barcomp_w.cc

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//  $Id: barcomp_w.cc,v 3.3 2009-03-19 17:17:20 mcneile Exp $
/*! \file
 *  \brief Construct all components of a baryon propagator
 */
 
 
#include "meas/hadron/barcomp_w.h"
 
namespace Chroma 
{
 
  //! Serialize generalized object
  multi1d<ComplexF> QQQSparse_t::serialize()
  { 
    // Dreadful hack - we will use 3 complexs to hold 6 ints. So, the size
    // of the array is the size of the correlators plus the size of the complexs
    multi1d<ComplexF> barprop_1d(corrs.size()*(3 + length));
 
    int cnt = 0;
    for(int s=0; s < corrs.size(); ++s)
    {
      const QQQElem_t& elem = corrs[s];
      const QQQSpinIndices_t& sp = elem.source_sink;
 
      // Dreadful hack - use a complex to hold an int
      barprop_1d[cnt++] = cmplx(Real(sp.source[0]), Real(sp.source[1]));
      barprop_1d[cnt++] = cmplx(Real(sp.source[2]), Real(sp.sink[0]));
      barprop_1d[cnt++] = cmplx(Real(sp.sink[1]), Real(sp.sink[2]));
 
      for(int t=0; t < length; ++t)
      {
        barprop_1d[cnt++] = elem.corr[t];
      }
    }
 
    if (cnt != barprop_1d.size())
    {
      QDPIO::cerr << "Size mismatch in QQQSparse_t serialization" << std::endl;
      QDP_abort(1);
    }
 
    return barprop_1d;
  }
 
 
 
  //! Construct all components of a baryon propagator
  /*!
   * \ingroup hadron
   *
   * This routine is specific to Wilson fermions!
   *
   * In all baryons the colour components are contracted with the totally
   * antisymmetric 'tensor' eps(a,b,c) = antisym_tensor(a,b,c).
   *
   * \param barprop                  baryon correlation function (in real space) ( Write )
   * \param quark_propagator_1       quark propagator ( Read )
   * \param quark_propagator_2       quark propagator ( Read )
   * \param quark_propagator_3       quark propagator ( Read )
   * \param spin_indices             holds list of source/sink spin indices ( Read )
   * \param phases                   object holds list of momenta ( Read )
   * \param t0                       coordinates of source in decay direction ( Read )
   * \param bc_spec                  boundary condition for spectroscopy ( Read )
   */
 
  void barcompSparse(QQQSparse_t& barprop,
                     const LatticePropagator& quark_propagator_1, 
                     const LatticePropagator& quark_propagator_2,
                     const LatticePropagator& quark_propagator_3,
                     const multi1d<QQQSpinIndices_t> spin_indices,
                     const SftMom& phases,
                     int t0, int bc_spec)
  {
    START_CODE();
    if ( Nc != 3 ){    /* Code is specific to Ns=4 and Nc=3. */
      QDPIO::cerr<<" code only works for Nc=3 and Ns=4\n";
      QDP_abort(111) ;
    }
#if QDP_NC == 3
 
 
    // Length of lattice in decay direction
    int length  = phases.numSubsets();
 
    // This object is composed of the spin indices and the correlators
    barprop.length = length;
    barprop.corrs.resize(spin_indices.size());
 
    // Temporaries
    multi1d<DComplex> hsum;
    LatticeComplex b_prop;
 
    // Loop over all source/sink spin indices
    for(int i=0; i < spin_indices.size(); ++i)
    {
      const QQQSpinIndices_t& d = spin_indices[i];
      barprop.corrs[i].source_sink = d;
 
      // Contract over color indices with antisym tensors
      b_prop = 
        colorContract(peekSpin(quark_propagator_1,
                               d.source[0],d.sink[0]),  // (si_1,sf_1)
                      peekSpin(quark_propagator_2,
                               d.source[1],d.sink[1]),  // (si_2,sf_2)
                      peekSpin(quark_propagator_3,
                               d.source[2],d.sink[2])); // (si_3,sf_3)
 
      /* Project on zero momentum: Do a slice-wise sum. */
      hsum = sumMulti(b_prop, phases.getSet());
      
      barprop.corrs[i].corr.resize(length);
      for(int t=0; t < length; ++t)   // t
      {
        int t_eff = (t - t0 + length) % length;
        barprop.corrs[i].corr[t] = (bc_spec < 0 && (t_eff+t0) >= length) ? -hsum[t] : hsum[t];
      }
    }
 
#endif
    END_CODE();
  }
 
 
 
  //! Serialize generalized object
  multi1d<ComplexF> QQQDense_t::serialize()
  {
    multi1d<int> ranks(7);
 
    multi1d<ComplexF> barprop_1d(length*Ns*Ns*Ns*Ns*Ns*Ns);
 
    int cnt = 0;
    for(ranks[0]=0; ranks[0] < Ns; ++ranks[0])           // sf_3
      for(ranks[1]=0; ranks[1] < Ns; ++ranks[1])         // sf_2
        for(ranks[2]=0; ranks[2] < Ns; ++ranks[2])       // sf_1
          for(ranks[3]=0; ranks[3] < Ns; ++ranks[3])     // si_3
            for(ranks[4]=0; ranks[4] < Ns; ++ranks[4])   // si_2
              for(ranks[5]=0; ranks[5] < Ns; ++ranks[5]) // si_1
                for(ranks[6] = 0; ranks[6] < length; ++ranks[6])
                {
                  barprop_1d[cnt++] = corrs[ranks];
                }
 
    return barprop_1d;
  }
 
 
 
  //! Construct all components of a baryon propagator
  /*!
   * \ingroup hadron
   *
   * This routine is specific to Wilson fermions!
   *
   * In all baryons the colour components are contracted with the totally
   * antisymmetric 'tensor' eps(a,b,c) = antisym_tensor(a,b,c).
   *
   * \param barprop                  baryon correlation function (in real space) ( Write )
   * \param quark_propagator_1       quark propagator ( Read )
   * \param quark_propagator_2       quark propagator ( Read )
   * \param quark_propagator_3       quark propagator ( Read )
   * \param phases                   object holds list of momenta ( Read )
   * \param t0                       coordinates of source in decay direction ( Read )
   * \param bc_spec                  boundary condition for spectroscopy ( Read )
   */
 
  void barcomp(QQQDense_t& barprop,
               const LatticePropagator& quark_propagator_1, 
               const LatticePropagator& quark_propagator_2,
               const LatticePropagator& quark_propagator_3,
               const SftMom& phases,
               int t0, int bc_spec)
  {
    START_CODE();
    if ( Nc != 3 ){    /* Code is specific to Ns=4 and Nc=3. */
      QDPIO::cerr<<"barcomp code only works for Nc=3 and Ns=4\n";
      QDP_abort(111) ;
    }
#if QDP_NC == 3
 
 
    // Length of lattice in decay direction
    int length  = phases.numSubsets();
  
    multi1d<int> ranks(7);
    ranks = Ns;
    ranks[6] = length;
 
    barprop.length = length;
    barprop.corrs.resize(ranks);
 
    // Temporaries
    multi1d<DComplex> hsum;
    LatticeComplex b_prop;
 
    for(ranks[0]=0; ranks[0] < Ns; ++ranks[0])           // sf_3
      for(ranks[1]=0; ranks[1] < Ns; ++ranks[1])         // sf_2
        for(ranks[2]=0; ranks[2] < Ns; ++ranks[2])       // sf_1
          for(ranks[3]=0; ranks[3] < Ns; ++ranks[3])     // si_3
            for(ranks[4]=0; ranks[4] < Ns; ++ranks[4])   // si_2
              for(ranks[5]=0; ranks[5] < Ns; ++ranks[5]) // si_1
              {
                // Contract over color indices with antisym tensors
                b_prop = 
                  colorContract(peekSpin(quark_propagator_1,
                                         ranks[5],ranks[2]),  // (si_1,sf_1)
                                peekSpin(quark_propagator_2,
                                         ranks[4],ranks[1]),  // (si_2,sf_2)
                                peekSpin(quark_propagator_3,
                                         ranks[3],ranks[0])); // (si_3,sf_3)
 
                /* Project on zero momentum: Do a slice-wise sum. */
                hsum = sumMulti(b_prop, phases.getSet());
      
                for(ranks[6] = 0; ranks[6] < length; ++ranks[6])   // t
                {
                  int t_eff = (ranks[6] - t0 + length) % length;
 
                  barprop.corrs[ranks] = 
                    (bc_spec < 0 && (t_eff+t0) >= length) ? -hsum[ranks[6]] : 
                    hsum[ranks[6]];
                }
              }
 
#endif
    END_CODE();
  }
 
 
}  // end namespace Chroma