4 research outputs found
Baryogenesis with Superheavy Squarks
We consider a setup where R-parity is violated in the framework of split
supersymmetry. The out-of-equilibrium decays of heavy squarks successfully lead
to the generation of a baryon asymmetry. We restrict the R-parity violating
couplings to the baryon number violating subset to keep the neutralino
sufficiently stable to provide the dark matter. The observed baryon asymmetry
can be generated for squark masses larger than 10^11 GeV, while neutralino dark
matter induces a stronger bound of 10^13 GeV. Some mass splitting between left-
and right-handed squarks may be needed to satisfy also constraints from gluino
cosmology.Comment: 18 pages, LaTeX, 4 figure
Can we distinguish between h^{SM} and h^0 in split supersymmetry?
We investigate the possibility to distinguish between the Standard Model
Higgs boson and the lightest Higgs boson in Split Supersymmetry. We point out
that the best way to distinguish between these two Higgs bosons is through the
decay into two photons. It is shown that there are large differences of several
percent between the predictions for \Gamma(h\to\gamma\gamma) in the two models,
making possible the discrimination at future photon-photon colliders. Once the
charginos are discovered at the next generation of collider experiments, the
well defined predictions for the Higgs decay into two photons will become a
cross check to identify the light Higgs boson in Split Supersymmetry.Comment: 8 pages, 3 Figures, typos fixed, version published in J.Phys. G31
(2005) 563-56
Simplified Models for LHC New Physics Searches
This document proposes a collection of simplified models relevant to the
design of new-physics searches at the LHC and the characterization of their
results. Both ATLAS and CMS have already presented some results in terms of
simplified models, and we encourage them to continue and expand this effort,
which supplements both signature-based results and benchmark model
interpretations. A simplified model is defined by an effective Lagrangian
describing the interactions of a small number of new particles. Simplified
models can equally well be described by a small number of masses and
cross-sections. These parameters are directly related to collider physics
observables, making simplified models a particularly effective framework for
evaluating searches and a useful starting point for characterizing positive
signals of new physics. This document serves as an official summary of the
results from the "Topologies for Early LHC Searches" workshop, held at SLAC in
September of 2010, the purpose of which was to develop a set of representative
models that can be used to cover all relevant phase space in experimental
searches. Particular emphasis is placed on searches relevant for the first
~50-500 pb-1 of data and those motivated by supersymmetric models. This note
largely summarizes material posted at http://lhcnewphysics.org/, which includes
simplified model definitions, Monte Carlo material, and supporting contacts
within the theory community. We also comment on future developments that may be
useful as more data is gathered and analyzed by the experiments.Comment: 40 pages, 2 figures. This document is the official summary of results
from "Topologies for Early LHC Searches" workshop (SLAC, September 2010).
Supplementary material can be found at http://lhcnewphysics.or