Scalar Higgs boson production in fusion of two off-shell gluons

The amplitude for scalar Higgs boson Production in the fusion of two off-shell gluons is calculated including finite (not infinite) masses of quarks in the triangle loop. In comparison to the effective Lagrangian approach, we have found a new term in the amplitude. The matrix element found can be used in the k(perpendicular to)-factorization approach to the Higgs boson production. The results are compared with the calculations for on-shell gluons. Small deviations from the cos(2) phi-dependence are predicted. The off-shell effects found are practically negligible.