Physics of Coulomb Corrections in Hanbury-Brown Twiss Interferometry in Ultrarelativistic Heavy Ion Collisions

We discuss the elementary physics of the final state Coulomb interactions in Hanbury-Brown Twiss interferometry, showing -- with explicit comparison to E877 data for $\pi^+\pi^-$ and $\pi^\pm p$ -- that the Coulomb corrections in the pair correlation function can be well understood in terms of simple classical physics. We connect the classical picture with descriptions in terms of Coulomb wave functions, and investigate the influence of the ``central'' Coulomb potential on the pair correlation function.