Higgs-boson production via bottom-quark fusion

Higgs bosons with enhanced coupling to bottom quarks are copiously produced at hadron colliders via $b\overline{b}\to h,$ 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 $m_h/4,$ rather than $m_h,$ 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 $g\overrightarrow{g}b\overline{b}h,$ integrated over the momenta of the final-state particles, is very sensitive to the factorization and renormalization scales. For scales of order $m_h/4\mathrm{}$ the $g\overrightarrow{g}b\overline{b}h$ cross section is comparable to that of $b\overline{b}\to h,$ in contrast with the order-of-magnitude discrepancy between these two calculations for the scale $m_h.$ The result we obtain improves the prospects for Higgs-boson discovery at hadron colliders for large values of $\tan \beta .$