Next-to-leading order QCD predictions for pair production of neutral Higgs bosons at the CERN Large Hadron Collider

Abstract

We present the calculations of the complete next-to-leading-order (NLO) inclusive total cross sections for pair production of neutral Higgs bosons through $b\overline{b}$ annihilation in the minimal supersymmetric standard model at the CERN Large Hadron Collider. In our calculations, we used both the dimensional regularization scheme and the dimensional reduction scheme and found that the NLO total cross sections in these two schemes are the same. Our results show that the $b\overline{b}$-annihilation contributions can exceed those of $gg$ fusion and $q\overline{q}$ annihilation for ${h}^{0}{H}^{0}$, ${A}^{0}{h}^{0}$, and ${A}^{0}{H}^{0}$ productions when $\mathrm{tan}\ensuremath{\beta}$ is large. In the case of $\ensuremath{\mu}>0$, the NLO corrections enhance the leading-order total cross sections significantly, reaching a few tens of percent, while for $\ensuremath{\mu}<0$, the corrections are relatively small, and are negative in most of parameter space. Moreover, the NLO QCD corrections reduce the dependence of the total cross sections on the renormalization/factorization scale, especially for $\ensuremath{\mu}<0$. We also used the CTEQ6.1 parton distribution function sets to estimate the uncertainty of leading-order and NLO total cross sections, and found that the uncertainty arising from the choice of parton distribution functions increases with the increasing ${m}_{{A}^{0}}$.