Operating a PbWO4 EM calorimeter in a harsh radiation environment

The CMS Electromagnetic Calorimeter (ECAL) is the largest calorimeter operating in a high energy physics experiment. During the course of the LHC Run 1, Run 2, and Run 3, ECAL has made essential contributions to the CMS physics program by precisely measuring the energy, position, and time of arrival of photons and electrons, and of hadronic jets. Among the masterpieces of physics results achieved with its excellent energy resolution is the observation of the Higgs boson in its two photon decay in 2012, and the precise measurement of its properties. Operating a lead-tungstate scintillating calorimeter to such high precision and in a harsh radiation environment requires full control of the environmental conditions, such as temperature and bias voltages of the photodetectors, and a continuous correction of the crystal response changes. This paper focuses on the challenges faced over the recent Run 3 years -- experiencing the largest instantaneous luminosity up to now -- and describes the calibration techniques developed and the achieved results, also including the evolution of the monitoring system in preparation of the High Luminosity phase of the LHC

CERN openlab Summer Student Lightning Talks (1/2)

Due to its intrinsic quantum mechanical nature, applications in chemistry and materials science are among the strongest candidates for algorithmic quantum advantage. However, to understand the problem size at the break-equal point between quantum and classical solutions, one requires large-scale simulations of quantum circuits. Here, we propose to develop and investigate an emulation approach to reduce the cost of simulating trotterized Hamiltonian evolution (a very common subroutine of many chemistry applications) by efficiently emulating multi-qubit rotations. To assess the practical impact and efficiency of our emulation strategy, we are conducting comprehensive benchmarks. These benchmarks compare the performance and resource utilization of multi-qubit rotation implementations against the single and double-qubit rotations. Following the evaluation, we aim to explore ways to integrate the emulation strategy into the Intel Quantum SDK or other quantum computing frameworks to enhance their efficacy and accessibility for quantum chemistry computations

The First Release of ATLAS Open Data for Research

The ATLAS Collaboration has recently, for the first time, released a large volume of data for use in research publications. The entire 2015 and 2016 proton collision dataset has been made public, along with a large quantity of matching simulated data, in a light format, PHYSLITE, which is also used internally for ATLAS analysis. In order to allow detailed analyses of these data, all the corresponding software has been made public, along with extensive documentation targeting several different levels of users, from those who are new to particle physics to experienced researchers that need only an introduction to the ATLAS-specific details of the data. This contribution describes the data, the corresponding metadata and software, and the documentation of the open data, along with the first interactions with non-ATLAS researchers

Analysis of threshold oscillations observed in CMS Phase 2 Inner Tracker modules

During Long Shutdown 3, between 2026 and 2028, the CMS detector will be updated in order to fulfill the requirements of the new LHC era, called High-Luminosity LHC. The updated version of the CMS pixel detector is called Inner Tracker, and it is based on silicon pixel sensor technology. The base unit of the detector is the detector module, which is the assembly of the silicon sensor connected to one or more readout chips and the appropriate printed circuit board for powering and readout. These modules went thought an intense R\&D and validation campaign. In this study, results obtained with prototype modules are presented. The modules are formed by a sensor with 145\,152 pixels bump-bonded to the CMS readout chip. In this study, effects that affect the module threshold, which is a crucial parameter for the detection of a particle signal, have been observed. The deep characterization of this phenomenon allowed to optimize the module calibration procedure through the development of a dedicated software

Advancements on Aerial Robotic Systems and Sensor Technologies for Future HEP Detectors

The European Organization for Nuclear Research (CERN) has pioneered the development of a robotic Lighter-than-Air (LtA) Unmanned Aerial Vehicle (UAV), specifically a blimp, aimed at mitigating radiation exposure risks for human personnel and optimizing detector uptime. This document elucidates the evolution of a blimp detection model based on deep learning algorithms and its integration within a localization system based on external cameras. Furthermore, it explores the integration process of a hybrid pixel detector for real-time radiation monitoring within the blimp payload

Top quark and quarkonia production in heavy- ion collisions with the ATLAS experiment

Measurements of top quarks in heavy-ion collisions are expected to provide novel probes of nuclear modifications to parton distribution functions as well as to bring unique information about the evolution of strongly interacting mat- ter. We report the observation of the top-quark pair production in proton-lead collisions at the centre-of-mass energy of 8.16 TeV in the ATLAS experiment at the LHC. Top-quark pair production is measured in the lepton+jets and the dilepton channels, with a significance well above 5 standard deviations in each channel separately. The results from the measurement of the nuclear modifica- tion factor RpA are also presented. If available, results from the measurement of top-quark production in Pb+Pb collisions will be presented and discussed and will be complemented by an overview of the most recent quarkonia mea- surements with ATLAS

Performance and calibration of the ATLAS Tile Calorimeter

The Tile Calorimeter (TileCal) is a sampling hadronic calorimeter covering the central region of the ATLAS experiment, with steel as absorber and plastic scintillators as active medium. The scintillators are read-out by the wavelength shifting fibres coupled to the photomultiplier tubes (PMTs). The analogue signals from the PMTs are amplified, shaped, digitized by sampling the signal every 25 ns and stored on detector until a trigger decision is received. The TileCal front-end electronics reads out the signals produced by about 10000 channels measuring energies ranging from about 30 MeV to about 2 TeV. Each stage of the signal production from scintillation light to the signal reconstruction is monitored and calibrated. During LHC Run-2, high-momentum isolated muons have been used to study and validate the electromagnetic scale, while hadronic response has been probed with isolated hadrons. The calorimeter time resolution has been studied with multi-jet events. First results using early LHC Run-3 data will be shown. A summary of the performance results, including the calibration, stability, absolute energy scale, uniformity and time resolution, will be presented

Dark matter searches at accelerators

The understanding of the nature of dark matter is one of the most pressing questions begging for an answer in fundamental physics today. In this contribution we will review the searches performed recently at accelerators, in particular the ones at the Large Hadron Collider