Related papers: Possible Chandra-Mechanism for Generation Bound
We propose a simple extension of the standard model by adding a fourth generation vector-like lepton doublet and show that if the fourth neutrino is a massive pseudo-Dirac fermion with mass in the few hundred GeV range and mass splitting of…
Phenomenological analysis to the R-parity violating supersymmetry with a vector-like extra generation is performed in detail. It is found that, via the trilinear couplings, the correct neutrino spectrum can be obtained. The Higgs mass rises…
Globular Cluster (GC) formation seems to be a widespread mode of star formation in extreme starbursts triggered by strong interactions and mergers of massive gas-rich galaxies. We use our detailed chemically consistent evolutionary…
From non-observation at LEP1, a lower mass limit of 45 GeV has been established on any additional sequential fermion beyond the three generations. Precision measurements have further constrained the number of such additional generations,…
Contributed talk at the Seventh Marcel Grossman Meeting on Gravity, June 24-30. A theory of evolution of the universe requires both a mutation mechanism and a selection mechanism. We believe that both can be encountered in the stochastic…
Recent progress in lattice QCD, combined with the imminent advent of a new generation of dedicated supercomputers and advances in chiral extrapolation mean that the next few years will bring quite novel insights into hadron structure. We…
While computing the Fermi degeneracy pressure of electrons in a white dwarf star within the framework of hydrostatic equilibrium, we depart from the extant practice of treating the electrons as a free fermion gas, by including the effect of…
We present model independent constraints on the masses and couplings to fermions of $B$ and $L$ conserving leptoquarks. Such vector or scalar particles could have masses below 100 GeV and be produced at HERA; we list the generation…
A dynamical scheme where the third generation of quarks plays a distinctive role is implemented. New interactions with a $\theta$ term induce the breaking of the electroweak symmetry and the top-bottom mass splitting. A large CP-violating…
We consider a branching process with Poissonian immigration where individuals have inheritable types. At rate theta, new individuals singly enter the total population and start a new population which evolves like a supercritical,…
A new model of radiative neutrino masses generated via two-loop diagrams is proposed involving a charge 2/3 vector-like quark and a doublet of leptoquark scalars. This model predicts one of the neutrinos to be massless and admits both the…
We investigate a proposal to address several outstanding shortcomings of the perturbative Standard Model (SM) of particle physics. The appeal of this proposal is that these features are a manifestation of the non-perturbative sector of the…
The problem of quark-lepton families is discussed in the "bottom-up" phenomenological approach to the extensions of the Standard model. It provides the possibility of the {\it Horizontal unification} of the three known families on the basis…
It is shown that existing data on the mixing between up and down fermion states and on the hierarchical mass ratios between fermion generations, as far as can be so analysed at present, are all consistent with the two phenomena being both…
We consider constraints on models in which a top quark mass is generated through unenhanced extended technicolor interactions. The deviation in the $\rho$ parameter from unity and $B$--$\overline{B}$ mixing could be large, but given the…
Scattering from a compound barrier, one composed of a number of distinct non-overlapping sub-barriers, has a number of interesting and subtle mathematical features. If one is scattering classical particles, where the wave aspects of the…
We consider large classes of chiral extensions of the Standard Model, including new quark generations that do not involve additional neutrinos as well as lepton generations without quarks. An analysis of renormalization flows of Yukawa and…
We suggest a model which addresses both the fermion mass hierarchy problem and the family problem in two-layer warped extra dimensions. In this model, 3 family fermions in 4 dimensions (4D) generate from 1 family in two-layer warped 6D by…
We consider the possibility that Dirac neutrino masses may be a manifestation of chiral symmetry breaking via non-perturbative QCD dynamics. The key role played by light quarks in this mechanism can naturally lead to signals that are…
The scale of fermion mass generation can, as shown by Appelquist and Chanowitz, be bounded from above by relating it to the scale of unitarity violation in the helicity nonconserving amplitude for fermion-anti-fermion pairs to scatter into…