The calm after the storm

Marco, Barbara, Georg and Jester's summaries didn't leave much room for improvement. But here's my take - in the weeks and months following ICHEP, I'm sure we'll hear much more from the LHC. The collider's performance continues to improve (this weekend's milestone was the first inverse nanobarn delivered to the ATLAS and CMS experiments). Fermilab will continue to make the most of its last year(s?) of Tevatron data. New neutrino experiments will come online, existing ones will deliver some much-anticipated data, ditto for ground-based and space-based particle astrophysics experiments. And we'll all look forward to the next ICHEP, in 2012 in Melbourne, where we'll hear the latest in theoretical and experimental particle physics, see what the future looks like two years later, and....get a new ICHEP bag. As I've discovered, not only do they make excellent laptop carriers, but they also work pretty well as beach bags.

Physicists gone wild

Most (perhaps all?) physics conferences share the conference dinner tradition. One evening during the conference, all participants are invited to get together to share a meal, usually featuring cuisine from the local area. Last night was the ICHEP banquet (the fancier term ensured that quite a few attendees came in fancier attire than they wore to the sessions). The banquet took place at the Grande Galerie d'Evolution, and while the gallery, stuffed and mounted wild animals, and line to get in and check our laptop bags was certainly grand, the food and drink were another story. The crowds surrounding the tables holding tapas-style food from various areas of France wouldn't have looked out of place on a rugby field.

(Here's a photo of physicists in the wild, during the calm before the food-induced storm.)



But the point of conference dinners isn't really food, but to talk to old and new colleagues, and that went off without a hitch. The food situation also provided a perfect ice-breaker for conversation, and I heard many a story about banquet disasters from conferences past.

Tonight will see a gathering of a very different sort in Paris: the Nuit des Particules, a particle-physics-themed evening for the public. The event at the Grand Rex theater in Paris starts off with a public lecture by scientist Michel Davier (in French), at which French actress Irene Jacob will also be present, and ends with a showing of the science fiction film Sunshine (in English).

The present and future of the LHC

Today's been a hectic day: between Sarkozy's speech, the press conference, and the lack of wireless internet in the auditorium where the plenary talks are being held, there's been little time to blog. So any time I've been able to grab during coffee breaks has been spent uploading blog entries to my usual haunt, symmetry breaking. There you can read about the 10-year plan for LHC running and whether or not it might affect some Tevatron scientists' hopes to run their accelerator for a further three years. Plus my take on the new measurements reported by the LHC experiments at ICHEP, such as the W cross section measurements at 7 TeV, and the limits ATLAS and CMS have placed on some exotic physics. (Keep in mind that symmetry is for a more general audience; my fellow ICHEP bloggers have covered those results in much more detail here.)

Searching for Higgs; finding colleagues

The hot topic at ICHEP is definitely the Higgs search (even President Sarkozy has caught it!). I just posted a few more Higgs-y details to symmetry breaking. Here I'll discuss something (slightly) less massive--the interactions between physics bloggers.

While a few of the bloggers knew each other (or of each other) before we joined the ICHEP effort, most of us hadn't met in person. So we gathered yesterday for lunch, to discuss blogging, rumors, and bagels. (Our attempt to eat at a French brasserie was thwarted by dozens of other particle physicists, so we ended up enjoying a very American lunch at the Westside Cafe - something especially appreciated by this expat American, who can't find bagels anywhere near Geneva.)

See if you can spot your favorite ICHEP blogger... It's a lot easier than finding the Higgs!

From LHC sessions: First top candidates, and one experiment has had enough!

I've spent this morning in the "Early Experience and Results from LHC" sessions. They've been almost as packed as yesterday's Higgs session, and have included two interesting firsts (for me, at least).

From ATLAS, in the presentation of the first results on QCD, Quarkonia and Heavy-Flavour Physics, one of the experiment's very first top quark candidate events. I expect that many more such events are being presented by ATLAS and CMS at this very moment in the parallel session devoted to top quarks.

And from LHCf, I learned that this small experiment is the first at LHC to have finished data taking. That's right, while the big experiments are just barely getting started, the smallest experiment has already collected all the data they need and even removed their detectors from the beamline on July 20.

The LHCf speaker was quite good - unlike the big experiments, the speakers from LHCf and TOTEM don't assume that everyone in the room already knows the details of their experiment, so they spend time at the beginning of the talk explaining their physics goals and how the experiment is set up and works. As a non-specialist, this is something I really appreciate. So I learned that the goal of LHCf is to provide input to the study of ultra-high-energy cosmic rays (UHECR) created by high-energy particles colliding with Earth's atmosphere, by studying the production of similarly ultra-high-energy showers that are man-made at the LHC. I also learned that they can distinguish between the various theories that currently exist to describe such UHECRs with a relatively small amount of data from LHC collisions (compared to the ATLAS experiment, for example, around which their detector is placed).

This isn't the end of the story for LHCf; they will be back at the start of the LHC's run with 7 TeV beams, currently scheduled to start in 2013. Between now and then they will continue and refine their analysis of 450 GeV and 3.5 TeV data, and upgrade their detector to withstand the higher radiation that will come with 7 TeV beams.

Hunting the Higgs in the Palais de Congres

Having just arrived at ICHEP, it's clear that it isn't just the media who have Higgs fever; the particle physicists have caught it too. The first session I attended focused on the performance of the LHC experiments with first data - it was well-attended, but there were plenty of empty seats. I'm now in the 16:15 Standard Model and Electroweak Symmetry Breaking session, and it's standing room only to hear the five Higgs talks; four of which are low-mass and high-mass Higgs search results from CDF and DZero.

Of course one could argue that the LHC presentations are being held in a larger room (the Salle Maillot, where the presentations are also being webcast), but I think that's only part of the story. Wandering around during the afternoon coffee break I couldn't help but overhear several conversations with a Higgs theme, and I suspect the Higgs also had quite a lot to do with the presence of a good number of journalists at the Palais de Congres during these first parallel sessions.

Can't wait to see what the presentations will reveal, this afternoon and over the next week - and how the physicists in attendance (including my fellow bloggers) will interpret them!

Sneak peak at Tevatron results for ICHEP

You don't need to wait for ICHEP to see some of what the CDF znd DZero experiments at Fermilab's Tevatron will present. Fermilab's daily online newsletter reports today that "a large fraction" of the Tevatron results to be presented at ICHEP were shown this past Friday in the laboratory's "wine-and-cheese" seminar. The talks from CDF and DZero are available for online viewing.

And a note for Higgs-watchers: you'll have to wait until Monday, July 26 for new results from the Tevatron experiments' combined Higgs searches.

How do you know ICHEP's just around the corner?

Two ways you know that ICHEP is imminent:

1. The blogosphere, Twitterverse and science media are abuzz with rumors regarding possible new results;
2. The families of particle physicists worldwide bemoan the temporary disappearance of their loved ones.
   

Here at CERN, activity among scientists involved with the LHC experiment has reached fever pitch. Students, postdocs and senior physicists alike are consuming even more coffee than usual, as they work to put the final touches on data analyses, results, posters and PowerPoint presentations.

With the size of today's particle physics collaborations - peaking at more than 3,000 people each for the ATLAS and CMS collaborations - getting a result approved for presentation at a major conference like ICHEP is no simple task. With so many people involved, the collaborations put in place rules and procedures governing approval processes for results and publications, with the goal of ensuring that all results have passed rigorous review and that every collaboration member has the opportunity to review and comment on every result. For the LHC experiments, the rules that have been painstakingly assembled over a decade or more have been getting their first real workout this summer, first for the PLHC conference in Hamburg, and now for ICHEP.

To give you an idea of the work behind each plot presented in an LHC talk at ICHEP, here's a quick overview of the steps involved (symmetry Magazine has a more in-depth look at this data-to-discovery process).

A small group of a few to a few dozen physicists spends weeks, months, or years analyzing data and preparing a result. Depending on the nature of the result, it may or may not be combined with result(s) from other group(s) within the same collaboration. It's then unveiled to the entire collaboration for review, and after a certain period where any collaboration member can comment (remember: 3,000 people!), receives final approval for presentation in public. Or not, in which case the process starts all over again.

And that's all just the first step. Once the result is approved, be it in the form of a plot, chart or paper for publication, then the work begins for the people who have been selected to present it and other results in public at a conference like ICHEP. They select from the approved results, prepare their poster or PowerPoint, go through a similar approval process, and practice in front of their colleagues in the collaboration.

And in cases like the current Higgs limits from the Tevatron, results could be combined from two different experiments, which doubles the complexity of the entire process. It's no wonder that, around the time of major conferences, sleep is a rare commodity.

(But even with ICHEP just around the corner, I bet some of those same hard-working scientists will take a few hours off to attend CERN's annual music extravaganza, the Hardronic Festival.)

I'll end with a quick introduction, since I'm the new girl on the blog - I'm a nuclear physicist turned science communicator, working for Fermilab Office of Communication but based at CERN for the past three years. I spend most of my time telling the story of the LHC project and U.S. scientists' involvement to journalists and the public, and the rest of my time trying to keep up with developments in the larger world of particle physics. So I can't wait to see and hear what's presented at ICHEP, and to write about it here and at the other blog I contribute to, symmetry breaking.