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fe4da5cc | 1 | * |
2 | * $Id$ | |
3 | * | |
4 | * $Log$ | |
5 | * Revision 1.1.1.2 1996/10/30 08:30:46 cernlib | |
6 | * Version 7.04 | |
7 | * | |
8 | * Revision 1.1.1.1 1996/04/12 15:29:46 plothow | |
9 | * Version 7.01 | |
10 | * | |
11 | * | |
12 | #include "pdf/pilot.h" | |
13 | c------------------------------------------------------- | |
14 | subroutine SFWHI6(ZX,ZQ,ZUV,ZDV,ZUB,ZDB,ZSB,ZCB,ZGL) | |
15 | c------------------------------------------------------- | |
16 | c WHIT6 parton distribution in the photon | |
17 | c | |
18 | c INPUT: integer ic : if ic=0 then qc=0 | |
19 | c else qc is calculated | |
20 | c DOUBLE PRECISION Q2 : energy scale Q^2 (GeV^2) | |
21 | c DOUBLE PRECISION x : energy fraction | |
22 | c | |
23 | c OUTPUT: DOUBLE PRECISION qu : up-quark dist. | |
24 | c DOUBLE PRECISION qd : down- or strange-quark dist. | |
25 | c DOUBLE PRECISION qc : charm-quark dist. | |
26 | c DOUBLE PRECISION g : gluon dist. | |
27 | c------------------------------------------------------- | |
28 | c Modified by M.Tanaka on July 22, 1994. | |
29 | c The bug pointed out by M.Drees is fixed. | |
30 | c------------------------------------------------------- | |
31 | c Modified by I.Watanabe on July 22, 1994. | |
32 | c------------------------------------------------------- | |
33 | implicit none | |
34 | external WHIT6G | |
35 | #include "pdf/expdp.inc" | |
36 | + ZX,ZQ,ZUV,ZDV,ZUB,ZDB,ZSB,ZCB,ZGL | |
37 | c arg | |
38 | integer ic | |
39 | DOUBLE PRECISION Q2,x | |
40 | DOUBLE PRECISION qu,qd,qc,g | |
41 | c const | |
42 | DOUBLE PRECISION q42it,q52it,lam42,lam52 | |
43 | DOUBLE PRECISION alinv,mc,PI | |
44 | c local | |
45 | DOUBLE PRECISION qv,qsea,cv,cs,dcv,dcs | |
46 | DOUBLE PRECISION A0val,A1val,A2val,Bval,Cval, | |
47 | $ A0sea,B0sea,BB0sea,C0sea | |
48 | DOUBLE PRECISION A0dcv,A1dcv,A2dcv,A3dcv,Bdcv,Cdcv | |
49 | DOUBLE PRECISION Adcs, B0dcs, B1dcs, Cdcs | |
50 | DOUBLE PRECISION x1,x2,mc2q2 | |
51 | DOUBLE PRECISION s,s2,s3,s4,prsccf,alstpi | |
52 | DOUBLE PRECISION WHIT6G | |
53 | c parameters | |
54 | parameter(lam42=0.16d0, lam52=0.091411319d0) | |
55 | parameter(Q42IT=4.0d0, Q52IT=100.0d0) | |
56 | parameter(alinv=137.036d0, mc=1.5d0) | |
57 | parameter(pi=3.14159265358979323846d0) | |
58 | common /scale/ s,s2,s3,s4,prsccf | |
59 | c | |
60 | c begin | |
61 | x=ZX | |
62 | Q2=ZQ*ZQ | |
63 | ic=1 | |
64 | c | |
65 | x1=1.0d0-x | |
66 | x2=x**2 | |
67 | mc2q2=mc**2/Q2 | |
68 | c | |
69 | if(Q2.lt.100.0d0) then | |
70 | c under 100 GeV^2 | |
71 | c | |
72 | c set scale s | |
73 | if(Q2.lt.4.0d0) then | |
74 | cccc for under 4GeV^2 prescription | |
75 | s= 0.0d0 | |
76 | prsccf = log(Q2/LAM42)/ log(Q42IT/LAM42) | |
77 | alstpi = 6.0d0/25.0d0/ log(Q42IT/LAM42) | |
78 | else | |
79 | s= log( log(Q2/LAM42)/ log(Q42IT/LAM42)) | |
80 | prsccf = 1.0d0 | |
81 | alstpi = 6.0d0/25.0d0/ log(Q2/LAM42) | |
82 | endif | |
83 | s2=s**2 | |
84 | s3=s2*s | |
85 | s4=s2**2 | |
86 | c | |
87 | cccccc WHIT6 quark (U100) | |
88 | c | |
89 | A0val= 2.540000d+00+s*( 2.000000d+00)+s2*( 7.180000d-01) | |
90 | A1val= 6.230000d-02+s*(-7.010000d+00)+s2*( 1.251000d-01) | |
91 | A2val=-1.642000d-01+s*(-4.360000d-01)+s2*( 1.048000d+01) | |
92 | $ +s3*(-5.200000d+00) | |
93 | Bval = 6.990000d-01+s*(-2.796000d-02)+s2*(-3.650000d-03) | |
94 | Cval = 4.420000d-01+s*(-1.255000d+00)+s2*( 1.941000d+00) | |
95 | $ +s3*(-9.950000d-01) | |
96 | A0sea= 3.180000d+00+s*( 8.690000d+00)+s2*(-2.287000d+01) | |
97 | $ +s3*( 1.896000d+01)+s4*(-5.140000d+00) | |
98 | B0sea=-1.003000d-01+s*( 1.603000d-01)+s2*(-1.037000d+00) | |
99 | $ +s3*( 9.440000d-01)+s4*(-2.915000d-01) | |
100 | BB0sea=5.690000d+00+s*( 1.867000d+01)+s2*(-4.670000d+01) | |
101 | $ +s3*( 5.050000d+01)+s4*(-1.835000d+01) | |
102 | C0sea= 2.149000d+01+s*(-5.650000d+01)+s2*( 1.293000d+02) | |
103 | $ +s3*(-1.459000d+02)+s4*( 5.750000d+01) | |
104 | c | |
105 | qv = prsccf/alinv/x* | |
106 | $ (A0val+A1val*x+A2val*x2) * x**Bval * x1**Cval | |
107 | qsea= prsccf/alinv/x* | |
108 | $ A0sea * x**(B0sea+BB0sea*x) * x1**C0sea | |
109 | c | |
110 | qu = qv/3.0d0 + qsea/6.0d0 | |
111 | qu = qu*x | |
112 | ZUV=qu | |
113 | ZUB=qu | |
114 | qd = qv/12.0d0 + qsea/6.0d0 | |
115 | qd = qd*x | |
116 | ZDV=qd | |
117 | ZDB=qd | |
118 | ZSB=qd | |
119 | c | |
120 | if((ic.ne.0) .and. (x*(1.0d0+4.0d0*mc2q2).lt.1.0d0)) then | |
121 | call WHIT6Q(x,mc2q2,cv,cs) | |
122 | qc = cv/alinv/2.0d0/PI + cs*alstpi | |
123 | qc = qc*x | |
124 | ZCB=qc | |
125 | else | |
126 | qc = 0.0d0 | |
127 | ZCB=qc | |
128 | endif | |
129 | c | |
130 | g = WHIT6G(x,Q2) | |
131 | g = g*x | |
132 | ZGL=g | |
133 | c | |
134 | else | |
135 | c over 100 GeV^2 | |
136 | c | |
137 | c set scale s | |
138 | s= log( log(Q2/LAM52)/ log(Q52IT/LAM52)) | |
139 | prsccf = 1.0d0 | |
140 | alstpi = 6.0d0/23.0d0/ log(Q2/LAM52) | |
141 | s2=s**2 | |
142 | s3=s2*s | |
143 | s4=s2**2 | |
144 | c | |
145 | cccccc WHIT6 quark (O100) | |
146 | c | |
147 | A0val= 4.270000d+00+s*( 3.096000d+00)+s2*( 1.621000d+00) | |
148 | A1val=-4.740000d+00+s*(-6.900000d+00)+s2*(-2.439000d+00) | |
149 | A2val= 2.837000d+00+s*( 6.460000d+00)+s2*( 4.100000d+00) | |
150 | Bval = 6.780000d-01+s*(-3.940000d-02)+s2*( 1.758000d-02) | |
151 | Cval = 1.728000d-01+s*(-2.493000d-02)+s2*( 1.451000d-01) | |
152 | A0sea= 3.340000d+00+s*(-5.610000d+00)+s2*( 5.000000d+01) | |
153 | $ +s3*(-2.207000d+02)+s4*( 3.028000d+02) | |
154 | B0sea=-2.402000d-01+s*(-4.090000d-01)+s2*( 2.263000d+00) | |
155 | $ +s3*(-1.050000d+01)+s4*( 1.487000d+01) | |
156 | BB0sea=8.790000d+00+s*(-8.860000d+00)+s2*( 1.640000d+02) | |
157 | $ +s3*(-7.120000d+02)+s4*( 9.730000d+02) | |
158 | C0sea= 9.160000d+00+s*( 9.290000d+00)+s2*(-2.784000d+02) | |
159 | $ +s3*( 1.175000d+03)+s4*(-1.592000d+03) | |
160 | c | |
161 | qv = 1.0d0/alinv/x* | |
162 | $ (A0val+A1val*x+A2val*x2) * x**Bval * x1**Cval | |
163 | qsea= 1.0d0/alinv/x* | |
164 | $ A0sea * x**(B0sea+BB0sea*x) * x1**C0sea | |
165 | c | |
166 | qu = qv/3.0d0 + qsea/6.0d0 | |
167 | qu = qu*x | |
168 | ZUV=qu | |
169 | ZUB=qu | |
170 | qd = qv/12.0d0 + qsea/6.0d0 | |
171 | qd = qd*x | |
172 | ZDV=qd | |
173 | ZDB=qd | |
174 | ZSB=qd | |
175 | g = WHIT6G(x,Q2) | |
176 | g = g*x | |
177 | ZGL=g | |
178 | c | |
179 | if((ic.ne.0) .and. (x*(1.0d0+4.0d0*mc2q2).lt.1.0d0)) then | |
180 | A0dcv= s*( 1.219000d-01)+s2*( 6.200000d+00) | |
181 | $ +s3*(-2.504000d+01)+s4*( 3.098000d+01) | |
182 | A1dcv= s*( 1.913000d+00)+s2*(-7.690000d+01) | |
183 | $ +s3*( 3.180000d+02)+s4*(-3.920000d+02) | |
184 | A2dcv= s*(-7.160000d+00)+s2*( 2.503000d+02) | |
185 | $ +s3*(-1.062000d+03)+s4*( 1.308000d+03) | |
186 | A3dcv= s*( 3.190000d+00)+s2*(-2.301000d+02) | |
187 | $ +s3*( 1.012000d+03)+s4*(-1.250000d+03) | |
188 | Bdcv = 4.990000d-01+s*( 3.470000d+00)+s2*(-1.526000d+01) | |
189 | $ +s3*( 1.967000d+01) | |
190 | Cdcv = 3.290000d-01+s*( 8.240000d+00)+s2*(-3.800000d+01) | |
191 | $ +s3*( 4.630000d+01) | |
192 | Adcs = s*(-4.990000d-02)+s2*( 1.026000d-01) | |
193 | $ +s3*(-7.870000d-02) | |
194 | B0dcs=-3.610000d-01+s*(-5.760000d-01)+s2*( 2.257000d-01) | |
195 | B1dcs= 7.680000d+00+s*(-8.830000d+00)+s2*( 3.880000d+00) | |
196 | Cdcs = 2.548000d+00+s*( 6.910000d-01)+s2*(-8.700000d+00) | |
197 | $ +s3*( 1.065000d+01) | |
198 | c | |
199 | dcv = 1.0d0/alinv/x* | |
200 | $ (A0dcv+x*A1dcv+x2*A2dcv+x2*x*A3dcv) * x**Bdcv * x1**Cdcv | |
201 | dcs = 1.0d0/alinv/x* | |
202 | $ Adcs * x**(B0dcs+B1dcs*x) * x1**Cdcs | |
203 | c | |
204 | call WHIT6Q(x,mc*mc/Q2,cv,cs) | |
205 | qc = cv/alinv/2.0d0/PI + cs*alstpi + dcs + dcv | |
206 | qc = qc*x | |
207 | ZCB=qc | |
208 | else | |
209 | qc = 0.0d0 | |
210 | ZCB=qc | |
211 | endif | |
212 | endif | |
213 | c | |
214 | return | |
215 | end |