6. Searches for pair-produced new particles: trade-off between integrated luminosity and centre-of-mass energy

When searching for massive, pair-produced, new particles close to the kinematic limit at LEP, achieving the maximum possible centre-of-mass energy E-CM has the benefit of giving the highest possible production cross section. However, because of, e.g. operational Instabilities when running at the highest possible energy, a larger integrated luminosity (L) may be achieved when running at a somewhat lower E-CM. It therefore becomes interesting to consider the possible trade-off between E-CM and L.