Speaker
Description
Optics measurements are usually performed with low-intensity, non-colliding pilot beams in the interest of machine safety. However, Long-Range Beam-Beam (LRBB) interactions can drive substantial optics perturbations. In 2024, a weak-strong measurement scheme was developed that probes the weak beam while leaving the strong beam unaffected, and machine tests validated this method. In 2025, a reported luminosity discrepancy between ATLAS and CMS motivated further study of the LRBB-induced beta-beat in the new 18 cm flat-optics configuration. A large beta-beat was observed, reaching typical LHC machine-protection limits. Correction strategies using magnets in the experimental insertions were demonstrated successfully, and, for the first time, non-linear corrections addressing sextupolar and octupolar resonance driving terms were also successfully demonstrated.
| Paper status | Proceeding files received |
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