p\_[3]{}) (Q\_+ p\_[4]{})\
V\_[h(0\^-)]{} & = & ( (Q\_- p\_[3]{}) (Q\_+ p\_[4]{}))n\_0. \[eq:rat4\]

The $f_g$’s are the skewed unintegrated gluon densities of the proton at the hard scale $\mu$, taken to be $m_h/2$, with

[l l l]{} Q\_3 & = & {Q\_,|(Q\_- p\_[3]{})|},\
Q\_4 & = & {Q\_,|(Q\_+ p\_[4]{})|}. \[eq:rat5\]

Below, we assume factorization of the unintegrated distributions, f\_g(x,x’,Q\^2,\^2;t) = f\_g(x,x’,Q\^2,\^2)F\_N(t), \[eq:rat5a\] where we parameterize the form factor of the proton vertex by the form $F_N(t) = \exp(bt)$ with $b=2~\GeV^{-2}$. To single log accuracy, we have [@MR01] f\_g(x,x’,Q\_i\^2,\^2) = R\_g ( xg(x,Q\_i\^2)), \[eq:rat6\] where $T$ is the usual Sudakov form factor which ensures that the gluon remains untouched in the evolution up to the hard scale $\mu$, so that the rapidity gaps survive. The square root arises because the bremsstrahlung survival probability $T$ is only relevant to the hard gluon. $R_g$ is the ratio of the skewed $x'\ll x$ integrated distribution to the conventional diagonal density $g(x,Q^2)$. For $x\ll 1$ it is completely determined [@SGMR]. The apparent infrared divergence of [(\[eq:rat3\])]{} is nullified[^4] for $h(0^+)$ production by the Sudakov factors embodied in the gluon densities $f_g$. However the amplitude for $h(0^-)$ production is much more sensitive to the infrared contribution. 