Bluemlein and Boettcher POLARIZED PARTON DISTRIBUTIONS


ppdf.f
Fortran subroutine package returning the BB polarized parton distribution function values and g1(p,n) at the given point in Q**2 and XB by interpolating the data on the specified grid.
example.f
An example fortran program showing use of the ppdf.f subroutine

Requires the grid files:
bb01_xpdf_lo_8pN.grid
bb01_xpdf_lo_8pS.grid
bb01_xpdf_nlo_8pN.grid
bb01_xpdf_nlo_8pS.grid

ppdf.uu is a tarred, gzipped and uuencoded version of the complete package (1.72 MB).


Reference: hep-ph/0203155


Summary Details:
*********************************************************************
*                                                                   *
*        POLARIZED PARTON DISTRIBUTION FUNCTION WITH ERRORS         *
*                        FOR LO AND NLO                             *
*                                                                   *
*            Johannes Bluemlein and Helmut Boettcher                *
*                        hep-ph/0203155                             *
*                                                                   *
*   PROBLEMS/QUESTIONS TO blumlein@ifh.de OR hboett@ifh.de          *
*                                                                   *
*   INPUT:   iset = number of the parton set :                      *
*                                                                   *
*            iset = 1  LEADING ORDER - Scenario 1                   *
*                      data file: bb01_xpdf_lo_8pN.grid            *
*                                                                   *
*            iset = 2  LEADING ORDER - Scenario 2                   *
*                      data file: bb01_xpdf_lo_8pS.grid             *
*                                                                   *
*            iset = 3  NEXT-TO-LEADING ORDER (MS-bar) - Scenario 1  *
*                      data file: bb01_xpdf_nlo_8pN.grid            *
*                                                                   *
*            iset = 4  NEXT-TO-LEADING ORDER (MS-bar) - Scenario 2  *
*                      data file: bb01_xpdf_nlo_8pS.grid            *
*                                                                   *
*            x  = Bjorken-x       (between  1.0E-9 and 1.0E+0)      *
*            q2 = scale in GeV**2 (between  0.1E+1 and 1.0E+6)      *
*                                                                   *
*   OUTPUT:  UV = DELTA u_v    & error: DUV                         *
*            DV = DELTA d_v    & error: DDV                         *
*            GL = DELTA gluon  & error: DGL                         *
*            QB = DELTA qbar   & error: DQB                         *
*            G1P = g_1^proton  & error: DG1P                        *
*            G1N = g_1^neutron & error: DG1N                        *
*                                                                   *
*            NOTE:                                                  *
*            -----                                                  *
*            For the parton distributions and for g1(p,n)           *
*            always x times the distribution is returned.           *
*                                                                   *
*            The sets are the result of a combined fit to the       *
*            world data for the spin asymmetries, i.e. A_1(p,n,d)   *
*            or g_1/F_1(p,n,d).                                     *
*                                                                   *
*            The subroutine PPDF returns the BB polarized parton    *
*            distribution function values and g1(p,n) at the given  *
*            point in Q**2 and XB by interpolating the data on the  *
*            specified grid.                                        *
*                                                                   *
*            Note: No charm is included                             *
*                                                                   *
*   COMMON:  The main program or the calling routine has to have    *
*            a common block  COMMON / INTINI / IINI , and  IINI     *
*            has always to be ZERO when POLPDF is called for the    *
*            first time or when 'ISET' has been changed.            *
*                                                                   *
*********************************************************************