arXiv subjects
Publications and source records attributed to Ernest Ma.
Recently a model of chaotic inflation was proposed, where the right handed sneutrinos drive the baryogenesis. We study some of the details of the model, particularly the aspect of CP violation, and determine the number of right handed sneutrinos required for the viability of such models.
If the standard electroweak gauge model is embedded in a larger theory which is supersymmetric and the latter breaks down to the former at some mass scale, then the reduced Higgs potential at the electroweak mass scale may differ from that of the well-known minimal supersymmetric extension. Specifically, if the larger theory is based on $\rm {SU(2)_L \times SU(2)_R \times U(1)}$, an interesting alternative exists for two Higgs doublets.
In the minimal supersymmetric standard model, the Higgs sector has two unknown parameters, usually taken to be $\tan β\equiv v_2/v_1$ and $m_A$, the mass of its one physical pseudoscalar particle. By minimizing the minimum of the Higgs potential along a certain direction in parameter space, it is shown that $m_A = M_Z$ + radiative correction, and if one further plausible assumption is made, $\tan β> \sqrt 3$.
There is a good reason why the standard electroweak SU(2) X U(1) gauge model may be supplemented by two Higgs scalar doublets. They may be remnants of the spontaneous breaking of an SU(2) X SU(2) X U(1) gauge symmetry at a much higher energy scale. In one case, the two-doublet Higgs potential has a custodial SU(2) symmetry and implies an observable scalar triplet. In another, a light neutral scalar becomes possible.
If one or more otherwise divergent quantities in the standard model are actually finite, they may be indications of underlying dynamics. In particular, one-loop finiteness of the m_H renormalization is achieved if m_t^2 \simeq m_H^2 = (2M_W^2 + M_Z^2)/3.
In extensions of the standard model, light scalar particles are often possible because of symmetry considerations. We study the decay of the Z boson into such particles. In particular, we consider for illustration the scalar sector of a recently proposed model of the 17-keV neutrino which satisfies all laboratory, astrophysical, and cosmological constraints.
It is shown by explicit calculation that the one-loop mass renormalization of the Higgs boson in the standard model is gauge-independent. It could even be rendered finite if the following mass relationships were satisfied: $m_t^2 \simeq m_H^2 = (2 M_W^2 + M_Z^2)/3$. Numerically, this would imply $m_t \simeq 84~GeV$ which is below the current experimental lower bound of 91 GeV, but since higher-order corrections are yet to be calculated, the above hypothesis could still have a chance of being realized.
A gauge model of generation nonuniversality proposed in 1981 is reexamined in the light of present precision electroweak measurements. Two necessary features of this model are that the tau lifetime should be longer than predicted by the standard model and that the rho parameter measured at the Z peak should have an additional negative contribution. Both trends are noticeable in present data. A future decisive test of this model would be the discovery of new W and Z bosons with nearly degenerate masses of a few TeV.
The universality of $e-μ-τ$ interactions may only be an accidental approximate symmetry analogous to that of flavor SU(2) and SU(3). This was specifically realized by an extension of the standard model proposed in 1981. Two key predictions are that the $τ$ lifetime should be longer and that the $ρ$ parameter measured at the Z peak should have an additional negative contribution. These are consistent with present precision electroweak measurements. A future decisive test of this model would be the discovery of new W and Z bosons with nearly degenerate masses of a few TeV.
If the quadratic divergence of the standard electroweak model and its local variation with mass scale are both assumed to be zero, then a modified one-loop calculation yields m_t = 117 GeV and m_H = 183 GeV. Such a scenario may be the result of an underlying theory to be revealed at a much higher mass scale.