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Heavy-ion Results from CMS
No full textThe Compact Muon Solenoid detector (CMS) was designed to analyze data mainly from proton–proton collision, but its robust design allows also for the analysis of data from heavy-ion collisions. This contribution describes a few examples of recent results of heavy-ion data analyses from CMS
Prospects for forward emitted positronium from nanoporous membranes at AEgIS
No full textAntihydrogen formation at AEgIS at CERN leverages charge exchange between Rydberg positronium (Ps*) and antiprotons, with cross-sections scaling with the Ps principal quantum number and inversely with relative velocity . However, the motional Stark effect and velocity mismatch between Ps and antiprotons impose stringent constraints, limiting efficiency. Advances in transmission positroniumconverters mitigate self-ionization losses and improve velocity alignment, promising a significant boost in antihydrogen yield. This work evaluates formation cross-sections, Ps velocity profiles, and the integration of advanced transmission Ps converters for precision gravitational studies
β- and α-decay spectroscopy of Au182
No full textAn α- and β-decay study of a pure source of laser-ionized and mass-separated Au182 (Z = 79, N = 103) was carried out at the ISOLDE Decay Station at the ISOLDE-CERN facility. Detailed γ-γ analysis following EC/β+ decay of Au182 was performed, and the level scheme of daughter nuclide Pt182 was considerably extended via the identification of 125 new levels and 336 new γ-ray transitions. The nonexistence of a relatively long-lived isomeric state in Au182 and influence of the pandemonium effect on β-decay feeding intensities are discussed. Differences in feeding for two coexisting bands in Pt182 were investigated. The α-decay scheme of Au182 was extended and an α-decay branching ratio of 0.129(11)% was measured. Hindrance factors for α-decay branches were calculated and Iπ=(1+,2+,3+) assignment for the Ir178 ground state was proposed
Countdown to LS3
No full textCountdown to LS3 event. LS3 Coordination team, LS3 Committee members, LS3 project representatives, LS3 project safety officers, LHC Experiments Technical Coordinator
Enhancing the ATLAS Level-1 endcap muon trigger with New Small Wheel integration in Run3
No full textThe Level-1 muon endcap trigger in the ATLAS experiment utilises signals from the Thin Gap Chambers (TGCs) located in the outer muon stations. A significant challenge for this system has been the high background rate caused by particles not originating at the interaction point, which increased the Level-1 trigger rate. To address this issue, the New Small Wheel (NSW) detectors, installed at the inner muon stations during Long Shutdown 2, were integrated into the Level-1 endcap muon trigger system for Run3 operations. In 2024, the full integration of the NSW sectors into the Level-1 trigger decision was successfully completed. By cross-checking the consistency between muon candidates identified by TGC signals and those by the NSW, the system achieved a significant improvement in the discrimination between muons and background particles. This advancement reduced the Level-1 trigger rate by approximately 15 kHz, effectively decreasing the load on the Trigger and DAQ systems and substantially enhancing the data-taking efficiency of the ATLAS experiment
8th International Conference on Physics and Astrophysics of Quark Gluon Plasma
No full textThe 8th International Conference on Physics and Astrophysics of Quark Gluon Plasma (ICPAQGP-2023) will take place during 7-10 February 2023 at Blue Lily Beach Resort, Puri, Odisha, India. The Conference will focus on the recent theoretical and experimental developments in the field of Quark-Gluon Plasma (QGP) and its astrophysical connection with the early Universe
Letter of Intent: AICE - Atom Interferometry CERN Experiment
No full textWe propose a O(100)m Atom Interferometer (AI) experiment to be installed against a wall of the PX46 access shaft to the LHC. This experiment would probe unexplored ranges of the possible couplings of bosonic ultralight dark matter (ULDM) to atomic constituents and undertake a pioneering search for gravitational waves (GWs) at frequencies intermediate between those to which existing and planned experiments are sensitive, among other fundamental physics studies. A conceptual feasibility study showed that this AI experiment could be isolated from the LHC by installing a shielding wall in the TX46 gallery, and surveyed issues related to the proximity of the LHC machine, finding no technical obstacles. A detailed technical implementation study has shown that the preparatory civil‐engineering work, installation of bespoke radiation shielding, deployment of access‐control systems and safety alarms, and installation of an elevator platform could be carried out during LS3, allowing installation and operation of the detector to proceed during Run 4 without impacting HL-LHC operation. These studies have established that PX46 is a uniquely promising location for an AI experiment. We foresee that, if the CERN management encourages this LoI, a significant fraction of the Terrestrial Very Long Baseline Atom Interferometer (TVLBAI) Proto-Collaboration may wish to contribute to such an AI experiment, as discussed in Appendix A.We propose an O(100)m Atom Interferometer (AI) experiment -- AICE -- to be installed against a wall of the PX46 access shaft to the LHC. This experiment would probe unexplored ranges of the possible couplings of bosonic ultralight dark matter (ULDM) to atomic constituents and undertake a pioneering search for gravitational waves (GWs) at frequencies intermediate between those to which existing and planned experiments are sensitive, among other fundamental physics studies. A conceptual feasibility study showed that this AI experiment could be isolated from the LHC by installing a shielding wall in the TX46 gallery, and surveyed issues related to the proximity of the LHC machine, finding no technical obstacles. A detailed technical implementation study has shown that the preparatory civil-engineering work, installation of bespoke radiation shielding, deployment of access-control systems and safety alarms, and installation of an elevator platform could be carried out during LS3, allowing installation and operation of the AICE detector to proceed during Run 4 without impacting HL-LHC operation. These studies have established that PX46 is a uniquely promising location for an AI experiment. We foresee that, if the CERN management encourages this Letter of Intent, a significant fraction of the Terrestrial Very Long Baseline Atom Interferometer (TVLBAI) Proto-Collaboration may wish to contribute to AICE
Axion lines from nuclear de-excitations in galactic stellar populations
No full textWe show that mono-energetic axions are produced in abundance through nuclear de-excitations in nearby galaxies such as M87, which is the central galaxy of the Virgo cluster, and the starburst galaxy M82. If the axion couples to both nucleons and photons and is ultralight, then monochromatic hard X-ray signatures are induced by the subsequent axion-to-photon conversion in the magnetic fields permeating these systems. We search for evidence of such signals using NuSTAR data, focusing specifically on the Fe de-excitation line at 14.4 keV, and we catalog other potentially relevant nuclear lines. We find no evidence for axions from M87 or M82 and set leading constraints on the combined axion-nucleon and axion-photon coupling at the level of GeV in the limit eV, at 95% confidence