Collaboration and communication between theorists and experimentalists is a critical part of the LHC physics program. It is in this context that I was invited to the NNPDF collaboration meeting in September order to provide an experimentalist perspective through an invited talk and participation in the discussion throughout the three day meeting, together with Maarten Boonekamp (Saclay/ATLAS) and Gavin Salam (Oxford) as an invited theorist.
The meeting took place on Lake Garda in Gargnano, near Milan. There were many useful discussions on the use of LHC measurements in global PDF fits, both in terms of best practices for PDF groups to interpret the data, and for the experiments in how the measurements are carried out and presented. There was also an important discussion on the tension between different global pdf sets in the context of precision electroweak measurements at the LHC, including the W mass, the weak mixing angle, and the strong coupling constant. This discussion is continuing in the context of the PDF4LHC group and the LHC Electroweak working group. I also learned a lot about how the proverbial sausage of global PDF fits is made, and this has also lead to further collaboration on phenomenological topics.
The meeting agenda and slides for the invited talks are available at here.
I love the Lago di Garda. What a nice setting the PDF folks chose. I would be interested to understand better what the LHC can do to better constrain the various aspects of the PDFs. We have so much data! If the W mass measurement itself is so sensitive to the PDFs there should be an inverse way to constrain the PDFs with our data.