Low-scale inflation in a model of dark energy and dark matter

We present a complete particle physics model that explains three major problems of modern cosmology: inflation, dark matter and dark energy, and also gives a mechanism for leptogenesis. The model has a new gauge group $SU(2)_Z$ that grows strong at a scale $\Lambda\sim 10^{-3}$ eV. We focus on the inflationary aspects of the model. Inflation occurs with a Coleman-Weinberg potential at a low scale, down to \sim 6\times 10^5\gev, being compatible with observational data.Comment: 5 two-column pages, RevTex4; two reference added and minor changes made in the text; published in JCA

A phenomenological Theory of Fermion Masses and Mixings

A phenomenological theory of fermion masses and mixings is constructed within the framework of a four- family symmetry. It is found that the most favored set of relevant CKM elements are $|V_{us}|\approx 0.222$, $|V_{cb}|\approx 0.044$, $|V_{ub}/V_{cb}|\approx 0.082$, $|V_{ud}|\approx 0.974$, $|V_{cs}|\approx 0.9736$, $|V_{cd}|\approx 0.224$ with $\hat{B}_K \approx 0.8$. The top quark mass is predicted to be 258 GeV at 1 GeV with its physical mass approximately equal to 153 GeV. The Majorana scale associated with the fourth neutrino is bound from above to be 6.4 TeV.Comment: 13 pages RevTeX, INPP-UVA-94-

Teeny, tiny Dirac neutrino masses: an unorthodox point of view

There are now strong hints suggesting that neutrinos do have a mass after all. If they do have a mass, it would have to be tiny. Why is it so? Is it Dirac or Majorana? Can one build a model in which a teeny, tiny Dirac neutrino mass arises in a natural way? Can one learn something else other than just neutrino masses? What are the extra phenomenological consequences of such a model? These are the questions that I will try to focus on in this talk.Comment: 11 pages, 2 figures, LateX, aipproc style. Talk presented at the Second Tropical Workshop on Particle Physics and Cosmology, Neutrino and Flavor Physics, 1-6 May 2000, San Juan, Puerto Ric

The Lifetime Frontier: Search for New Physics with Long-Lived Particles

The search for new physics with long-lived particles is an ongoing and thriving effort in the High Energy Physics community which necessitates new search strategies such as novel algorithms, novel detectors, etc...For these reasons, one could perhaps add another frontier, the Lifetime Frontier, to the standard three (Energy, Intensity and Cosmic). In this talk, I will describe a BSM physics model whose characteristic signatures are decays of new (mirror) fermions at displaced vertices, a domain belonging to the Lifetime Frontier. It is a model of {\em non-sterile} right-handed neutrinos whose masses are proportional to the electroweak scale $\Lambda_{EW} \sim 246 \, GeV$. The model proposed a solution to the strong CP problem with a surprising connection between the sizes of the neutrino masses and the $\theta$-angle which contributes to the neutron electric dipole moment.Comment: 6 pages, 3 figures, contribution to the 2019 EW/QCD/Gravitation session of the 54th Rencontres de Morion