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The irradiation of the CMS Hadron Calorimeter (HCAL) subdetectors results in decreased signal output from the active materials as well as increased noise in the photodetectors used to read out the system. The HCAL has a dedicated calibration system used to monitor and correct for these effects and to help synchronise the timing of the subdetectors. The calibration system is described with a focus on the upgrades to the laser system, which has undergone significant changes since the end of Run 2 of the LHC in 2018. A new solid state laser has been installed and commissioned, and the optical setup for light distribution has been simplified. An upgrade to the laser trigger board has reduced the laser trigger jitter by an order of magnitude. A new system has also been developed to fire the laser, based on existing HCAL electronics. Future improvements to the system are also presented, including ongoing work on extending the system to include remote monitoring capabilities. 

The MUon proton Scattering Experiment (MUSE) at the PiM1 beam line of the Paul Scherrer Institute is simultaneously measuring the elastic scattering of electrons and muons from a liquid hydrogen target to extract the charge radius of the proton with both positive and negative beam polarities. In addition to providing precise data for addressing the proton radius puzzle, comparing the four scattering cross sections directly tests lepton universality, radiative corrections, and two-photon exchange effects for electrons and muons. In order to study radiative correction and get more precise incident lepton energy at the scattering vertex for the cross section measurements, MUSE uses a lead-glass calorimeter located at the downstream end of the beam line. This proceeding discusses the specifications and calibration process of the calorimeter detector. Data are compared to simulation to demonstrate the performance of the detector. 

FASER is searching for light, weakly-interacting particles at the Large Hadron Collider. The first search for Axion-like particles (ALPs) decaying to a photon pair using data collected in 2022 and 2023 was performed and successfully excluded regions not previously ruled out. To further reduce neutrino background, a new preshower detector will be installed by the end of 2024. The detector is based on a monolithic active pixel sensor in 130 nm SiGe BiCMOS, which will allow resolving the photon pairs interacting in the preshower detector. The final ASICs have been produced in May 2024 and are currently being validated. 

The evolution of jets showers in high energy nuclear collisions is influenced in various ways by the presence of a surrounding medium. The interaction of jet constituents with the medium can happen during the partonic stage of the jet, during hadronization, and even during its hadronic stage. We demonstrate how flow of the ambient medium in a direction transverse to the jet can introduce both dipole and quadrupole defomations. We propose to analyze then= 1 andn= 2 harmonic deformations of soft and semi-hard hadrons or subjets in a jet with respect to the jet core using the method ofq-vectors. We discuss simulations which show how the transverse shapes and their preferred angles evolve when the ambient environment of jets changes from the vacuum to a parton medium without flow and finally to a medium with various rates of transverse flow. Our study includes the effects of both flow during the development of the parton shower and hadronization. The existence of dipole deformations, and the correlation of the angles of dipole and quadrupole deformations could constitute promising experimental signals for the presence and size of ambient transverse flow. 

We investigate the impact of the hadronic phase on jet quenching in nuclear collider experiments, an open question in heavy-ion physics. Previous studies in a simplified setup suggest that hadronic interactions could have significant effects, but a systematic analysis is needed. Using the X-SCAPE event generator with the SMASH afterburner, we study the role of hadronic rescattering on jet fragmentation hadrons. Applying this framework toe⁺+e⁻collisions, we demonstrate that even in small systems with limited particle production, hadronic interactions lead to measurable modifications in final-state hadronic and jet observables by comparing scenarios with and without after-burner rescattering.