110 research outputs found
A probe of the Radion-Higgs mixing in the Randall-Sundrum model at e^+ e^- colliders
In the Randall-Sundrum model, the radion-Higgs mixing is weakly suppressed by
the effective electroweak scale. A novel feature of the existence of
gravity-scalar mixing would be a sizable three-point vertex among the KK
graviton, Higgs and radion. We study this vertex in the process e^+ e^- -> h
phi, which is allowed only with a non-zero radion-Higgs mixing. It is shown
that the angular distribution is a unique characteristic of the exchange of
massive spin-2 gravitons, and the total cross section at the future e^+ e^-
collider is big enough to cover a large portion of the parameter space where
the LEP/LEP II data cannot constrain.Comment: 14pages, RevTeX, 5 figure
Kinematic Cusps: Determining the Missing Particle Mass at Colliders
In many extensions of the SM, neutral massive stable particles (dark matter
candidates) are produced at colliders in pairs due to an exact symmetry called
a "parity". These particles escape detection, rendering their mass measurement
difficult. In the pair production of such particles via a specific ("antler")
decay topology, kinematic cusp structures are present in the invariant mass and
angular distributions of the observable particles. Together with the
end-points, such cusps can be used to measure the missing particle mass and the
intermediate particle mass in the decay chain. Our simulation of a benchmark
scenario in a Z' supersymmetric model shows that the cusp feature survives
under the consideration of detector simulation and the standard model
backgrounds. This technique for determining missing particle masses should be
invaluable in the search for new physics at the LHC and future lepton
colliders.Comment: final version in Phys. Lett.
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