Away from Palais des Congrès ?

As usual, when you attend a conference, you tend to forget that there are other things happening and other people living outside from the venue of the conference. This is particularly true when you are abroad, away from the daily routine, and the time and attention spent in the session rooms makes you forget where you are, and whether it is morning, afternoon or night...

However, even if you are not around Palais des Congrès now, you can follow all the talks on the webcast of the conference here. This is true for the plenary talks of next week, which will be broadcasted live, but you can also access all the parallel talks that took place in Salle Maillot last week.


In case you want to enjoy a bit your time in Paris (or skip a session, but shhh...), you may still bump into ICHEP 2010 during your walks. Indeed, if you stroll along the Seine and enjoy Paris-Plages, you will certainly notice a stand for kids around physics -- with a "trombinosquark" and other fun activities...

And on Tuesday evening, if you enjoy the atmosphere of the "Grands Boulevards", you will again see another ICHEP-related event. But this time, we have moved from Palais des Congrès to the Grand Rex theatre hall, with the "Night of the Particles" : a popular physics conference and a good movie ! Another way of enjoying ICHEP away from Porte Maillot...

End of Part One

Sunday... Time for a rest for the participants... as well as for the organisers. Obviously, the last three days were quite hectic for me, since I had both kinds of duties (hard to explain to sa colleague that you see only once every two years that you must post first then discuss physics afterwards). Thus it was not really blogging time for me, as we had a few things to sort out here and there.

As expected, I followed quite extensively the flavour-related sessions. Obviously, now that Babar and Belle have intensively studied the Bd and B+ mesons, the Bs meson is the focus of all interests -- which explains the large crowd gathering in the small room. D0 reported again their exciting results shown at ICHEP for the dimuon asymmetry, which rely on a clever cancellation of some of their background by combining the dimuon asymmetry with the single muon one. As reported by Jester, things are getting far less optimistic -- if you like New Physics -- for the phase in Bs mixing, since CDF agrees now with the SM, whereas D0 remains in muddy waters. Let us hope that both collaboration will provide an average very soon...

Fortunately, the other sessions were less overcrowded, but still quite lively. Belle has showed its ability to run nicely at the Υ(5S), yielding interesting results on some nonleptonic decays for the Bs mesons after analysing only 1/5 of its sample. This makes all the more interesting the prospects of a super-B factory and will probably renew our interest in old-fashionned (but still so reliable) studies on SU(3) and U-spin symmetries. On the lighter side of CKM, the KOTO experiment seems to be right on track, with a completion of the detector in 2011 to reach a sensitivy around 10^-9 on Br(K⁰->π⁰νν-bar) in 2012. Considering how well we understand this mode from the theoretical point of view in the Standard Model, this is excellent news. There were also preliminary results from MEG on μ to e conversion: a few events can be seen in the signal region -- still compatible with no signal at 90% CL (but the best fit result corresponding to 3 signal events, which makes you dream that maybe, with an increased statistics...).

I popped into other sessions to hear a few interesting talks, like the first results from LHCb (with the first measurements of b-bar production cross-section, as well as the first W and Z events), the not-so-surprising non-discovery of the Higgs at CDF/D0, and the related (and maybe underestimated) theoretical uncertainties on the channels used for this search. Unfortunately, our "presidential" change of schedule kept me quite busy out of the session rooms at the time of the new results on neutrinos and cosmic rays, but I have still the plenary talks to learn about them...

Let Part Two begin !

Time and again

The day before... no, not Christmas, ICHEP. As usual just before the premiere, everybody starts being quite hectic: the speakers, the organisers, and the airports. Well, actually, not so much for the latter, since we have a strike from air controller today -- which however should remain limited (so they say on the radio this morning). Let us hope that everybody arrives safely (if late) at their hotels.

Obviously, the last days before the opening are quite tense for the organisers. There is all the preparation of the material (bags, programmes, goodies, computers, cameras...) and its installation on the venue, rather obviously. But it is not the end of the story, far from that. With the help of the conveners, you have to fix the last details of the schedule --and with three days of 6 parallel sessions running at the same time, you are bound to encounter some unexpected troubles : a thousand people starts being a large statistical sample, with rare events (cancellations, changes of speakers...) occurring more often than you would expect naively.

Last but not least : check that each presenter will upload his/her talk on time, so that each session runs smoothly and without delays... I guess that this taks will keep us quite busy during a good part of the conference, especially during the parallel sessions where the organising committee will have to be delocalised over different parts of the Palais des Congrès. It is actually a general rule : the organisers spend half of their own conference out of the rooms where physics is discussed, because they have to sort out all kinds of last-minute small issues...

But I can always day-dream and assume that everything is so perfectly organised right now that I will be able to sit down, relax and enjoy the conference as any participant will. What would I pick for the parallel sessions, in addition to the talks directly related to my own work ? Obviously, some of the LHC talks. I bet that I will get out of the room with the comforting impression that the LHC experiments have started understanding the details of their detectors and of the Standard Model physics that they will have to fight against as a background for their studies. But that should not go beyond that. I will definitely go and listen to the CDF/D0 talks, even though I had already information in smaller workshops on the flavour-related results that we discussed here some time ago. I will add theoretical works beyond the Standard Model, and a couple of other talks from experiments out of my field, just to get recent news from neutrinos (Miniboone, Minos...) or from astroparticles (Fermi...). After all, the whole point of these big-scale conferences consists in listening to talks that you would not go to in more topical conferences, devoted to one or two precise subjects !

Since I am of a rather pessimistic nature, I preferer to keep my expectations low. This is the best policy to be surprised happily by the unexpected rather than disappointed by something too much awaited. Therefore, I do not expect outstanding surprises from all these talks. But who knows ? I might easily be proven wrong here. And even if we do not get striking news from the LHC, or from other experiments, there are plenty of ways for a conference to be surprising, if not on Thursday (for the beginning of the parallel sessions), maybe on Monday (for the official opening of the conference) !

Let's the fun start !

On and off (stage)

As you might have noticed reading the posts by Mu-Chun and Georg, summer is a the heyday season for physics conferences and workshops. This is not only because we like to gather in gorgeous places that we can enjoy where the sun shines (Athens, Sardinia... or, yes, Paris), but also for a more mundane reason : many physicists lecture at university, and summer is the only time of the year where they can leave the classroom and travel to week-long international conferences without messing up their teaching schedule -- or their colleagues'.

I like to think of conferences as theatre plays, or operas. After all, they are all cultural events, aren't they ? You have the stage (the conference rooms), the actors (the speakers, with their share of drama kings and queens, happy jesters and uninspired declamatory comedians), the spectators (the good-humoured or bad-tempered participants), the director and conductor (the lucky organisers)... and the technicians taking care of everything basically, from the curtains to the lighting, passing through the costume and the make-up (the administrative and technical staff). And quite often, feelings are quite different on which side of the curtain you stand. At best, the innocent participant can sit and relax, enjoying the happy spectacle of a smoothly-run conference. But off-stage, eveybody jumps up and down like madmen to check minute details of costumes (or microphones) or to prevent major disasters looming (like the crash of the computer network).

Inasmuch as some plays become experiences of a lifetime, and some shows remain just a pleasant evening out, a thin line exists between run-of-the-mill conferences and truly memorable ones. Part of the job of the organising committee consists in gathering the right people talking on the right subjects at the right moment, and another part to propose the right social events with the right mood... Well, you need a bit of luck too. But no matter how outstanding the speakers are, and how exciting the topics turn out to be, the organising committee must also take care of another essential aspect : infrastructure. The best play in the world needs the theater to be open and working in full order.

Murphy's law being unfortunately well obeyed in real life, bad things happen on that side, but you should solve them before they affect the participants. This is a tough lesson that I learned taking part in the organisation of conferences before the ICHEP one. My more personal version is : never organise a conference in Paris in october or november. Or you will be in the same nightmare as Mu-Chun, because autumn is the heyday season for strikes in France as much as summer is for physics conferences. Fortunately (or thoughtfully) ICHEP takes place in July... At the same time as many theater and opera festivals taking place in Southern France like Avignon or Aix-en-Provence, but I do not expect a harsh competition from that side.

Another key element that cannot go astray under any circumstance : computers. Obviously, you need a good internet connection for the participants to check out mails and papers regularly (in Paris, if not in Sardinia, as mentionned by Georg). But with more than 900 participants and almost 600 talks and posters to be presented, you need a powerful tool to manage the huge data-base of people, title, places, times... and slides required by our very dense program (we have only 3 days of parallel sessions !). And for particle physics, all this rhymes with Integrated Digital Conference, or Indico, born at CERN, like so many great computer inventions. The CERN computer team has been incredibly efficient in designing and improving the Indico system that we use, Actually, by its size and its length, ICHEP is a good benchmark to test their new version of the software, and we spent a bit of time helping them to tune the system to our own needs.

Therefore, for physics as much as for many other aspects, ICHEP as a true première... And like for all premieres, both the participants and the organisers look forward to seing the play, that is, the results that will be presented for the first time in summertime Paris !

Up and down

The Standard Model works so well that you wish sometimes that we had not designed such an efficient theory. So where to look for excitement, since everything seems so much and so boringly in control ? Where does New Physics hide, waiting for us to be discovered ?

"LHC" seems the most obvious answer -- test the least-understood sector of the theory (the breaking of electroweak symmetry) by trying to produce the missing piece of the Standard Model (the Higgs boson) and/or hopefully something else, and unexpected. We all hope to be in Rabi's position, who exclaimed "who ordered that ?", when the muon was discovered and did not fit into anybody's plans. So should we just wait for the LHC to give all the answers ?

Fortunately not. Jester's posts show at least one place where things are moving fast, if not always in the direction of your dream -- flavour physics, i.e. the electroweak transitions under which a quark or a lepton changes from one type to another. Obviously, this is not an easy game. Quarks are subjected to strong interaction -- and thus confined into hadrons, so that you never actually observe the decay of a naked quark into another one, but rather that of a meson to one or several others. The computation of such processes is a theorist's nightmare, involving hadronic quantities that are very hard to estimate and possibly hiding faint contributions from New Physics. Leptonic processes are much cleaner, and provide signals of New Physics almost completely free of Standard Model backgrounds, like $\mu\to e\gamma$. But it is a "hit or miss" game : you need New Physics to make such processes frequent enough so that you can detect them... but you have no clue if this will be indeed the case.

The power of flavour physics lies in its sensitivity to virtual effects : by measuring accurately this process, you are sensitive to quantum corrections induced by particles/interactions at much higher energy scales. The past history has proved that it was not only theorists' daydreaming : the non-observation of $K_L\to\mu\mu$ led to the introduction of charm, the violation of the CP symmetry in the kaon system suggested the existence of a third generation of quarks and leptons, and neutrino oscillations were the first hint of physics beyond the Standard Model with the need for right-handed neutrinos. Moreover, despite our difficulties with the strong interactions, we can make (sometimes) quantitative statements : for instance, the upper limits on the difference of masses in the $B\bar{B}$ system showed that the top quark had to be much heavier than previously thought...

The present is a reflection of the past, as the philosophers say. Flavour physics keeps being a stringent constraint on many models of new physics, since they often predict transitions at much higher rates than observed. $\epsilon_K$, $b\to s\gamma$, electric dipole moments and so on have proved stubborn killers for unsuspecting theories for what lies beyond the Standard Model. They are indeed so powerful that for most theories, they push the scale for New Physics much above 1 TeV to make their impact negligible on the processes currently observed... Eh but wait a minute ! This is not what we want -- we want New Physics at the TeV scale !

Fortunately, you can find specific scenarios (such as Minimal Flavour Violation) to accomodate both the data from flavour physics and our LHC expectations. But it would be far more natural (historically speaking) and exciting (scientifically speaking) to see hints of new physics already in some flavour processes, before actually producing new particles at LHC responsible for these deviations. Hence all the recent discussions on the CDF/D0 results, taking back from one hand (CDF $\phi_s$) what they gave us from the other (D0 $A_{SL}$). That is the fundamental problem of flavour physics: since you do not observe new particles, you must spend your time on assessing how much your process has drifted from the Standard Model expectation. And it is a cruel game. Among the many deviations from the Standard Model observed in flavour physics, the majority stays in the grey area between 2 and $3\sigma$ before fading slowly into 1 $\sigma$ oblivion after a more careful scrutiny, both from experimentalists and theorists... Who is still excited by the $b\to s\bar{s}s$ processes, which used to deviate at 3 $\sigma$ from the Standard Model expectations and are now in perfect agreement with it ?

Are the recent results from CDF and D0 two different points in these Russian hills, or will one of these anomalies stay with us to finally be confirmed as a real effect ? Only time -- and experiment ! -- will tell.

In and out

Two months and a few weeks before the start of the show... and my first post on this blog. Where should I start ? Writer's block, already ? Uhuh, don't get me wrong, I have plenty to write upon - otherwise I would not be here, would I ?

ICHEP is not the first conference for which I belong to the local organising committee, but it is definitely the biggest one. A conference with several hundreds of people flocking from all over the world is clearly a challenge for the organisers. We knew it from the beginning, and thus we have prepared it since... 2008. A good thing to plan things ahead -- but it makes the conference look very far away in time.

A few blinks later, it is already mid-May 2010, and even though you have kept on filling in Powerpoint slides, Excel sheets and Indico timetables, you have not realised fully that the conference starts... hem, now, basically. Writing this blog will definitely help me to keep track of time. Well, this and a couple of other tasks related to the conference, in particular the organisation of the parallel sessions... which will certaily take me more and more time as the opening of the conference approaches.

As both a physicist and a conference organiser I plan to provide you with glimpses of on-stage news but also off-stage surprises. And I expect quite a few. Physicswise, in addition to the fact that LHC is taking data to be presented here, we expect many other new results from high-energy experiments -- as shown by the number of talks proposed for parallel sessions. And as far as organisation is concerned... well, France is a country full of surprise, as I learned when I organised an earlier conference near Paris -- but I will keep this story for another post...

In any case, welcome to this blog, and welcome Paris for this new edition of ICHEP. We will do our best to make it a truly memorable conference for you -- as it surely will be for us !