the down-sector: • Allowed regions from b→sγ.Chirally enhanced corrections must be taken into account.A.C., Ulrich Nierste 2009
Non-decoupling effects • Non-holomorphic self-energies induce flavour-changing neutral Higgs couplings. • Effect proportional to εb
Higgs effects: Bs→μ+μ- • Constructive contribution due to
Higgs effects: Bs mixing • Contribution only if due to Peccei-Quinn symmetry
Correlations between Bs mixing and Bs→μ+μ- • Br[Bs→μ+μ-]x10-9
Conclusions • RFV solves the SUSY flavour and the SUSY CP problem. • Constraints from b→sγ and Kaon mixing satisfied for SUSY masses O(1 TeV) • Large effects in K→πνν possible • Can explain the Bs mixing phase and enhance Bs→μ+μ-