Comparisons of existing tools for SM (MC, PDFs, underlying events,...): Session I
M. Kraemer, C. Buttar and J. D'Hondt (Conveners)

   Currently, the group activities are in the process of being planned. An outline of topics that are being considered is given below.

1) how to present LHC cross section results in 2008

• can we measure the luminosity precisely
• should we quote absolute or relative cross sections
• to which process we should normalize our cross sections
• theoretical expectations

2) diffractive processes - minimum bias

• experiments determine the trigger efficiencies via minimum bias events simulated with PYTHIA (trigger bias)
• how correct are those, compare current generators
• can we improve the tuning or is there a better way to get the diffractive part right
• develop tools to estimate the trigger rates

3) PDF fitting

• which cross-sections and/or distributions from the LHC will improve our knowledge of PDF's
• how to estimate and the handle systematics (reweighting techniques using hadron level info)
• how to fit and ensure new physics is not absorbed in the fit

4) real and virtual EW corrections for high Et QCD processes

• implementation in generators, check consistency
• effect on distributions (p_t, m_t, m_ttbar, spin correlations, ...)
• estimate the effect on measurements
• is this the end of the story or is more work requested
• issue of experimental v. theoretical event selection (whether inclusive or not wrt W/Z emission)

For yet more information and for an up-to-date status of this working group, jump to their wikipage