The CMS Experiment has unveiled its most precise and comprehensive measurement of the Higgs boson to date, utilising LHC Run 2 data collected between 2016 and 2018. This significant legacy combination of Higgs boson studies confirms theories regarding the origin of mass in the Universe with a 5% precision for its production rate. Scientists achieved this by statistically combining measurements from all accessible Higgs boson decay channels and production modes. Furthermore, the experiment employed Simplified Template Cross Sections (STXS) to map the Higgs boson's behaviour across 32 distinct categories, and interpreted these findings using Standard Model Effective Field Theory (SMEFT) to search for new physics in a model-independent way, examining 43 different SMEFT interactions. While largely confirming the Standard Model, the results also show intriguing small deviations in high-momentum regions, which could hint at physics beyond the current understanding.

Links:

- https://cms-results.web.cern.ch/cms-results/public-results/preliminary-results/HIG-21-018/index.html

- https://cms.cern/news/pieces-precision-building-higgs-bosons-clearest-portrait-date

he ATLAS Experiment at CERN has embraced modern AI techniques to revolutionise jet flavour tagging, a crucial process in analysing particle collisions. A new algorithm called GN2, powered by a Transformer neural network, directly analyses information from particle tracks and jets, eliminating the need for previous, hand-crafted algorithms. This advancement significantly improves the identification of b-jets and c-jets, which are vital for Standard Model measurements and the search for new physics phenomena. The ATLAS Collaboration has established robust pipelines to integrate and train these AI algorithms, leading to a substantial leap in performance and offering deeper insights into the physics signatures learned by the model. This innovative approach is already having a significant impact on ATLAS physics research, including enhancing the precision of Higgs boson studies and the search for new particles.

Paper link: https://arxiv.org/pdf/2505.19689

The CMS Collaboration's "An all-round boosted chase for supersymmetry" explores the concept of supersymmetry (SUSY), a theoretical extension of the Standard Model of particle physics. The article details how scientists at CERN's CMS Experiment are searching for superparticles by analysing final states that include Lorentz-boosted objects, which are formed when heavy superparticles decay into lighter, high-momentum particles. This new "razor boost" analysis broadens the search to 25 distinct final states, including boosted W, Z, Higgs bosons, top quarks, and uniquely, boosted leptonic jets, using machine learning and razor kinematic variables to identify potential SUSY signals. Although no significant deviations from Standard Model predictions were observed, the findings have allowed the collaboration to set strong limits on superparticle production rates and masses within various SUSY models, with further interpretations of complete SUSY models ongoing.

Links: https://cms-results.web.cern.ch/cms-results/public-results/preliminary-results/SUS-23-014/index.html