CMS
Next-Generation CO₂ Cooling Systems Powering the Future of ATLAS and CMS
Four CO2 cooling plants and accumulators in the service cavern of CMS in May 2025. (Photo by Jérôme Daguin) During recent shutdown periods, CERN engineers and technicians — in collaboration with the ATLAS and CMS teams — began installing the…
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CMS Inaugurates Its New Control Room
On 15 May 2025, CMS officially inaugurated its new control room at Point 5 in Cessy, France. The celebration brought together guests from CERN management and representatives of all LHC experiments to mark this significant upgrade to CMS’s…
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CLUE: A Scalable Clustering Algorithm for the Data Challenges of Tomorrow
The foreseen increase in luminosity and pileup at the High-Luminosity Large Hadron Collider (HL-LHC) [1] will challenge both the detector hardware and the reconstruction software. With higher pile-up, calorimeter energy reconstruction depends even…
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Anomaly at the Threshold: A Closer Look at tt̄ Events in CMS
Some of the most intriguing developments in physics begin not with a discovery, but with an anomaly, subtle, persistent, and difficult to ignore. In 2019, CMS reported a mild excess of around three standard deviations in a search for heavy…
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CMS Launches New Monthly Newsletter: Le Point Cinq
The CMS collaboration is excited to announce the launch of its new monthly newsletter, "Le Point Cinq." This fresh communication channel will provide regular updates on CMS physics highlights, the progress of upgrade projects, and essential…
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CMS Achieves LHC's Most Precise W boson Mass Measurement Yet
The first measurement of the W boson mass (mw) performed by the CMS Collaboration was announced in September 2024. This result has been long-awaited—the first LHC measurement of mW, by the ATLAS Collaboration, was shown nearly 7 years ago. In the…
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Tracing the Path to Precision: The Historical Evolution of Electroweak Physics at the LHC
The unification of the electromagnetic and weak-nuclear forces into an electroweak theory was one of the major breakthroughs of 20th century particle physics. In the 1960s, Steven Weinberg, Sheldon Glashow, and Abdus Salam proposed that these two…
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Extended Scalar Sectors are considered from all angles at CERN
It has been more than ten years since the discovery of the first scalar particle at the electroweak scale. This particle was discovered at the LHC in 2012, and it was quickly found to be a scalar that is compatible with the Higgs boson predicted by…
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LHC Run 3: A Marathon of Progress and Perseverance
Earlier this month, the Large Hadron Collider reached an unprecedented milestone of 100 inverse femtobarns – equivalent to 10 million billion collisions – delivered to the ATLAS and CMS experiments in 2024, with 28 days of proton-proton collisions…
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CMS Detector in 2024: Advancements in Data Collection and Detector Performance
On April 5th, 2024, stable beams returned to the LHC, marking the official start of the 2024 physics data-taking season. The photo captures CMS' Run Coordination team in the newly upgraded CMS control center, ready to oversee the exciting season…
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