Q: question about the graphical interface: seems too sophisticated for students. Is it possible to custumize it to simplify for the students? A: the view is sophisticated, we could customize it in principle. With the experience, it doesn't seem to be an issue for the students. Q: we would like to hide some options / functionalities for beginners and possibly re-enable them for more advanced students. It's the first time we organize this - we don't know if it's easy enough for the students. A: it depends how you teach them to use it. What we really need is the information window (ie click on a track) & the file management system. We will provide a new style file, it's up to you if you want to use it or not - it will be sent around to all the participants. Q: all the events we are analysing are data? A: yes, no MC. Q: is it ok to tell the students to cut on pT of objects (>10 GeV)? A: you have to be careful - it is possible that, doing so, the students are not aware anymore of objects like jets - the isolation criterion may get biased. You could misidentify pions as electrons for example. You can cross check - it is written in the guide for tutors how many W events are in there. Q: The dPhi diagram won't be much different with the Higgs / without the Higgs. What should be the discussion on this diagram? A: First you could say in order to announce a particle discovery, you need more data to analyse. Second, we have chosen this plot because it may be easier to understand (an angle, the students know about angles). It's important to give the big picture of what is going on. You can explain only with MC expectation what the main objective of this analysis is. The aim is to increase the signal to background ratio: what can be done? Cut on it for example using the histogram plot? From MC expectation, more events are expected at less than 90deg, and hist 2 cut on it. You'll see you can increase S/B. Could be discussed, with easy words. Q: two years ago, we did some interpretation which were not correct for the ratio W+/W-, do we do the interpretation? What can we learn from the W+/W- ratio? A: discuss the results, ask the students before the measurement: what are your expectations? eg: ratio of 2 ? or a bit more in the proton so less than2. Do the measurement and discuss the results. You have to fit the understanding of the students. Q: but our students hear about this for the first time A: we removed the calculation because it was not representing reality well (too simplified). You can discuss why it's less than 2: Where do the W+/- come from? There are two processes: one which prefers W+, the other one which is symmetric. Observing an event, you can't distinguish the original production process. The two processes take place at the same time, so one ends up with a value between 1 and 2. Still, if you want to discuss the simplified calculation that was dicussed in the past years, it is okay, just that it shows a too simplified picture of the proton. Q: what to do if we have less participants than datasets? A: it's not a problem Q: and if we have more participants than datasets? A: contact us, we can assign more datasets if needed, on a case-by-case basis Q: why use the WW channel for the Higgs, it doesn't seem the best? A: the WW channel seems an obvious extension of the W identification which the students are able to produce with the W exercise. The photon would be more difficult to do. Q can we show the atlas full stat plot for the angular plot ? A: we could, but the selection is a bit different Contribution as important as ZZ or 4 leptions... just no inv. mass. But delta phi distribution shows a significant excess A: Cern could present Atlas figures, for discussion after all data is combined. Will be in the tutor informaiton and shown by the moderators Q : Need to analyse all data set to have a significant statistics A: yes