Restriction on the energy and luminosity of e(+)e(-) storage rings due to beamstrahlung.

The role of beamstrahlung in high-energy e(+)e(-) storage-ring colliders (SRCs) is examined. Particle loss due to the emission of single energetic beamstrahlung photons is shown to impose a fundamental limit on SRC luminosities at energies 2E(0)≳140  GeV for head-on collisions and 2E(0)≳40  GeV for crab-waist collisions. With beamstrahlung taken into account, we explore the viability of SRCs in the 2E(0)=240-500   GeV range, which is of interest in the precision study of the Higgs boson. At 2E(0)=240  GeV, SRCs are found to be competitive with linear colliders; however, at 2E(0)=400-500  GeV, the attainable SRC luminosity would be a factor 15-25 smaller than desired.