C********************************************************************* SUBROUTINE PYSTPR(X,Q2,XPPR) C...Gives proton structure functions according to a few different C...parametrizations. COMMON/LUDAT1/MSTU(200),PARU(200),MSTJ(200),PARJ(200) COMMON/LUDAT2/KCHG(500,3),PMAS(500,4),PARF(2000),VCKM(4,4) COMMON/PYPARS/MSTP(200),PARP(200),MSTI(200),PARI(200) COMMON/PYINT1/MINT(400),VINT(400) SAVE /LUDAT1/,/LUDAT2/ SAVE /PYPARS/,/PYINT1/ DIMENSION XPPR(-6:6),XQ(9),TX(6),TT(6),TS(6),NEHLQ(8,2), &CEHLQ(6,6,2,8,2),CDO(3,6,5,2) C...The following data lines are coefficients needed in the C...Eichten, Hinchliffe, Lane, Quigg proton structure function C...parametrizations, see below. C...Powers of 1-x in different cases. DATA NEHLQ/3,4,7,5,7,7,7,7,3,4,7,6,7,7,7,7/ C...Expansion coefficients for up valence quark distribution. DATA (((CEHLQ(IX,IT,NX,1,1),IX=1,6),IT=1,6),NX=1,2)/ 1 7.677E-01,-2.087E-01,-3.303E-01,-2.517E-02,-1.570E-02,-1.000E-04, 2-5.326E-01,-2.661E-01, 3.201E-01, 1.192E-01, 2.434E-02, 7.620E-03, 3 2.162E-01, 1.881E-01,-8.375E-02,-6.515E-02,-1.743E-02,-5.040E-03, 4-9.211E-02,-9.952E-02, 1.373E-02, 2.506E-02, 8.770E-03, 2.550E-03, 5 3.670E-02, 4.409E-02, 9.600E-04,-7.960E-03,-3.420E-03,-1.050E-03, 6-1.549E-02,-2.026E-02,-3.060E-03, 2.220E-03, 1.240E-03, 4.100E-04, 1 2.395E-01, 2.905E-01, 9.778E-02, 2.149E-02, 3.440E-03, 5.000E-04, 2 1.751E-02,-6.090E-03,-2.687E-02,-1.916E-02,-7.970E-03,-2.750E-03, 3-5.760E-03,-5.040E-03, 1.080E-03, 2.490E-03, 1.530E-03, 7.500E-04, 4 1.740E-03, 1.960E-03, 3.000E-04,-3.400E-04,-2.900E-04,-1.800E-04, 5-5.300E-04,-6.400E-04,-1.700E-04, 4.000E-05, 6.000E-05, 4.000E-05, 6 1.700E-04, 2.200E-04, 8.000E-05, 1.000E-05,-1.000E-05,-1.000E-05/ DATA (((CEHLQ(IX,IT,NX,1,2),IX=1,6),IT=1,6),NX=1,2)/ 1 7.237E-01,-2.189E-01,-2.995E-01,-1.909E-02,-1.477E-02, 2.500E-04, 2-5.314E-01,-2.425E-01, 3.283E-01, 1.119E-01, 2.223E-02, 7.070E-03, 3 2.289E-01, 1.890E-01,-9.859E-02,-6.900E-02,-1.747E-02,-5.080E-03, 4-1.041E-01,-1.084E-01, 2.108E-02, 2.975E-02, 9.830E-03, 2.830E-03, 5 4.394E-02, 5.116E-02,-1.410E-03,-1.055E-02,-4.230E-03,-1.270E-03, 6-1.991E-02,-2.539E-02,-2.780E-03, 3.430E-03, 1.720E-03, 5.500E-04, 1 2.410E-01, 2.884E-01, 9.369E-02, 1.900E-02, 2.530E-03, 2.400E-04, 2 1.765E-02,-9.220E-03,-3.037E-02,-2.085E-02,-8.440E-03,-2.810E-03, 3-6.450E-03,-5.260E-03, 1.720E-03, 3.110E-03, 1.830E-03, 8.700E-04, 4 2.120E-03, 2.320E-03, 2.600E-04,-4.900E-04,-3.900E-04,-2.300E-04, 5-6.900E-04,-8.200E-04,-2.000E-04, 7.000E-05, 9.000E-05, 6.000E-05, 6 2.400E-04, 3.100E-04, 1.100E-04, 0.000E+00,-2.000E-05,-2.000E-05/ C...Expansion coefficients for down valence quark distribution. DATA (((CEHLQ(IX,IT,NX,2,1),IX=1,6),IT=1,6),NX=1,2)/ 1 3.813E-01,-8.090E-02,-1.634E-01,-2.185E-02,-8.430E-03,-6.200E-04, 2-2.948E-01,-1.435E-01, 1.665E-01, 6.638E-02, 1.473E-02, 4.080E-03, 3 1.252E-01, 1.042E-01,-4.722E-02,-3.683E-02,-1.038E-02,-2.860E-03, 4-5.478E-02,-5.678E-02, 8.900E-03, 1.484E-02, 5.340E-03, 1.520E-03, 5 2.220E-02, 2.567E-02,-3.000E-05,-4.970E-03,-2.160E-03,-6.500E-04, 6-9.530E-03,-1.204E-02,-1.510E-03, 1.510E-03, 8.300E-04, 2.700E-04, 1 1.261E-01, 1.354E-01, 3.958E-02, 8.240E-03, 1.660E-03, 4.500E-04, 2 3.890E-03,-1.159E-02,-1.625E-02,-9.610E-03,-3.710E-03,-1.260E-03, 3-1.910E-03,-5.600E-04, 1.590E-03, 1.590E-03, 8.400E-04, 3.900E-04, 4 6.400E-04, 4.900E-04,-1.500E-04,-2.900E-04,-1.800E-04,-1.000E-04, 5-2.000E-04,-1.900E-04, 0.000E+00, 6.000E-05, 4.000E-05, 3.000E-05, 6 7.000E-05, 8.000E-05, 2.000E-05,-1.000E-05,-1.000E-05,-1.000E-05/ DATA (((CEHLQ(IX,IT,NX,2,2),IX=1,6),IT=1,6),NX=1,2)/ 1 3.578E-01,-8.622E-02,-1.480E-01,-1.840E-02,-7.820E-03,-4.500E-04, 2-2.925E-01,-1.304E-01, 1.696E-01, 6.243E-02, 1.353E-02, 3.750E-03, 3 1.318E-01, 1.041E-01,-5.486E-02,-3.872E-02,-1.038E-02,-2.850E-03, 4-6.162E-02,-6.143E-02, 1.303E-02, 1.740E-02, 5.940E-03, 1.670E-03, 5 2.643E-02, 2.957E-02,-1.490E-03,-6.450E-03,-2.630E-03,-7.700E-04, 6-1.218E-02,-1.497E-02,-1.260E-03, 2.240E-03, 1.120E-03, 3.500E-04, 1 1.263E-01, 1.334E-01, 3.732E-02, 7.070E-03, 1.260E-03, 3.400E-04, 2 3.660E-03,-1.357E-02,-1.795E-02,-1.031E-02,-3.880E-03,-1.280E-03, 3-2.100E-03,-3.600E-04, 2.050E-03, 1.920E-03, 9.800E-04, 4.400E-04, 4 7.700E-04, 5.400E-04,-2.400E-04,-3.900E-04,-2.400E-04,-1.300E-04, 5-2.600E-04,-2.300E-04, 2.000E-05, 9.000E-05, 6.000E-05, 4.000E-05, 6 9.000E-05, 1.000E-04, 2.000E-05,-2.000E-05,-2.000E-05,-1.000E-05/ C...Expansion coefficients for up and down sea quark distributions. DATA (((CEHLQ(IX,IT,NX,3,1),IX=1,6),IT=1,6),NX=1,2)/ 1 6.870E-02,-6.861E-02, 2.973E-02,-5.400E-03, 3.780E-03,-9.700E-04, 2-1.802E-02, 1.400E-04, 6.490E-03,-8.540E-03, 1.220E-03,-1.750E-03, 3-4.650E-03, 1.480E-03,-5.930E-03, 6.000E-04,-1.030E-03,-8.000E-05, 4 6.440E-03, 2.570E-03, 2.830E-03, 1.150E-03, 7.100E-04, 3.300E-04, 5-3.930E-03,-2.540E-03,-1.160E-03,-7.700E-04,-3.600E-04,-1.900E-04, 6 2.340E-03, 1.930E-03, 5.300E-04, 3.700E-04, 1.600E-04, 9.000E-05, 1 1.014E+00,-1.106E+00, 3.374E-01,-7.444E-02, 8.850E-03,-8.700E-04, 2 9.233E-01,-1.285E+00, 4.475E-01,-9.786E-02, 1.419E-02,-1.120E-03, 3 4.888E-02,-1.271E-01, 8.606E-02,-2.608E-02, 4.780E-03,-6.000E-04, 4-2.691E-02, 4.887E-02,-1.771E-02, 1.620E-03, 2.500E-04,-6.000E-05, 5 7.040E-03,-1.113E-02, 1.590E-03, 7.000E-04,-2.000E-04, 0.000E+00, 6-1.710E-03, 2.290E-03, 3.800E-04,-3.500E-04, 4.000E-05, 1.000E-05/ DATA (((CEHLQ(IX,IT,NX,3,2),IX=1,6),IT=1,6),NX=1,2)/ 1 1.008E-01,-7.100E-02, 1.973E-02,-5.710E-03, 2.930E-03,-9.900E-04, 2-5.271E-02,-1.823E-02, 1.792E-02,-6.580E-03, 1.750E-03,-1.550E-03, 3 1.220E-02, 1.763E-02,-8.690E-03,-8.800E-04,-1.160E-03,-2.100E-04, 4-1.190E-03,-7.180E-03, 2.360E-03, 1.890E-03, 7.700E-04, 4.100E-04, 5-9.100E-04, 2.040E-03,-3.100E-04,-1.050E-03,-4.000E-04,-2.400E-04, 6 1.190E-03,-1.700E-04,-2.000E-04, 4.200E-04, 1.700E-04, 1.000E-04, 1 1.081E+00,-1.189E+00, 3.868E-01,-8.617E-02, 1.115E-02,-1.180E-03, 2 9.917E-01,-1.396E+00, 4.998E-01,-1.159E-01, 1.674E-02,-1.720E-03, 3 5.099E-02,-1.338E-01, 9.173E-02,-2.885E-02, 5.890E-03,-6.500E-04, 4-3.178E-02, 5.703E-02,-2.070E-02, 2.440E-03, 1.100E-04,-9.000E-05, 5 8.970E-03,-1.392E-02, 2.050E-03, 6.500E-04,-2.300E-04, 2.000E-05, 6-2.340E-03, 3.010E-03, 5.000E-04,-3.900E-04, 6.000E-05, 1.000E-05/ C...Expansion coefficients for gluon distribution. DATA (((CEHLQ(IX,IT,NX,4,1),IX=1,6),IT=1,6),NX=1,2)/ 1 9.482E-01,-9.578E-01, 1.009E-01,-1.051E-01, 3.456E-02,-3.054E-02, 2-9.627E-01, 5.379E-01, 3.368E-01,-9.525E-02, 1.488E-02,-2.051E-02, 3 4.300E-01,-8.306E-02,-3.372E-01, 4.902E-02,-9.160E-03, 1.041E-02, 4-1.925E-01,-1.790E-02, 2.183E-01, 7.490E-03, 4.140E-03,-1.860E-03, 5 8.183E-02, 1.926E-02,-1.072E-01,-1.944E-02,-2.770E-03,-5.200E-04, 6-3.884E-02,-1.234E-02, 5.410E-02, 1.879E-02, 3.350E-03, 1.040E-03, 1 2.948E+01,-3.902E+01, 1.464E+01,-3.335E+00, 5.054E-01,-5.915E-02, 2 2.559E+01,-3.955E+01, 1.661E+01,-4.299E+00, 6.904E-01,-8.243E-02, 3-1.663E+00, 1.176E+00, 1.118E+00,-7.099E-01, 1.948E-01,-2.404E-02, 4-2.168E-01, 8.170E-01,-7.169E-01, 1.851E-01,-1.924E-02,-3.250E-03, 5 2.088E-01,-4.355E-01, 2.239E-01,-2.446E-02,-3.620E-03, 1.910E-03, 6-9.097E-02, 1.601E-01,-5.681E-02,-2.500E-03, 2.580E-03,-4.700E-04/ DATA (((CEHLQ(IX,IT,NX,4,2),IX=1,6),IT=1,6),NX=1,2)/ 1 2.367E+00, 4.453E-01, 3.660E-01, 9.467E-02, 1.341E-01, 1.661E-02, 2-3.170E+00,-1.795E+00, 3.313E-02,-2.874E-01,-9.827E-02,-7.119E-02, 3 1.823E+00, 1.457E+00,-2.465E-01, 3.739E-02, 6.090E-03, 1.814E-02, 4-1.033E+00,-9.827E-01, 2.136E-01, 1.169E-01, 5.001E-02, 1.684E-02, 5 5.133E-01, 5.259E-01,-1.173E-01,-1.139E-01,-4.988E-02,-2.021E-02, 6-2.881E-01,-3.145E-01, 5.667E-02, 9.161E-02, 4.568E-02, 1.951E-02, 1 3.036E+01,-4.062E+01, 1.578E+01,-3.699E+00, 6.020E-01,-7.031E-02, 2 2.700E+01,-4.167E+01, 1.770E+01,-4.804E+00, 7.862E-01,-1.060E-01, 3-1.909E+00, 1.357E+00, 1.127E+00,-7.181E-01, 2.232E-01,-2.481E-02, 4-2.488E-01, 9.781E-01,-8.127E-01, 2.094E-01,-2.997E-02,-4.710E-03, 5 2.506E-01,-5.427E-01, 2.672E-01,-3.103E-02,-1.800E-03, 2.870E-03, 6-1.128E-01, 2.087E-01,-6.972E-02,-2.480E-03, 2.630E-03,-8.400E-04/ C...Expansion coefficients for strange sea quark distribution. DATA (((CEHLQ(IX,IT,NX,5,1),IX=1,6),IT=1,6),NX=1,2)/ 1 4.968E-02,-4.173E-02, 2.102E-02,-3.270E-03, 3.240E-03,-6.700E-04, 2-6.150E-03,-1.294E-02, 6.740E-03,-6.890E-03, 9.000E-04,-1.510E-03, 3-8.580E-03, 5.050E-03,-4.900E-03,-1.600E-04,-9.400E-04,-1.500E-04, 4 7.840E-03, 1.510E-03, 2.220E-03, 1.400E-03, 7.000E-04, 3.500E-04, 5-4.410E-03,-2.220E-03,-8.900E-04,-8.500E-04,-3.600E-04,-2.000E-04, 6 2.520E-03, 1.840E-03, 4.100E-04, 3.900E-04, 1.600E-04, 9.000E-05, 1 9.235E-01,-1.085E+00, 3.464E-01,-7.210E-02, 9.140E-03,-9.100E-04, 2 9.315E-01,-1.274E+00, 4.512E-01,-9.775E-02, 1.380E-02,-1.310E-03, 3 4.739E-02,-1.296E-01, 8.482E-02,-2.642E-02, 4.760E-03,-5.700E-04, 4-2.653E-02, 4.953E-02,-1.735E-02, 1.750E-03, 2.800E-04,-6.000E-05, 5 6.940E-03,-1.132E-02, 1.480E-03, 6.500E-04,-2.100E-04, 0.000E+00, 6-1.680E-03, 2.340E-03, 4.200E-04,-3.400E-04, 5.000E-05, 1.000E-05/ DATA (((CEHLQ(IX,IT,NX,5,2),IX=1,6),IT=1,6),NX=1,2)/ 1 6.478E-02,-4.537E-02, 1.643E-02,-3.490E-03, 2.710E-03,-6.700E-04, 2-2.223E-02,-2.126E-02, 1.247E-02,-6.290E-03, 1.120E-03,-1.440E-03, 3-1.340E-03, 1.362E-02,-6.130E-03,-7.900E-04,-9.000E-04,-2.000E-04, 4 5.080E-03,-3.610E-03, 1.700E-03, 1.830E-03, 6.800E-04, 4.000E-04, 5-3.580E-03, 6.000E-05,-2.600E-04,-1.050E-03,-3.800E-04,-2.300E-04, 6 2.420E-03, 9.300E-04,-1.000E-04, 4.500E-04, 1.700E-04, 1.100E-04, 1 9.868E-01,-1.171E+00, 3.940E-01,-8.459E-02, 1.124E-02,-1.250E-03, 2 1.001E+00,-1.383E+00, 5.044E-01,-1.152E-01, 1.658E-02,-1.830E-03, 3 4.928E-02,-1.368E-01, 9.021E-02,-2.935E-02, 5.800E-03,-6.600E-04, 4-3.133E-02, 5.785E-02,-2.023E-02, 2.630E-03, 1.600E-04,-8.000E-05, 5 8.840E-03,-1.416E-02, 1.900E-03, 5.800E-04,-2.500E-04, 1.000E-05, 6-2.300E-03, 3.080E-03, 5.500E-04,-3.700E-04, 7.000E-05, 1.000E-05/ C...Expansion coefficients for charm sea quark distribution. DATA (((CEHLQ(IX,IT,NX,6,1),IX=1,6),IT=1,6),NX=1,2)/ 1 9.270E-03,-1.817E-02, 9.590E-03,-6.390E-03, 1.690E-03,-1.540E-03, 2 5.710E-03,-1.188E-02, 6.090E-03,-4.650E-03, 1.240E-03,-1.310E-03, 3-3.960E-03, 7.100E-03,-3.590E-03, 1.840E-03,-3.900E-04, 3.400E-04, 4 1.120E-03,-1.960E-03, 1.120E-03,-4.800E-04, 1.000E-04,-4.000E-05, 5 4.000E-05,-3.000E-05,-1.800E-04, 9.000E-05,-5.000E-05,-2.000E-05, 6-4.200E-04, 7.300E-04,-1.600E-04, 5.000E-05, 5.000E-05, 5.000E-05, 1 8.098E-01,-1.042E+00, 3.398E-01,-6.824E-02, 8.760E-03,-9.000E-04, 2 8.961E-01,-1.217E+00, 4.339E-01,-9.287E-02, 1.304E-02,-1.290E-03, 3 3.058E-02,-1.040E-01, 7.604E-02,-2.415E-02, 4.600E-03,-5.000E-04, 4-2.451E-02, 4.432E-02,-1.651E-02, 1.430E-03, 1.200E-04,-1.000E-04, 5 1.122E-02,-1.457E-02, 2.680E-03, 5.800E-04,-1.200E-04, 3.000E-05, 6-7.730E-03, 7.330E-03,-7.600E-04,-2.400E-04, 1.000E-05, 0.000E+00/ DATA (((CEHLQ(IX,IT,NX,6,2),IX=1,6),IT=1,6),NX=1,2)/ 1 9.980E-03,-1.945E-02, 1.055E-02,-6.870E-03, 1.860E-03,-1.560E-03, 2 5.700E-03,-1.203E-02, 6.250E-03,-4.860E-03, 1.310E-03,-1.370E-03, 3-4.490E-03, 7.990E-03,-4.170E-03, 2.050E-03,-4.400E-04, 3.300E-04, 4 1.470E-03,-2.480E-03, 1.460E-03,-5.700E-04, 1.200E-04,-1.000E-05, 5-9.000E-05, 1.500E-04,-3.200E-04, 1.200E-04,-6.000E-05,-4.000E-05, 6-4.200E-04, 7.600E-04,-1.400E-04, 4.000E-05, 7.000E-05, 5.000E-05, 1 8.698E-01,-1.131E+00, 3.836E-01,-8.111E-02, 1.048E-02,-1.300E-03, 2 9.626E-01,-1.321E+00, 4.854E-01,-1.091E-01, 1.583E-02,-1.700E-03, 3 3.057E-02,-1.088E-01, 8.022E-02,-2.676E-02, 5.590E-03,-5.600E-04, 4-2.845E-02, 5.164E-02,-1.918E-02, 2.210E-03,-4.000E-05,-1.500E-04, 5 1.311E-02,-1.751E-02, 3.310E-03, 5.100E-04,-1.200E-04, 5.000E-05, 6-8.590E-03, 8.380E-03,-9.200E-04,-2.600E-04, 1.000E-05,-1.000E-05/ C...Expansion coefficients for bottom sea quark distribution. DATA (((CEHLQ(IX,IT,NX,7,1),IX=1,6),IT=1,6),NX=1,2)/ 1 9.010E-03,-1.401E-02, 7.150E-03,-4.130E-03, 1.260E-03,-1.040E-03, 2 6.280E-03,-9.320E-03, 4.780E-03,-2.890E-03, 9.100E-04,-8.200E-04, 3-2.930E-03, 4.090E-03,-1.890E-03, 7.600E-04,-2.300E-04, 1.400E-04, 4 3.900E-04,-1.200E-03, 4.400E-04,-2.500E-04, 2.000E-05,-2.000E-05, 5 2.600E-04, 1.400E-04,-8.000E-05, 1.000E-04, 1.000E-05, 1.000E-05, 6-2.600E-04, 3.200E-04, 1.000E-05,-1.000E-05, 1.000E-05,-1.000E-05, 1 8.029E-01,-1.075E+00, 3.792E-01,-7.843E-02, 1.007E-02,-1.090E-03, 2 7.903E-01,-1.099E+00, 4.153E-01,-9.301E-02, 1.317E-02,-1.410E-03, 3-1.704E-02,-1.130E-02, 2.882E-02,-1.341E-02, 3.040E-03,-3.600E-04, 4-7.200E-04, 7.230E-03,-5.160E-03, 1.080E-03,-5.000E-05,-4.000E-05, 5 3.050E-03,-4.610E-03, 1.660E-03,-1.300E-04,-1.000E-05, 1.000E-05, 6-4.360E-03, 5.230E-03,-1.610E-03, 2.000E-04,-2.000E-05, 0.000E+00/ DATA (((CEHLQ(IX,IT,NX,7,2),IX=1,6),IT=1,6),NX=1,2)/ 1 8.980E-03,-1.459E-02, 7.510E-03,-4.410E-03, 1.310E-03,-1.070E-03, 2 5.970E-03,-9.440E-03, 4.800E-03,-3.020E-03, 9.100E-04,-8.500E-04, 3-3.050E-03, 4.440E-03,-2.100E-03, 8.500E-04,-2.400E-04, 1.400E-04, 4 5.300E-04,-1.300E-03, 5.600E-04,-2.700E-04, 3.000E-05,-2.000E-05, 5 2.000E-04, 1.400E-04,-1.100E-04, 1.000E-04, 0.000E+00, 0.000E+00, 6-2.600E-04, 3.200E-04, 0.000E+00,-3.000E-05, 1.000E-05,-1.000E-05, 1 8.672E-01,-1.174E+00, 4.265E-01,-9.252E-02, 1.244E-02,-1.460E-03, 2 8.500E-01,-1.194E+00, 4.630E-01,-1.083E-01, 1.614E-02,-1.830E-03, 3-2.241E-02,-5.630E-03, 2.815E-02,-1.425E-02, 3.520E-03,-4.300E-04, 4-7.300E-04, 8.030E-03,-5.780E-03, 1.380E-03,-1.300E-04,-4.000E-05, 5 3.460E-03,-5.380E-03, 1.960E-03,-2.100E-04, 1.000E-05, 1.000E-05, 6-4.850E-03, 5.950E-03,-1.890E-03, 2.600E-04,-3.000E-05, 0.000E+00/ C...Expansion coefficients for top sea quark distribution. DATA (((CEHLQ(IX,IT,NX,8,1),IX=1,6),IT=1,6),NX=1,2)/ 1 4.410E-03,-7.480E-03, 3.770E-03,-2.580E-03, 7.300E-04,-7.100E-04, 2 3.840E-03,-6.050E-03, 3.030E-03,-2.030E-03, 5.800E-04,-5.900E-04, 3-8.800E-04, 1.660E-03,-7.500E-04, 4.700E-04,-1.000E-04, 1.000E-04, 4-8.000E-05,-1.500E-04, 1.200E-04,-9.000E-05, 3.000E-05, 0.000E+00, 5 1.300E-04,-2.200E-04,-2.000E-05,-2.000E-05,-2.000E-05,-2.000E-05, 6-7.000E-05, 1.900E-04,-4.000E-05, 2.000E-05, 0.000E+00, 0.000E+00, 1 6.623E-01,-9.248E-01, 3.519E-01,-7.930E-02, 1.110E-02,-1.180E-03, 2 6.380E-01,-9.062E-01, 3.582E-01,-8.479E-02, 1.265E-02,-1.390E-03, 3-2.581E-02, 2.125E-02, 4.190E-03,-4.980E-03, 1.490E-03,-2.100E-04, 4 7.100E-04, 5.300E-04,-1.270E-03, 3.900E-04,-5.000E-05,-1.000E-05, 5 3.850E-03,-5.060E-03, 1.860E-03,-3.500E-04, 4.000E-05, 0.000E+00, 6-3.530E-03, 4.460E-03,-1.500E-03, 2.700E-04,-3.000E-05, 0.000E+00/ DATA (((CEHLQ(IX,IT,NX,8,2),IX=1,6),IT=1,6),NX=1,2)/ 1 4.260E-03,-7.530E-03, 3.830E-03,-2.680E-03, 7.600E-04,-7.300E-04, 2 3.640E-03,-6.050E-03, 3.030E-03,-2.090E-03, 5.900E-04,-6.000E-04, 3-9.200E-04, 1.710E-03,-8.200E-04, 5.000E-04,-1.200E-04, 1.000E-04, 4-5.000E-05,-1.600E-04, 1.300E-04,-9.000E-05, 3.000E-05, 0.000E+00, 5 1.300E-04,-2.100E-04,-1.000E-05,-2.000E-05,-2.000E-05,-1.000E-05, 6-8.000E-05, 1.800E-04,-5.000E-05, 2.000E-05, 0.000E+00, 0.000E+00, 1 7.146E-01,-1.007E+00, 3.932E-01,-9.246E-02, 1.366E-02,-1.540E-03, 2 6.856E-01,-9.828E-01, 3.977E-01,-9.795E-02, 1.540E-02,-1.790E-03, 3-3.053E-02, 2.758E-02, 2.150E-03,-4.880E-03, 1.640E-03,-2.500E-04, 4 9.200E-04, 4.200E-04,-1.340E-03, 4.600E-04,-8.000E-05,-1.000E-05, 5 4.230E-03,-5.660E-03, 2.140E-03,-4.300E-04, 6.000E-05, 0.000E+00, 6-3.890E-03, 5.000E-03,-1.740E-03, 3.300E-04,-4.000E-05, 0.000E+00/ C...The following data lines are coefficients needed in the C...Duke, Owens proton structure function parametrizations, see below. C...Expansion coefficients for (up+down) valence quark distribution. DATA ((CDO(IP,IS,1,1),IS=1,6),IP=1,3)/ 1 4.190E-01, 3.460E+00, 4.400E+00, 0.000E+00, 0.000E+00, 0.000E+00, 2 4.000E-03, 7.240E-01,-4.860E+00, 0.000E+00, 0.000E+00, 0.000E+00, 3-7.000E-03,-6.600E-02, 1.330E+00, 0.000E+00, 0.000E+00, 0.000E+00/ DATA ((CDO(IP,IS,1,2),IS=1,6),IP=1,3)/ 1 3.740E-01, 3.330E+00, 6.030E+00, 0.000E+00, 0.000E+00, 0.000E+00, 2 1.400E-02, 7.530E-01,-6.220E+00, 0.000E+00, 0.000E+00, 0.000E+00, 3 0.000E+00,-7.600E-02, 1.560E+00, 0.000E+00, 0.000E+00, 0.000E+00/ C...Expansion coefficients for down valence quark distribution. DATA ((CDO(IP,IS,2,1),IS=1,6),IP=1,3)/ 1 7.630E-01, 4.000E+00, 0.000E+00, 0.000E+00, 0.000E+00, 0.000E+00, 2-2.370E-01, 6.270E-01,-4.210E-01, 0.000E+00, 0.000E+00, 0.000E+00, 3 2.600E-02,-1.900E-02, 3.300E-02, 0.000E+00, 0.000E+00, 0.000E+00/ DATA ((CDO(IP,IS,2,2),IS=1,6),IP=1,3)/ 1 7.610E-01, 3.830E+00, 0.000E+00, 0.000E+00, 0.000E+00, 0.000E+00, 2-2.320E-01, 6.270E-01,-4.180E-01, 0.000E+00, 0.000E+00, 0.000E+00, 3 2.300E-02,-1.900E-02, 3.600E-02, 0.000E+00, 0.000E+00, 0.000E+00/ C...Expansion coefficients for (up+down+strange) sea quark distribution. DATA ((CDO(IP,IS,3,1),IS=1,6),IP=1,3)/ 1 1.265E+00, 0.000E+00, 8.050E+00, 0.000E+00, 0.000E+00, 0.000E+00, 2-1.132E+00,-3.720E-01, 1.590E+00, 6.310E+00,-1.050E+01, 1.470E+01, 3 2.930E-01,-2.900E-02,-1.530E-01,-2.730E-01,-3.170E+00, 9.800E+00/ DATA ((CDO(IP,IS,3,2),IS=1,6),IP=1,3)/ 1 1.670E+00, 0.000E+00, 9.150E+00, 0.000E+00, 0.000E+00, 0.000E+00, 2-1.920E+00,-2.730E-01, 5.300E-01, 1.570E+01,-1.010E+02, 2.230E+02, 3 5.820E-01,-1.640E-01,-7.630E-01,-2.830E+00, 4.470E+01,-1.170E+02/ C...Expansion coefficients for charm sea quark distribution. DATA ((CDO(IP,IS,4,1),IS=1,6),IP=1,3)/ 1 0.000E+00,-3.600E-02, 6.350E+00, 0.000E+00, 0.000E+00, 0.000E+00, 2 1.350E-01,-2.220E-01, 3.260E+00,-3.030E+00, 1.740E+01,-1.790E+01, 3-7.500E-02,-5.800E-02,-9.090E-01, 1.500E+00,-1.130E+01, 1.560E+01/ DATA ((CDO(IP,IS,4,2),IS=1,6),IP=1,3)/ 1 0.000E+00,-1.200E-01, 3.510E+00, 0.000E+00, 0.000E+00, 0.000E+00, 2 6.700E-02,-2.330E-01, 3.660E+00,-4.740E-01, 9.500E+00,-1.660E+01, 3-3.100E-02,-2.300E-02,-4.530E-01, 3.580E-01,-5.430E+00, 1.550E+01/ C...Expansion coefficients for gluon distribution. DATA ((CDO(IP,IS,5,1),IS=1,6),IP=1,3)/ 1 1.560E+00, 0.000E+00, 6.000E+00, 9.000E+00, 0.000E+00, 0.000E+00, 2-1.710E+00,-9.490E-01, 1.440E+00,-7.190E+00,-1.650E+01, 1.530E+01, 3 6.380E-01, 3.250E-01,-1.050E+00, 2.550E-01, 1.090E+01,-1.010E+01/ DATA ((CDO(IP,IS,5,2),IS=1,6),IP=1,3)/ 1 8.790E-01, 0.000E+00, 4.000E+00, 9.000E+00, 0.000E+00, 0.000E+00, 2-9.710E-01,-1.160E+00, 1.230E+00,-5.640E+00,-7.540E+00,-5.960E-01, 3 4.340E-01, 4.760E-01,-2.540E-01,-8.170E-01, 5.500E+00, 1.260E-01/ C...Euler's beta function, requires ordinary Gamma function EULBET(X,Y)=PYGAMM(X)*PYGAMM(Y)/PYGAMM(X+Y) C...Reset output array. DO 100 KFL=-6,6 XPPR(KFL)=0. 100 CONTINUE IF(MSTP(51).EQ.1.OR.MSTP(51).EQ.2) THEN C...Proton structure functions from Eichten, Hinchliffe, Lane, Quigg. C...Allowed variable range: 5 GeV^2 < Q^2 < 1E8 GeV^2; 1E-4 < x < 1 C...Determine set, Lambda and x and t expansion variables. NSET=MSTP(51) IF(NSET.EQ.1) ALAM=0.2 IF(NSET.EQ.2) ALAM=0.29 VINT(231)=5. TMIN=LOG(5./ALAM**2) TMAX=LOG(1E8/ALAM**2) IF(MSTP(57).EQ.0) THEN T=TMIN ELSE T=LOG(MAX(1.,Q2/ALAM**2)) ENDIF VT=MAX(-1.,MIN(1.,(2.*T-TMAX-TMIN)/(TMAX-TMIN))) NX=1 IF(X.LE.0.1) NX=2 IF(NX.EQ.1) VX=(2.*X-1.1)/0.9 IF(NX.EQ.2) VX=MAX(-1.,(2.*LOG(X)+11.51293)/6.90776) CXS=1. IF(X.LT.1E-4.AND.ABS(PARP(51)-1.).GT.0.01) CXS= & (1E-4/X)**(PARP(51)-1.) C...Chebyshev polynomials for x and t expansion. TX(1)=1. TX(2)=VX TX(3)=2.*VX**2-1. TX(4)=4.*VX**3-3.*VX TX(5)=8.*VX**4-8.*VX**2+1. TX(6)=16.*VX**5-20.*VX**3+5.*VX TT(1)=1. TT(2)=VT TT(3)=2.*VT**2-1. TT(4)=4.*VT**3-3.*VT TT(5)=8.*VT**4-8.*VT**2+1. TT(6)=16.*VT**5-20.*VT**3+5.*VT C...Calculate structure functions. DO 130 KFL=1,6 XQSUM=0. DO 120 IT=1,6 DO 110 IX=1,6 XQSUM=XQSUM+CEHLQ(IX,IT,NX,KFL,NSET)*TX(IX)*TT(IT) 110 CONTINUE 120 CONTINUE XQ(KFL)=XQSUM*(1.-X)**NEHLQ(KFL,NSET)*CXS 130 CONTINUE C...Put into output array. XPPR(0)=XQ(4) XPPR(1)=XQ(2)+XQ(3) XPPR(2)=XQ(1)+XQ(3) XPPR(3)=XQ(5) XPPR(4)=XQ(6) XPPR(-1)=XQ(3) XPPR(-2)=XQ(3) XPPR(-3)=XQ(5) XPPR(-4)=XQ(6) C...Special expansion for bottom (threshold effects). IF(MSTP(58).GE.5) THEN IF(NSET.EQ.1) TMIN=8.1905 IF(NSET.EQ.2) TMIN=7.4474 IF(T.GT.TMIN) THEN VT=MAX(-1.,MIN(1.,(2.*T-TMAX-TMIN)/(TMAX-TMIN))) TT(1)=1. TT(2)=VT TT(3)=2.*VT**2-1. TT(4)=4.*VT**3-3.*VT TT(5)=8.*VT**4-8.*VT**2+1. TT(6)=16.*VT**5-20.*VT**3+5.*VT XQSUM=0. DO 150 IT=1,6 DO 140 IX=1,6 XQSUM=XQSUM+CEHLQ(IX,IT,NX,7,NSET)*TX(IX)*TT(IT) 140 CONTINUE 150 CONTINUE XPPR(5)=XQSUM*(1.-X)**NEHLQ(7,NSET)*CXS XPPR(-5)=XPPR(5) ENDIF ENDIF C...Special expansion for top (threshold effects). IF(MSTP(58).GE.6) THEN IF(NSET.EQ.1) TMIN=11.5528 IF(NSET.EQ.2) TMIN=10.8097 TMIN=TMIN+2.*LOG(PMAS(6,1)/30.) TMAX=TMAX+2.*LOG(PMAS(6,1)/30.) IF(T.GT.TMIN) THEN VT=MAX(-1.,MIN(1.,(2.*T-TMAX-TMIN)/(TMAX-TMIN))) TT(1)=1. TT(2)=VT TT(3)=2.*VT**2-1. TT(4)=4.*VT**3-3.*VT TT(5)=8.*VT**4-8.*VT**2+1. TT(6)=16.*VT**5-20.*VT**3+5.*VT XQSUM=0. DO 170 IT=1,6 DO 160 IX=1,6 XQSUM=XQSUM+CEHLQ(IX,IT,NX,8,NSET)*TX(IX)*TT(IT) 160 CONTINUE 170 CONTINUE XPPR(6)=XQSUM*(1.-X)**NEHLQ(8,NSET)*CXS XPPR(-6)=XPPR(6) ENDIF ENDIF ELSEIF(MSTP(51).EQ.3.OR.MSTP(51).EQ.4) THEN C...Proton structure functions from Duke, Owens. C...Allowed variable range: 4 GeV^2 < Q^2 < approx 1E6 GeV^2. C...Determine set, Lambda and s expansion parameter. NSET=MSTP(51)-2 IF(NSET.EQ.1) ALAM=0.2 IF(NSET.EQ.2) ALAM=0.4 VINT(231)=4. IF(MSTP(57).LE.0) THEN SD=0. ELSE Q2IN=MIN(1E6,MAX(4.,Q2)) SD=LOG(LOG(Q2IN/ALAM**2)/LOG(4./ALAM**2)) ENDIF C...Calculate structure functions. DO 190 KFL=1,5 DO 180 IS=1,6 TS(IS)=CDO(1,IS,KFL,NSET)+CDO(2,IS,KFL,NSET)*SD+ & CDO(3,IS,KFL,NSET)*SD**2 180 CONTINUE IF(KFL.LE.2) THEN XQ(KFL)=X**TS(1)*(1.-X)**TS(2)*(1.+TS(3)*X)/(EULBET(TS(1), & TS(2)+1.)*(1.+TS(3)*TS(1)/(TS(1)+TS(2)+1.))) ELSE XQ(KFL)=TS(1)*X**TS(2)*(1.-X)**TS(3)*(1.+TS(4)*X+TS(5)*X**2+ & TS(6)*X**3) ENDIF 190 CONTINUE C...Put into output arrays. XPPR(0)=XQ(5) XPPR(1)=XQ(2)+XQ(3)/6. XPPR(2)=3.*XQ(1)-XQ(2)+XQ(3)/6. XPPR(3)=XQ(3)/6. XPPR(4)=XQ(4) XPPR(-1)=XQ(3)/6. XPPR(-2)=XQ(3)/6. XPPR(-3)=XQ(3)/6. XPPR(-4)=XQ(4) ELSEIF(MSTP(51).GE.5.AND.MSTP(51).LE.10) THEN C...Interface to the CTEQ 2 structure functions. NSET=MSTP(51)-4 QRT=SQRT(MAX(1.,Q2)) C...Loop over flavours; put u and d in right order. DO 200 I=-6,2 KFL=I IF(I.EQ.1) KFL=2 IF(I.EQ.2) KFL=1 IF(I.EQ.-1) KFL=-2 IF(I.EQ.-2) KFL=-1 IF(I.LE.0) THEN XPPR(KFL)=PYCTQ2(NSET,I,X,QRT) XPPR(-KFL)=XPPR(KFL) ELSE XPPR(KFL)=PYCTQ2(NSET,I,X,QRT)+XPPR(-KFL) ENDIF 200 CONTINUE C...Leading order proton structure functions from Gluck, Reya and Vogt. C...Allowed variable range: 0.25 GeV^2 < Q^2 < 10^8 GeV^2 and C...10^-5 < x < 1. ELSE C...Determine s expansion variable and some x expressions. VINT(231)=0.25 IF(MSTP(57).LE.0) THEN SD=0. ELSE Q2IN=MIN(1E8,MAX(0.25,Q2)) SD=LOG(LOG(Q2IN/0.232**2)/LOG(0.25/0.232**2)) ENDIF SD2=SD**2 XL=-LOG(X) XS=SQRT(X) C...Evaluate valence, gluon and sea distributions. XFVUD=(0.663+0.191*SD-0.041*SD2+0.031*SD**3)*X**0.326* & (1.+(-1.97+6.74*SD-1.96*SD2)*XS+(24.4-20.7*SD+4.08*SD2)*X)* & (1.-X)**(2.86+0.70*SD-0.02*SD2) XFVDD=(0.579+0.283*SD+0.047*SD2)*X**(0.523-0.015*SD)* & (1.+(2.22-0.59*SD-0.27*SD2)*XS+(5.95-6.19*SD+1.55*SD2)*X)* & (1.-X)**(3.57+0.94*SD-0.16*SD2) XFGLU=(X**(1.00-0.17*SD)*((4.879*SD-1.383*SD2)+ & (25.92-28.97*SD+5.596*SD2)*X+(-25.69+23.68*SD-1.975*SD2)*X**2)+ & SD**0.558*EXP(-(0.595+2.138*SD)+SQRT(4.066*SD**1.218*XL)))* & (1.-X)**(2.537+1.718*SD+0.353*SD2) XFSEA=(X**(0.412-0.171*SD)*(0.363-1.196*X+ & (1.029+1.785*SD-0.459*SD2)*X**2)*XL**(0.566-0.496*SD)+ & SD**1.396*EXP(-(3.838+1.944*SD)+SQRT(2.845*SD**1.331*XL)))* & (1.-X)**(4.696+2.109*SD) XFSTR=SD**0.803*(1.+(-3.055+1.024*SD**0.67)*XS+ & (27.4-20.0*SD**0.154)*X)*(1.-X)**6.22* & EXP(-(4.33+1.408*SD)+SQRT((8.27-0.437*SD)*SD**0.563*XL))/ & XL**(2.082-0.577*SD) IF(SD.LE.0.888) THEN XFCHM=0. ELSE XFCHM=(SD-0.888)**1.01*(1.+(4.24-0.804*SD)*X)* & (1.-X)**(3.46+1.076*SD)*EXP(-(4.61+1.49*SD)+ & SQRT((2.555+1.961*SD)*SD**0.37*XL)) ENDIF IF(SD.LE.1.351) THEN XFBOT=0. ELSE XFBOT=(SD-1.351)*(1.+1.848*X)*(1.-X)**(2.929+1.396*SD)* & EXP(-(4.71+1.514*SD)+SQRT((4.02+1.239*SD)*SD**0.51*XL)) ENDIF C...Put into output array. XPPR(0)=XFGLU XPPR(1)=XFVDD+XFSEA XPPR(2)=XFVUD-XFVDD+XFSEA XPPR(3)=XFSTR XPPR(4)=XFCHM XPPR(5)=XFBOT XPPR(-1)=XFSEA XPPR(-2)=XFSEA XPPR(-3)=XFSTR XPPR(-4)=XFCHM XPPR(-5)=XFBOT ENDIF RETURN END