DC99 (Stolarski Reply) Status

Page maintainer: DC99

This is a working page which will continuously change. The content is not reviewed and is intended for people working on this specific topic.

This page catalogues the on-going work on the DC99 analysis. It is only meant collect studies, information and ideas for the purposes of aiding in discussion. Please consult dc99@hermes.desy.de before using any of the content on this page.

(possible) Main Messages in the Reply Comments

• Highest priority: to show the HERMES multiplicity analysis is sound
  • clarify consistency of multiplicity data base
  • convince community that x behavior of multiplicities is not an instrumental effect
  • clarify misunderstandings in the unfolding and acceptance correction procedure
• Second Priority: defend the LO approach to extract S(x)
  • how much can/should we support conclusion of DC94 that s(x) is "strikingly different from ... other QCD fits of LO PDFs"?

Main ToDo List (likely to go into the Reply Comments)

• clarify effect of averaging over x vs. averaging over Q2
  • we should use this opportunity to clearly spell out how to use the HERMES multiplicity database
• x-dependence of pion multiplicities from
  • PYTHIA
  • Marco (DSS++)
  • check Leader et al. gluon to pion FF and compare e.g., to DSS++
• redo Fig. 2 of Stolarski but with HERMES choice of PDFs and FFs (see, e.g., our Referee report ) and compare with Stolarski's version - New HERMES versions of Fig.2a/b with CTEQ6L,MSTW08L, and NNPDF3.0L pdf sets are now available at [1]. Also posted here are the plots which use NNPDFL2.3,the PDF set used in the original dc94 publication.
  • check that NNPDF3.0L exists and is LO - Yes, NNPDF3.0L does have LO data grids. - The pdfs at HERMES kinematics differ significantly from those of NNPDF2.3L.

Further Studies

• underlying subproccess as fct of x and Q2 as modeled in PYTHIA
• inclusive cross section vs. pion SIDIS cross section - well, already done: we look at multiplicities, so the ratio SIDIS to inclusive DIS and it is NOT flat (i.e., not the same shape)
• understand HEPGEN and how its VM model compares to the one in PYTHIA
  • is it usable for LiD target
  • how is the sigma_T part of the exclusive cross section handled