Masahisa Matsuda

Explicit CP Violation of the Higgs Sector in the Next-to-Minimal Supersymmetric Standard Model

We study the explicit {ital CP} violation of the Higgs sector in the minimal supersymmetric standard model with a gauge singlet Higgs field. The magnitude of {ital CP} violation is discussed in the limiting cases of {ital x}{much_gt}{ital v}{sub 1},{ital v}{sub 2} and {ital x}{much_lt}{ital v}{sub 1}, {ital v}{sub 2}, where {ital x} and {ital v}{sub 1,2} denote the VEV`s of singlet and doublet Higgs scalars, respectively. Our numerical predictions of the electric dipole moments of the electron and neutron lie around the present experimental upper limts. It is found that the large {ital CP} violation effect reduces the magnitude of the lightest Higgs boson mass on the order of a few tens of GeV.

Spontaneous CP violation and Higgs boson masses in the next-to-minimal supersymmetric model.

We study the possibility of spontaneous {ital CP} violation in the next-to-minimal supersymmetric standard model. It is shown that the spontaneous {ital CP} violation is induced by the radiative effects of top quark, top squark, bottom quark, and bottom squark superfields. The available regions of parameters, which are obtained by imposing the constraints from experiments, are rather narrow. We also obtain strong constraints for light Higgs boson masses such as {ital m}{sub {ital H}}{le}36 GeV numerically. The sum of the masses of the two light neutral Higgs boson should set around 93 GeV and the charged Higgs boson has a somewhat higher mass, larger than 700 GeV. {copyright} {ital 1996 The American Physical Society.}

A Possible Interpretation of the New Event in the Cosmic Ray Experiment. II

In a previous paper we have analysed a new event observed by Niu and others in cosmic ray experiments, and have been able to present a reasonable interpretation of it on the basis of the new (modified) Nagoya model for urbaryons. Anticipating the accumulation of such new events, we shall give a further study in this paper, especially about the details of weak decay processes which were not fully developed in the previous work.

New Possibility of Solving the Problem of the Lifetime Ratio τ(Λb ) / τ(Bd)

We discuss the problem of the large discrepancy between the observed lifetime ratio of

Hard gamma emission from b-decay and the Higgs boson doublet model

\Lambda_b

Fermion Masses and Mixings in a String Inspired Model

to

Electric dipole moments of neutron and electron in two-Higgs-doublet model with maximal CP violation.

B_d

A large Majorana mass from Calabi-Yau superstring models

and the theoretical prediction obtained by the heavy quark effective theory. A new possibility of solving this problem is proposed from the viewpoint of operator product expansion and the lifetime ratio of

On the possible existence of a diproton resonance. A proposal of p-p scattering experiment at about 500 MeV

\Omega_b

THE SEARCH FOR THE DECAY OF Z BOSON INTO TWO PHOTONS AS A TEST OF BOSE STATISTICS

to