4,419 research outputs found
Oscillating Asymmetric Sneutrino Dark Matter from the Maximally Supersymmetric Inverse Seesaw
The inverse seesaw mechanism provides an attractive approach to generate
small neutrino mass, which origins from a tiny breaking. In this
paper, we work in the supersymmetric version of this mechanism, where the
singlet-like sneutrino could be an asymmetric dark matter (ADM) candidate in
the maximally symmetric limit. However, even a tiny , the
mass splitting between sneutrino and anti-sneutrino as a result of the tiny
breaking effect, could lead to fast oscillation between sneutrino
and anti-sneutrino and thus spoils the ADM scenario. We study the evolution of
this oscillation and find that a weak scale sneutrino, which tolerates a
relatively larger eV, is strongly favored. We also
investigate possible natural ways to realize that small in the
model.Comment: PLB versio
Isospin-Violating Dark Matter and Neutrinos From the Sun
We study the indirect detection of dark matter through neutrino flux from
their annihilation in the center of the Sun, in a class of theories where the
dark matter-nucleon spin-independent interactions break the isospin symmetry.
We point out that, while the direct detection bounds with heavy targets like
Xenon are weakened and reconciled with the positive signals in DAMA and CoGeNT
experiments, the indirect detection using neutrino telescopes can impose a
relatively stronger constraint and brings tension to such explanation, if the
annihilation is dominated by heavy quark or -lepton final states. As a
consequence, the qualified isospin violating dark matter candidate has to
preferably annihilate into light flavors.Comment: 5 pages, 3 figures, 1 tabl
Exotic Fermions and Bosons in the Quartification Model
Exotic fermions of half-integral charges at the TeV energy scale are
predicted by the quartification model of Babu, Ma, and Willenbrock. We add to
these one copy of their scalar analogs and discuss the ensuing phenomenological
implications, i.e. radiative contributions to lepton masses and flavor-changing
leptonic decays.Comment: 7 pages, including 3 figure
Constraints on Unparticle Interactions from Invisible Decays of Z, Quarkonia and Neutrinos
Unparticles (\U) interact weakly with particles. The direct signature of
unparticles will be in the form of missing energy. We study constraints on
unparticle interactions using totally invisible decay modes of , vector
quarkonia and neutrinos. The constraints on the unparticle interaction
scale \Lambda_\U are very sensitive to the dimension d_\U of the
unparticles. From invisible and decays, we find that with d_\U close
to 1 for vector \U, the unparticle scale \Lambda_\U can be more than
TeV, and for d_\U around 2, the scale can be lower than one TeV. From
invisible neutrino decays, we find that if d_\U is close to 3/2, the scale
can be more than the Planck mass, but with d_\U around 2 the scale can be as
low as a few hundred GeV. We also study the possibility of using V (Z)\to
\gamma + \U to constrain unparticle interactions, and find that present data
give weak constraints.Comment: 12 pages, 4 figures, version to appear in JHEP
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