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pystpr.F
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1  SUBROUTINE pystpr(X,Q2,XPPR)
2 
3 C...Gives proton structure functions according to a few different
4 C...parametrizations.
5  common/ludat1/mstu(200),paru(200),mstj(200),parj(200)
6  common/ludat2/kchg(500,3),pmas(500,4),parf(2000),vckm(4,4)
7  common/pypars/mstp(200),parp(200),msti(200),pari(200)
8  common/pyint1/mint(400),vint(400)
9  SAVE /ludat1/,/ludat2/
10  SAVE /pypars/,/pyint1/
11  dimension xppr(-6:6),xq(9),tx(6),tt(6),ts(6),nehlq(8,2),
12  &cehlq(6,6,2,8,2),cdo(3,6,5,2)
13 
14 
15 C...The following data lines are coefficients needed in the
16 C...Eichten, Hinchliffe, Lane, Quigg proton structure function
17 C...parametrizations, see below.
18 C...Powers of 1-x in different cases.
19  DATA nehlq/3,4,7,5,7,7,7,7,3,4,7,6,7,7,7,7/
20 C...Expansion coefficients for up valence quark distribution.
21  DATA (((cehlq(ix,it,nx,1,1),ix=1,6),it=1,6),nx=1,2)/
22  1 7.677e-01,-2.087e-01,-3.303e-01,-2.517e-02,-1.570e-02,-1.000e-04,
23  2-5.326e-01,-2.661e-01, 3.201e-01, 1.192e-01, 2.434e-02, 7.620e-03,
24  3 2.162e-01, 1.881e-01,-8.375e-02,-6.515e-02,-1.743e-02,-5.040e-03,
25  4-9.211e-02,-9.952e-02, 1.373e-02, 2.506e-02, 8.770e-03, 2.550e-03,
26  5 3.670e-02, 4.409e-02, 9.600e-04,-7.960e-03,-3.420e-03,-1.050e-03,
27  6-1.549e-02,-2.026e-02,-3.060e-03, 2.220e-03, 1.240e-03, 4.100e-04,
28  1 2.395e-01, 2.905e-01, 9.778e-02, 2.149e-02, 3.440e-03, 5.000e-04,
29  2 1.751e-02,-6.090e-03,-2.687e-02,-1.916e-02,-7.970e-03,-2.750e-03,
30  3-5.760e-03,-5.040e-03, 1.080e-03, 2.490e-03, 1.530e-03, 7.500e-04,
31  4 1.740e-03, 1.960e-03, 3.000e-04,-3.400e-04,-2.900e-04,-1.800e-04,
32  5-5.300e-04,-6.400e-04,-1.700e-04, 4.000e-05, 6.000e-05, 4.000e-05,
33  6 1.700e-04, 2.200e-04, 8.000e-05, 1.000e-05,-1.000e-05,-1.000e-05/
34  DATA (((cehlq(ix,it,nx,1,2),ix=1,6),it=1,6),nx=1,2)/
35  1 7.237e-01,-2.189e-01,-2.995e-01,-1.909e-02,-1.477e-02, 2.500e-04,
36  2-5.314e-01,-2.425e-01, 3.283e-01, 1.119e-01, 2.223e-02, 7.070e-03,
37  3 2.289e-01, 1.890e-01,-9.859e-02,-6.900e-02,-1.747e-02,-5.080e-03,
38  4-1.041e-01,-1.084e-01, 2.108e-02, 2.975e-02, 9.830e-03, 2.830e-03,
39  5 4.394e-02, 5.116e-02,-1.410e-03,-1.055e-02,-4.230e-03,-1.270e-03,
40  6-1.991e-02,-2.539e-02,-2.780e-03, 3.430e-03, 1.720e-03, 5.500e-04,
41  1 2.410e-01, 2.884e-01, 9.369e-02, 1.900e-02, 2.530e-03, 2.400e-04,
42  2 1.765e-02,-9.220e-03,-3.037e-02,-2.085e-02,-8.440e-03,-2.810e-03,
43  3-6.450e-03,-5.260e-03, 1.720e-03, 3.110e-03, 1.830e-03, 8.700e-04,
44  4 2.120e-03, 2.320e-03, 2.600e-04,-4.900e-04,-3.900e-04,-2.300e-04,
45  5-6.900e-04,-8.200e-04,-2.000e-04, 7.000e-05, 9.000e-05, 6.000e-05,
46  6 2.400e-04, 3.100e-04, 1.100e-04, 0.000e+00,-2.000e-05,-2.000e-05/
47 C...Expansion coefficients for down valence quark distribution.
48  DATA (((cehlq(ix,it,nx,2,1),ix=1,6),it=1,6),nx=1,2)/
49  1 3.813e-01,-8.090e-02,-1.634e-01,-2.185e-02,-8.430e-03,-6.200e-04,
50  2-2.948e-01,-1.435e-01, 1.665e-01, 6.638e-02, 1.473e-02, 4.080e-03,
51  3 1.252e-01, 1.042e-01,-4.722e-02,-3.683e-02,-1.038e-02,-2.860e-03,
52  4-5.478e-02,-5.678e-02, 8.900e-03, 1.484e-02, 5.340e-03, 1.520e-03,
53  5 2.220e-02, 2.567e-02,-3.000e-05,-4.970e-03,-2.160e-03,-6.500e-04,
54  6-9.530e-03,-1.204e-02,-1.510e-03, 1.510e-03, 8.300e-04, 2.700e-04,
55  1 1.261e-01, 1.354e-01, 3.958e-02, 8.240e-03, 1.660e-03, 4.500e-04,
56  2 3.890e-03,-1.159e-02,-1.625e-02,-9.610e-03,-3.710e-03,-1.260e-03,
57  3-1.910e-03,-5.600e-04, 1.590e-03, 1.590e-03, 8.400e-04, 3.900e-04,
58  4 6.400e-04, 4.900e-04,-1.500e-04,-2.900e-04,-1.800e-04,-1.000e-04,
59  5-2.000e-04,-1.900e-04, 0.000e+00, 6.000e-05, 4.000e-05, 3.000e-05,
60  6 7.000e-05, 8.000e-05, 2.000e-05,-1.000e-05,-1.000e-05,-1.000e-05/
61  DATA (((cehlq(ix,it,nx,2,2),ix=1,6),it=1,6),nx=1,2)/
62  1 3.578e-01,-8.622e-02,-1.480e-01,-1.840e-02,-7.820e-03,-4.500e-04,
63  2-2.925e-01,-1.304e-01, 1.696e-01, 6.243e-02, 1.353e-02, 3.750e-03,
64  3 1.318e-01, 1.041e-01,-5.486e-02,-3.872e-02,-1.038e-02,-2.850e-03,
65  4-6.162e-02,-6.143e-02, 1.303e-02, 1.740e-02, 5.940e-03, 1.670e-03,
66  5 2.643e-02, 2.957e-02,-1.490e-03,-6.450e-03,-2.630e-03,-7.700e-04,
67  6-1.218e-02,-1.497e-02,-1.260e-03, 2.240e-03, 1.120e-03, 3.500e-04,
68  1 1.263e-01, 1.334e-01, 3.732e-02, 7.070e-03, 1.260e-03, 3.400e-04,
69  2 3.660e-03,-1.357e-02,-1.795e-02,-1.031e-02,-3.880e-03,-1.280e-03,
70  3-2.100e-03,-3.600e-04, 2.050e-03, 1.920e-03, 9.800e-04, 4.400e-04,
71  4 7.700e-04, 5.400e-04,-2.400e-04,-3.900e-04,-2.400e-04,-1.300e-04,
72  5-2.600e-04,-2.300e-04, 2.000e-05, 9.000e-05, 6.000e-05, 4.000e-05,
73  6 9.000e-05, 1.000e-04, 2.000e-05,-2.000e-05,-2.000e-05,-1.000e-05/
74 C...Expansion coefficients for up and down sea quark distributions.
75  DATA (((cehlq(ix,it,nx,3,1),ix=1,6),it=1,6),nx=1,2)/
76  1 6.870e-02,-6.861e-02, 2.973e-02,-5.400e-03, 3.780e-03,-9.700e-04,
77  2-1.802e-02, 1.400e-04, 6.490e-03,-8.540e-03, 1.220e-03,-1.750e-03,
78  3-4.650e-03, 1.480e-03,-5.930e-03, 6.000e-04,-1.030e-03,-8.000e-05,
79  4 6.440e-03, 2.570e-03, 2.830e-03, 1.150e-03, 7.100e-04, 3.300e-04,
80  5-3.930e-03,-2.540e-03,-1.160e-03,-7.700e-04,-3.600e-04,-1.900e-04,
81  6 2.340e-03, 1.930e-03, 5.300e-04, 3.700e-04, 1.600e-04, 9.000e-05,
82  1 1.014e+00,-1.106e+00, 3.374e-01,-7.444e-02, 8.850e-03,-8.700e-04,
83  2 9.233e-01,-1.285e+00, 4.475e-01,-9.786e-02, 1.419e-02,-1.120e-03,
84  3 4.888e-02,-1.271e-01, 8.606e-02,-2.608e-02, 4.780e-03,-6.000e-04,
85  4-2.691e-02, 4.887e-02,-1.771e-02, 1.620e-03, 2.500e-04,-6.000e-05,
86  5 7.040e-03,-1.113e-02, 1.590e-03, 7.000e-04,-2.000e-04, 0.000e+00,
87  6-1.710e-03, 2.290e-03, 3.800e-04,-3.500e-04, 4.000e-05, 1.000e-05/
88  DATA (((cehlq(ix,it,nx,3,2),ix=1,6),it=1,6),nx=1,2)/
89  1 1.008e-01,-7.100e-02, 1.973e-02,-5.710e-03, 2.930e-03,-9.900e-04,
90  2-5.271e-02,-1.823e-02, 1.792e-02,-6.580e-03, 1.750e-03,-1.550e-03,
91  3 1.220e-02, 1.763e-02,-8.690e-03,-8.800e-04,-1.160e-03,-2.100e-04,
92  4-1.190e-03,-7.180e-03, 2.360e-03, 1.890e-03, 7.700e-04, 4.100e-04,
93  5-9.100e-04, 2.040e-03,-3.100e-04,-1.050e-03,-4.000e-04,-2.400e-04,
94  6 1.190e-03,-1.700e-04,-2.000e-04, 4.200e-04, 1.700e-04, 1.000e-04,
95  1 1.081e+00,-1.189e+00, 3.868e-01,-8.617e-02, 1.115e-02,-1.180e-03,
96  2 9.917e-01,-1.396e+00, 4.998e-01,-1.159e-01, 1.674e-02,-1.720e-03,
97  3 5.099e-02,-1.338e-01, 9.173e-02,-2.885e-02, 5.890e-03,-6.500e-04,
98  4-3.178e-02, 5.703e-02,-2.070e-02, 2.440e-03, 1.100e-04,-9.000e-05,
99  5 8.970e-03,-1.392e-02, 2.050e-03, 6.500e-04,-2.300e-04, 2.000e-05,
100  6-2.340e-03, 3.010e-03, 5.000e-04,-3.900e-04, 6.000e-05, 1.000e-05/
101 C...Expansion coefficients for gluon distribution.
102  DATA (((cehlq(ix,it,nx,4,1),ix=1,6),it=1,6),nx=1,2)/
103  1 9.482e-01,-9.578e-01, 1.009e-01,-1.051e-01, 3.456e-02,-3.054e-02,
104  2-9.627e-01, 5.379e-01, 3.368e-01,-9.525e-02, 1.488e-02,-2.051e-02,
105  3 4.300e-01,-8.306e-02,-3.372e-01, 4.902e-02,-9.160e-03, 1.041e-02,
106  4-1.925e-01,-1.790e-02, 2.183e-01, 7.490e-03, 4.140e-03,-1.860e-03,
107  5 8.183e-02, 1.926e-02,-1.072e-01,-1.944e-02,-2.770e-03,-5.200e-04,
108  6-3.884e-02,-1.234e-02, 5.410e-02, 1.879e-02, 3.350e-03, 1.040e-03,
109  1 2.948e+01,-3.902e+01, 1.464e+01,-3.335e+00, 5.054e-01,-5.915e-02,
110  2 2.559e+01,-3.955e+01, 1.661e+01,-4.299e+00, 6.904e-01,-8.243e-02,
111  3-1.663e+00, 1.176e+00, 1.118e+00,-7.099e-01, 1.948e-01,-2.404e-02,
112  4-2.168e-01, 8.170e-01,-7.169e-01, 1.851e-01,-1.924e-02,-3.250e-03,
113  5 2.088e-01,-4.355e-01, 2.239e-01,-2.446e-02,-3.620e-03, 1.910e-03,
114  6-9.097e-02, 1.601e-01,-5.681e-02,-2.500e-03, 2.580e-03,-4.700e-04/
115  DATA (((cehlq(ix,it,nx,4,2),ix=1,6),it=1,6),nx=1,2)/
116  1 2.367e+00, 4.453e-01, 3.660e-01, 9.467e-02, 1.341e-01, 1.661e-02,
117  2-3.170e+00,-1.795e+00, 3.313e-02,-2.874e-01,-9.827e-02,-7.119e-02,
118  3 1.823e+00, 1.457e+00,-2.465e-01, 3.739e-02, 6.090e-03, 1.814e-02,
119  4-1.033e+00,-9.827e-01, 2.136e-01, 1.169e-01, 5.001e-02, 1.684e-02,
120  5 5.133e-01, 5.259e-01,-1.173e-01,-1.139e-01,-4.988e-02,-2.021e-02,
121  6-2.881e-01,-3.145e-01, 5.667e-02, 9.161e-02, 4.568e-02, 1.951e-02,
122  1 3.036e+01,-4.062e+01, 1.578e+01,-3.699e+00, 6.020e-01,-7.031e-02,
123  2 2.700e+01,-4.167e+01, 1.770e+01,-4.804e+00, 7.862e-01,-1.060e-01,
124  3-1.909e+00, 1.357e+00, 1.127e+00,-7.181e-01, 2.232e-01,-2.481e-02,
125  4-2.488e-01, 9.781e-01,-8.127e-01, 2.094e-01,-2.997e-02,-4.710e-03,
126  5 2.506e-01,-5.427e-01, 2.672e-01,-3.103e-02,-1.800e-03, 2.870e-03,
127  6-1.128e-01, 2.087e-01,-6.972e-02,-2.480e-03, 2.630e-03,-8.400e-04/
128 C...Expansion coefficients for strange sea quark distribution.
129  DATA (((cehlq(ix,it,nx,5,1),ix=1,6),it=1,6),nx=1,2)/
130  1 4.968e-02,-4.173e-02, 2.102e-02,-3.270e-03, 3.240e-03,-6.700e-04,
131  2-6.150e-03,-1.294e-02, 6.740e-03,-6.890e-03, 9.000e-04,-1.510e-03,
132  3-8.580e-03, 5.050e-03,-4.900e-03,-1.600e-04,-9.400e-04,-1.500e-04,
133  4 7.840e-03, 1.510e-03, 2.220e-03, 1.400e-03, 7.000e-04, 3.500e-04,
134  5-4.410e-03,-2.220e-03,-8.900e-04,-8.500e-04,-3.600e-04,-2.000e-04,
135  6 2.520e-03, 1.840e-03, 4.100e-04, 3.900e-04, 1.600e-04, 9.000e-05,
136  1 9.235e-01,-1.085e+00, 3.464e-01,-7.210e-02, 9.140e-03,-9.100e-04,
137  2 9.315e-01,-1.274e+00, 4.512e-01,-9.775e-02, 1.380e-02,-1.310e-03,
138  3 4.739e-02,-1.296e-01, 8.482e-02,-2.642e-02, 4.760e-03,-5.700e-04,
139  4-2.653e-02, 4.953e-02,-1.735e-02, 1.750e-03, 2.800e-04,-6.000e-05,
140  5 6.940e-03,-1.132e-02, 1.480e-03, 6.500e-04,-2.100e-04, 0.000e+00,
141  6-1.680e-03, 2.340e-03, 4.200e-04,-3.400e-04, 5.000e-05, 1.000e-05/
142  DATA (((cehlq(ix,it,nx,5,2),ix=1,6),it=1,6),nx=1,2)/
143  1 6.478e-02,-4.537e-02, 1.643e-02,-3.490e-03, 2.710e-03,-6.700e-04,
144  2-2.223e-02,-2.126e-02, 1.247e-02,-6.290e-03, 1.120e-03,-1.440e-03,
145  3-1.340e-03, 1.362e-02,-6.130e-03,-7.900e-04,-9.000e-04,-2.000e-04,
146  4 5.080e-03,-3.610e-03, 1.700e-03, 1.830e-03, 6.800e-04, 4.000e-04,
147  5-3.580e-03, 6.000e-05,-2.600e-04,-1.050e-03,-3.800e-04,-2.300e-04,
148  6 2.420e-03, 9.300e-04,-1.000e-04, 4.500e-04, 1.700e-04, 1.100e-04,
149  1 9.868e-01,-1.171e+00, 3.940e-01,-8.459e-02, 1.124e-02,-1.250e-03,
150  2 1.001e+00,-1.383e+00, 5.044e-01,-1.152e-01, 1.658e-02,-1.830e-03,
151  3 4.928e-02,-1.368e-01, 9.021e-02,-2.935e-02, 5.800e-03,-6.600e-04,
152  4-3.133e-02, 5.785e-02,-2.023e-02, 2.630e-03, 1.600e-04,-8.000e-05,
153  5 8.840e-03,-1.416e-02, 1.900e-03, 5.800e-04,-2.500e-04, 1.000e-05,
154  6-2.300e-03, 3.080e-03, 5.500e-04,-3.700e-04, 7.000e-05, 1.000e-05/
155 C...Expansion coefficients for charm sea quark distribution.
156  DATA (((cehlq(ix,it,nx,6,1),ix=1,6),it=1,6),nx=1,2)/
157  1 9.270e-03,-1.817e-02, 9.590e-03,-6.390e-03, 1.690e-03,-1.540e-03,
158  2 5.710e-03,-1.188e-02, 6.090e-03,-4.650e-03, 1.240e-03,-1.310e-03,
159  3-3.960e-03, 7.100e-03,-3.590e-03, 1.840e-03,-3.900e-04, 3.400e-04,
160  4 1.120e-03,-1.960e-03, 1.120e-03,-4.800e-04, 1.000e-04,-4.000e-05,
161  5 4.000e-05,-3.000e-05,-1.800e-04, 9.000e-05,-5.000e-05,-2.000e-05,
162  6-4.200e-04, 7.300e-04,-1.600e-04, 5.000e-05, 5.000e-05, 5.000e-05,
163  1 8.098e-01,-1.042e+00, 3.398e-01,-6.824e-02, 8.760e-03,-9.000e-04,
164  2 8.961e-01,-1.217e+00, 4.339e-01,-9.287e-02, 1.304e-02,-1.290e-03,
165  3 3.058e-02,-1.040e-01, 7.604e-02,-2.415e-02, 4.600e-03,-5.000e-04,
166  4-2.451e-02, 4.432e-02,-1.651e-02, 1.430e-03, 1.200e-04,-1.000e-04,
167  5 1.122e-02,-1.457e-02, 2.680e-03, 5.800e-04,-1.200e-04, 3.000e-05,
168  6-7.730e-03, 7.330e-03,-7.600e-04,-2.400e-04, 1.000e-05, 0.000e+00/
169  DATA (((cehlq(ix,it,nx,6,2),ix=1,6),it=1,6),nx=1,2)/
170  1 9.980e-03,-1.945e-02, 1.055e-02,-6.870e-03, 1.860e-03,-1.560e-03,
171  2 5.700e-03,-1.203e-02, 6.250e-03,-4.860e-03, 1.310e-03,-1.370e-03,
172  3-4.490e-03, 7.990e-03,-4.170e-03, 2.050e-03,-4.400e-04, 3.300e-04,
173  4 1.470e-03,-2.480e-03, 1.460e-03,-5.700e-04, 1.200e-04,-1.000e-05,
174  5-9.000e-05, 1.500e-04,-3.200e-04, 1.200e-04,-6.000e-05,-4.000e-05,
175  6-4.200e-04, 7.600e-04,-1.400e-04, 4.000e-05, 7.000e-05, 5.000e-05,
176  1 8.698e-01,-1.131e+00, 3.836e-01,-8.111e-02, 1.048e-02,-1.300e-03,
177  2 9.626e-01,-1.321e+00, 4.854e-01,-1.091e-01, 1.583e-02,-1.700e-03,
178  3 3.057e-02,-1.088e-01, 8.022e-02,-2.676e-02, 5.590e-03,-5.600e-04,
179  4-2.845e-02, 5.164e-02,-1.918e-02, 2.210e-03,-4.000e-05,-1.500e-04,
180  5 1.311e-02,-1.751e-02, 3.310e-03, 5.100e-04,-1.200e-04, 5.000e-05,
181  6-8.590e-03, 8.380e-03,-9.200e-04,-2.600e-04, 1.000e-05,-1.000e-05/
182 C...Expansion coefficients for bottom sea quark distribution.
183  DATA (((cehlq(ix,it,nx,7,1),ix=1,6),it=1,6),nx=1,2)/
184  1 9.010e-03,-1.401e-02, 7.150e-03,-4.130e-03, 1.260e-03,-1.040e-03,
185  2 6.280e-03,-9.320e-03, 4.780e-03,-2.890e-03, 9.100e-04,-8.200e-04,
186  3-2.930e-03, 4.090e-03,-1.890e-03, 7.600e-04,-2.300e-04, 1.400e-04,
187  4 3.900e-04,-1.200e-03, 4.400e-04,-2.500e-04, 2.000e-05,-2.000e-05,
188  5 2.600e-04, 1.400e-04,-8.000e-05, 1.000e-04, 1.000e-05, 1.000e-05,
189  6-2.600e-04, 3.200e-04, 1.000e-05,-1.000e-05, 1.000e-05,-1.000e-05,
190  1 8.029e-01,-1.075e+00, 3.792e-01,-7.843e-02, 1.007e-02,-1.090e-03,
191  2 7.903e-01,-1.099e+00, 4.153e-01,-9.301e-02, 1.317e-02,-1.410e-03,
192  3-1.704e-02,-1.130e-02, 2.882e-02,-1.341e-02, 3.040e-03,-3.600e-04,
193  4-7.200e-04, 7.230e-03,-5.160e-03, 1.080e-03,-5.000e-05,-4.000e-05,
194  5 3.050e-03,-4.610e-03, 1.660e-03,-1.300e-04,-1.000e-05, 1.000e-05,
195  6-4.360e-03, 5.230e-03,-1.610e-03, 2.000e-04,-2.000e-05, 0.000e+00/
196  DATA (((cehlq(ix,it,nx,7,2),ix=1,6),it=1,6),nx=1,2)/
197  1 8.980e-03,-1.459e-02, 7.510e-03,-4.410e-03, 1.310e-03,-1.070e-03,
198  2 5.970e-03,-9.440e-03, 4.800e-03,-3.020e-03, 9.100e-04,-8.500e-04,
199  3-3.050e-03, 4.440e-03,-2.100e-03, 8.500e-04,-2.400e-04, 1.400e-04,
200  4 5.300e-04,-1.300e-03, 5.600e-04,-2.700e-04, 3.000e-05,-2.000e-05,
201  5 2.000e-04, 1.400e-04,-1.100e-04, 1.000e-04, 0.000e+00, 0.000e+00,
202  6-2.600e-04, 3.200e-04, 0.000e+00,-3.000e-05, 1.000e-05,-1.000e-05,
203  1 8.672e-01,-1.174e+00, 4.265e-01,-9.252e-02, 1.244e-02,-1.460e-03,
204  2 8.500e-01,-1.194e+00, 4.630e-01,-1.083e-01, 1.614e-02,-1.830e-03,
205  3-2.241e-02,-5.630e-03, 2.815e-02,-1.425e-02, 3.520e-03,-4.300e-04,
206  4-7.300e-04, 8.030e-03,-5.780e-03, 1.380e-03,-1.300e-04,-4.000e-05,
207  5 3.460e-03,-5.380e-03, 1.960e-03,-2.100e-04, 1.000e-05, 1.000e-05,
208  6-4.850e-03, 5.950e-03,-1.890e-03, 2.600e-04,-3.000e-05, 0.000e+00/
209 C...Expansion coefficients for top sea quark distribution.
210  DATA (((cehlq(ix,it,nx,8,1),ix=1,6),it=1,6),nx=1,2)/
211  1 4.410e-03,-7.480e-03, 3.770e-03,-2.580e-03, 7.300e-04,-7.100e-04,
212  2 3.840e-03,-6.050e-03, 3.030e-03,-2.030e-03, 5.800e-04,-5.900e-04,
213  3-8.800e-04, 1.660e-03,-7.500e-04, 4.700e-04,-1.000e-04, 1.000e-04,
214  4-8.000e-05,-1.500e-04, 1.200e-04,-9.000e-05, 3.000e-05, 0.000e+00,
215  5 1.300e-04,-2.200e-04,-2.000e-05,-2.000e-05,-2.000e-05,-2.000e-05,
216  6-7.000e-05, 1.900e-04,-4.000e-05, 2.000e-05, 0.000e+00, 0.000e+00,
217  1 6.623e-01,-9.248e-01, 3.519e-01,-7.930e-02, 1.110e-02,-1.180e-03,
218  2 6.380e-01,-9.062e-01, 3.582e-01,-8.479e-02, 1.265e-02,-1.390e-03,
219  3-2.581e-02, 2.125e-02, 4.190e-03,-4.980e-03, 1.490e-03,-2.100e-04,
220  4 7.100e-04, 5.300e-04,-1.270e-03, 3.900e-04,-5.000e-05,-1.000e-05,
221  5 3.850e-03,-5.060e-03, 1.860e-03,-3.500e-04, 4.000e-05, 0.000e+00,
222  6-3.530e-03, 4.460e-03,-1.500e-03, 2.700e-04,-3.000e-05, 0.000e+00/
223  DATA (((cehlq(ix,it,nx,8,2),ix=1,6),it=1,6),nx=1,2)/
224  1 4.260e-03,-7.530e-03, 3.830e-03,-2.680e-03, 7.600e-04,-7.300e-04,
225  2 3.640e-03,-6.050e-03, 3.030e-03,-2.090e-03, 5.900e-04,-6.000e-04,
226  3-9.200e-04, 1.710e-03,-8.200e-04, 5.000e-04,-1.200e-04, 1.000e-04,
227  4-5.000e-05,-1.600e-04, 1.300e-04,-9.000e-05, 3.000e-05, 0.000e+00,
228  5 1.300e-04,-2.100e-04,-1.000e-05,-2.000e-05,-2.000e-05,-1.000e-05,
229  6-8.000e-05, 1.800e-04,-5.000e-05, 2.000e-05, 0.000e+00, 0.000e+00,
230  1 7.146e-01,-1.007e+00, 3.932e-01,-9.246e-02, 1.366e-02,-1.540e-03,
231  2 6.856e-01,-9.828e-01, 3.977e-01,-9.795e-02, 1.540e-02,-1.790e-03,
232  3-3.053e-02, 2.758e-02, 2.150e-03,-4.880e-03, 1.640e-03,-2.500e-04,
233  4 9.200e-04, 4.200e-04,-1.340e-03, 4.600e-04,-8.000e-05,-1.000e-05,
234  5 4.230e-03,-5.660e-03, 2.140e-03,-4.300e-04, 6.000e-05, 0.000e+00,
235  6-3.890e-03, 5.000e-03,-1.740e-03, 3.300e-04,-4.000e-05, 0.000e+00/
236 
237 C...The following data lines are coefficients needed in the
238 C...Duke, Owens proton structure function parametrizations, see below.
239 C...Expansion coefficients for (up+down) valence quark distribution.
240  DATA ((cdo(ip,is,1,1),is=1,6),ip=1,3)/
241  1 4.190e-01, 3.460e+00, 4.400e+00, 0.000e+00, 0.000e+00, 0.000e+00,
242  2 4.000e-03, 7.240e-01,-4.860e+00, 0.000e+00, 0.000e+00, 0.000e+00,
243  3-7.000e-03,-6.600e-02, 1.330e+00, 0.000e+00, 0.000e+00, 0.000e+00/
244  DATA ((cdo(ip,is,1,2),is=1,6),ip=1,3)/
245  1 3.740e-01, 3.330e+00, 6.030e+00, 0.000e+00, 0.000e+00, 0.000e+00,
246  2 1.400e-02, 7.530e-01,-6.220e+00, 0.000e+00, 0.000e+00, 0.000e+00,
247  3 0.000e+00,-7.600e-02, 1.560e+00, 0.000e+00, 0.000e+00, 0.000e+00/
248 C...Expansion coefficients for down valence quark distribution.
249  DATA ((cdo(ip,is,2,1),is=1,6),ip=1,3)/
250  1 7.630e-01, 4.000e+00, 0.000e+00, 0.000e+00, 0.000e+00, 0.000e+00,
251  2-2.370e-01, 6.270e-01,-4.210e-01, 0.000e+00, 0.000e+00, 0.000e+00,
252  3 2.600e-02,-1.900e-02, 3.300e-02, 0.000e+00, 0.000e+00, 0.000e+00/
253  DATA ((cdo(ip,is,2,2),is=1,6),ip=1,3)/
254  1 7.610e-01, 3.830e+00, 0.000e+00, 0.000e+00, 0.000e+00, 0.000e+00,
255  2-2.320e-01, 6.270e-01,-4.180e-01, 0.000e+00, 0.000e+00, 0.000e+00,
256  3 2.300e-02,-1.900e-02, 3.600e-02, 0.000e+00, 0.000e+00, 0.000e+00/
257 C...Expansion coefficients for (up+down+strange) sea quark distribution.
258  DATA ((cdo(ip,is,3,1),is=1,6),ip=1,3)/
259  1 1.265e+00, 0.000e+00, 8.050e+00, 0.000e+00, 0.000e+00, 0.000e+00,
260  2-1.132e+00,-3.720e-01, 1.590e+00, 6.310e+00,-1.050e+01, 1.470e+01,
261  3 2.930e-01,-2.900e-02,-1.530e-01,-2.730e-01,-3.170e+00, 9.800e+00/
262  DATA ((cdo(ip,is,3,2),is=1,6),ip=1,3)/
263  1 1.670e+00, 0.000e+00, 9.150e+00, 0.000e+00, 0.000e+00, 0.000e+00,
264  2-1.920e+00,-2.730e-01, 5.300e-01, 1.570e+01,-1.010e+02, 2.230e+02,
265  3 5.820e-01,-1.640e-01,-7.630e-01,-2.830e+00, 4.470e+01,-1.170e+02/
266 C...Expansion coefficients for charm sea quark distribution.
267  DATA ((cdo(ip,is,4,1),is=1,6),ip=1,3)/
268  1 0.000e+00,-3.600e-02, 6.350e+00, 0.000e+00, 0.000e+00, 0.000e+00,
269  2 1.350e-01,-2.220e-01, 3.260e+00,-3.030e+00, 1.740e+01,-1.790e+01,
270  3-7.500e-02,-5.800e-02,-9.090e-01, 1.500e+00,-1.130e+01, 1.560e+01/
271  DATA ((cdo(ip,is,4,2),is=1,6),ip=1,3)/
272  1 0.000e+00,-1.200e-01, 3.510e+00, 0.000e+00, 0.000e+00, 0.000e+00,
273  2 6.700e-02,-2.330e-01, 3.660e+00,-4.740e-01, 9.500e+00,-1.660e+01,
274  3-3.100e-02,-2.300e-02,-4.530e-01, 3.580e-01,-5.430e+00, 1.550e+01/
275 C...Expansion coefficients for gluon distribution.
276  DATA ((cdo(ip,is,5,1),is=1,6),ip=1,3)/
277  1 1.560e+00, 0.000e+00, 6.000e+00, 9.000e+00, 0.000e+00, 0.000e+00,
278  2-1.710e+00,-9.490e-01, 1.440e+00,-7.190e+00,-1.650e+01, 1.530e+01,
279  3 6.380e-01, 3.250e-01,-1.050e+00, 2.550e-01, 1.090e+01,-1.010e+01/
280  DATA ((cdo(ip,is,5,2),is=1,6),ip=1,3)/
281  1 8.790e-01, 0.000e+00, 4.000e+00, 9.000e+00, 0.000e+00, 0.000e+00,
282  2-9.710e-01,-1.160e+00, 1.230e+00,-5.640e+00,-7.540e+00,-5.960e-01,
283  3 4.340e-01, 4.760e-01,-2.540e-01,-8.170e-01, 5.500e+00, 1.260e-01/
284 
285 C...Euler's beta function, requires ordinary Gamma function
286  eulbet(x,y)=pygamm(x)*pygamm(y)/pygamm(x+y)
287 
288 C...Reset output array.
289  DO 100 kfl=-6,6
290  xppr(kfl)=0.
291  100 CONTINUE
292 
293  IF(mstp(51).EQ.1.OR.mstp(51).EQ.2) THEN
294 C...Proton structure functions from Eichten, Hinchliffe, Lane, Quigg.
295 C...Allowed variable range: 5 GeV^2 < Q^2 < 1E8 GeV^2; 1E-4 < x < 1
296 
297 C...Determine set, Lambda and x and t expansion variables.
298  nset=mstp(51)
299  IF(nset.EQ.1) alam=0.2
300  IF(nset.EQ.2) alam=0.29
301  vint(231)=5.
302  tmin=log(5./alam**2)
303  tmax=log(1e8/alam**2)
304  IF(mstp(57).EQ.0) THEN
305  t=tmin
306  ELSE
307  t=log(max(1.,q2/alam**2))
308  ENDIF
309  vt=max(-1.,min(1.,(2.*t-tmax-tmin)/(tmax-tmin)))
310  nx=1
311  IF(x.LE.0.1) nx=2
312  IF(nx.EQ.1) vx=(2.*x-1.1)/0.9
313  IF(nx.EQ.2) vx=max(-1.,(2.*log(x)+11.51293)/6.90776)
314  cxs=1.
315  IF(x.LT.1e-4.AND.abs(parp(51)-1.).GT.0.01) cxs=
316  & (1e-4/x)**(parp(51)-1.)
317 
318 C...Chebyshev polynomials for x and t expansion.
319  tx(1)=1.
320  tx(2)=vx
321  tx(3)=2.*vx**2-1.
322  tx(4)=4.*vx**3-3.*vx
323  tx(5)=8.*vx**4-8.*vx**2+1.
324  tx(6)=16.*vx**5-20.*vx**3+5.*vx
325  tt(1)=1.
326  tt(2)=vt
327  tt(3)=2.*vt**2-1.
328  tt(4)=4.*vt**3-3.*vt
329  tt(5)=8.*vt**4-8.*vt**2+1.
330  tt(6)=16.*vt**5-20.*vt**3+5.*vt
331 
332 C...Calculate structure functions.
333  DO 130 kfl=1,6
334  xqsum=0.
335  DO 120 it=1,6
336  DO 110 ix=1,6
337  xqsum=xqsum+cehlq(ix,it,nx,kfl,nset)*tx(ix)*tt(it)
338  110 CONTINUE
339  120 CONTINUE
340  xq(kfl)=xqsum*(1.-x)**nehlq(kfl,nset)*cxs
341  130 CONTINUE
342 
343 C...Put into output array.
344  xppr(0)=xq(4)
345  xppr(1)=xq(2)+xq(3)
346  xppr(2)=xq(1)+xq(3)
347  xppr(3)=xq(5)
348  xppr(4)=xq(6)
349  xppr(-1)=xq(3)
350  xppr(-2)=xq(3)
351  xppr(-3)=xq(5)
352  xppr(-4)=xq(6)
353 
354 C...Special expansion for bottom (threshold effects).
355  IF(mstp(58).GE.5) THEN
356  IF(nset.EQ.1) tmin=8.1905
357  IF(nset.EQ.2) tmin=7.4474
358  IF(t.GT.tmin) THEN
359  vt=max(-1.,min(1.,(2.*t-tmax-tmin)/(tmax-tmin)))
360  tt(1)=1.
361  tt(2)=vt
362  tt(3)=2.*vt**2-1.
363  tt(4)=4.*vt**3-3.*vt
364  tt(5)=8.*vt**4-8.*vt**2+1.
365  tt(6)=16.*vt**5-20.*vt**3+5.*vt
366  xqsum=0.
367  DO 150 it=1,6
368  DO 140 ix=1,6
369  xqsum=xqsum+cehlq(ix,it,nx,7,nset)*tx(ix)*tt(it)
370  140 CONTINUE
371  150 CONTINUE
372  xppr(5)=xqsum*(1.-x)**nehlq(7,nset)*cxs
373  xppr(-5)=xppr(5)
374  ENDIF
375  ENDIF
376 
377 C...Special expansion for top (threshold effects).
378  IF(mstp(58).GE.6) THEN
379  IF(nset.EQ.1) tmin=11.5528
380  IF(nset.EQ.2) tmin=10.8097
381  tmin=tmin+2.*log(pmas(6,1)/30.)
382  tmax=tmax+2.*log(pmas(6,1)/30.)
383  IF(t.GT.tmin) THEN
384  vt=max(-1.,min(1.,(2.*t-tmax-tmin)/(tmax-tmin)))
385  tt(1)=1.
386  tt(2)=vt
387  tt(3)=2.*vt**2-1.
388  tt(4)=4.*vt**3-3.*vt
389  tt(5)=8.*vt**4-8.*vt**2+1.
390  tt(6)=16.*vt**5-20.*vt**3+5.*vt
391  xqsum=0.
392  DO 170 it=1,6
393  DO 160 ix=1,6
394  xqsum=xqsum+cehlq(ix,it,nx,8,nset)*tx(ix)*tt(it)
395  160 CONTINUE
396  170 CONTINUE
397  xppr(6)=xqsum*(1.-x)**nehlq(8,nset)*cxs
398  xppr(-6)=xppr(6)
399  ENDIF
400  ENDIF
401 
402  ELSEIF(mstp(51).EQ.3.OR.mstp(51).EQ.4) THEN
403 C...Proton structure functions from Duke, Owens.
404 C...Allowed variable range: 4 GeV^2 < Q^2 < approx 1E6 GeV^2.
405 
406 C...Determine set, Lambda and s expansion parameter.
407  nset=mstp(51)-2
408  IF(nset.EQ.1) alam=0.2
409  IF(nset.EQ.2) alam=0.4
410  vint(231)=4.
411  IF(mstp(57).LE.0) THEN
412  sd=0.
413  ELSE
414  q2in=min(1e6,max(4.,q2))
415  sd=log(log(q2in/alam**2)/log(4./alam**2))
416  ENDIF
417 
418 C...Calculate structure functions.
419  DO 190 kfl=1,5
420  DO 180 is=1,6
421  ts(is)=cdo(1,is,kfl,nset)+cdo(2,is,kfl,nset)*sd+
422  & cdo(3,is,kfl,nset)*sd**2
423  180 CONTINUE
424  IF(kfl.LE.2) THEN
425  xq(kfl)=x**ts(1)*(1.-x)**ts(2)*(1.+ts(3)*x)/(eulbet(ts(1),
426  & ts(2)+1.)*(1.+ts(3)*ts(1)/(ts(1)+ts(2)+1.)))
427  ELSE
428  xq(kfl)=ts(1)*x**ts(2)*(1.-x)**ts(3)*(1.+ts(4)*x+ts(5)*x**2+
429  & ts(6)*x**3)
430  ENDIF
431  190 CONTINUE
432 
433 C...Put into output arrays.
434  xppr(0)=xq(5)
435  xppr(1)=xq(2)+xq(3)/6.
436  xppr(2)=3.*xq(1)-xq(2)+xq(3)/6.
437  xppr(3)=xq(3)/6.
438  xppr(4)=xq(4)
439  xppr(-1)=xq(3)/6.
440  xppr(-2)=xq(3)/6.
441  xppr(-3)=xq(3)/6.
442  xppr(-4)=xq(4)
443 
444  ELSEIF(mstp(51).GE.5.AND.mstp(51).LE.10) THEN
445 C...Interface to the CTEQ 2 structure functions.
446  nset=mstp(51)-4
447  qrt=sqrt(max(1.,q2))
448 
449 C...Loop over flavours; put u and d in right order.
450  DO 200 i=-6,2
451  kfl=i
452  IF(i.EQ.1) kfl=2
453  IF(i.EQ.2) kfl=1
454  IF(i.EQ.-1) kfl=-2
455  IF(i.EQ.-2) kfl=-1
456  IF(i.LE.0) THEN
457  xppr(kfl)=pyctq2(nset,i,x,qrt)
458  xppr(-kfl)=xppr(kfl)
459  ELSE
460  xppr(kfl)=pyctq2(nset,i,x,qrt)+xppr(-kfl)
461  ENDIF
462  200 CONTINUE
463 
464 C...Leading order proton structure functions from Gluck, Reya and Vogt.
465 C...Allowed variable range: 0.25 GeV^2 < Q^2 < 10^8 GeV^2 and
466 C...10^-5 < x < 1.
467  ELSE
468 
469 C...Determine s expansion variable and some x expressions.
470  vint(231)=0.25
471  IF(mstp(57).LE.0) THEN
472  sd=0.
473  ELSE
474  q2in=min(1e8,max(0.25,q2))
475  sd=log(log(q2in/0.232**2)/log(0.25/0.232**2))
476  ENDIF
477  sd2=sd**2
478  xl=-log(x)
479  xs=sqrt(x)
480 
481 C...Evaluate valence, gluon and sea distributions.
482  xfvud=(0.663+0.191*sd-0.041*sd2+0.031*sd**3)*x**0.326*
483  & (1.+(-1.97+6.74*sd-1.96*sd2)*xs+(24.4-20.7*sd+4.08*sd2)*x)*
484  & (1.-x)**(2.86+0.70*sd-0.02*sd2)
485  xfvdd=(0.579+0.283*sd+0.047*sd2)*x**(0.523-0.015*sd)*
486  & (1.+(2.22-0.59*sd-0.27*sd2)*xs+(5.95-6.19*sd+1.55*sd2)*x)*
487  & (1.-x)**(3.57+0.94*sd-0.16*sd2)
488  xfglu=(x**(1.00-0.17*sd)*((4.879*sd-1.383*sd2)+
489  & (25.92-28.97*sd+5.596*sd2)*x+(-25.69+23.68*sd-1.975*sd2)*x**2)+
490  & sd**0.558*exp(-(0.595+2.138*sd)+sqrt(4.066*sd**1.218*xl)))*
491  & (1.-x)**(2.537+1.718*sd+0.353*sd2)
492  xfsea=(x**(0.412-0.171*sd)*(0.363-1.196*x+
493  & (1.029+1.785*sd-0.459*sd2)*x**2)*xl**(0.566-0.496*sd)+
494  & sd**1.396*exp(-(3.838+1.944*sd)+sqrt(2.845*sd**1.331*xl)))*
495  & (1.-x)**(4.696+2.109*sd)
496  xfstr=sd**0.803*(1.+(-3.055+1.024*sd**0.67)*xs+
497  & (27.4-20.0*sd**0.154)*x)*(1.-x)**6.22*
498  & exp(-(4.33+1.408*sd)+sqrt((8.27-0.437*sd)*sd**0.563*xl))/
499  & xl**(2.082-0.577*sd)
500  IF(sd.LE.0.888) THEN
501  xfchm=0.
502  ELSE
503  xfchm=(sd-0.888)**1.01*(1.+(4.24-0.804*sd)*x)*
504  & (1.-x)**(3.46+1.076*sd)*exp(-(4.61+1.49*sd)+
505  & sqrt((2.555+1.961*sd)*sd**0.37*xl))
506  ENDIF
507  IF(sd.LE.1.351) THEN
508  xfbot=0.
509  ELSE
510  xfbot=(sd-1.351)*(1.+1.848*x)*(1.-x)**(2.929+1.396*sd)*
511  & exp(-(4.71+1.514*sd)+sqrt((4.02+1.239*sd)*sd**0.51*xl))
512  ENDIF
513 
514 C...Put into output array.
515  xppr(0)=xfglu
516  xppr(1)=xfvdd+xfsea
517  xppr(2)=xfvud-xfvdd+xfsea
518  xppr(3)=xfstr
519  xppr(4)=xfchm
520  xppr(5)=xfbot
521  xppr(-1)=xfsea
522  xppr(-2)=xfsea
523  xppr(-3)=xfstr
524  xppr(-4)=xfchm
525  xppr(-5)=xfbot
526 
527  ENDIF
528 
529  RETURN
530  END