International Linear Collider
Not a member yet
509047 research outputs found
Sort by
Exploiting GPU Resources at VEGA for CMS Software Validation
No full textIn recent years, the CMS experiment has expanded the usage of HPC systems for data processing and simulation activities. These resources significantly extend the conventional pledged Grid compute capacity. Within the EuroHPC program, CMS applied for a Benchmark Access grant at VEGA in Slovenia, an HPC centre that is being used very successfully by the ATLAS experiment.For CMS, VEGA was integrated transparently as a sub-site extension to the Italian Tier-1 site at CNAF. In that first approach, only CPU resources were used, while all storage access was handled via CNAF through the network. Extending Grid sites with HPC resources was an established concept for CMS, however, in this project, HPC resources located in a different country from the Grid site were first integrated.CMS used the allocation primarily to validate a recent CMSSW release regarding its readiness for GPU usage. Former developments in the CMS workload management system that allow the targeting of GPU resources in the distributed infrastructure turned out to be instrumental and jobs could be submitted like any other release validation workflow.The presentation will detail aspects of the actual integration, some required tuning to achieve reasonable GPU utilisation, and an assessment of operational parameters like error rates compared to traditional Grid sites
The ATLAS RPC Phase II upgrade for High Luminosity LHC era
No full textResistive Plate Chamber detectors play a crucial role in triggering events with muons in the ATLAS central region. In view of the High Luminosity LHC program, this system is facing a significant upgrade In the next few years, 306 triplets of new generation RPCs will be installed in the innermost region of the ATLAS Muon Barrel Spectrometer, increasing the number of tracking layers from 6 to 9, doubling the trigger lever arm and increasing the coverage. The new Barrel Inner RPC (BI-RPC) have an improved rate capability up to 10 /cm^2 to withstand the HL-LHC conditions.This contribution will present an overview of the ATLAS RPC Phase II project, the qualification of gas volumes and read out planes, the present status of RPC singlets production and tests
Top-quark pair production in heavy-ion collisions with the ATLAS experiment
No full textMeasurements of top quarks in heavy-ion collisions are expected to provide novel probes of nuclear modifications to parton distribution functions as well as to bring unique information about the evolution of strongly interacting matter. We report the observation of the top-quark pair production in proton-lead collisions at the centre-of-mass energy of 8.16 TeV in the ATLAS experiment at the LHC. Top-quark pair production is measured in the lepton+jets and the dilepton channels, with a significance well above 5 standard deviations in each channel separately. The results from the measurement of the nuclear modification factor are also presented
(Re)interpretation of the LHC results for new physics
No full textThis talk will give an overview of the CMS statistical model format (Combine datacards) and demonstrate their evaluation with Combine. In addition the review process automated in gitlab-ci will be highlighted
(Re)interpretation of the LHC results for new physics
No full textGlobal SMEFT analyses combine a vast range of LHC measurements to construct likelihoods to put constraints on physics beyond the Standard Model. However, constructing and evaluating profile likelihoods for such analyses is computationally intensive and prone to instability and noise. We show how modern numerical techniques, similar to neural importance sampling, can dramatically enhance both efficiency and stability. Specifically, we focus on datasets used in previous SFitter analyses, combining data from the Top sector with Higgs, Di-Boson, and electroweak precision measurements to simultaneously constrain up to 42 Wilson coefficients
A generalized picture of colour decoherence in dense QCD media
No full textWe revisit the calculation of the soft gluon emission probability off a colour-singlet system that evolves in a quark-gluon plasma. The antenna is created in the presence of a medium and then emits a soft gluon outside. The gluon emission probability is modified with respect to the vacuum baseline due to interactions with the medium during the formation of the antenna and its propagation. Previous studies disregarded the former effect and found that the medium modification to the interference pattern of the antenna was controlled by the so-called critical angle θ, that exclusively depends on medium properties. We find that accounting for medium interactions during the antenna formation enhances the total rate of emissions off the antenna. Interestingly, it also promotes the notion of a critical angle to a dynamic quantity, denoted , that depends on both the medium and the antenna properties and is thus different for every splitting. As a consequence, depending on the region of parameter space, colour decoherence can either be delayed or accelerated with respect to previous estimates.We revisit the calculation of the soft gluon emission probability off a colour-singlet system that evolves in a quark-gluon plasma. The antenna is created in the presence of a medium and then emits a soft gluon outside. The gluon emission probability is modified with respect to the vacuum baseline due to interactions with the medium during the formation of the antenna and its propagation. Previous studies disregarded the former effect and found that the medium modification to the interference pattern of the antenna was controlled by the so-called critical angle , that exclusively depends on medium properties. We find that accounting for medium interactions during the antenna formation enhances the total rate of emissions off the antenna. Interestingly, it also promotes the notion of a critical angle to a dynamic quantity, denoted , that depends on both the medium and the antenna properties and is thus different for every splitting. As a consequence, depending on the region of parameter space, colour decoherence can either be delayed or accelerated with respect to previous estimates
The Value of an Open Scientific Data and Documentation Platform in a Global Project: The Case of Zenodo
No full textOpen Science is a movement aimed at promoting public access to all scientific research products, without barriers or restrictions. Open Data refers to the practice of sharing research data in a way that assures that the research is accessible, reusable, and reproducible for everyone. Leveraging these two principles, scientists can validate results, and findings, conduct new research, and promote scientific progress. Open data also enables interdisciplinary collaborations and the exploration of research questions beyond the original scope of the data. The most appropriate means used for implementing Open science and open data are digital, collaborative technologies. One notable example of a platform facilitating information dissemination is Zenodo, a free virtual repository based on the CERN developed Invenio software suite. Zenodo serves as an open access and open data platform, offering researchers, scientists, and individuals a centralized, durable, reliable, scalable, free, and accessible space to share, publish, and preserve their research outputs. Zenodo provides various features and benefits that foster knowledge advancement and collaboration within the research community. By promoting open access, Zenodo enables the global dissemination of research findings, eliminating obstacles such as geographic and financial constraints. It is challenging to accurately capture the impact of scientific dissemination, both social and economic. This is particularly the case for a free, “catch-all” repository, which permits any user to supply and access non-reviewed information. This report provides a quantitative estimate of the monetary value that a virtual repository represents based on a multi-component model in which the different parts of the system are quantified using appropriate distinct methods. This study uses the virtual repository Zenodo as a reference case for the ex-ante societal impact analysis for the Future Circular Collider (FCC) at CERN, assuming that in the lifetime of such a new research infrastructure, at least one comparable development will be required due to the collaborative nature of scientific physics research with particle accelerators and colliders. Our results indicate a discounted socio-economic impact potential of about 2.8 billion CHF for an observation period of 29 years, from 2028 to 2057
The Value of Open Science at CERN: An Analysis Based on a Travel Cost Model
No full textOpen science is a fundamental root of the European Organization for Nuclear Research, known by its acronym CERN. This international organization, located between Switzerland and France, has distinguished itself since its inception by sharing its discoveries, innovative technologies, and the information generated by its most ambitious project, the Large Hadron Collider (LHC) so that researchers around the world and society can benefit from the data gathered and the knowledge created. One of the main characteristics of the organization is the possibility to freely visit the particle accelerators and the experiments at these machines. On these occasions, visitors can meet the scientists and learn directly from them about the organization, its discoveries, and its daily activities. This study is one of the few assessing the economic value of these initiatives. It is based on a survey using a sample size of 900 visitors to CERN during one calendar year. Results from a travel cost application show that visitor would be willing to pay a total on average at least 0.72 € over the cost of the trip per person, owing to the experience and knowledge gained during their visit to the infrastructure