  We calculate the cross sections of electromagnetic productions of muon and
tauon pair productions from the ultra-relativistic heavy ion collisions. Since
the Compton wavelengths of muon and tauon are comparable to the radius of the
colliding ions, nuclear form factors play important roles for calculating the
cross sections. Recent measurement [1] indicates that the neutrons are
differently distributed from the protons therefore this affects the cross
section of the heavy lepton pair production. In order to see the effects of the
neutron distributions in the nucleus, we used analytical expression of the
Fourier transforms of the Wood-Saxon distribution. Cross section calculations
show that Wood-Saxon distribution function is more sensitive to the parameter R
compare to the parameter a.
