The Large Hadron Collider (LHC) employs special optics and configurations, alongside low-beta* collision optics, to address specific experimental requirements. These include calibrating luminosity monitors (vdM) and facilitating forward physics measurements in TOTEM and ALFA experiments (high-beta). The special optics have been in use since Run 1, and for Run 3, they have been updated for compatibility with standard low-beta collision optics to ensure streamlined commissioning and reduced setup time. For vdM optics in Run 3, beam de-squeezing yields beta* values of 19 to 24 m, while in the high-beta optics, beams are de-squeezed to round beams with beta* of 120 m, followed by a second step to asymmetric optics with beta* of 3 km and 6 km in the horizontal and vertical planes. The 2023 high-beta optics run with the km beta* optics, incorporates tight collimation settings and the use of crystals at top energy for the first time, aiming to substantially reduce backgrounds in the experiments. This publication introduces and discusses the updated optics for Run 3, covering their validation, optics measurement results, and operational insights.

Dynamic Aperture (DA) studies, based on single-particle tracking simulations including important non-linear fields such as beam-beam effects, have played a crucial role in guiding the operation of the Large Hadron Collider (LHC) in proton-proton collisions. The correspondence between DA computed through simulations and the actual beam lifetime during operation has been established for proton beams through dedicated experiments at the LHC. However, such an approach has not yet been applied to the Pb ion operation of the accelerator, as the simulation tools have not been rigorously benchmarked against experimental data yet. The present paper presents the simulation studies and experimental tests performed to establish the correlation between DA and beam lifetime for ions. The main focus lies on exploring the beam-beam limit when the crossing angle is significantly reduced in all LHC experiments as compared to the nominal configuration. This approach opens the possibility to operate with reduced crossing angles or reduced $\beta^*$ within the beam-beam limit, potentially leading to an enhanced performance of the accelerator with ions.

A comprehensive model accurately depicts and tracks emittance and luminosity evolution in the Large Hadron Collider (LHC), considering known effects like IBS, synchrotron radiation damping, coupling and incorporating data-driven factors on emittance growth and intensity losses. Used extensively in LHC Run 2, the model is updated for compatibility with new optics and operational schemes in Run 3, featuring luminosity leveling. This paper discusses the analysis of 2022 and 2023 LHC data, exploring emittance evolution and identifying extra blow-up at injection and collision energies compared to model predictions. Examining the model's agreement with collision data provides insights into the impact of degradation mechanisms, configuration options, filling schemes, and beam types on delivered luminosity. These studies offer valuable insights into potential gains in integrated luminosity for subsequent Run 3 years.

The discovery of neutrino Charge-Parity Violation (CPV) became an important candidate to explain the matter dominance in the Universe. The goal of the ESSnuSB project is to discover and measure neutrino CPV with unprecedented sensitivity*. The construction of the European Spallation Source, ESS, the world’s most intense proton source, represents an outstanding opportunity for such project to take place. ESSnuSB has been granted from EU in the framework of H2020 (2018-2022) and Horizon Europe (2023-2026) to make Design Studies. The aim of the first Design Study was to demonstrate that the ESS linac can be used to generate an intense neutrino beam by doubling its average beam power and that a megaton water Cherenkov detector can be constructed in a mine 360 km from ESS providing detection of neutrinos at the 2nd neutrino oscillation maximum. A CDR** has been published in which it is shown the high physics performance to discover CPV and precisely measure the violating parameter δCP. For this, the modification for neutrino generation to compress the proton pulse length from 2.86 ms, to 1.3 μs has been studied. The second, ongoing, Design Study, ESSnuSB+, is devoted to neutrino cross-section measurements relevant to the CPV discovery. Two facilities are proposed, a low energy nuSTORM (muons decaying to neutrinos in a race-track storage ring) and low energy ENUBET (pions decaying to a muon and a neutrino, allowing the neutrino beam to be monitored by detection of the decay muon).

Optimizing the configuration of an operational cycle of a collider such as the LHC is a complex process, requiring various simulation studies. In particular, Dynamic Aperture (DA) simulations, based on particle tracking, serve as indispensable tools for achieving this goal. In the framework of the high-luminosity LHC (HL-LHC) studies, our primary focus lies in performing parametric beam-beam DA simulations for the critical phases of the collision process, which includes the collapse of the beam separation bump, as well as the start, and the end of the luminosity leveling. In this paper, we present the status of our ongoing studies for different optics and filling schemes, and we comment on how they could guide the orchestration of the operational settings along the luminosity leveling phase of the HL-LHC cycle.

European Laboratories for Accelerator Based Sciences (EURO-LABS), a program for research infrastructures services advancing the frontiers of knowledge, aims to provide unified transnational access (TNA) to leading Research Infrastructures (RI) across Europe. Taking over from previously running independent TNA programs, the new program brings the nuclear physics, the high-energy accelerator, and the high-energy detector R&D communities together to foster collaborations and to stimulate synergies. With 33 partners from European countries, EURO-LABS forms a large network of RIs. These RIs offer TNAs ranging from a modest size test infrastructure to large scale ESFRI facilities. The offered access will enable research at the technological frontiers in accelerator and detector development to explore new physics ideas and will open wider avenues in both basic and applied research in diverse topics ranging from optimal running of reactors to mimicking reactions in the stars. Within this large network, EURO-LABS will ensure diversity, and actively support researchers from different nationalities, gender, age, grade, and variety of professional expertise.