9,593 research outputs found
Unified TeV Scale Picture of Baryogenesis and Dark Matter
We present a simple extension of MSSM which provides a unified picture of
cosmological baryon asymmetry and dark matter. Our model introduces a gauge
singlet field and a color triplet field which couple to the
right--handed quark fields. The out--of equilibrium decay of the Majorana
fermion mediated by the exchange of the scalar field generates adequate
baryon asymmetry for GeV and TeV. The scalar partner
of (denoted ) is naturally the lightest SUSY particle as it
has no gauge interactions and plays the role of dark matter.
annihilates into quarks efficiently in the early universe via the exchange of
the fermionic field. The model is experimentally testable in (i)
neutron--antineutron oscillations with a transition time estimated to be around
sec, (ii) discovery of colored particles at LHC with mass of
order TeV, and (iii) direct dark matter detection with a predicted cross
section in the observable range.Comment: 10 pages, one reference updated. Version to appear in Phys. Rev. Let
New vector-scalar contributions to neutrinoless double beta decay and constraints on R-parity violation
We show that in minimal supersymmetric standard model (MSSM) with R-parity
breaking as well as in the left-right symmetric model, there are new observable
contributions to neutrinoless double beta decay arising from hitherto
overlooked diagrams involving the exchange of one W boson and one scalar boson.
In particular, in the case of MSSM, the present experimental bounds on
neutrinoless double beta decay lifetime improves the limits on certain R-parity
violating couplings by about two orders of magnitude. It is shown that similar
diagrams also lead to enhanced rates for conversion in
nuclei, which are in the range accessible to ongoing experiments.Comment: Latex file; 9 pages; 3 figures available on reques
A Theory of Anomaly With Right-Handed Currents
We present an ultraviolet complete theory for the and anomaly
in terms of a low mass gauge boson of a class of left-right symmetric
models. These models, which are based on the gauge symmetry , utilize vector-like fermions to
generate quark and lepton masses via a universal seesaw mechanism. A parity
symmetric version as well as an asymmetric version are studied. A light sterile
neutrino emerges naturally in this setup, which allows for new decay modes of
-meson via right-handed currents. We show that these models can explain
and anomaly while being consistent with LHC and LEP data as
well as low energy flavor constraints arising from , mixing, etc., but only for a limited range
of the mass: for
parity asymmetric (symmetric) Yukawa sectors. The light sterile neutrinos
predicted by the model may be relevant for explaining the MiniBoone and LSND
neutrino oscillation results. The parity symmetric version of the model
provides a simple solution to the strong CP problem without relying on the
axion. It also predicts an isospin singlet top partner with a mass TeV.Comment: 43 pages, 7 figures, references added, model slightly modifie
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