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Gravitational-wave emission from binary systems of compact objects
No full textBinary systems comprising black holes and or neutron stars represent the strongest sources of gravitational waves and have recently been revealed by detectors such as LIGO and Virgo. In this series of lectures I will provide a brief introduction to the mathematical and numerical techniques that are needed for the theoretical modelling of these systems. At the same time, I will discuss how neutron-star binaries represent fantastic tools to explore fundamental aspects of gravitational and particle physics. In particular, I will provide a few examples of the ways in which neutron stars can be used to explore fundamental physics, ranging from their spectral properties, the possibility of phase transition to quark matter, the amplification of super-strong magnetic fields, and the copious emission of neutrinos.
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Firmware implementation of Phase-2 Overlap Muon Track Finder algorithm for CMS Level-1 trigger
No full textThe Overlap Muon Track Finder (OMTF) is one of the subsystems of the Compact Muon Solenoid (CMS) Level-1 Trigger. For the High-Luminosity Large Hadron Collider era (CMS phase-2 upgrade), a new version of the OMTF is currently under development. This upgraded version will be implemented on a custom ATCA board X2O, which houses a Xilinx UltraScale+ FPGA and 25 Gbps optical transceivers. This contribution focuses on the firmware implementation of the muon trigger algorithm and input data pre-processing, leveraging the High-Level Synthesis (HLS) technique. The paper presents current design and verification results, as well as experiences in using both standard and non-standard HLS development workflows
Design of hardware interfaces for the LHC Phase-2 CMS ECAL Barrel Safety System
No full textThe CMS Electromagnetic Calorimeter (ECAL) uses lead tungstate scintillating crystals to measure the energy of electrons and photons produced at the Large Hadron Collider (LHC). The High Luminosity upgrade of the LHC (HL-LHC) at CERN during the LHC Long Shutdown 3 imposes significant challenges for its experiments. The higher luminosity changes the environmental conditions in which the ECAL detector will operate. In this contribution the upgrade plans and preliminary designs to accommodate the new operational requirements of the CMS ECAL Barrel Safety System are summarized, including the design and development of hardware components for Resistance Temperature Detector (RTD) interfacing and the interlock control
Search for the decay of the Higgs boson to charm quarks in p-p collisions at TeV in the LHC-ATLAS experiment
No full textThis thesis describes the latest search on the Higgs boson decay to a charm and anti-charm quark pair (), where the Higgs boson is produced in association with a vector boson. The associated production of a Higgs boson with a vector boson gives the best sensitivity to probe the Higgs-charm coupling strength, since the leptonic decay of the vector bosons can be used to trigger this process. The search is based on the full proton-proton collision dataset recorded by the ATLAS experiment from 2015 to 2018. The analysis utilizes a new jet-flavor tagging algorithm and new analysis techniques to increase the signal sensitivity compared to the previous search by the ATLAS experiment. The new analysis techniques include a multivariate analysis to discriminate signal and background events, and an event weighting method to effectively use all the simulated events, which helps in reducing the statistical error attributed to simulated samples. In the new analysis, an observed (expected) upper limit at 95\% confidence level of 12 (11) times the standard model prediction on the signal strength is obtained. The expected upper limit is a factor of three times improvement compared to the previous ATLAS result
CERN Tape Archive Workshop : CTA 2025
No full textThe Tapeguy is TRIUMF's home build tape system for ATLAS T1 data center, It was designed to be a stable system that can reliably store and retrieve LHC produced data as a tiered HSM system. we also open to other solutions, evaluated CERN CTA at site in 2024. the talk will present current tapeguy status, recent updates, and the evaluation done at site
CERN Tape Archive Workshop : CTA 2025
No full textS3 is a popular protocol for object storage, in use at CERN since 2018. CERN's Ceph S3 service provides a disk storage back-end for various use cases including backup. In principle it is possible to archive S3 objects to tape using the S3 GLACIER storage class extensions. However, this is not yet supported in an open source solution. This talk gives a brief overview of the landscape of support for S3+tape and describes CERN's planned proof-of-concept for an open source S3+tape implementation using CTA
Fresh results (and surprises) from the James Webb Space Telescope
No full textIn less than three years since the release of the first data, the James Webb Space Telescope has revolutionised our knowledge and understanding of the Universe.
My talk will be a non-specialist review of the concept and current status of the mission, that is designed around an innovative technology combining unprecedented collecting area and IR sensitivity, and of some of the latest results, covering a wide range of topics from the exploration of our solar system, the atmosphere of exoplanets and the search for extraterrestrial life, the evolution of galaxies and black holes in the young Universe.
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CEMTM "The White Rabbit Collaboration"
No full textWhite Rabbit (WR) is an open-source synchronisation technology born at CERN and developed with other institutes and companies. It is commercially available from several vendors, and its adoption in industry and academia increased significantly after it was standardised as part of the Precise Time Protocol (IEEE 1588). As a result, the number of requests for support grew, and the core WR team found it difficult to justify the time needed to help new users and developers. This triggered the creation of the WR Collaboration (WRC). Members of the WRC pay a yearly fee which is mainly used to staff the so-called WRC Bureau, whose main tasks include maintaining the fundamental building blocks of WR (the WR Switch and the WR PTP Core) and providing guaranteed support to members. The WRC is also an experiment in public-private partnerships and knowledge transfer, which can become a template for other projects and technologies. After a quick historical and technological introduction, the talk will cover the rationale for past strategic decisions in WR and for the main driving ideas in the WRC. The evolution of the WRC during its first year of existence will be analysed, and the presentation will finish with plans for the short and medium-term future.</p
Probing the nature of electroweak symmetry breaking with Higgs boson pair-production at ATLAS
No full textIn the Standard Model, the ground state of the Higgs field is not found at zero but instead corresponds to one of the degenerate solutions minimising the Higgs potential. In turn, this spontaneous electroweak symmetry breaking provides a mechanism for the mass generation of nearly all fundamental particles. The Standard Model makes a definite prediction for the Higgs boson self-coupling and thereby the shape of the Higgs potential. Experimentally, both can be probed through the production of Higgs boson pairs (HH), a rare process that presently receives a lot of attention at the LHC. In this talk, the latest HH searches by the ATLAS experiment are reported, with emphasis on the results obtained with the full LHC Run 2 dataset at 13 TeV. Non-resonant HH search results are interpreted both in terms of sensitivity to the Standard Model and as limits on the Higgs boson self-coupling and the quartic VVHH coupling. The Higgs boson self-coupling can be also constrained by exploiting higher-order electroweak corrections to single Higgs boson production. A combined measurement of both results yields the overall highest precision, and reduces model dependence by allowing for the simultaneous determination of the single Higgs boson couplings. Additionally, extrapolations of recent HH results towards the High Luminosity LHC upgrade are also discussed. Many new physics models predict the existence of resonances decaying into two bosons, including the Higgs boson or new scalar S bosons making these important signatures in the search for new physics. Searches for HH or SH resonances have been performed in various final states. In some of these searches, jet substructure techniques are used to disentangle the hadronic decay products in highly boosted configurations.Recent ATLAS searches with Run 2 data collected at the LHC and explains the experimental methods used, including vector- and Higgs-boson-tagging techniques are presented
Observation of a family of all-charm tetraquark candidates at the LHC
No full textThree structures, , , and , have been reported in the channel. These are prime candidates for all-charm tetraquarks. We extend our earlier study of these structures in proton-proton collisions using the CMS detector at the LHC, with 3.6 times more pairs ( of total integrated luminosity). The statistical uncertainties on the masses and widths are reduced by about a factor of three, and the systematic uncertainties are also substantially reduced. For the first time all three structures are established with a significance well above five standard deviations (). Good descriptions of the spectrum were based on quantum interference among structures, which is now validated with significances of more than relative to the fit with no interference---implying all structures have the same quantum numbers, and suggests a family of states