14 research outputs found
More Energy, More Searches, but the pMSSM Lives On
We further examine the capability of the 7 and 8 TeV LHC to explore the
parameter space of the p(henomenological)MSSM with neutralino LSPs. Here we
present an updated study employing all of the relevant ATLAS SUSY analyses, as
well as all relevant LHC non-MET searches, whose data were publically available
as of mid-September 2012. We find that roughly 1/3 of our pMSSM model points
are excluded at present with an important role being played by both the heavy
flavor and multi-lepton searches, as well as those for heavy stable charged
particles. Nonetheless, we find that light gluinos, 1st/2nd generation squarks,
and stop/sbottoms (\lsim 400-700 GeV), as well as models with 1% fine-tuning or
better, are still viable in the pMSSM. In addition, we see that increased
luminosity at 8 TeV is unlikely to significantly improve the reach of the
"vanilla" searches. The impact of these null searches on the SUSY sparticle
spectrum is discussed in detail and the implications of these results for
models with low fine-tuning, a future lepton collider and dark matter searches
are examined.Comment: 33 pages, 9 figure
pMSSM Benchmark Models for Snowmass 2013
We present several benchmark points in the phenomenological Minimal
Supersymmetric Standard Model (pMSSM). We select these models as experimentally
well-motivated examples of the MSSM which predict the observed Higgs mass and
dark matter relic density while evading the current LHC searches. We also use
benchmarks to generate spokes in parameter space by scaling the mass parameters
in a manner which keeps the Higgs mass and relic density approximately
constant.Comment: 10 pages, 6 figure
The CP-violating pMSSM at the Intensity Frontier
In this Snowmass whitepaper, we describe the impact of ongoing and proposed
intensity frontier experiments on the parameter space of the Minimally
Supersymmetric Standard Model (MSSM). We extend a set of phenomenological MSSM
(pMSSM) models to include non-zero CP-violating phases and study the
sensitivity of various flavor observables in these scenarios Future electric
dipole moment and rare meson decay experiments can have a strong impact on the
viability of these models that is relatively independent of the detailed
superpartner spectrum. In particular, we find that these experiments have the
potential to probe models that are expected to escape searches at the
high-luminosity LHC.Comment: 10 pages, 2 figures. Contributed to the Community Summer Study 2013,
Minneapolis, MN July 29 - August 6, 201
SLAC-PUB-15458 pMSSM Benchmark Models for Snowmass 2013 ∗
We present several benchmark points in the phenomenological Minimal Supersymmetric Standard Model (pMSSM). We select these models as experimentally wellmotivated examples of the MSSM which predict the observed Higgs mass and dark matter relic density while evading the current LHC searches. We also use benchmarks to generate spokes in parameter space by scaling the mass parameters in a manner which keeps the Higgs mass and relic density approximately constant. 1 pMSSM Model Generation Despite the continued null results from the LHC, supersymmetry in general and the MSSM in particular remain well-motivated and therefore of considerable interest to future experimental programs. We therefore introduce several benchmark points within the MSSM which predict the observed Higgs mass and dark matter relic density, yet are allowed by current experimental data. These points were taken from scans of the phenomenological MSSM (pMSSM), a subspace of the MSSM with parameters defined at the electroweak scale [1]. The pMSSM is defined by applying the following experimentally-motivated constraints to the R-parity conserving MSSM: (i) CP conservation, (ii) Minimal Flavor Violation at the electroweak scale, (iii) degenerate first and second generation sfermion masses, (iv) negligible Yukawa couplings and A-terms for the first two generations. In particular, no assumptions are made about physics at high scales, e.g. unification or SUSY breaking, in order to capture electroweak scale phenomenology for which a UV-complete theory may not yet exist. Imposing the constraints (i)-(v) decreases the number of free parameters from 105 to 19, o
The New Look pMSSM with Neutralino and Gravitino LSPs
The pMSSM provides a broad perspective on SUSY phenomenology. In this paper
we generate two new, very large, sets of pMSSM models with sparticle masses
extending up to 4 TeV, where the lightest supersymmetric particle (LSP) is
either a neutralino or gravitino. The existence of a gravitino LSP necessitates
a detailed study of its cosmological effects and we find that Big Bang
Nucleosynthesis places strong constraints on this scenario. Both sets are
subjected to a global set of theoretical, observational and experimental
constraints resulting in a sample of \sim 225k viable models for each LSP type.
The characteristics of these two model sets are briefly compared. We confront
the neutralino LSP model set with searches for SUSY at the 7 TeV LHC using both
the missing (MET) and non-missing ET ATLAS analyses. In the MET case, we employ
Monte Carlo estimates of the ratios of the SM backgrounds at 7 and 8 TeV to
rescale the 7 TeV data-driven ATLAS backgrounds to 8 TeV. This allows us to
determine the pMSSM parameter space coverage for this collision energy. We find
that an integrated luminosity of \sim 5-20 fb^{-1} at 8 TeV would yield a
substantial increase in this coverage compared to that at 7 TeV and can probe
roughly half of the model set. If the pMSSM is not discovered during the 8 TeV
run, then our model set will be essentially void of gluinos and lightest first
and second generation squarks that are \lesssim 700-800 GeV, which is much less
than the analogous mSUGRA bound. Finally, we demonstrate that non-MET SUSY
searches continue to play an important role in exploring the pMSSM parameter
space. These two pMSSM model sets can be used as the basis for investigations
for years to come.Comment: 54 pages, 22 figures; typos fixed, references adde
Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans
Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have
fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in
25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16
regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of
correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP,
while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in
Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium
(LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region.
Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant
enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the
refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa,
an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of
PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent
signals within the same regio
The Higgs Sector and Fine-Tuning in the pMSSM
The recent discovery of a 125 GeV Higgs, as well as the lack of any positive
findings in searches for supersymmetry, has renewed interest in both the
supersymmetric Higgs sector and fine-tuning. Here, we continue our study of the
phenomenological MSSM (pMSSM), discussing the light Higgs and fine-tuning
within the context of two sets of previously generated pMSSM models. We find an
abundance of models with experimentally-favored Higgs masses and couplings. We
investigate the decay modes of the light Higgs in these models, finding strong
correlations between many final states. We then examine the degree of
fine-tuning, considering contributions from each of the pMSSM parameters at up
to next-to-leading-log order. In particular, we examine the fine-tuning
implications for our model sets that arise from the discovery of a 125 GeV
Higgs. Finally, we investigate a small subset of models with low fine-tuning
and a light Higgs near 125 GeV, describing the common features of such models.
We generically find a light stop and bottom with complex decay patterns into a
set of light electroweak gauginos, which will make their discovery more
challenging and may require novel search techniques.Comment: 52 pages, 31 figures; minor changes, typos fixed, references adde