56 research outputs found
A Couplet from Flavored Dark Matter
We show that a couplet, a pair of closely spaced photon lines, in the X-ray
spectrum is a distinctive feature of lepton flavored dark matter models for
which the mass spectrum is dictated by Minimal Flavor Violation. In such a
scenario, mass splittings between different dark matter flavors are determined
by Standard Model Yukawa couplings and can naturally be small, allowing all
three flavors to be long-lived and contribute to the observed abundance. Then,
in the presence of a tiny source of flavor violation, heavier dark matter
flavors can decay via a dipole transition on cosmological timescales, giving
rise to three photon lines. The ratios of the line energies are completely
determined in terms of the charged lepton masses, and constitute a firm
prediction of this framework. For dark matter masses of order the weak scale,
the couplet lies in the keV-MeV region, with a much weaker line in the eV-keV
region. This scenario constitutes a potential explanation for the recent claim
of the observation of a 3.5 keV line. The next generation of X-ray telescopes
may have the necessary resolution to resolve the double line structure of such
a couplet.Comment: 17 pages, 4 figures, 1 haik
Detecting Dark Matter with Aharonov-Bohm
While the evidence for dark matter continues to grow, the nature of the dark
matter remains a mystery. A dark gauge theory can have a small kinetic
mixing with the visible photon which provides a portal to the dark sector.
Magnetic monopoles of the dark can obtain small magnetic couplings to
our photon through this kinetic mixing. This coupling is only manifest below
the mass of the dark photon; at these scales the monopoles are bound together
by tubes of dark magnetic flux. These flux tubes can produce phase shifts in
Aharonov-Bohm type experiments. We outline how this scenario might be realized,
examine the existing constraints, and quantify the experimental sensitivity
required to detect magnetic dipole dark matter in this novel way.Comment: 14 pages, 2 figures; Updated references and expanded discussion
agrees with published versio
Interactions of a Stabilized Radion and Duality
We determine the couplings of the graviscalar radion in Randall-Sundrum
models to Standard Model fields propagating in the bulk of the space, taking
into account effects arising from the dynamics of the Goldberger-Wise scalar
that stabilizes the size of the extra dimension. The leading corrections to the
radion couplings are shown to arise from direct contact interactions between
the Goldberger-Wise scalar and the Standard Model fields. We obtain a detailed
interpretation of the results in terms of the holographic dual of the radion,
the dilaton. In doing so, we determine how the familiar identification of the
parameters on the two sides of the AdS/CFT correspondence is modified in the
presence of couplings of the bulk Standard Model fields to the Goldberger-Wise
scalar. We find that corrections to the form of the dilaton couplings from
effects associated with the stabilization of the extra dimension are suppressed
by the square of the ratio of the dilaton mass to the Kaluza-Klein scale, in
good agreement with results from the CFT side of the correspondence.Comment: 22 pages plus appendices and reference
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