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10th International Conference on Precision Physics and Fundamental Physical Constants
No full textThe 10th International Conference on Precision Physics and Fundamental Physical Constants will take place in Warsaw (Poland) from May 26th to 30th, 2025. This edition is co-organized by the Candela Foundation and the University of Warsaw. The conference continues the tradition of workshops on the following topics: fundamental physical constants; quantum electrodynamics of bound systems; spectroscopy of exotic atoms; quantum standards; precision measurements in fundamental physics, astrophysics and cosmology; low energy tests of the Standard Model of elementary particles
RF Design and Optimization of Linacs for the CLIC Main Beam Injector Complex
No full textThe design of the CLIC main beam injector complex linacs necessitates high-gradient, traveling-wave accelerating structures engineered to withstand substantial beam-loading effects due to the elevated beam current and demanding acceleration requirements of CLIC operations. In this work, we present a comprehensive design and optimization study of 2 GHz traveling-wave structures tailored to the stringent requirements of the CLIC main beam injector complex. The electron and positron linacs accelerate the beams up to 2.8 GeV, with a nominal bunch charge of 1 nC, followed by the booster linac, which further increases the energy of both beams to 9 GeV with a nominal bunch charge of 0.83 nC. Each bunch train consists of 352 bunches, necessitating careful management of beam dynamics to ensure stable operation. Through detailed analytical modeling and extensive parameter sweeps, we optimized the accelerating structures' iris geometry to enhance shunt impedance, regulate surface electric fields and suppress long-range wakefields, thereby minimizing undesired beam-cavity interactions. Given the high beam current, we thoroughly analyzed beam-loading effects and devised compensation techniques to minimize bunch-to-bunch energy spread, ensuring reliable acceleration. This study advances the development of high-efficiency accelerating structures operating with high beam current crucial for achieving CLIC goals
P371 Experiment at CERN - quest for polarized antiprotons
No full textPolarization effects in the production of antiprotons at the CERN PS beam line T11 at 3.5 GeV/c have been investigated within the P371 experiment. These effects, if found to be significant could provide a simple method to generate polarized antiproton beams with existing facilities. First precursor measurements were carried out by the P349 collaboration, though the available statistics were insufficient for a quantitative conclusion. With an upgraded detector setup and extended beam time, the experiment aims at determining whether a measurable degree of antiproton polarization exists
Observation of long-range collective flow in OO and NeNe collisions and implications for nuclear structure studies
No full textThe long-range collective flow of particles produced in oxygen-oxygen (OO) and neon-neon (NeNe) collisions is measured with the CMS detector at the CERN LHC. The data samples were collected at a center-of-mass energy per nucleon pair of 5.36 TeV, with integrated luminosities of 7 nb and 0.8 nb for OO and NeNe collisions, respectively. Two- and four-particle azimuthal correlations are measured over nearly five units of pseudorapidity. Significant elliptic () and triangular () flow harmonics are observed in both systems. The ratios of coefficients between NeNe and OO collisions reveal sensitivity to quadrupole correlations in the nuclear wave functions. Hydrodynamic models with ab initio nuclear structure inputs qualitatively reproduce the collision-overlap dependence of both the values and the NeNe to OO ratios. These measurements provide new constraints on hydrodynamic models for small collision systems and offer valuable input on the nuclear structure of O and Ne.The long-range collective flow of particles produced in oxygen-oxygen (OO) and neon-neon (NeNe) collisions is measured with the CMS detector at the CERN LHC. The data samples were collected at a center-of-mass energy per nucleon pair of 5.36 TeV, with integrated luminosities of 7 nb and 0.8 nb for OO and NeNe collisions, respectively. Two- and four-particle azimuthal correlations are measured over nearly five units of pseudorapidity. Significant elliptic () and triangular () flow harmonics are observed in both systems. The ratios of coefficients between NeNe and OO collisions reveal sensitivity to quadrupole correlations in the nuclear wave functions. Hydrodynamic models with nuclear structure inputs qualitatively reproduce the collision-overlap dependence of both the values and the NeNe to OO ratios. These measurements provide new constraints on hydrodynamic models for small collision systems and offer valuable input on the nuclear structure of O and Ne
Triple Higgs search in the 6b final state at the ATLAS detector
No full textI present the search for HHH production in the 6b final state with the ATLAS detector using pp collisions at 13 TeV. The presentation includes motivation, analysis strategy, results, and brief future aspects
Advancing the CMS Level-1 Trigger Jet Tagging with DeepSets at the HL-LHC
No full textAt the High Luminosity LHC, selecting important physics processes such as (di-) Higgs production will be a high priority. The Phase-2 Upgrade of the CMS Level-1 Trigger will reconstruct particle candidates and use pileup mitigation for the 200 simultaneous proton-proton interactions. A fast cone algorithm will reconstruct jets from these particles, providing access to jet constituents for the first time. We introduce a new multi-class jet tagger with a small, quantized DeepSets neural network. The tagger, trained on a mix of simulated CMS events, predicts various hadronic and leptonic classes. We present the tagger, its performance, and its improvements for triggering on (di-) Higgs events
Design and deployment of a fast neural network for measuring the properties of muons originating from displaced vertices in the CMS Endcap Muon Track Finder
No full textWe report on the development, implementation, and performance of a fast neural network used to measure the transverse momentum in the CMS Level-1 Endcap Muon Track Finder. The network aims to improve the triggering efficiency of muons produced in the decays of long-lived particles (LLPs). We implemented it in firmware for a Xilinx Virtex-7 FPGA and deployed it during the LHC Run 3 data-taking in 2023. The new displaced muon triggers that use this algorithm broaden the phase space accessible to the CMS experiment for searches that look for evidence of LLPs that decay into muons