## Posts Tagged ‘Higgs’

### Nobel Dreams

Friday, October 4th, 2013

## The liveblog

Greeting from Brussels! This is my liveblog of the Nobel Prize Announcement Ceremony, bringing you the facts and the retweets as they happen.

14:14: Press Conference ongoing. “This is a great day for young people.”

13:56: A moving statement from Kibble (source):

I am glad to see that the Swedish Academy has recognized the importance of the mass-generating mechanism for gauge theories and the prediction of the Higgs boson, recently verified at CERN. My two collaborators, Gerald Guralnik and Carl Richard Hagen, and I contributed to that discovery, but our paper was unquestionably the last of the three to be published in Physical Review Letters in 1964 (though we naturally regard our treatment as the most thorough and complete) and it is therefore no surprise that the Swedish Academy felt unable to include us, constrained as they are by a self-imposed rule that the Prize cannot be shared by more than three people. My sincere congratulations go to the two Prize winners, François Englert and Peter Higgs. A sad omission from the list was Englert’s collaborator Robert Brout, now deceased.

13:37: CERN are holding a press conference at 14:00 (CET) link

13:22: Commentary continues at the Nobel Prize page. Currently discussing why the boson was so hard to find. “This particle has been looked for at every accelerator that has existed.”

13:20: As expected, so many news sites have been created: CMS, ATLAS, ULB, Edinburgh

13:14: I think my twitter account has exploded with tweets. Also, some Belgian news pages are down, probably due to high traffic. Wow!

13:11: Wow, what a great announcement. Too short though!

13:08: Find out more about the physics at Brussels, where the Brout-Englert-Higgs mechanism was born! The IIHE and the Nobel Prize

13:01: Englert is on the phone. Good to hear from him 🙂

12:59: Animation of the boson appearing, cool!

12:57: We just opened the champagne here at ULB!

12:52: Text for the announcement:

“For the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider”

12:48: The award goes to Englert and Higgs!

12:44: One minute to go!

12:39: We all know what the Brout-Englert-Higgs mechanism is and what the boson discovery means, so let’s instead take a look at the other likely awards. The prize could go to the discovery of extra solar planets. 51 Pegasi b was an extra solar planet discovered in 1995, orbiting a sun-like star. This discovery could have far reaching implications. What would happen if we saw spectral lines suggesting the presence amino acids coming from the planet? (I’m not sure such a phenomenon is even possible, but if it is it would be a very strong indicator of RNA-like life from another planet.) That discovery took place 18 years ago, and the Brout-Englert-Higgs boson was discovered only one year ago. Either discovery would certainly be worthy of the prize.

12:33: A quantum approach to the delay problem:

Someone go observe the academy and make them leave this terrible superposition. (@lievenscheire)

12:32: Another possible reason for the delay:

There’ll be a new hunt for the #Higgs. He’s gone to the Highlands to avoid the fuss if he wins #nobelprize. Maybe reason for delay. (@BBCPallab)

12:31: The Nobel Prize committee are stalling by suggesting we look at previous awards. At least they are trying to keep up amused while we wait 🙂

12:29: Around the world people are patiently waiting. People from the US have been awake since 5:00am. In Marakech the ATLAS Collaboration looks on. Here are ULB/IIHE the cafeteria seem deserted. (I’m glad there’s a coffee machine on the desk next time mine.) I’m starting to think this is a plot to get some more media attention for what is bound to be a controversial year for physics. There are many good choices of topic this year, and even some of the topics have controversial choices of Laureates.

12:21: Some humourous speculation about the delay:

The Academy only has 3 #sigma evidence of more votes for than against, waiting for more data (@SethZenz)

They can’t get Comic Sans installed on the Academy’s computer (@orzelc)

The committee were mobbed trying to get across a cocktail party. (@AstroKatie)

12:07: The announcement is delayed until 12:45 CET. People are complaining about the background music!

11:58: The announcement is delayed until 12:30 CET.

11:44: According to the Guardian (source) there will be a delay of 30 minutes.

11:42: Just over two minutes to go. This could be a very exciting year for Belgium.

11:33: See the livecast.

## Other info

On Tuesday October 8th the recipient(s) of the 2013 Nobel Prize in Physics will be announced. There has already been a lot of speculation about who might be the Nobel Laureates this year, and there is a lot of interest in the likely contenders! Each year Thomson Reuters publishes predictions of who might receive the Nobel Prizes, and this year they have narrowed the scope down to three likely awards in physics:

• ‣ Francois Englert and Peter Higgs, for their prediction of the Brout-Englert-Higgs mechanism. (Brout is deceased and the Nobel Prize is not awarded posthumously.)
• ‣ Hideo Hosono, for his discovery of iron-based superconductors.
• ‣ Geoffrey Marcy, Michel Mayor, and Didier Queloz, for their discoveries of extrasolar planets.

The 2012 Nobel Prize Award Ceremony (Copyright © Nobel Media AB 2012 Photo: Alexander Mahmoud)

There has also been speculation that either Anderson or Nambu may receive a second Nobel Prize for their work related to spontaneous symmetry breaking.

With so many different predictions and so many opinions it can be hard to keep up with all the latest news and blogs! I know that a lot of people plan to share their views and experiences of the day, so I’ll be keep a list of bloggers and tweeters that you can follow.

### Seth Zenz:

See Seth’s excellent post about the Nobel Prize, Englert and Higgs, and CERN. You can also follow his twitter account: @SethZenz

### James Doherty:

See James’s great post about the Nobel Prize, He’s on twitter too: @JimmyDocco

### A Higgs Nobel? And to Whom?

Tuesday, October 1st, 2013

The smart money for this year’s Nobel Prize, it seems, is on Peter Higgs and François Englert to win for developing the theory of the boson that bears one of their names. Awarding the prize to the two of them would, of course, be a great oversimplification of assigning credit for that theory. Robert Brout, who worked with Englert, died in 2011 and so is ineligible for the prize. Gerald Guralnik, C. R. Hagen, and Tom Kibble published independent work on the same problems at the same time. All six shared the 2010 Sakurai Prize “for elucidation of the properties of spontaneous symmetry breaking in four-dimensional relativistic gauge theory and of the mechanism for the consistent generation of vector boson masses,” but the Nobel rules are more restrictive.

If the Nobel Prize goes to only two of six theorists, it is certainly in the tradition of the prize, whose structure implicitly assumes that great scientific breakthroughs are made by great people through well-defined leaps of genius. More often, though, theoretical work is incremental. Ideas are exchanged, developed partially by one person before being expanded upon by the next. The positive way to look at it is that the prize would be symbolic, awarded to two people who represent a broader effort.

Of course, the main reason the Higgs boson is of interest right now is the experimental work done in finding it! Could there be a Nobel Prize for that? Well, I can’t see any way to award an individual for the efforts of thousands of people over decades. An untold number of “little” problems have been solved by those people in building a bigger and better accelerator, and bigger and better detectors, than have ever been built before. So what I would like to see is the Nobel Committee changing its traditions and awarding the physics prize to CERN along with the theorists.

A prize to CERN would again be symbolic. Not everyone who made important contributions to finding the Higgs works at CERN. Thousands of the contributors worked at United States labs and universities from the very beginning, for example. But as the center of the LHC effort, it does represent all that work. Not a sudden flash of genius, but lots of hardworking people tackling tough scientific and technical problems. In other words, the way great science is usually done.

Katie Yurkewicz, Flip Tanedo, and the Higgs boson. (Originally for this contest in Symmetry.)

For a more humorous take on all this, please see this Scientific American article on the early awarding of the prize to the boson itself. My favorite bit is this: “A member of CERN’s PR division also wore a large, squishy Higgs costume, doing his best to mimic the behavior of the fleeting particle as he whizzed from one end of the room to another, hid and emerged from behind a curtain and breathlessly answered questions about gauge symmetry and vacuum fluctuations.” As you can see at right, this is frighteningly close to what some USLHC communicators have actually been involved in.

The real Nobel Prize in Physics will be announced next Tuesday, October 8. So stay tuned!

### Higgs Hunting in Progress

Wednesday, August 28th, 2013

Last month I was at the annual Higgs Hunting workshop, in Orsay and  Paris, France.  Starting less than a week after EPS, it didn’t have much in the way of new results.  What it did give us is an opportunity to talk through where we are and where we’re going.  What do we know about the Higgs so far?  What do we still need to find out, and how do we go about it?  Why aren’t the coffees stronger, or at least larger?

It’s true, the last question isn’t about the Higgs, but it does reflect that a lot of the learning and discussion went on during the coffee breaks.  (I should stress in case the organizing committee reads this that the drinks and snacks at the coffee breaks were, on the whole, quite excellent.)  But of course we had talks too, and you can see both the slides and videos here.  I should warn you, though, that the talks are very technical — even more technical than might be usual for a Higgs conference, because it was generally assumed that participants already know the strategy for hunting the Higgs.

My talk was about the CMS search for Higgs decays to bottom quark pairs.  It covered four analyses, which are different from each other not because of what the Higgs decays into but because of what it’s produced in association with.  Without extra particles, we can’t see the Higgs in this decay channel because of all the bottom quark pairs from QCD.  But this direction of looking at different production mechanisms is also where Higgs searches as a whole are going, because ultimately Higgs production tells us as much about what the Higgs interacts with as Higgs decay.  And what we really hope to find is some difference from the Standard Model in those interactions.

From what we’ve seen so far, it looks like we’re hunting precisely the Standard Model Higgs.  But we are far from an exact answer; we haven’t even officially established evidence for the Higgs to bottom quark pair decay at all, yet.  So we’ll keep hunting, and hope the Higgs Beast turns out to be subtly different from the one we’re expecting.

### The International Linear Collider: More than Just a Higgs Factory

Friday, August 23rd, 2013

The ILC site has been chosen. What does this mean for Japan?

The two ILC candidate sites: Sefuri in the South and Kitakami in the North. Credit: linearcollider.org

Hi Folks,

It is official [Japanese1,Japanese2]: the Linear Collider Collaboration and the Japanese physics community have selected the Kitakami mountain range in northern Japan as the site for the proposed International Linear Collider. Kitakami is a located in the Iwate Prefecture and is just north of the Miyagi prefecture, the epicenter of the 2011 Tohoku Earthquake. Having visited the site in June, I cannot aptly express how gorgeous the area is, but more importantly, how well-prepared Iwate City is for this responsibility.

Science is cumulative: new discoveries are used to make more discoveries about how nature works, and physics is no different. The discovery of the Higgs boson at the Large Hadron Collider was a momentous event. With its discovery, physicists proved how some particles have mass and why others have no mass at all. The Higgs boson plays a special role in this process, and after finally finding it, we are determined to learn more about the Higgs. The International Linear Collider (ILC) is a proposed Higgs boson factory that would allow us to intimately understand the Higgs. Spanning 19 miles (31 km) [310 football pitches/soccer fields], if constructed, the ILC will smash together electrons and their antimatter partners, positrons, to produce a Higgs boson (along with a Z boson). In such a clean environment (compared to proton colliders), ultra-precise measurements of the Higgs boson’s properties can be made, and thereby elucidate the nature of this shiny new particle.

The general overview schematic of the International Linear Collider. Credit: linearcollider.org

However, the ILC is more than just a experiment. Designing, constructing, and operating the machine for 20 years will be a huge undertaking with lasting effects. For staters, the collider’s Technical Design Report (TDR), which contains every imaginable detail minus the actual blueprints, estimates the cost of the new accelerator to be 7.8 billion USD (2012 dollars). This is not a bad thing. Supposing 50% of the support came from Asia, 25% from the Americas, and 25% from Europe, that would be nearly 2 billion USD invested in new radio frequency technology in England, Germany, and Italy. In the US, it would be nearly 2 billion USD invested in coastal and Midwestern laboratories developing new cryogenic and superconducting technology. In Asia, this would be nearly 4 billion USD invested in these technologies as well as pure labor and construction. Just as the LHC was a boon on the European economy, a Japanese-based ILC will be a boon for an economy temporarily devastated  by an historic earthquake and tsunami. These are just hypothetical numbers; the real economic impact will be  larger.

I had the opportunity to visit Kitakami this past June as a part of a Higgs workshop hosted by Tohoku University. Many things are worth noting. The first is just how gorgeous the site is. Despite its lush appearance, the site offers several geological advantages, including stability against earthquakes of any size. Despite its proximity to the 2011 earthquake and the subsequent tsunami, this area was naturally protected by the mountains. Below is a photo of the Kitakami mountains that I took while visiting the site. Interestingly, I took the photo from the UNESCO World Heritage site Hiraizumi. The ILC is designed to sit between the two mountains in the picture.

The Kitamaki Mountain Range as seen from the UNESCO World Heritage Site in Hiraizumi, Japan. Credit: Mine

What I want to point out in the picture below is the futuristic-looking set of tracks running across the photo. That is the rail line for the JR East bullet train, aka the Tohoku Shinkansen. In other words, the ILC site neighbours a very major transportation line connecting the Japanese capital Tokyo to the northern coast. It takes the train just over 2 hours to traverse the 250 miles (406.3 km) from Tokyo station to the Ichinoseki station in Iwate. The nearest major city is Sendai, capital of Miyagi, home to the renown Tohoku University, and is only a 10 minute shinkansen ride from Ichinoseki station.

The Kitamaki Mountain Range as seen from the UNESCO World Heritage Site in Hiraizumi, Japan. Credit: Mine

What surprised me is how excited the local community is about the collider. After exiting the Ichinoseki station I discovered this subtle sign of support:

There is much community support for the ILC: The Ichinoseki Shinkansen Station in Iwate Prefecture, Japan. Credit: Mine

The residents of Iwate and Miyagi, independent of any official lobbying organization, have formed their own “ILC Support Committee.” They even have their own facebook page. Over the past year, the residents have invited local university physicists to give public lectures on what the ILC is; they have requested that more English, Chinese, Korean, and Tagalog language classes be offered at local community centers; that more Japanese language classes for foreigners are offered in these same facilities; and have even discussed with city officials how to prepare Iwate for the prospect of a rapid increase in population over the next 20 years.

Despite all this, the real surprises were the pamphlets. Iwate has seriously thought this through.

Pamphlets showcasing the Kitakami Mountain Range in Iwate, Japan. Credit: Mine

The level of detail in the pamphlets is impressive. My favourite pamphlet has the phrase, “Ray of Hope: Tohoku Is Ready to Welcome the ILC” on the front cover. Inside is a list of ways to reach the ILC site and the time it takes. For example: it takes 12 hours 50 minutes to reach Tokyo from Rome and 9 hours 40 minutes from Sydney. The brochure elaborates that the Kitakami mountains maintain roughly the same temperature as Switzerland (except in August-September) but collects much more precipitation through the year. Considering that CERN is located in Geneva, Switzerland, and that many LHC experimentalists will likely become ILC experimentalists, the comparison is very helpful. The at-a-glance annual festival schedule is just icing on the cake.

“Ray of Hope” pamphlet describing how to each different ILC campuses by train.  Credit: Mine

Now that the ILC site has been selected, surveys of the land can be conducted so that blue prints and a finalized cost estimate can be established. From my discussions with people involved in the site selection process, the decision was very difficult. I have not visited the Fukuoka site, though I am told it is a comparably impressive location. It will be a while still before any decision to break ground is made. And until that happens, there is plenty of work to do.

Happy Colliding

– Richard (@bravelittlemuon)

### Petite chronique d’un prof au CERN (V)

Wednesday, June 5th, 2013

À l’occasion de l’ouverture de l’appel à candidature 2013 de “Sciences à l’Ecole” pour l’accueil d’enseignants français au CERN durant une semaine, nous publions ces jours-ci le journal quotidien plein d’humour de Jocelyn Etienne qui a suivi ce programme l’année dernière, au mois de novembre dernier.

La visite s’accélère !
Jeudi 08 novembre 2012

Un élément d’un accélérateur (je ne sais plus lequel).

La journée commence par une citation de notre collègue Joseph : « si tu veux pas entendre parler de protons, va à Conforama ! » Notre guide ce matin s’appelle François. Il est belge et ingénieur en informatique. Il nous présente le site LINAC-LEIR où l’on trouve tous ce qu’il faut pour préparer les noyaux que l’on va injecter ensuite dans les différents accélérateurs. Il porte un détecteur de radioactivité pour mesurer les doses qu’il reçoit dans une journée. D’ailleurs, il y a des détecteurs de radioactivité à l’entrée et à la sortie du CERN, et gare à celui qui a subi une injection de radio-isotopes pour une analyse médicale, il va sonner aux portiques pendant une semaine (c’est déjà arrivé). Sinon, en cas de problème, faire le 74444 (les pompiers).

Mario Campanelli et sa  tablette tactile géante.

Mario Campanelli est un physicien italien qui travaille sur le projet ATLAS (après le Tevatron aux USA, Gran Sasso en Italie…), ce n’est pas une tablette tactile même géante qui va lui faire peur.

Il nous montre une représentation quasiment en temps réel des informations qui circulent  sur le réseau de calcul du CERN à travers le monde. Il s’agit du GRID, sorte de WEB des logiciels, un partage réseau mondial dont on voit un bout à droite, nécessaire pour traiter les milliards de données qu’engendrent les collisions de particules dans le LHC (sous linux toujours).

On appelle ce lieu le CCC : le Centre de Contrôle du CERN. On voit les personnels à travers une vitre mais la plupart ne contrôle rien à l’instant car un apéro est organisé pour fêter les objectifs de puissance atteints. Tout est prétexte pour faire la fête hein ?!

A 11h, petite pause conférence (Solène Chevalier-Théry de Sciences à l’école puis Morgan Piezel professeur, pour l’exploitation de ce stage dans nos lycées) dans la salle où a été annoncée la découverte du Higgs, ou en tout cas, quelque chose qui s’en rapproche. Les physiciens que nous rencontrons espèrent d’ailleurs que ce n’est pas exactement le boson prévu par le Modèle Standard, car alors… ça serait trop simple.

La soirée se termine avec une partie de quarks poker, un jeu inventé par le physicien retraité Patrick Roudeau. En comprendre les règles fut un des exercices les plus difficiles de la semaine.

À suivre…

Jocelyn Etienne est enseignant au lycée Feuillade de la ville de Lunel.

Pour soumettre sa candidature pour la prochaine session du stage au CERN, c’est par ici.

### Loterie de bosons de Higgs: quand le CERN fait des poissons d’avril

Tuesday, April 9th, 2013

Le premier avril, j’ai annoncé ici que le CERN donnerait dix bosons de Higgs pour remercier le public pour son incroyable intérêt pour la recherche faite au CERN. Environ 1500 personnes se sont inscrites pour ce tirage au sort. Plusieurs ont décrit leur enthousiasme, expliquant combien ils aimeraient en avoir un et ce que cela signifierait pour eux. D’autres n’ont pas été dupes, mais ont voulu jouer le jeu.

C’était vraiment amusant d’avoir la chance de jouer un poisson d’avril qui a fait marcher des gens partout dans le monde. Les inscriptions sont venues de lieux aussi divers que le Pakistan, le Rwanda, la Finlande, le Canada, l’Australie, la Chine et le Portugal. Cela montre l’intérêt incroyable que le boson de Higgs a généré sur tous les continents.

J’ai utilisé un générateur de nombres aléatoires pour sélectionner les gagnant-e-s qui viennent du Mexique, Royaume-Uni, Etats-Unis, Biélorussie (3), Russie (3),  Kazakhstan et Pays-Bas. Une grande partie des entrées venait de Biélorussie et de Russie où un site d’information populaire a reproduit la nouvelle. Les gens ont mordu, même si, comme chacun sait: “Первого апреля никому не верю!” (Le premier avril, ne fais confiance à personne).

Même des étudiant-e-s en physique se sont fait prendre au piège tant leur désir d’avoir leur propre boson de Higgs était fort. Bien sûr, c’était un peu tricher que d’utiliser la renommée du CERN puisque cela donne beaucoup de poids peu importe l’annonce. Mais beaucoup se sont bien amusé-e-s: un homme a essayé de me soudoyer avec un monopôle magnétique. Une femme a promis de le nourrir seulement avec les meilleurs particules. Une autre a dit qu’elle avait déjà beaucoup d’antimatière et saurait comment bien prendre soin d’un boson de Higgs. Un étudiant en physique a indiqué que compte tenu de la courte durée de vie de ce boson, il craignait de se retrouver avec seulement deux bosons W ou Z. Une personne a exprimé combien il était bien que le CERN partage. Certains ont demandé un bosun, bozzon ou bison de Higgs. Un homme m’a dit combien l’obtention d’un boson pourrait l’aider à gagner le coeur de son amie alors qu’il était sur le point de la demander en mariage. Un étudiant très déçu a répondu que les physicien-ne-s étaient cruel-le-s quand il a réalisé que c’était une blague. Il a vite changé d’avis en apprenant qu’il était l’un des dix heureux gagnants.

Des bosons de Higgs spécialement faits pour cette occasion et tout juste échappés du zoo de particules sont en route vers leur nouvelle vie où tous les gagnant-e-s ont dit qu’ils et elles allaient les accueillir chaleureusement.

Pauline Gagnon

Pour être averti-e lors de la parution de nouveaux blogs, suivez-moi sur Twitter: @GagnonPauline ou par e-mail en ajoutant votre nom à cette liste de distribution

### Higgs boson lottery: when CERN plays April Fools jokes

Tuesday, April 9th, 2013

For April first, I wrote that CERN was to give away ten Higgs bosons in a gesture to thank the public for its incredible interest in CERN’s scientific research. About 1500 people eagerly entered the lottery. Most of them wrote very enthusiastic notes, explaining how much they would love one and how much it would mean to them. Many people were not completely fooled but played along just as eagerly.

It was great fun to have a chance to play an April Fools joke that got people all over the world. Entries came from places as diverse as Pakistan, Rwanda, Finland, Canada, Australia, China and Portugal. This shows the incredible interest the Higgs boson has generated on all continents.

I used a random number generator to select the winners who are from Mexico, UK, USA, Belarus (3), Russia (3), Kazakhstan and The Netherlands. Nearly half the entries came from Belarus or Russia, where a popular news agency ran the story. People fell for it even though as everyone knows: “Первого апреля никому не верю!” (On April first, do not trust anyone).

Even some physics students fell for it, so strong was their desire to get their own Higgs boson. Granted, using CERN’s fame is cheating a bit, giving any claim a lot of clout. But many played along: one tried to bribe me with a magnetic monopole, while another promised to feed it only the best particles. Another woman said she already had lots of antimatter and would know how to properly care for a Higgs boson. One physics student said that given the short lifetime of a Higgs boson, he might end up with just two W or Z bosons. One person expressed how great it was for CERN to share. Some asked for a Higgs bosun, bozzon or bison. A guy told me how much this would help him win his girlfriend’s heart as he was about to propose to her. A very disappointed student replied physicists were cruel when he realized it was a joke. But I hope he changed his mind when he found out he was one of the 10 lucky winners.

Custom-made Higgs bosons recently escaped from the Particle Zoo and are on their way to their new home, where all the winners said they would warmly welcome them.

Pauline Gagnon

### The Substandard Model of Particle Physics

Monday, April 1st, 2013

Now that we are on the verge of completing the Standard Model of Particle Physics, it’s time to look to the future of the field. Five physicists at CERN present their new state of the art* theory: The Substandard Model of Physics!

“It’s easy to understand but questionably accurate.” Mandy Baxter (Marine Biogeochemical Microbiologist, USCB)

Thanks to the actors.
Androula Alekou (Neutrino Expert)
Katie Malone (Higgs Expert)
Stephen Ogilvy (Flavor Expert)
Aidan Randle-Conde (QCD Expert)
Lee Tomlinson (QFT Expert)

Steve Marsden (Standard Model Expert)
Helen Lambert (Environmental Sanitization Team)

@sigsome @aidanatcern

Visit the US LHC Blogs at Quantum Diaries:
http://www.quantumdiaries.org/lab-81

Music: Off to Osaka, Kevin Macleod, http://www.incompetech.com

Images taken from CKMFitter (http://ckmfitter.in2p3.fr), UTFit (http://www.utfit.org), Wikimedia.

This video does not reflect the views of CERN. It does not even reflect the views of the actors. In fact I’d be surprised if it reflected the views of anyone at all.

Thanks to Adam Davidson for inspiring the name. It was a off handed comment you made about 7 years ago that stuck with me ever since. Finally it has become a reality!

Apologies for the slightly out of focus footage and extra frame. Some small technical glitches always get through.

(*We’re just not sure what kind of a state, and what kind of art it is.)

### La réponse sur le boson de Higgs est-t-elle imminente?

Friday, March 1st, 2013

Non! Mais de belles surprises pourraient bien émerger après la conférence de Moriond, une fois que les théoricien-ne-s auront eu le temps de combiner et interpréter tous les nouveaux résultats et mises à jour qui seront présentés pendant les deux semaines à venir. Ces résultats viendront de tous les secteurs et pas seulement des recherches sur le boson de Higgs.  C’est exactement ce dont les théoricien-ne-s ont besoin pour soumettre le Modèle Standard aux tests les plus rigoureux et détecter peut-être la faille révélant une théorie plus complète. Les mesures de précision comme celles présentées l’an dernier par LHCb ont un impact majeur en limitant la marge de manœuvre du modèle.

Les “Rencontres de Moriond” sont la première conférence de physique majeure de l’année. Elles débutent le 2 mars dans une station des Alpes italiennes. Traditionnellement, c’est là que la plupart des expériences de physique des particules présentent leurs résultats mais cette année, elle arrive un peu trop tôt après la fin de la prise des données au Grand collisionneur de hadrons (LHC), ne laissant pas suffisamment de temps aux expériences pour résoudre toutes les complexités reliées à la calibration et reconstruction des données nécessaires pour produire des résultats sur toutes les analyses. De prochaines mises à jour viendront entre autres en mai (Large Hadron Collider Physics), en juillet (European Physical Society) et possiblement en décembre à la réunion du Conseil du CERN.

Plusieurs espéraient que CMS et ATLAS, les deux grandes expériences du LHC au CERN, annonceraient enfin que le boson découvert l’été dernier est bel et bien un boson de Higgs. Malheureusement, il est encore trop tôt pour en avoir le cœur net. Cependant, les deux expériences devraient révéler leurs toutes dernières analyses sur la masse, les modes de désintégrations et le spin du nouveau boson, toutes ces propriétés qui contribuent à en donner une image plus précise.

Un aspect à surveiller tout particulièrement : les petites déviations par rapport aux prédictions théoriques observées l’an dernier par les deux expériences dans les taux de désintégration du nouveau boson se maintiendront-elles ? ATLAS et CMS obtiennent parfois plus, parfois moins d’évènements que ce qui est prédit par la théorie, bien que les marges d’incertitude soient encore trop fortes pour qu’on puisse se prononcer. Tout demeure consistent avec le Modèle Standard mais un excès dans le canal de désintégration en deux photons par exemple pourrait révéler que de nouvelles particules contribuent à ces désintégrations, une possibilité que bien des théoricien-ne-s espèrent voir révéler la présence de nouvelles particules supersymétriques.

Un résumé de la situation en décembre dernier sur toutes les mesures de masse et de canaux de désintégration effectuées par ATLAS et CMS. L’intensité du signal devrait être 1.0 pour un boson de Higgs du Modèle Standard. Etant donné les marges d’incertitude, tout est toujours en accord avec les prévisons théoriques.

De nouveaux résultats sont aussi attendus sur la recherche de nouvelles particules tels que des bosons plus lourds ou des particules supersymétriques. Bien sûr, si une seule expérience présente une petite déviation, l’excitation sera limitée en attendant la réaction de l’autre expérience. Mais si les deux trouvent des indices similaires, il y aurait de quoi prêter attention.

Bien des sujets seront abordés et plusieurs théoricien-ne-s y présenteront leurs plus récents modèles et interprétations. Restez donc à l’écoute pour les deux semaines à venir, alors que j’expliquerai ici les points forts de la conférence.

Pauline Gagnon

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### Tweeting the Higgs

Wednesday, January 23rd, 2013

Back in July two seminars took place that discussed searches for the Higgs boson at the Tevatron and the LHC. After nearly 50 years of waiting an announcement of a $$5\sigma$$ signal, enough to claim discovery, was made and all of a sudden the twitter world went crazy. New Scientist presented an analysis of the tweets by Domenico et al. relating to the Higgs in their Short Sharp Scient article Twitter reveals how Higgs gossip reached fever pitch. I don’t want to repeat what is written in the article, so please take a few minutes to read it and watch the video featured in the article.

The distribution of tweets around the July 2nd and July 4th announcements (note the log scale)

Instead of focusing on the impressive number of tweets and how many people were interested in the news I think it’s more useful for me as a blogger to focus on how this gossip was shared with the world. The Higgs discovery was certainly not the only exciting physics news to come out of 2012, and the main reason for this is the jargon that was used. People were already familiar with acronyms such as CERN and LHC. The name “Higgs” was easy to remember (for some reason many struggled with “boson”, calling it “bosun”, or worse) and, much to physicists’ chagrin, “God particle” made quite a few appearances too. It seems that the public awareness was primed and ready to receive the message. There were many fellow bloggers who chose to write live blogs and live tweet the event (I like to think that I started bit of a trend there, with the OPERA faster than light neutrinos result, but that’s probably just wishful thinking!) Following the experiences of December 2011, when the webcast failed to broadcast properly for many users had twitter on standby, with tweets already composed, hungry for numbers. The hashtags were decided in advance and after a little jostling for the top spot it was clear which ones were going to be the most popular. Despite all the preparation we still saw huge numbers of #comicsans tweets. Ah well, we can’t win them all!

The point is that while the world learned about the Higgs results I think it’s just as important that we (the physicists) learn about the world and how to communicate effectively. This time we got it right, and I’m glad to see that it got out of our control as well. Our tweets went out, some questions were asked and points clarified and the news spread. I’m not particularly fond of the phrase “God particle” , but I’m very happy that it made a huge impact, carrying the message further and reaching more people than the less sensational phrase “Higgs boson”. Everyone knows who God is, but who is Higgs? I think that this was a triumph in public communication, something we should be building on. Social media technologies are changing more quickly each year, so we need to keep up.

A map of retweets on July 4th, showing the global spread.

But moving back to the main point, the Higgs tweets went global and viral because they were well prepared and the names were simple. Other news included things like the search for the $$B_s$$ meson decaying to two muons and the limits that places on SUSY, but how does one make a hashtag for that? I would not want to put the hashtag #bs on my life’s work. It’s always more exciting to announce a discovery than an exclusion too. The measurement of $$\theta_{13}$$ was just as exciting in my opinion, but that also suffered the same problem. How is the general public supposed to interpret a Greek character and two numbers? I should probably point out that this is all to do with finding the right jargon for the public, and not about the public’s capacity to understand abstract concepts (a capacity which is frequently underestimated.) Understanding how $$\theta_{13}$$ fits in the PMNS mixing matrix is no more difficult than understanding the Higgs mechanism (in fact it’s easier!) It’s just that there’s no nice nomenclature to help spread the news, and that’s something that we need to fix as soon as possible.
As a side note, $$\theta_{13}$$ is important because it tells us about how the neutrinos mix. Neutrino mixing is beyond the Standard Model physics, so we should be getting more excited about it! If $$\theta_{13}$$ is non-zero then that means that we can put another term into the matrix and this fourth term is what gives us matter-antimatter asymmetry in the lepton sector, helping to explain why we still have matter hanging around in the universe, why we have solid things instead of just heat and light. Put like that is sounds more interesting and newsworthy, but that can’t be squeezed into a tweet, let alone a hashtag. It’s a shame that result didn’t get more attention.