Monochromatization of $e^{+}{e}^{-}$ colliders with a large crossing angle

Abstract

The relative center-of-mass energy spread at $e^{+}{e}^{-}$ colliders is about $10^{-3}$, which is much larger than the widths of narrow resonances J/$\psi$, $\psi$(2S), ${\rm Y}$(1S), ${\rm Y}$(2S), ${\rm Y}$(3S) mesons, tauonium and some others. It's reduction would significantly increase the resonance production rates and open up great opportunities in the search for new physics. In this paper, we propose a new monochromatization method for colliders with a large crossing angle (which can provide a high luminosity). The contribution of the beam energy spread to the spread of the center-of-mass energy is canceled by introducing an appropriate energy-angle correlation at the interaction point; ${\sigma }_W/W\sim (0.5-1)10^{-5}$ appears possible.

Comments: 8 pages, 2 figures