Probing small parton densities in ultraperipheral A A and pA collisions at the CERN large Hadron Collider.

We calculate photoproduction rates for several hard processes in ultraperipheral proton-lead and lead-lead collisions at the CERN Large Hadron Collider (LHC) with square root of sNN = 8.8 and 5.5 TeV, respectively, which could be triggered in the large LHC detectors.

Measurement of mutual coulomb dissociation in sqrt[s(NN)] = 130 GeV Au + Au collisions.

We report on the first measurement of mutual Coulomb dissociation in heavy-ion collisions. We employ forward calorimeters to measure neutron multiplicity at beam rapidity. The cross section for simultaneous electromagnetic breakup of Au nuclei at a nucleon-nucleon center of mass energy sqrt[s(NN)] = 130 GeV is sigma(MCD) = 3.