  We point out that current calculations of inclusive two-particle correlations
in p-A collisions based on the Color Glass Condensate approach exhibit a
contribution from Hanbury-Brown-Twiss correlations. These HBT correlations are
quite distinct from the standard ones, in that they are apparent for particles
widely separated in rapidity. The transverse size of the emitter which is
reflected in these correlations is the gluonic size of the proton. This raises
an interesting possibility of measuring the proton size directly by the HBT
effect of particle pairs produced in p-A collisions.
