Higgs-boson production via bottom-quark fusion

Higgs bosons with enhanced coupling to bottom quarks are copiously produced at hadron colliders via bb̄→h, where the initial b quarks reside in the proton sea. We reexamine the calculation of the next-to-leading-order cross section for this process and argue that the appropriate factorization scale for the b distribution functions is approximately mₕ/4, rather than mₕ, as had been previously assumed. This greatly improves the convergence of the perturbation series, and yields a result with mild factorization-scale dependence. We also show that the leading-order calculation of g→gbb̄h, integrated over the momenta of the final-state particles, is very sensitive to the factorization and renormalization scales. For scales of order mₕ/4 the g→gbb̄h cross section is comparable to that of bb̄→h, in contrast with the order-of-magnitude discrepancy between these two calculations for the scale mₕ. The result we obtain improves the prospects for Higgs-boson discovery at hadron colliders for large values of tanβ.