Production of a pseudo-scalar Higgs boson at hadron colliders at next-to-next-to leading order

TL;DR

This paper computes the inclusive production cross section of a CP-odd Higgs boson A at hadron colliders to NNLO in QCD using a heavy-top effective Lagrangian that couples A to gluons via top-quark loops. The authors carefully treat Levi-Civita and gamma5 through the Larin scheme, and evaluate virtual, single-real, and double-real contributions, expressing partonic results in a compact form relative to the scalar Higgs case. They provide explicit NNLO partonic cross sections for all initial states, with the full result for the A case differing from the scalar one only by a small term tied to operator mixing, and they combine these with approximate NNLO PDFs to predict hadronic rates. The findings show NNLO corrections are similar in size to those for scalar Higgs production and that scale uncertainties are substantially reduced, yielding a more reliable total-rate prediction relevant for MSSM Higgs searches at the LHC and Tevatron.

Abstract

The production cross section for pseudo-scalar Higgs bosons at hadron colliders is computed at next-to-next-to-leading order (NNLO) in QCD. The pseudo-scalar Higgs is assumed to couple only to top quarks. The NNLO effects are evaluated using an effective lagrangian where the top quarks are integrated out. The NNLO corrections are similar in size to those found for scalar Higgs boson production.