NPR production code

Computes propagators and vertex functions for non-perturbative renormalization in regularization independent momentum-subtraction schemes with MOM and SMOM kinematics based on the NPR modules of Hadrons. The program can optionally compute fourquark vertex functions or QED_L corrections to first order in the electromagnetic coupling constant.

Execution

Install Grid and Hadrons on their develop branch. For CPU architectures compile via:

./bootstrap.sh
mkdir build
cd build
../configure --with-hadrons=<Hadrons install prefix> (CPPFLAGS=-DMOBIUS) (CPPFLAGS=-DBICGSTAB)
make

For Nvidia GPU accelerated architectures cross-compile via:

./bootstrap.sh
mkdir build
cd build
../configure --host=aarch64-linux-gnu --with-hadrons=<Hadrons install prefix> CC=gcc CXX=nvcc CPPFLAGS="-x cu -DBICGSTAB"
make

by default the WilsonExpClover action and the MixedPrecisionRBPrecCG solver are used. These defaults can be altered by specifying CPPFLAGS as indicated above. For now the Möbius DWF fermion action and the MixedPrecisionRBPrecBiCGSTAB are available as alternatives. (Note that the DWF action only works with the standard CG solver)

To execute the program run

mpirun -n N ./hadrons_npr ./input_file.xml --grid Nx.Ny.Nx.Nt --mpi Mx.My.Mz.Mt

where Nx.Ny.Nx.Nt is the geometry of the lattice, N is the number of MPI processes and Mx.My.Mz.Mt describes the MPI process decomposition such that the product of all four components equals N.

Database

The application tracks the exported files in an SQLite database. To get the in- and out- going momenta for every bilinear vertex one can for example query

SELECT bi.traj, bi.filename, ex1.momentum AS momIn, ex2.momentum AS momOut
  FROM bilinear bi
       LEFT OUTER JOIN externalLeg AS ex1 ON bi.qIn=ex1.qIn
       LEFT OUTER JOIN externalLeg AS ex2 ON bi.qOut=ex2.qIn