arXiv subjects
Publications and source records attributed to Mayumi Aoki.
The contributions from the Ochanomizu CP Study Group to the KEK meetings on "CP violation and its origin" (1993-1997) are summarized on electroweak baryogenesis and anomalous W-boson couplings. We survey planned new experiments which could examine some aspects studied in our contributions. We also discuss several issues on baryogenesis. Ten problems are presented for further studies.
The electric dipole moments (EDMs) of the neutron and the electron are reviewed within the framework of the supersymmetric standard model (SSM) based on grand unified theories coupled to N=1 supergravity. Taking into account one-loop and two-loop contributions to the EDMs, we explore SSM parameter space consistent with experiments and discuss predicted values for the EDMs. Implications of baryon asymmetry of our universe for the EDMs are also discussed.
We study baryogenesis at the electroweak phase transition of the universe within the framework of the supersymmetric standard model (SSM) based on N=1 supergravity. This model contains a new source of CP violation in the mass-squared matrices for squarks, which could enable $t$ squarks to mediate the charge transport mechanism for generating baryon asymmetry. The same CP-violating source also induces the electric dipole moment (EDM) of the neutron at the one-loop level. If the new CP-violating phase is not suppressed, it is shown, the $t$-squark transport can lead to baryon asymmetry consistent with its observed value within reasonable ranges of SSM parameters. For these parameter ranges the magnitude of the neutron EDM is predicted to be not much smaller than its present experimental upper bound.
We study the baryon asymmetry of the universe in the supersymmetric standard model (SSM). At the electroweak phase transition, the fermionic partners of the charged SU(2) gauge bosons and Higgs bosons are reflected from or transmitted to the bubble wallof the broken phase. Owing to a physical complex phase in their mass matrix, these reflections and transmissions have asymmetries between CP conjugate processes. Equilibrium conditions in the symmetric phaseare then shifted to favor a non-vanishing value for the baryon number density, which is realized through electroweak anomaly. We show that the resultant ratio of baryon number to entropy is consistent with its present observed value within reasonable ranges of SSM parameters, provided that the CP-violating phase intrinsic in the SSM is not much suppressed. The compatibility with the constraints on the parameters from the electric dipole moment of the neutron is also discussed.