The Simplified ACOT scheme with Massive Phase Space
We develop the Simplified Aivazis-Collins-Olness-Tung scheme with Massive Phase Space (S-ACOT-MPS) to deal with heavy-flavor hadroproduction, especially at the LHC. The heavy flavor can be produced through Flavor Creation (FC) or Flavor Excitation (FE) mechanisms. The overlapped contribution between the FC and FE terms is subtracted by an asymptotic term. We implement this scheme up to Next-to the Leading Order (NLO) in the platform of MCFM and apply it for the inclusive b-flavor production, which describes the B-meson production at the LHCb well. Our scheme can be potentially extended to NNLO straight-forwardly.
For fast NLO computations, we have generated the APPLgrids to calculate the heavy-flavor transverse momentum and rapidity for the FC and FC (SB) terms seperately, with the configuration of b-quark production at the LHCb 7 and 13 TeV. The grids and corresponding convolution code written in C++ can be found here.
The subtracted and residual PDFs for the CT14nnlo and CT18NNLO are also provided here.
For more details, please refer the following publication: