31 research outputs found
Stealth Supersymmetry
We present a broad class of supersymmetric models that preserve R-parity but
lack missing energy signatures. These models have new light particles with
weak-scale supersymmetric masses that feel SUSY breaking only through couplings
to the MSSM. This small SUSY breaking leads to nearly degenerate fermion/boson
pairs, with small mass splittings and hence small phase space for decays
carrying away invisible energy. The simplest scenario has low-scale SUSY
breaking, with missing energy only from soft gravitinos. This scenario is
natural, lacks artificial tunings to produce a squeezed spectrum, and is
consistent with gauge coupling unification. The resulting collider signals will
be jet-rich events containing false resonances that could resemble signatures
of R-parity violation. We discuss several concrete examples of the general
idea, and emphasize gamma + jet + jet resonances, displaced vertices, and very
large numbers of b-jets as three possible discovery modes.Comment: 12 pages, 4 figure
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
The Status of GMSB After 1/fb at the LHC
We thoroughly investigate the current status of supersymmetry in light of the
latest searches at the LHC, using General Gauge Mediation (GGM) as a
well-motivated signature generator that leads to many different simplified
models. We consider all possible promptly-decaying NLSPs in GGM, and by
carefully reinterpreting the existing LHC searches, we derive limits on both
colored and electroweak SUSY production. Overall, the coverage of GGM parameter
space is quite good, but much discovery potential still remains even at 7 TeV.
We identify several regions of parameter space where the current searches are
the weakest, typically in models with electroweak production, third generation
sfermions or squeezed spectra, and we suggest how ATLAS and CMS might modify
their search strategies given the understanding of GMSB at 1/fb. In particular,
we propose the use of leptonic to suppress backgrounds.
Because we express our results in terms of simplified models, they have broader
applicability beyond the GGM framework, and give a global view of the current
LHC reach. Our results on 3rd generation squark NLSPs in particular can be
viewed as setting direct limits on naturalness.Comment: 44 pages, refs added, typos fixed, improved MC statistics in fig 1
A Stealth Supersymmetry Sampler
The LHC has strongly constrained models of supersymmetry with traditional
missing energy signatures. We present a variety of models that realize the
concept of Stealth Supersymmetry, i.e. models with R-parity in which one or
more nearly-supersymmetric particles (a "stealth sector") lead to collider
signatures with only a small amount of missing energy. The simplest realization
involves low-scale supersymmetry breaking, with an R-odd particle decaying to
its superpartner and a soft gravitino. We clarify the stealth mechanism and its
differences from compressed supersymmetry and explain the requirements for
stealth models with high-scale supersymmetry breaking, in which the soft
invisible particle is not a gravitino. We also discuss new and distinctive
classes of stealth models that couple through a baryon portal or Z' gauge
interactions. Finally, we present updated limits on stealth supersymmetry in
light of current LHC searches.Comment: 45 pages, 16 figure
Proceedings of the 3rd Biennial Conference of the Society for Implementation Research Collaboration (SIRC) 2015: advancing efficient methodologies through community partnerships and team science
It is well documented that the majority of adults, children and families in need of evidence-based behavioral health interventionsi do not receive them [1, 2] and that few robust empirically supported methods for implementing evidence-based practices (EBPs) exist. The Society for Implementation Research Collaboration (SIRC) represents a burgeoning effort to advance the innovation and rigor of implementation research and is uniquely focused on bringing together researchers and stakeholders committed to evaluating the implementation of complex evidence-based behavioral health interventions. Through its diverse activities and membership, SIRC aims to foster the promise of implementation research to better serve the behavioral health needs of the population by identifying rigorous, relevant, and efficient strategies that successfully transfer scientific evidence to clinical knowledge for use in real world settings [3]. SIRC began as a National Institute of Mental Health (NIMH)-funded conference series in 2010 (previously titled the “Seattle Implementation Research Conference”; $150,000 USD for 3 conferences in 2011, 2013, and 2015) with the recognition that there were multiple researchers and stakeholdersi working in parallel on innovative implementation science projects in behavioral health, but that formal channels for communicating and collaborating with one another were relatively unavailable. There was a significant need for a forum within which implementation researchers and stakeholders could learn from one another, refine approaches to science and practice, and develop an implementation research agenda using common measures, methods, and research principles to improve both the frequency and quality with which behavioral health treatment implementation is evaluated. SIRC’s membership growth is a testament to this identified need with more than 1000 members from 2011 to the present.ii SIRC’s primary objectives are to: (1) foster communication and collaboration across diverse groups, including implementation researchers, intermediariesi, as well as community stakeholders (SIRC uses the term “EBP champions” for these groups) – and to do so across multiple career levels (e.g., students, early career faculty, established investigators); and (2) enhance and disseminate rigorous measures and methodologies for implementing EBPs and evaluating EBP implementation efforts. These objectives are well aligned with Glasgow and colleagues’ [4] five core tenets deemed critical for advancing implementation science: collaboration, efficiency and speed, rigor and relevance, improved capacity, and cumulative knowledge. SIRC advances these objectives and tenets through in-person conferences, which bring together multidisciplinary implementation researchers and those implementing evidence-based behavioral health interventions in the community to share their work and create professional connections and collaborations
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Psychosocial functioning of bullied youth who adopt versus deny the bully-victim label.
This study addressed a need for research on the association between adopting or denying the label of bully victim and students' psychosocial functioning. Participants were 1,063 students in Grades 5, 7, and 9 in a school district in the northeastern United States. Students were grouped based on their pattern of responses to (a) the California Bully Victimization Scale (Felix et al., 2011), which does not use the term "bully," but includes behavioral items assessing frequency of peer victimization and whether or not that victimization involved any perceived power disadvantage, and (b) the Olweus Bully/Victim Questionnaire (Solberg & Olweus, 2003; Solberg, Olweus, & Endresen, 2007), which queries self-identification as a bully victim. We compared groups using a series of planned comparisons with ANOVA on self-reported emotional distress and withdrawal, behavioral reactivity and conduct problems, and prosocial behavior and peer competence, as measured by the Strengths and Difficulties Questionnaire (Goodman, 1997). Results revealed complexities regarding the experience of bullying. The perception of a power difference and having been bullied both related to psychosocial functioning in an interactive way, suggesting that both are important to query. Moreover, students who labeled themselves as victims of bullying reported poorer psychosocial functioning than those who had the experience of being bullied but did not adopt that label
Psychosocial Functioning of Bullied Youth Who Adopt Versus Deny the Bully-Victim Label
This study addressed a need for research on the association between adopting or denying the label of bully victim and students' psychosocial functioning. Participants were 1,063 students in Grades 5, 7, and 9 in a school district in the northeastern United States. Students were grouped based on their pattern of responses to (a) the California Bully Victimization Scale , which does not use the term "bully," but includes behavioral items assessing frequency of peer victimization and whether or not that victimization involved any perceived power disadvantage, and (b) the Olweus Bully/Victim Questionnair
Psychosocial Functioning of Bullied Youth Who Adopt Versus Deny the Bully-Victim Label
This study addressed a need for research on the association between adopting or denying the label of bully victim and students' psychosocial functioning. Participants were 1,063 students in Grades 5, 7, and 9 in a school district in the northeastern United States. Students were grouped based on their pattern of responses to (a) the California Bully Victimization Scale (Felix et al., 2011), which does not use the term "bully," but includes behavioral items assessing frequency of peer victimization and whether or not that victimization involved any perceived power disadvantage, and (b) the Olweus Bully/Victim Questionnaire (Solberg & Olweus, 2003; Solberg, Olweus, & Endresen, 2007), which queries self-identification as a bully victim. We compared groups using a series of planned comparisons with ANOVA on self-reported emotional distress and withdrawal, behavioral reactivity and conduct problems, and prosocial behavior and peer competence, as measured by the Strengths and Difficulties Questionnaire (Goodman, 1997). Results revealed complexities regarding the experience of bullying. The perception of a power difference and having been bullied both related to psychosocial functioning in an interactive way, suggesting that both are important to query. Moreover, students who labeled themselves as victims of bullying reported poorer psychosocial functioning than those who had the experience of being bullied but did not adopt that label
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Brief Report: Insomnia and Risk of Myocardial Infarction Among People With HIV.
BackgroundInsomnia is common among people with HIV (PWH) and may be associated with increased risk of myocardial infarction (MI). This study examines the association between insomnia and MI by MI type among PWH.SettingLongitudinal cohort study of PWH at 5 Centers for AIDS Research Network of Integrated Clinical Systems sites.MethodsClinical data and patient-reported measures and outcomes from PWH in care between 2005 and 2018 were used in this study. Insomnia, measured at baseline, was defined as having difficulty falling or staying asleep with bothersome symptoms. The Centers for AIDS Research Network of Integrated Clinical Systems centrally adjudicates MIs using expert reviewers, with distinction between type 1 MI (T1MI) and type 2 MI (T2MI). Associations between insomnia and first incident MI by MI type were measured using separate Cox proportional hazard models adjusted for age, sex, race/ethnicity, traditional cardiovascular disease risk factors (hypertension, dyslipidemia, poor kidney function, diabetes, and smoking), HIV markers (antiretroviral therapy, viral suppression, and CD4 cell count), and stimulant use (cocaine/crack and methamphetamine).ResultsAmong 12,448 PWH, 48% reported insomnia. Over a median of 4.4 years of follow-up, 158 T1MIs and 109 T2MIs were identified; approximately half of T2MIs were attributed to sepsis or stimulant use. After adjustment for potential confounders, we found no association between insomnia and T1MI (hazard ratio = 1.05, 95% confidence interval: 0.76 to 1.45) and a 65% increased risk of T2MI among PWH reporting insomnia compared with PWH without insomnia (hazard ratio = 1.65, 95% confidence interval: 1.11 to 2.45).ConclusionsPWH reporting insomnia are at an increased risk of T2MI, but not T1MI, compared with PWH without insomnia, highlighting the importance of distinguishing MI types among PWH