Higgs-Boson Production via Bottom-Quark Fusion

Abstract

Higgs bosons with enhanced coupling to bottom quarks are copiously produced at hadron colliders via b\bar{b} -> h, where the initial b quarks reside in the proton sea. We revisit 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 gg -> b\bar{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 the gg -> b\bar{b}h cross section is comparable to that of b\bar{b} -> h, in contrast to 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(β).

19 pages, revtex4, 7 ps figures, references and 1 Table added, slightly more pedagogical introduction