103 research outputs found

    Measurement of the differential tt¯ production cross section as a function of the jet mass and extraction of the top quark mass in hadronic decays of boosted top quarks

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    Data Availability: This manuscript has no associated data or the data will not be deposited. [Authors’ comment: Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS policy as stated in https://cms-docdb.cern.ch/cgibin/PublicDocDB/RetrieveFile?docid=6032 &filename=CMSDataPolicyV1.2.pdf &version=2.]A measurement of the jet mass distribution in hadronic decays of Lorentz-boosted top quarks is presented. The measurement is performed in the lepton + jets channel of top quark pair production (tt¯ ) events, where the lepton is an electron or muon. The products of the hadronic top quark decay are reconstructed using a single large-radius jet with transverse momentum greater than 400GeV . The data were collected with the CMS detector at the LHC in proton-proton collisions and correspond to an integrated luminosity of 138fb−1 . The differential tt¯ production cross section as a function of the jet mass is unfolded to the particle level and is used to extract the top quark mass. The jet mass scale is calibrated using the hadronic W boson decay within the large-radius jet. The uncertainties in the modelling of the final state radiation are reduced by studying angular correlations in the jet substructure. These developments lead to a significant increase in precision, and a top quark mass of 173.06±0.84GeV.SCOAP

    Portable Acceleration of CMS Computing Workflows with Coprocessors as a Service

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    A preprint version of the article is available at: arXiv:2402.15366v2 [physics.ins-det], https://arxiv.org/abs/2402.15366 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/MLG-23-001 (CMS Public Pages). Report numbers: CMS-MLG-23-001, CERN-EP-2023-303.Data Availability: No datasets were generated or analyzed during the current study.Computing demands for large scientific experiments, such as the CMS experiment at the CERN LHC, will increase dramatically in the next decades. To complement the future performance increases of software running on central processing units (CPUs), explorations of coprocessor usage in data processing hold great potential and interest. Coprocessors are a class of computer processors that supplement CPUs, often improving the execution of certain functions due to architectural design choices. We explore the approach of Services for Optimized Network Inference on Coprocessors (SONIC) and study the deployment of this as-a-service approach in large-scale data processing. In the studies, we take a data processing workflow of the CMS experiment and run the main workflow on CPUs, while offloading several machine learning (ML) inference tasks onto either remote or local coprocessors, specifically graphics processing units (GPUs). With experiments performed at Google Cloud, the Purdue Tier-2 computing center, and combinations of the two, we demonstrate the acceleration of these ML algorithms individually on coprocessors and the corresponding throughput improvement for the entire workflow. This approach can be easily generalized to different types of coprocessors and deployed on local CPUs without decreasing the throughput performance. We emphasize that the SONIC approach enables high coprocessor usage and enables the portability to run workflows on different types of coprocessors.SCOAP3. Open access funding provided by CERN (European Organization for Nuclear Research

    Search for light Higgs bosons from supersymmetric cascade decays in pp collisions at √s=13TeV

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    A search is reported for pairs of light Higgs bosons (H1) produced in supersymmetric cascade decays in f inal states with small missing transverse momentum. A data set of LHC pp collisions collected with the CMS detector at √s = 13TeV and corresponding to an integrated lumi nosity of 138fb−1 is used. The search targets events where both H1 bosons decay into b¯b pairs that are reconstructed as large-radius jets using substructure techniques. No evi dence is found for an excess of events beyond the back ground expectations of the standard model (SM). Results from the search are interpreted in the next-to-minimal super symmetric extension of the SM, where a “singlino” of small mass leads to squark and gluino cascade decays that can pre dominantly end in a highly Lorentz-boosted singlet-like H1 andasinglino-likeneutralinoofsmalltransversemomentum. Upperlimitsaresetontheproductofthesquarkorgluinopair production cross section and the square of the b¯b branching fraction of the H1 in a benchmark model containing almost mass-degenerategluinosandlight-flavoursquarks.Underthe assumption of an SM-like H1 → b¯b branching fraction, H1 bosonswithmassesintherange40–120GeVarisingfromthe decays of squarks or gluinos with a mass of 1200–2500GeV are excluded at 95% confidence level.SCOA

    Measurements of Higgs boson production in the decay channel with a pair of ττ leptons in proton-proton collisions at s\sqrt{s} = 13 TeV

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    A preprint version of the article is available at arXiv:2204.12957v2 [hep-ex], https://arxiv.org/abs/2204.12957v2 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables, including additional supplementary figures and tables, can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-19-010 (CMS Public Pages). Report number: CMS-HIG-19-010, CERN-EP-2022-027.Measurements of Higgs boson production, where the Higgs boson decays into a pair of τ leptons, are presented, using a sample of proton-proton collisions collected with the CMS experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb^{−1}. Three analyses are presented. Two are targeting Higgs boson production via gluon fusion and vector boson fusion: a neural network based analysis and an analysis based on an event categorization optimized on the ratio of signal over background events. These are complemented by an analysis targeting vector boson associated Higgs boson production. Results are presented in the form of signal strengths relative to the standard model predictions and products of cross sections and branching fraction to τ leptons, in up to 16 different kinematic regions. For the simultaneous measurements of the neural network based analysis and the analysis targeting vector boson associated Higgs boson production signal strengths are found to be 0.82 ± 0.11 for inclusive Higgs boson production, 0.67 ± 0.19 (0.81 ± 0.17) for the production mainly via gluon fusion (vector boson fusion), and 1.79 ± 0.45 for vector boson associated Higgs boson production.SCOAP3

    Measuring Anxiety in Children: A Methodological Review of the Literature

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    This paper provides a comprehensive methodological review of the literature concerning anxiety measurement in children. Initially, a conceptual basis for anxiety measures is introduced, followed by specific approaches to measuring childhood anxiety based on 14 original articles. In particular, a variety of strategies that have been used in previous research are discussed in detail with theoretical underpinnings. Common approaches to measure anxiety such as self-reported instruments, observational ratings, and behavioral checklists are reviewed one by one with a critical look at the strengths and weaknesses of each of these approaches. While multiple measures of anxiety are available to assess the level of anxiety in children, selection of measurement approach should be an iterative process based on rigorous evaluation of evidence of reliability and cross-validation of the tool across different age groups of children

    The Experiences and Challenges of Caregivers of Frail or Chronically Ill Elderly: An Integrative Review

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    BACKGROUND: Social, legal, and economic factors have changed the delivery of care to elderly who are frail and/or chronically ill. Increasing number of the elderly are now treated in the community, while living with or in close proximity to their family. It is evident that families play a major role of support for elderly persons in our society. This paper provides a review and analysis of studies that have investigated informal caregiving issues encompassing physical, psychological, emotional, and social domains. RESULTS OF THE REVIEW: Family caregiving often interfered with workplace and other responsibilities, creating physical, emotional, and financial stress for caregivers. Relatively high volumes of research addressed caregiving issues in the families of Alzheimer patients and in the areas of emotional and psychological impact of caregiving. Few studies explicitly investigated the role of informal caregivers in the management of other chronic conditions such as stroke or depression or physical consequences of long-term caregiving. While most studies were focused on negative aspects of caregiving, a few studies found it rewarding. Often the burden, stress, and socio-economic effects on the family caregiving for an elderly person were not sufficiently appreciated. CONCLUSIONS: Positive outcomes for both the caregiver and the care recipient are more likely to occur when effective levels of collaboration exist between health professionals and caregivers. As a first step, a better understanding of the caregiving experience such as caregiver characteristics, care recipient characteristics, and social stigma is important for nurses to minimize the burden of care so that appropriate interventions can be developed. In addition, further studies are needed to examine the role and needs of informal caregivers in the care of increasing number of frail and/or chronic ill elderly treated in the community

    Sources of Health Information, Technology Access, and Use Among Non–English-Speaking Immigrant Women: Descriptive Correlational Study

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    BackgroundAs the world is becoming increasingly connected by the World Wide Web, the internet is becoming the main source of health information. With the novel COVID-19 pandemic, ubiquitous use of the internet has changed the daily lives of individuals, from working from home to seeking and meeting with health care providers through web-based sites. Such heavy reliance on internet-based technologies raises concerns regarding the accessibility of the internet for minority populations who are likely to already face barriers when seeking health information. ObjectiveThis study aims to examine the level of technology access and common modes of technology used by Korean American women and to investigate how key psychosocial determinants of health such as age, education, English proficiency, and health literacy are correlated with sources of health information used by Korean American women and by their use of the internet. MethodsWe used data from a subsample of Korean American women (N=157) who participated in a community-based randomized trial designed to test a health literacy–focused cancer screening intervention. In addition to descriptive statistics to summarize Korean American women’s internet access and common modes of technology use, we conducted backward stepwise logistic regression analyses to substantiate the association between the psychosocial determinants of health and internet use. ResultsApproximately two-thirds (103/157, 65.6%) of the sample had access to the internet, and nearly all had access to a mobile phone. The internet was the most commonly used channel to obtain health information 63% (99/157), and 70% (110/157) of the sample used text messaging. Nevertheless, only approximately 38.8% (40/103) of the sample were very confident in using the internet, and only 29.9% (47/157) were very confident in using text messaging. Multivariate analyses revealed that older age (>50 years) was associated with 79% lower odds of using the internet to seek health information (adjusted odds ratio [AOR] 0.21, 95% CI 0.10-0.46). The higher health literacy group (19+ on Rapid Estimate of Adult Literacy in Medicine) had 56% lower odds of using the internet to acquire health information (AOR 0.44, 95% CI 1.13-11.18). Higher education (college+) was associated with both internet use (AOR 4.42, 95% CI 1.88-9.21) and text messaging (AOR 3.42, 95% CI 1.55-7.54). Finally, English proficiency was associated with text messaging (AOR 4.20, 95% CI 1.44-12.24). ConclusionsThe differences in modes of technology access, use, and confidence by some of the key psychosocial determinants, as observed in our study sample, have important implications when health care teams develop dissemination plans

    Factors associated with missed appointments by adults with type 2 diabetes mellitus: a systematic review

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    Keeping regular medical appointments is a key indicator of patient engagement in diabetes care. Nevertheless, a significant proportion of adults with type 2 diabetes mellitus (T2DM) miss their regular medical appointments. In order to prevent and delay diabetes-related complications, it is essential to understand the factors associated with missed appointments among adults with T2DM. We synthesized evidence concerning factors associated with missed appointments among adults with T2DM. Using five electronic databases, including PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, PsycINFO and Web of Science, a systematic literature search was done to identify studies that describe factors related to missed appointments by adults with T2DM. A total of 18 articles met the inclusion criteria. The majority of studies included in this review were cohort studies using medical records. While more than half of the studies were of high quality, the operational definitions of missed appointments varied greatly across studies. Factors associated with missed appointments were categorized as patient characteristics, healthcare system and provider factors and interpersonal factors with inconsistent findings. Patient characteristics was the most commonly addressed category, followed by health system and provider factors. Only three studies addressed interpersonal factors, two of which were qualitative. An increasing number of people live with one or more chronic conditions which require more careful attention to patient-centered care and support. Future research is warranted to address interpersonal factors from patient perspectives to better understand the underlying causes of missed appointments among adults with T2DM
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