  We have constructed four new complete mass tables, referred to as HFB-4 to
HFB-7, each one including all the 9200 nuclei lying between the two drip lines
over the range of Z and N>8 and Z<120. HFB-4 and HFB-5 have the isoscalar
effective mass M*_s$ constrained to the value 0.92 M, with the former having a
density-independent pairing, and the latter a density-dependent pairing. HFB-6
and HFB-7 are similar, except that M*_s is constrained to 0.8 M. The rms errors
of the mass-data fits are 0.680, 0.675, 0.686, and 0.676 MeV, respectively,
almost as good as for the HFB-2 mass formula, for which M*_s was unconstrained.
However, as usual, the single-particle spectra depend significantly on M*_s.
This decoupling of the mass fits from the fits to the single-particle spectra
has been achieved only by making the cutoff parameter of the delta-function
pairing force a free parameter. An improved treatment of the center-of-mass
correction was adopted, but although this makes a difference to individual
nuclei it does not reduce the overall rms error of the fit. The extrapolations
of all four new mass formulas out to the drip lines are essentially the same as
for the original HFB-2 mass formula.
