Possibilities for polarized protons at HERA

This article explores the implications of obtaining polarized protons at high energy in HERA. A list of likely minimum modifications is given and a possible fundamental limitation on the polarization attainable at very high energy is explained. 1 Introduction HERA is the e \Sigma -p colliding beam facility at DESY in Hamburg. The maximum e \Sigma energy is 30 GeV and the current proton energy is 820 GeV. There are two experiments for observing e \Sigma -p collisions, namely H1 and ZEUS at the north and south interaction points (IP) respectively. At the east straight section the HERMES experiment is installed [1] and the HERA-B experiment will be installed in the west area. Electrons and positrons in storage rings can become spin polarized normal to the plane of the machine by the emission of synchrotron radiation [2]. However, the synchrotron radiation also causes stochastic disturbance to the orbit motion [3] and this can, owing to the necessary presence of quadrupole fields, l..