CTEQ5 Parton Distribution Function Sets

For details, see comment lines in the respective fortran files.

• Ctq5Pdf.uu (524070 bytes) uuencoded gzipped tar file of all files below
  
  
• Ctq5Pdf.f (11135 bytes) Fortran program to evaluate CTEQ5 parton distributions functions using {x,Q} data tables:
  
  
• cteq5m.tbl (125607 bytes)
• cteq5d.tbl (125607 bytes)
• cteq5l.tbl (134476 bytes)
• cteq5hj.tbl (125608 bytes)
• cteq5hq.tbl (125608 bytes)
• cteq5f3.tbl ( 94607 bytes)
• cteq5f4.tbl (110108 bytes)
• cteq5m1.tbl (125650 bytes)
• cteq5hq1.tbl (125650 bytes)
  
  
• demo.f (1491 bytes) sample Fortran code illustrating CTEQ5 function calls

( http://xxx.lanl.gov/abs/hep-ph/9903282 , 163 kb) to be published in Eur. Phys. J. C 1999.

These PDF's use quadratic interpolation of attached tables. A parametrized version of the same PDF's without external tables is under construction. They will become available later.

  This package contains 7 sets of CTEQ5 PDF's; plus two updated ones.
  The undated CTEQ5M1 and CTEQHQ1 use an improved evolution code.
  Both the original and the updated ones fit current data with comparable
  accuracy.  The CTEQHQ1 set also involve a different choice of scale,
  hence differs from CTEQHQ slightly more.  It is preferred over CTEQ5HQ.

  Details are:

 ---------------------------------------------------------------------------
  Iset   PDF        Description       Alpha_s(Mz)  Lam4  Lam5   Table_File
 ---------------------------------------------------------------------------
   1    CTEQ5M   Standard MSbar scheme   0.118     326   226    cteq5m.tbl
   2    CTEQ5D   Standard DIS scheme     0.118     326   226    cteq5d.tbl
   3    CTEQ5L   Leading Order           0.127     192   146    cteq5l.tbl
   4    CTEQ5HJ  Large-x gluon enhanced  0.118     326   226    cteq5hj.tbl
   5    CTEQ5HQ  Heavy Quark             0.118     326   226    cteq5hq.tbl
   6    CTEQ5F3  Nf=3 FixedFlavorNumber  0.106     (Lam3=395)   cteq5f3.tbl
   7    CTEQ5F4  Nf=4 FixedFlavorNumber  0.112     309   XXX    cteq5f4.tbl
       --------------------------------------------------------
   8    CTEQ5M1  Improved CTEQ5M         0.118     326   226    cteq5m1.tbl
   9    CTEQ5HQ1 Improved CTEQ5HQ        0.118     326   226    ctq5hq1.tbl
 ---------------------------------------------------------------------------
   
   The available applied range is 10^-5 < x < 1 and 1.0 < Q < 10,000 (GeV). 
   Lam5 (Lam4, Lam3) represents Lambda value (in MeV) for 5 (4,3) flavors. 
   The matching alpha_s between 4 and 5 flavors takes place at Q=4.5 GeV,  
   which is defined as the bottom quark mass, whenever it can be applied.

   The Table_Files are assumed to be in the working directory.
   
   Before using the PDF, it is necessary to do the initialization by
       Call SetCtq5(Iset) 
   where Iset is the desired PDF specified in the above table.
   
   The function Ctq5Pdf (Iparton, X, Q)
   returns the parton distribution inside the proton for parton [Iparton] 
   at [X] Bjorken_X and scale [Q] (GeV) in PDF set [Iset].
   Iparton  is the parton label (5, 4, 3, 2, 1, 0, -1, ......, -5)
                            for (b, c, s, d, u, g, u_bar, ..., b_bar),
      whereas CTEQ5F3 has, by definition, only 3 flavors and gluon;
              CTEQ5F4 has only 4 flavors and gluon.

These programs, as provided, are in double precision. By removing the "Implicit Double Precision" lines, they can also be run in single precision.

If you have detailed questions concerning these CTEQ5 distributions, or if you find problems/bugs using this package, direct inquires to Hung-Liang Lai (lai@phys.nthu.edu.tw) or Wu-Ki Tung (Tung@pa.msu.edu).

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