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Recent results on searches with boosted Higgs bosons at CMS
No full textThe study of boosted Higgs bosons at the LHC provides a unique window to probe Higgs boson couplings at high energy scales and search for signs of physics beyond the standard model. In these proceedings, we present recent results on boosted Higgs boson searches at the CMS experiment, highlighting innovative reconstruction and tagging techniques that enhance sensitivity in this challenging regime
Measurements of Diboson production and precision EFT constraints
No full textMeasuring diboson final states is a unique opportunity at the LHC, as they provide precision tests of QCD and EW predictions at unprecedented accuracies, shedding light on the non-Abelian structure of the SM EW theory, and leading to stringent constraints on Effective Field Theory Wilson coefficients. This talk summarizes recent results from ATLAS on this topic
Real-Time Dynamics in a (2+1)-D Gauge Theory: The Stringy Nature on a Superconducting Quantum Simulator
No full textUnderstanding the confinement mechanism in gauge theories and the universality of effective string-like descriptions of gauge flux tubes remains a fundamental challenge in modern physics. We probe string modes of motion with dynamical matter in a digital quantum simulation of a (2+1) dimensional gauge theory using a superconducting quantum processor with up to 144 qubits, stretching the hardware capabilities with quantum-circuit depths comprising up to 192 two-qubit layers. We realize the -Higgs model (HM) through an optimized embedding into a heavy-hex superconducting qubit architecture, directly mapping matter and gauge fields to vertex and link superconducting qubits, respectively. Using the structure of local gauge symmetries, we implement a comprehensive suite of error suppression, mitigation, and correction strategies to enable real-time observation and manipulation of electric strings connecting dynamical charges. Our results resolve a dynamical hierarchy of longitudinal oscillations and transverse bending at the end points of the string, which are precursors to hadronization and rotational spectra of mesons. We further explore multi-string processes, observing the fragmentation and recombination of strings. The experimental design supports 300,000 measurement shots per circuit, totaling 600,000 shots per time step, enabling high-fidelity statistics. We employ extensive tensor network simulations using the basis update and Galerkin method to predict large-scale real-time dynamics and validate our error-aware protocols. This work establishes a milestone for probing non-perturbative gauge dynamics via superconducting quantum simulation and elucidates the real-time behavior of confining strings
Thermomechanical properties and irradiation induced aging of SLA and FDM 3D printed high performance polymers
No full textThe thermomechanical properties of 3D printed polymers for potential use in superconducting devices have been compared. The FDM printed thermoplastics PEEK and ULTEM 9085 exhibit strongly anisotropic properties, with very high mechanical strength and fracture toughness in the flat and on edge printing directions, but much lower strength and toughness in the upright position. FDM printed PEEK exhibits comparatively good radiation hardness, with a moderate degradation of mechanical properties up to a dose of 10 MGy absorbed in ambient air. Among the SLA printed thermosetting resins RG35 has outstanding irradiation hardness, retaining comparatively good mechanical properties up to a dose of 10 MGy
CMS at EPS-HEP Conference 2025
No full textCMS at the EPS-HEP 2025 conference held at the Palais du Phare, Marseille, France. The week-long conference (6th to 11th July) saw many talks from CMS collaborators across all areas of physics, detector upgrades, and outreach. ATLAS confirmed CMS' study indicating toponium, which was announced as a press release during the conference. CMS' Thea Årrestad was awarded EPS Young Experimental Physicist Prize 2025, and Ludivine Ceard and Duc Minh Hoang won poster prizes for their posters
Quark-Gluon Constituent-Based Jet Taggers for the HL-LHC
No full textJet constituents provide a more detailed description of the radiation pattern within a jet compared to observables summarizing global jet properties. In Run 2 analyses at the LHC using the ATLAS detector, transformer-based taggers leveraging low-level variables outperformed traditional approaches based on high-level variables and conventional neural networks in distinguishing quark- and gluon-initiated jets. With the upcoming High-Luminosity LHC (HL-LHC) era, characterized by higher luminosity and increased center-of-mass energy, the ATLAS detector has undergone significant upgrades. This includes a new inner detector with extended coverage into the most forward region, previously unexplored with tracks. This study assesses how these advancements enhance jet tagger accuracy and robustness. These improvements are crucial for processes such as vector boson fusion, vector boson scattering, and supersymmetry, where precise jet identification enhances background discrimination
Detectability and Parameter Estimation for Einstein Telescope Configurations with GWJulia
No full textFuture gravitational-wave (GW) detectors are expected to detect tens of thousands of compact binary coalescences (CBC) per year, depending also on the final detectors layout. For this reason, it is essential to have a fast, reliable tool for forecasting how different detector layouts will affect parameter estimation for these events. The Fisher Information Matrix (FIM) is a common tool for tackling this problem. In this paper, we present a new open source code GWJulia to perform FIM analysis of CBC parameters, i.e., stellar black-hole binaries (BBH), neutron star binaries (BNS), and neutron star-black hole binaries (NSBH). The code is purely written in Julia, making it fast while maintaining a high level of accuracy. We consider a set of case studies to compare different Einstein Telescope (ET) designs. We compare a 10km triangular configuration with two 15km L-shaped detectors with different orientations and temperatures. We discuss also the accuracy of combinations of parameters, which is very informative for cosmology or population studies. Finally, we focus on the detection of golden events and explore how the FIM can guide posterior sampling of GW signals using a novel Hamiltonian Monte Carlo (HMC) sampler. The code is publicly available at https://github.com/andrea-begnoni/GW.j
A new avenue for Higgs boson self-coupling measurements
No full textA search is presented for non-resonant Higgs boson pair production decaying to multi-lepton final states using 140 fb-1 of proton-proton collision data at centre-of-mass energy 13 TeV, recorded with the ATLAS detector during Run 2 of the LHC. By combining nine distinct channels characterized by varying multiplicities of electrons, muons, taus, and photons, this analysis represents a novel and competitive approach to probing the Higgs self-coupling modifier, kappa lambda. The observed (expected) limit on the signal strength is found to be 17 (11) times the Standard Model prediction. The observed (expected) 95% confidence interval constraints on kappa lambda, are -6.2 < kappa lambda < 11.6 (-4.5 < kappa lambda < 9.6), making this analysis the third most sensitive channel for constraining the Higgs self-interaction. A projection of the sensitivity of this analysis to non-resonant Higgs boson pair production to the High Luminosity LHC (LH-LHC) is also presented, assuming a centre-of-mass energy 14 TeV and integrated luminosities up to 3000 fb-1
Observation of a cross-section enhancement near ̅ production threshold with the ATLAS detector
No full textThe exceptionally large dataset collected by the ATLAS detector at the highest proton-proton collision energies provided by the LHC enables precision testing of theoretical predictions using an extensive sample of top quark events. This wealth of data has opened the door to new measurements of top quark properties including those particularly sensitive to the ttbar threshold region, such as quantum entanglement, which were previously beyond reach. This contribution presents the latest highlights in this area from the ATLAS top quark physics