Jean-Marc Gérard

Geometrical T-violation

We investigate the possibility of having spontaneous T violation arising from complex vacuum expectation values with calculable phases, assuming geometrical values, entirely determined by the symmetry of the scalar potential.

Aspects of CP violation in supersymmetric theories

We give a comprehensive study of CP-violating effects in low-energy softly broken supersymmetric theories. We find that gluino exchange contributions to CP violation arising from the Kobayashi-Maskawa mixing matrix may provide indirect evidence of supersymmetry at low energy. Indeed, we point out two important departures from the predictions of the standard model: (i) in the kaon system, the experimental value of the var epsilon-parameter cannot be reconciled with a large B-lifetime (τB>10−12s) and light top quark (mtless, approximate50GeV) in the context of the usual three-generation standard model; this is no longer true when the additional supersymmetry contributions to CP violation are included; (ii) in the beon system, the presence of supersymmetry enhances Image mixing as well as off-shell and on-shell CP-violating phenomena making more likely an experimental detection of some of the effects. On the other hand, the electric dipole moment of the neutron due to the Kobayashi-Maskawa phase is still very small and var epsilon′/var epsilon continues to be consistent with the experimental bounds.

Super Kobayashi-Maskawa CP-violation

We argue that in the minimal SUSY extension of the standard model, CP-violation cannot be explained through SUSY phase alone. But SUSY graphs, especially with gluinos, can make important contributions to CP-violation through the Kobayashi-Maskawa phase.

Bottom Lifetime, Top Mass And Cp Violation In Supersymmetric Theories.

We demonstrate the compatibility of a light top quark, a long-lived bottom quark and Kobayashi-Maskawa CP-violation in supersymmetric theories without invoking for example the existence of a fourth generation. In certain cases, constraints on the s-particle spectrum are unavoidable and testable.

The value of ε′/ε in models based on SU(2)L × SU(2)R × U(1)

Abstract We emphasize that the e ′/ e ratio can play a crucial role in distinguishing between various electroweak models. It is shown that SU(2)L × SU(2)R × U(1) gauge theories provide a natural scenario for obtaining either vanishing or very small values for the e ′/ e ratio. They also have the attractive feature of establishing a link between the strength of CP and P breaking.

On the Breakdown of Chiral Symmetries in Supersymmetric {QCD}

We investigate the breakdown of chiral symetries in supersymmetric QCD with N colours and M flavours, using anomaly consistency conditions and an effective lagrangian approach. For M N, however, one needs at least unbroken SU(N)V × SU(M − N)R × SU(M − N)L × U(1) × U(1) to arrive at a consistent picture.

Gluino penguins and ε′/ε

We calculate the penguin diagrams involving gluinos and discuss their implications on e′/e. The dominant contribution originates in the Kobayashi-Maskawa phase. Fixing this phase from the e parameter, we find a smaller value of e′/e; than in the non-supersymmetric case alone.

Towards supersymmetric subconstituent models

Abstract t Hoofts consistency equations for subconstituent models are generalized to supersymmetric theories and a few solutions are outlined.

Phases and amplitudes in inclusive psi and psi-prime decays

Abstract In inclusive decays of the Ψ (3097), electromagnetic and gluonic annihilation amplitudes add incoherently, namely they are 90° out of phase. We argue that this incoherence must persist in each exclusive decay channel. For inclusive Ψ ′ (3686) decays, we suggest the absence of a significant direct annihilation amplitude into three gluons and propose a new amplitude via QCD anomalies and the h c (3526) off shell. Phenomenological implications for exclusive decay channels are pointed out.

Fermion mass hierarchy and global horizontal symmetries

We present a mechanism for quark mass generation in zeroth order using induced representations rather than the minimization of the horizontal potential. Using a simplicity criterion, we derive a realistic mass matrix. We also discuss a possible application of the mechanism to various models.