arXiv subjects

Tomomi Saito

Publications and source records attributed to Tomomi Saito.

3 recordsLinked to original sources

arXiv1999

CP-odd WWZ couplings induced by vector-like quarks

A minimal extension of the standard model includes extra quarks with charges 2/3 and/or -1/3, whose left-handed and right-handed components are both SU(2) singlets. This model predicts new interactions of flavor-changing neutral current at the tree level, which also violate CP invariance. We study CP-odd anomalous couplings for the gauge bosons W, W, and Z induced by the new interactions at the one-loop level. These couplings become nonnegligible only if both an up-type and a down-type extra quarks are incorporated. Their form factors are estimated to be maximally of order $10^{-5}$. Such magnitudes are larger than those predicted in the standard model, though smaller than those in certain other models.

hep-ph↗

arXiv1997

CP-odd Anomalous W-boson Couplings from Supersymmety

The supersymmetric standard model contains a new CP-violating phase in the mass matrices for charginos and neutralinos, which could induce CP-odd anomalous couplings for the WWZ and WWγvertices at the one-loop level. We study these couplings, paying attention to the model-parameter and q^2 dependencies. It is shown that the CP-odd form factors could have values of order 10^{-3}-10^{-4}, which are much larger than those predicted by the standard model. We also discuss the possibility of examining these form factors in experiments.

hep-ph↗

arXiv1997

Study of CP Violation: Electroweak Baryogenesis and Anomalous W-Boson Couplings

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.

hep-ph↗