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fe4da5cc | 1 | * |
2 | * $Id$ | |
3 | * | |
4 | * $Log$ | |
5 | * Revision 1.1.1.2 1996/10/30 08:29:02 cernlib | |
6 | * Version 7.04 | |
7 | * | |
8 | * Revision 1.1.1.1 1996/04/12 15:29:26 plothow | |
9 | * Version 7.01 | |
10 | * | |
11 | * | |
12 | #include "pdf/pilot.h" | |
13 | C | |
14 | FUNCTION PDXMT (ISET, IPARTON, X, Q, IRT) | |
15 | ||
16 | C For ISET = 1, 2 .. , returns sets of Parton Distributions | |
17 | C (in the proton) with parton label Iparton (6, 5, ...,0, .. | |
18 | C for (t, b, c, s, d, u, g, u-bar, ... t-bar), and kinematic | |
19 | C variables (X, Q). IRT is a return error code. | |
20 | C | |
21 | C Iset = 1, 2, 3, 4 corresponds to the S1, B1, B2, and E1 fits of M | |
22 | C Tung (Fermilab-Pub-90/74, IIT-90/11) to NLO in the DIS sch | |
23 | C | |
24 | C 5 corresponds to a new set with input strange quark distri | |
25 | C being 1/2 of the non-strange sea quarks (as prefered by so | |
26 | C | |
27 | C 6, 7, 8, 9 corresponds to the S1, B1, B2, and E1 fits of M | |
28 | C Tung (Fermilab-Pub-90/74, IIT-90/11) to NLO in the MSbar s | |
29 | C | |
30 | C 10 corresponds to a new set with input strange quark distr | |
31 | C being 1/2 of the non-strange sea quarks (as prefered by so | |
32 | C in the MSbar scheme | |
33 | C | |
34 | C All the above sets assume a SU(3)-symmetric sea. | |
35 | C | |
36 | C 11 corresponds to a set of LO distributions suitable to be | |
37 | C with LO hard scattering matrix elements. | |
38 | C | |
39 | C The "lambda" parameter (4-flavors) for each parton distribution set c | |
40 | C obtained by making the following FUNCTION call: | |
41 | C Alam = Vlambd (Iset, Iorder) | |
42 | C where Iset is the (input) set #, Iorder is the (output) order of the | |
43 | C for set 11, 2 for all the others), and Alam is the value of the effec | |
44 | C lambda for 4 flavors. | |
45 | ||
46 | C Details about the 1 - 5 distributions are | |
47 | C given in the above-mentioned preprint. | |
48 | C | |
49 | #include "pdf/impdp.inc" | |
50 | REAL PDZXMT,X,Q | |
51 | ||
52 | DIMENSION THRSLD(0:6) | |
53 | ||
54 | DATA (THRSLD(I), I=0,6) / 4*0.0, 1.5, 5.0, 90.0 / | |
55 | ||
56 | IFL = IPARTON | |
57 | JFL = ABS(IFL) | |
58 | C Return 0 if below th | |
59 | IF (Q .LE. THRSLD(JFL)) THEN | |
60 | PDXMT = 0.0 | |
61 | RETURN | |
62 | ENDIF | |
63 | C | |
64 | IF (IFL .LE. 0) THEN | |
65 | VL = 0 | |
66 | ELSEIF (IFL .LE. 2) THEN | |
67 | VL = PDZXMT(ISET, IFL, X, Q, IRT) | |
68 | ELSE | |
69 | VL = 0 | |
70 | ENDIF | |
71 | C | |
72 | SEA = PDZXMT (ISET, -JFL, X, Q, IRT) | |
73 | ||
74 | PDXMT = VL + SEA | |
75 | ||
76 | RETURN | |
77 | C ************************* | |
78 | END |