We had two presentations:

1)"Search for ttH at ATLAS" given by Aurelio Juste, and
2)"ttH@CMS: some comments" given by Chris Neu.

transparencies are available at:
https://indico.cern.ch/conferenceDisplay.py?confId=189783

Both presentation emphasized the fact that the main bottle 
neck in current analyses is the issue of properly modelling
the tt+jets and tt+HF (HF=heavy flavors, i.e. bb or cc) backgrounds.

The goal would be to have the NLO calculation for both tt+jj and
tt+HF interfaced with a PS Monte Carlo. This is a long term goal.

In the meanwhile, it would be important to address the following 
questions:

1) How to assess the systematic error when using tools such as 
   ALPGEN to model the background?
   
   Would it be possible to learn anything by comparing LO+PS to
   existing parton level NLO calculations? (see Aurelio's talk
   for more specific prototype questions: Q1-Q6)

   Can this help in having a more comprehensive list of theoretical 
   and experimental errors in each control region?


2) How can the existing NLO parton level calculations be used in the
   analysis to improve the background modeling? 

   For instance, the question was raised of how can we treat the
   regime of small b-bbar angles (in ttbb production)?
   Can this be better studied having the NLO calculation available?

   Also, can we study different kinematic regimes and different
   selection cuts using the NLO parton level calculations?


Unfortunately we could not have any input from the theory community who
worked on the NLO calculation of tt+HF and tt+jj. 
It was proposed that a few speakers from these community are invited 
to review existing tools and possibly start to address some of the
questions listed above. 
We would like to have a meeting the week of May, 14-18. The exact date
will depend on the speakers' availability.