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Optimal use of timing measurement in vertex reconstruction at CMS
No full textThe MIP Timing Detector (MTD) is a novel component of the CMS experiment, currently under construction as part of the upgrade program to prepare for the High Luminosity era of the LHC (HL-LHC). The MTD will provide precise time information for charged particles and will play an important role in the mitigation of the high pileup expected in HL-LHC. The timing will be used to disentangle vertices that cannot be distinguished spatially, thus reducing the vertex cross-contamination and the effects of pileup on the physics observables used for any data analysis. This contribution presents the recent developments in the vertex reconstruction with the use of timing, and introduces a new set of tools useful to evaluate the performance of different reconstruction algorithms, which can serve as a benchmark for future developments in the field
Her Excellency Ms Giorgia Meloni President of the Council of Ministers Italian Republic Friday, 7 March 2025
No full textVisit by Professor Michael Luck, Deputy Vice-Chancellor and Provost, University of Sussex, Great-Britain
No full textVisit by Professor Michael Luck, Deputy Vice-Chancellor and Provost, University of Sussex, United Kingdom of Great-Britain and Northern Irelan
Triple GEM detectors for the Phase-2 upgrade of the CMS experiment at the LHC
No full textThe High-Luminosity LHC (HL-LHC) will increase proton-proton collision rates to 5–7.5 times the nominal LHC luminosity, with an expected number of 140–200 pp-interactions per bunch crossing (Pile-up or PU). To maintain the performance of muon triggering and reconstruction under high background, the forward part of the Muon spectrometer of the CMS experiment will be upgraded with Gas Electron Multiplier (GEM) and improved Resistive Plate Chamber (iRPC) detectors. A first GEM station (GE1/1) was installed during Long Shutdown 2 (LS2, 2019–2021) while second and third stations (GE2/1 and ME0) will be installed in the third Long Shutdown (LS3, 2026–2028) and during the Run 4 technical stops. GE1/1, considered an early Phase-2 upgrade, will reduce the p threshold by combining GEM and Cathode Strip Chamber (CSC) hits in the forward muon system at twice the LHC design luminosity (2 × 10/cm s, 50 PU). The commissioning of the GE1/1 detector has been completed during Run 3 in 2022 and 2023. Most chambers are operating stably with an efficiency higher than 95%. Demonstration of the combined CSC-GEM trigger will take place in 2024. The first GE2/1 detectors were installed in the LHC 2023–24 technical stop and the ME0 detector is entering the production phase in 2024. This presentation discusses the commissioning and early performance of GE1/1, together with the lessons learnt which were used to improve the detector and electronics design for GE2/1 and ME0. We also present the R&D; performed to optimize the ME0 detector for its high-rate environment, together with the performance measurements of the first stack of ME0 detectors for standalone muon segment reconstruction
New physics searches in exotica sector at CMS experiment
No full textThe Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) has a vast physics programme ranging from precision measurements of the Standard Model (SM) predictions to the new physics searches beyond the SM. This paper presents an overview of the research highlights from the CMS experiment using LHC Run 2 and Run 3 data to explore the exotica sector physics beyond the SM, including searches for long lived particles, heavy resonances, extra dimensions, quantum black holes, vector like quarks and leptons, and heavy neutral leptons. These findings serve as tests of the SM predictions while probing subtle hints of new physics
