3,977 research outputs found
Interpretation of searches for supersymmetry with simplified models
The results of searches for supersymmetry by the CMS experiment are interpreted in the framework of simplified models. The results are based on data corresponding to an integrated luminosity of 4.73 to 4.98  fb^(-1). The data were collected at the LHC in proton–proton collisions at a center-of-mass energy of 7 TeV. This paper describes the method of interpretation and provides upper limits on the product of the production cross section and branching fraction as a function of new particle masses for a number of simplified models. These limits and the corresponding experimental acceptance calculations can be used to constrain other theoretical models and to compare different supersymmetry-inspired analyses
Interpretation of searches for supersymmetry with simplified models
The results of searches for supersymmetry by the CMS experiment are interpreted in the framework of simplified models. The results are based on data corresponding to an integrated luminosity of 4.73 to 4.98  fb^(-1). The data were collected at the LHC in proton–proton collisions at a center-of-mass energy of 7 TeV. This paper describes the method of interpretation and provides upper limits on the product of the production cross section and branching fraction as a function of new particle masses for a number of simplified models. These limits and the corresponding experimental acceptance calculations can be used to constrain other theoretical models and to compare different supersymmetry-inspired analyses
Simplified models for same-spin new physics scenarios
Simplified models are an important tool for the interpretation of searches
for new physics at the LHC. They are defined by a small number of new particles
together with a specific production and decay pattern. The simplified models
adopted in the experimental analyses thus far have been derived from
supersymmetric theories, and they have been used to set limits on
supersymmetric particle masses. We investigate the applicability of such
simplified supersymmetric models to a wider class of new physics scenarios, in
particular those with same-spin Standard Model partners. We focus on the pair
production of quark partners and analyze searches for jets and missing energy
within a simplified supersymmetric model with scalar quarks and a simplified
model with spin-1/2 quark partners. Despite sizable differences in the
detection efficiencies due to the spin of the new particles, the limits on
particle masses are found to be rather similar. We conclude that the
supersymmetric simplified models employed in current experimental analyses also
provide a reliable tool to constrain same-spin BSM scenarios.Comment: 11 pages + references, 7 figures; v2: added references, minor
improvements in the presentatio
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
Searches for Supersymmetry with the ATLAS Detector
This is a review of searches for supersymmetry (SUSY) with the ATLAS detector
in proton-proton collisions at a center-of-mass energy of 7 TeV at the Large
Hadron Collider at CERN. The review covers results that have been published, or
submitted for publication, up to September 2012, many of which cover the full 7
TeV data-taking period. No evidence for SUSY has been seen; some possibilities
for future directions are discussed.Comment: 15 pages, 2 figures. Invited review article for Modern Physics
Letters A. Electronic version of an article published as Mod. Phys. Lett. A,
Vol. 27, No. 32 (2012) 1230033 DOI: 10.1142/S0217732312300339 copyright World
Scientific Publishing Company http://www.worldscientific.com/worldscinet/mpl
Constraining supersymmetry at the LHC with simplified models for squark production
An important tool for interpreting LHC searches for new physics are
simplified models. They are characterized by a small number of parameters and
thus often rely on a simplified description of particle production and decay
dynamics. Considering the production of squarks of the first two generations we
compare the interpretation of current LHC searches for hadronic jets plus
missing energy signatures within simplified models with the interpretation
within a complete supersymmetric model. Although we find sizable differences in
the signal efficiencies, in particular for large supersymmetric particle
masses, the differences between the mass limits derived from a simplified model
and from the complete supersymmetric model are moderate given the current LHC
sensitivity. We conclude that simplified models provide a reliable tool to
interpret the current hadronic jets plus missing energy searches at the LHC in
a more model-independent way.Comment: 11 pages + references, 5 figures; v2: title changed, minor
improvements in the presentatio
LHC Coverage of RPV MSSM with Light Stops
We examine the sensitivity of recent LHC searches to signatures of
supersymmetry with R-parity violation (RPV). Motivated by naturalness of the
Higgs potential, which would favor light third-generation squarks, and the
stringent LHC bounds on spectra in which the gluino or first and second
generation squarks are light, we focus on scenarios dominated by the pair
production of light stops. We consider the various possible direct and cascade
decays of the stop that involve the trilinear RPV operators. We find that in
many cases, the existing searches exclude stops in the natural mass range and
beyond. However, typically there is little or no sensitivity to cases dominated
by UDD operators or LQD operators involving taus. We propose several ideas for
searches which could address the existing gaps in experimental coverage of
these signals.Comment: 41 pages, 12 figures; v2: included new searches (see footnote 10),
minor corrections and improvement
- …