arXiv subjects

Tadashi Yoshikawa

Publications and source records attributed to Tadashi Yoshikawa.

21 records · Page 2Linked to original sources

arXiv2001

Model of Soft CP Violation

We propose a model of soft CP violation that evades the strong CP problem and can describe observed CP violation in the neutral kaon sector, both direct and indirect. Our model requires two ``duark'' mesons carrying quark number two that have complex (CP-violating) bare masses and are coupled to quark pairs. Aside from the existence of these potentially observable new particles with masses of several hundred GeV, we predict a flat unitarity triangle ({\it i.e.,} no observable direct CP violation in the $B$-meson sector) and a possibly anomalous branching ratio for the decay mode $K^+\to π^++\barν ν$.

hep-ph↗

arXiv1995

The Effects of a Vector-like Doublet as the Fourth Generation to $R_b$

We study the effects of a vector-like SU(2) doublet quarks as the fourth generation on $R_b$ and $R_c$. By considering the constraint from the experimental data of forward-backward asymmetry, $A_{FB}^b$ and $A_{FB}^c$,as well as FCNC among light quarks, we show that there is an allowed region of parameters for $R_b$ but not for $R_c$.

hep-ph↗

arXiv1995

The Oblique Corrections from the Diagonal ETC Interaction

We study the effect of the diagonal extended technicolor(ETC) gauge boson on the oblique correction parameters. It is shown that in the $T$ parameter is unacceptably large when the $Zbb$ vertex correction and $S$ parameter are consistent with the experiments in the ETC model.

hep-ph↗