  Two particle correlations are used to extract information about the
characteristic size of the system in proton-proton and heavy ion collisions.
The size of the system can be extracted from the Bose-Einstein quantum
mechanical effect for identical particles. However there are also long range
correlations that shift the baseline of the correlation function from the
expected flat behavior. A possible source of these correlations is the
conservation of energy and momentum, especially for small systems, where the
energy available for particle production is limited. A new technique, first
used by the STAR collaboration, of quantifying these long range correlations
using energy-momentum conservation considerations is presented in this talk.
Using Monte Carlo simulations of proton-proton collisions at 900 GeV, it is
shown that the baseline of the two particle correlation function can be
described using this technique.
