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MMHT PDFs

25 Apr 2018

MMHT 2014 PDFs: LHAPDF grids

Here we enclose the LHAPDF 5 and 6 grid files corresponding to the MMHT 2014 PDFs, published in

  L. A. Harland-Lang, A. D. Martin, P. Motylinski, R. S. Thorne
  "Parton distributions in the LHC era: MMHT 2014 PDFs"
  arXiv:1412.3989

Please reference this paper if you use the PDFs for a publication.

We provide LO, NLO and NNLO grids for the central fit and 50 eigvectors sets (corresponding to 25 eigenvectors in the '+' and '-' directions), for a 68% confidence interval. These are defined using the Hessian approach and dynamical tolerance criteria described in arXiv:0901.0002. Grids for the central fit + eigenvectors are provided for αS=0.135 and 0.118 at LO and NNLO, respectively, at or close to the best fit values. At NLO these are provided for αS=0.118 and 0.120. Finally, central grids are provided for a short and large ranges of αS values. For the short range, at LO, αS=0.134-0.136, at NLO αS=0.117-0.121 and at NNLO αS=0.118-0.120, in increments of 0.001. For the large range, no grids are available at LO, while at NLO and NNLO αS=0.108-0.128, in increments of 0.001. For further information about the uncertainties on αS, and the corresponding χ2 profiles across the large range, see:

  L. A. Harland-Lang, A. D. Martin, P. Motylinski, R. S. Thorne
  "Uncertainties on alpha_s in the MMHT2014 global PDF anaylsis and implications for SM predictions"
  arXiv:1506.05682

****Important - Using LHAPDF 5 Grids****

The LHAPDF 5 Grids must be run using the older MSTW interpolation code provided with LHAPDF 5, as no further updates of version 5 are forseen. The number of eigenvector sets is hard-coded in the interpolation code and must be increased to account for the larger number of eigenvectors in the MMHT14 PDFs, compared to MSTW08. To achieve this, simply change the parameter 'nhess' on line 33 of 'src/wrapmstw.f' to 'nhess=2*25' (in the most up-to-date versions of LHAPDF 5 this currently reads 'nhess=2*23'), and recompile LHAPDF. Note that increasing this parameter will not affect the result of using the MSTW08 PDFs.

Central + eigenvector sets


LHAPDF 5 LO grids   LHAPDF 6 LO grids  
  MMHT2014lo68cl.LHgrid     MMHT2014lo68cl  


LHAPDF 5 NLO grids LHAPDF 6 NLO grids
  αS=0.120     MMHT2014nlo68cl.LHgrid     MMHT2014nlo68cl  
  αS=0.118     MMHT2014nlo68clas118.LHgrid     MMHT2014nlo68clas118  


LHAPDF 5 NNLO grids   LHAPDF 6 NNLO grids  
  MMHT2014nnlo68cl.LHgrid     MMHT2014nnlo68cl  


Central sets, variable αS


LHAPDF 5 LO grids LHAPDF 6 LO grids
  MMHT2014lo_asmzsmallrange.LHgrid     MMHT2014lo_asmzsmallrange  


LHAPDF 5 NLO grids LHAPDF 6 NLO grids
  MMHT2014nlo_asmzsmallrange.LHgrid     MMHT2014nlo_asmzsmallrange  
  MMHT2014nlo_asmzlargerange.LHgrid     MMHT2014nlo_asmzlargerange  


LHAPDF 5 NNLO grids LHAPDF 6 NNLO grids
  MMHT2014nnlo_asmzsmallrange.LHgrid     MMHT2014nnlo_asmzsmallrange  
  MMHT2014nnlo_asmzlargerange.LHgrid     MMHT2014nnlo_asmzlargerange  


Central + eigenvector sets, different flavour schemes

           
LHAPDF 5 NLO grids LHAPDF 6 NLO grids
  αS=0.120     MMHT2014nlo68cl_nf3.LHgrid     MMHT2014nlo68cl_nf3  
  MMHT2014nlo68cl_nf4.LHgrid     MMHT2014nlo68cl_nf4  
  MMHT2014nlo68cl_nf4as5.LHgrid     MMHT2014nlo68cl_nf4as5  
  αS=0.118     MMHT2014nlo68clas118_nf3.LHgrid     MMHT2014nlo68clas118_nf3  
  MMHT2014nlo68clas118_nf4.LHgrid     MMHT2014nlo68clas118_nf4  
  MMHT2014nlo68clas118_nf4as5.LHgrid     MMHT2014nlo68clas118_nf4as5  

     
LHAPDF 5 NNLO grids LHAPDF 6 NNLO grids
  MMHT2014nnlo68cl_nf3.LHgrid     MMHT2014nnlo68cl_nf3  
  MMHT2014nnlo68cl_nf4.LHgrid     MMHT2014nnlo68cl_nf4  
  MMHT2014nnlo68cl_nf4as5.LHgrid     MMHT2014nnlo68cl_nf4as5  

Central sets, variable αS, different flavour schemes


LHAPDF 5 NLO grids LHAPDF 6 NLO grids
  MMHT2014nlo_asmzsmallrange_nf3.LHgrid     MMHT2014nlo_asmzsmallrange_nf3  
  MMHT2014nlo_asmzsmallrange_nf4.LHgrid     MMHT2014nlo_asmzsmallrange_nf4  


LHAPDF 5 NNLO grids LHAPDF 6 NNLO grids
  MMHT2014nnlo_asmzsmallrange_nf3.LHgrid     MMHT2014nnlo_asmzsmallrange_nf3  
  MMHT2014nnlo_asmzsmallrange_nf4.LHgrid     MMHT2014nnlo_asmzsmallrange_nf4  


Central sets, variable mc, different flavour schemes

           
LHAPDF 5 NLO grids LHAPDF 6 NLO grids
  αS=0.120     MMHT2014nlo_mcrange_nf3.LHgrid     MMHT2014nlo_mcrange_nf3  
  MMHT2014nlo_mcrange_nf4.LHgrid     MMHT2014nlo_mcrange_nf4  
  MMHT2014nlo_mcrange_nf5.LHgrid     MMHT2014nlo_mcrange_nf5  
  αS=0.118     MMHT2014nloas118_mcrange_nf3.LHgrid     MMHT2014nloas118_mcrange_nf3  
  MMHT2014nloas118_mcrange_nf4.LHgrid     MMHT2014nloas118_mcrange_nf4  
  MMHT2014nloas118_mcrange_nf5.LHgrid     MMHT2014nloas118_mcrange_nf5  

     
LHAPDF 5 NNLO grids LHAPDF 6 NNLO grids
  αS=0.120     MMHT2014nnlo_mcrange_nf3.LHgrid     MMHT2014nnlo_mcrange_nf3  
  MMHT2014nnlo_mcrange_nf4.LHgrid     MMHT2014nnlo_mcrange_nf4  
  MMHT2014nnlo_mcrange_nf5.LHgrid     MMHT2014nnlo_mcrange_nf5  

Central sets, variable mb, different flavour schemes

           
LHAPDF 5 NLO grids LHAPDF 6 NLO grids
  αS=0.120     MMHT2014nlo_mbrange_nf3.LHgrid     MMHT2014nlo_mbrange_nf3  
  MMHT2014nlo_mbrange_nf4.LHgrid     MMHT2014nlo_mbrange_nf4  
  MMHT2014nlo_mbrange_nf5.LHgrid     MMHT2014nlo_mbrange_nf5  
  αS=0.118     MMHT2014nloas118_mbrange_nf3.LHgrid     MMHT2014nloas118_mbrange_nf3  
  MMHT2014nloas118_mbrange_nf4.LHgrid     MMHT2014nloas118_mbrange_nf4  
  MMHT2014nloas118_mbrange_nf5.LHgrid     MMHT2014nloas118_mbrange_nf5  

     
LHAPDF 5 NNLO grids LHAPDF 6 NNLO grids
  αS=0.118     MMHT2014nnlo_mbrange_nf3.LHgrid     MMHT2014nnlo_mbrange_nf3  
  MMHT2014nnlo_mbrange_nf4.LHgrid     MMHT2014nnlo_mbrange_nf4  
  MMHT2014nnlo_mbrange_nf5.LHgrid     MMHT2014nnlo_mbrange_nf5