A left-right model with spontaneous
CP breakdown, consistent with the particle physics phenomenology, is presented. Constraints on free parameters of the model: mass of the new righthanded gauge ...boson
M
2 and ratio
r of the two vacuum expectation valuesof the bidoublet, are found from the measurement of ϵ in the kaon system. For most of the parameter space,
M
2 is restricted to be below 10 TeV Higher masses can be achieved only by fine tuning of Kobayashi-Maskawa matrix elements, quark masses,
r and the phase α which is the unique source of
CP violation in the model. Large number of combinations of signs of quark masses, which are observables of the model, are found to be not allowed since they contradict with data. The range of ϵ'/ϵ the model predicts is around 10
−4 in magnitude.
We argue that large non-decoupling effects of heavy neutrinos can appear naturally in manifestly left-right symmetric models due to the minimization conditions of the scalar potential and the ...structure of vev's imposed by phenomenology. We derive constraints on off-diagonal light-heavy and heavy-heavy neutrino mixings from the searches for lepton violating decays
μ →
eγ,
μ →
ee
−
e
+ and
μ −
e conversion in nuclei. The most stringent limits come from the latter process because its amplitude shows a quadratic non-decoupling dependence on the heavy neutrino mass. Due to the suppression of right-handed currents by the large
W
R
mass the present experiment are not sensitive to the intergenerational mixings between heavy neutrinos if
M
W
R
> 200 TeV.
We present a new approach to quintessential inflation, in which both dark energy and inflation are explained by the evolution of a single scalar field. We start from a simple scalar potential with ...both oscillatory and exponential behavior. We employ the conventional reheating mechanism of new inflation, in which the scalar decays to light fermions with a decay width that is proportional to the scalar mass. Because our scalar mass is proportional to the Hubble rate, this gives adequate reheating at early times while shutting off at late times to preserve quintessence and satisfy nucleosynthesis constraints. We discuss a simple model which solves the horizon, flatness, and “why now” problems. Without any additional tuning of parameters, this model satisfies all constraints from CMB, large scale structure, and nucleosynthesis. The predictions for the inflationary spectral indices are nS=nT=1. In this model we are currently beginning the third cosmic epoch of accelerated expansion.
We investigate the allowed ranges of masses for an unstable tau neutrino in the context of
SO(10) GUTs. In light of the new nucleosynthesis results we obtain that there is a narrow window for
m
ν
τ
...where the LEP, neutrino oscillation and nucleosynthesis data are compatible. This window, which depends on the effective number of neutrinos contributing to nucleosynthesis, has important cosmological consequences and will be tested by ongoing neutrino oscillation and LEP II experiments.
PDF
