Track-Induced Clustering in Position Sensitive Detector Characterization

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Performance of Heterogeneous Algorithm Scheduling in CMSSW

The CMS experiment started to utilize Graphics Processing Units (GPU) to accelerate the online reconstruction and event selection running on its High Level Trigger (HLT) farm in the 2022 data taking period. The projections of the HLT farm to the High-Luminosity LHC foresee a significant use of compute accelerators in the LHC Run 4 and onwards in order to keep the cost, size, and power budget of the farm under control. This direction of leveraging compute accelerators has synergies with the increasing use of HPC resources in HEP computing, as HPC machines are employing more and more compute accelerators that are predominantly GPUs today. In this work we review the features developed for the CMS data processing framework, CMSSW, to support the effective utilization of both compute accelerators and many-core CPUs within a highly concurrent task-based framework. We measure the impact of various design choices for the scheduling of heterogeneous algorithms on the event processing throughput, using the Run-3 HLT application as a realistic use case

Secure Cloud Connectivity for Scientific Applications

Cloud computing improves utilization and flexibility in allocating computing resources while reducing the infrastructural costs. However, in many cases cloud technology is still proprietary and tainted by security issues rooted in the multi-user and hybrid cloud environment. A lack of secure connectivity in a hybrid cloud environment hinders the adaptation of clouds by scientific communities that require scaling-out of the local infrastructure using publicly available resources for large-scale experiments. In this article, we present a case study of the DII-HEP secure cloud infrastructure and propose an approach to securely scale-out a private cloud deployment to public clouds in order to support hybrid cloud scenarios. A challenge in such scenarios is that cloud vendors may offer varying and possibly incompatible ways to isolate and interconnect virtual machines located in different cloud networks. Our approach is tenant driven in the sense that the tenant provides its connectivity mechanism. We provide a qualitative and quantitative analysis of a number of alternatives to solve this problem. We have chosen one of the standardized alternatives, Host Identity Protocol, for further experimentation in a production system because it supports legacy applications in a topologically-independent and secure way.Peer reviewe

Ideal tau tagging with the multivariate data-analysis toolkit TMVA

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Search for Microscopic Black Hole Signatures at the Large Hadron Collider

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Measurement of W-gamma and Z-gamma production in pp collisions at sqrt(s) = 7 TeV

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Fragmentation of jets containing a prompt J/psi meson in PbPb and pp collisions at root s(NN)=5.02 TeV

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Measurements of the associated production of a W boson and a charm quark in proton–proton collisions at s√=8TeV

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Search for decays of the 125 GeV Higgs boson into a Z boson and a rho or phi meson

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Observation of B-s(0) mesons and measurement of the B-s(0)/B+ yield ratio in PbPb collisions at root S-NN=5.02 TeV

The B-s(0) and B+ production yields are measured in PbPb collisions at a center-of-mass energy per nucleon pair of 5.02 TeV. The data sample, collected with the CMS detector at the LHC, corresponds to an integrated luminosity of 1.7 nb(-1). The mesons are reconstructed in the exclusive decay channels B-s(0) -> J/psi (mu(+)mu(-))phi(K+K-) and B+ -> J/psi(mu(+)mu(-))K+ in the transverse momentum range 7-50 GeV/c and absolute rapidity 0-2.4. The B-s(0) meson is observed with a statistical significance in excess of five standard deviations for the first time in nucleus-nucleus collisions. The measurements are performed as functions of the transverse momentum of the B mesons and of the PbPb collision centrality. The ratio of production yields of B-s(0) and B+ is measured and compared to theoretical models that include quark recombination effects. (C) 2022 The Author(s). Published by Elsevier B.V.Peer reviewe