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CMS ECAL: Meeting the trigger performance challenges of Run 3
No full textThe CMS electromagnetic calorimeter (ECAL) at the CERN LHC is a high-resolution crystal calorimeter equipped with fast digital signal processing algorithms for measuring the energy and timing of calorimeter deposits. These trigger primitives are sent to the Level-1 trigger system at a rate of 40 MHz to help decide whether to store the event data offline. This paper summarizes the ECAL trigger performance during LHC Run 3 (2022+), highlighting enhanced calibration methods for trigger primitives. A key focus is the commissioning of a new automated procedure for deriving, validating, and deploying time-dependent response corrections using in-situ measurements from a dedicated laser monitoring system. Additionally, the rejection of unwanted large signals (“spikes”) caused by hadronic deposits on the APD photodetectors in the ECAL barrel region (<η< 1.48) has been a persistent issue since 2009. The evolution of spike rejection techniques in ECAL’s on-detector and o↵-detector electronics, along with the potential of currently unused features of the ECAL electronics to further enhance spike rejection, will be discussed
Probing the Weak Equivalence Principle with a Moiré Deflectometer Using Antihydrogen at AEḡIS
No full textThe nature of gravity’s influence on antimatter systems is still one of the most profound questions in modern physics, probing the very foundation of both General Relativity and the Weak Equivalence Principle (WEP). By performing a precise measurement on the free-fall acceleration of antihydrogen () experiments investigate whether antimatter experiences acceleration due to gravity in the same way as ordinary matter systems, a fundamental assumption that, if falsified, could signal new physics beyond the Standard Model. In the Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEIS), located at CERN, a pulsed beam is formed via charge-exchange reaction of positronium (Ps) and antiprotons (). The ultimate intention for this beam is to pass the through an instrument designed to measure the free-fall of particles, this device is known as a moiré deflectometer. In transport from the formation to the moiré deflectometer, the produced encounter both physical obstacles and nonuniform environmental conditions. atoms entering the moiré deflectometer will be monitored from multiple detector systems designed to measure annihilation radiation both axially and radially. The purpose of this report is to present the operating physics principles and current developmental status of the moiré deflectometer
