Caveats
The results provided by the interpolation program and parton tables
presented in these pages
do not necessarily reproduce accurately the parton distributions
as provided by their creators (MRS, CTEQ, GRV) in certain cases:
- In large x regions, the original parton distributions are
sometimes not smooth. In these cases, we have first smoothed the
data in the original tables before making our tables. Thus the
results interpolated from our tables
do not match the original in these regions. This is not of great
concern since the original parton distribution functions are small in these
regions.
- Heavy quark distribution functions have a discontinuity in their
first derivative with respect to the scale mu at mu =
MQ. Our interpolation handles this in a fashion
that makes the parton distribution function too small in the region
of mu just above the heavy quark mass. This effect can
be reduced by using more lattice points in mu. However,
we consider this problem to be not serious for the typical uses
of parton distribution functions and, in
the tables presented in these pages, we use rather few lattice points in mu.
Davison E. Soper and Parvez Anandam
Institute of Theoretical Science
University of Oregon
Eugene OR 97403. USA.
soper@bovine.uoregon.edu
anandam@darkwing.uoregon.edu