Speaker
Cynthia Keppel
(Hampton University)
Description
The results of a global next-to-leading order fit of parton
distribution functions in which cuts on W and Q are relaxed, thereby
including more data at high values of x, will be reported. Effects of
target mass corrections (TMC), higher twist contributions, and nuclear
corrections for deuterium data are significant in the large-x region.
The leading twist parton distributions are found to be stable to TMC
model variations as long as higher twist contributions are also
included. Importantly, uncertainties in parton distribution functions
(PDFs) at large x arising from nuclear effects in deuterium F2
structure function data are evaluated. Within this global analysis,
the impact on the PDFs from uncertainties in the deuteron wave
function at short distances and nucleon off-shell effects, the use of
relativistic kinematics, as well as the use of less a restrictive
parametrization of the d/u ratio, have been assessed. In particular
the d-quark and gluon PDFs are found to vary significantly with the
choice of nuclear model. The impact of these uncertainties on the
determination of the neutron structure function, and on W boson
production and parton luminosity at the Tevatron and the LHC are
highlighted. Prospects for new measurements sensitive to the d-quark
and gluon distributions but insensitive to nuclear corrections will
also be discussed.
Primary author
Cynthia Keppel
(Hampton University)
