MD 402: Head-on limits. Separation leveling.

HL-LHC will rely on very large beam-beam head-on shift and spread. Also LHC to push for higher luminosity will go in the same direction. A clear understanding of colling high brightness beams is fundamental to guarantee the operation of such beams and to anticipate problematics linked to such configuration. We want to explore the beam dynamics of colliding beams with high brightness: intensities as high as possible close to 2e11 ppb or higher and small emittances. The goal is to monitor the beam lifetimes and emittance behavior around the machine working point for full head-on collision and for collisions with small transverse offsets. The study aims to highlight emittance growth driven by beam-beam and possible issues with instabilities due to mode coupling at injection energy.