Transverse Polarization for Energy Calibration at the Z peak

Abstract

In this paper we deal with aspects of transverse polarization for the purpose of energy calibration of proposed circular colliders like the FCC-ee and the CEPC. The main issues of such a measurement will be discussed. The possibility of using this method to accurately determine the energy at the WW threshold as well as the Z peak will be addressed. The use of wigglers for reducing long polarization times will be discussed and a possible strategy will be presented for minimising the energy uncertainty error in these large machines.Comment: Talk presented at HF2014, "the 55th ICFA Advanced Beam Dynamics Workshop on High Luminosity Circular e+e- Colliders - Higgs Factory", Beijing, 9-12 October 201