1 C-----------------------------------------------------------------------
3 C============================================================================
4 C CTEQ Parton Distribution Functions: Version 4
7 C By: H.L. Lai, J. Huston, S. Kuhlmann, F. Olness, J. Owens, D. Soper
9 C Ref: MSUHEP-60426, CTEQ-604, e-Print Archive: hep-ph/9606399
11 C This package contains 9 sets of CTEQ4 PDF's. Details are:
12 C ---------------------------------------------------------------------------
13 C Iset PDF Description Alpha_s(Mz) Q0(GeV) Table_File
14 C ---------------------------------------------------------------------------
15 C 1 CTEQ4M Standard MSbar scheme 0.116 1.6 cteq4m.tbl
16 C 2 CTEQ4D Standard DIS scheme 0.116 1.6 cteq4d.tbl
17 C 3 CTEQ4L Leading Order 0.116 1.6 cteq4l.tbl
18 C 4 CTEQ4A1 Alpha_s series 0.110 1.6 cteq4a1.tbl
19 C 5 CTEQ4A2 Alpha_s series 0.113 1.6 cteq4a2.tbl
20 C 6 CTEQ4A3 same as CTEQ4M 0.116 1.6 cteq4m.tbl
21 C 7 CTEQ4A4 Alpha_s series 0.119 1.6 cteq4a4.tbl
22 C 8 CTEQ4A5 Alpha_s series 0.122 1.6 cteq4a5.tbl
23 C 9 CTEQ4HJ High Jet 0.116 1.6 cteq4hj.tbl
24 C 10 CTEQ4LQ Low Q0 0.114 0.7 cteq4lq.tbl
25 C ---------------------------------------------------------------------------
27 C The available applied range is 10^-5 < x < 1 and 1.6 < Q < 10,000 (GeV)
28 C except CTEQ4LQ for which Q starts at a lower value of 0.7 GeV.
29 C The Table_Files are assumed to be in the working directory.
31 C The function Ctq4Fn (Iset, Iparton, X, Q)
32 C returns the parton distribution inside the proton for parton [Iparton]
33 C at [X] Bjorken_X and scale [Q] (GeV) in PDF set [Iset].
34 C Iparton is the parton label (5, 4, 3, 2, 1, 0, -1, ......, -5)
35 C for (b, c, s, d, u, g, u_bar, ..., b_bar)
37 C For detailed information on the parameters used, e.q. quark masses,
38 C QCD Lambda, ... etc., see info lines at the beginning of the
41 C These programs, as provided, are in double precision. By removing the
42 C "Implicit Double Precision" lines, they can also be run in single
45 C If you have detailed questions concerning these CTEQ4 distributions,
46 C or if you find problems/bugs using this package, direct inquires to
47 C Hung-Liang Lai(Lai_H@pa.msu.edu) or Wu-Ki Tung(Tung@pa.msu.edu).
49 C===========================================================================
50 #if defined(CERNLIB_SINGLE)
51 Function Ctq4Fn (Iset, Iparton, X, Q)
53 #if defined(CERNLIB_DOUBLE)
54 DOUBLE PRECISION FUNCTION Ctq4Fn (Iset, Iparton, X, Q)
56 #include "pdf/impdp.inc"
57 Data Isetold, Isetmin, Isetmax / -987, 1, 10 /
60 C If data file not initialized, do so.
61 If(Iset.ne.Isetold) then
62 if(Iset.eq.1) Call Ctq4RM (Iset)
63 if(Iset.eq.2) Call Ctq4RD (Iset)
64 if(Iset.eq.3) Call Ctq4RL (Iset)
65 if(Iset.eq.4) Call Ctq4RA1 (Iset)
66 if(Iset.eq.5) Call Ctq4RA2 (Iset)
67 if(Iset.eq.6) Call Ctq4RM (Iset)
68 if(Iset.eq.7) Call Ctq4RA4 (Iset)
69 if(Iset.eq.8) Call Ctq4RA5 (Iset)
70 if(Iset.eq.9) Call Ctq4RHJ (Iset)
71 if(Iset.eq.10) Call Ctq4RlQ (Iset)
75 Ctq4Fn = Ctq4PnX (Iparton, X, Q)
76 if(Ctq4Fn.lt.0.D0) Ctq4Fn = 0.D0
79 C ********************