We present a new measurement of the B+ meson differential cross
section d sigma/dp(t) at s**(1/2) = 1960 GeV. The data correspond to an
integrated luminosity of 739 pb-1 collected with the upgraded CDF detector
(CDF II) at the Fermilab Tevatron collider. B+ candidates are
reconstructed through the decay B+ --> J/psi K+, with J/phi --> mu+ mu-.
The integrated cross section for producing B+ mesons with p(t) > 6 GeV/c and
|y| < 1 is measured to be 2.78 +/- 0.24 mu b.