Various and Sundry

  • It seems that Jean-Pierre Serre now spends his time commenting on blogs.
  • For those interested in particle physics history, there’s an interesting article by George Zweig here about his role in the discovery of quarks (which he called “aces”).
  • There’s a very nice new survey article by Mikhail Shifman about QCD, especially about hopes to exploit supersymmetric models to better understand non-perturbative issues.
  • Blogger String Theory Fan still gets hits from the trackback to his blog entry over there. Trackbacks to hep-th papers from here still seem to be censored, but people find out about the postings anyway. For instance, the authors of this recent paper have put out a revised version adding a reference to the earlier calculation in the math literature pointed out here.
  • If you like listening to talks by Nobel Laureates, there’s a whole bunch here.
  • One person who is more than distinguished enough to be a Nobel Laureate but isn’t one since he made the mistake of being born too late is Edward Witten. Last week he was in Europe collecting other well-deserved medals: the Lorentz Medal in Amsterdam and the Newton Medal in London. Evidently he was giving two talks, one for the public and one more technical. The public one was entitled String Theory and the Universe and probably not to my taste. It should appear at some point here, but for now there’s a report here at Physics World. Michael Green introduced Witten with the accurate title of “Master of the Path Integral”. The more technical one may have better shown off Witten’s mastery; it had the fascinating title of A New Look At The Path Integral of Quantum Mechanics, and I’m hoping it will appear soon here (or maybe a commenter who has heard the talk in Amsterdam or elsewhere can tell us more about it…)
  • While I’m not sure how strongly Witten feels about string theory these days, there’s not much ambiguity in the case of Michio Kaku. He was on the Colbert Report Monday night and has a recent blog entry arguing that We Physicists Are the Only Scientists Who Can Say the Word “God” and Not Blush:

    As you know, I work in something called String Theory which makes the statement that we are reading the mind of God. It’s based on music or little vibrating strings thus giving us particles that we see in nature. The laws of chemistry that we struggled with in high school would be the melodies that you can play on these vibrating strings. The Universe would be a symphony of these vibrating strings and the mind of God that Einstein wrote about at length would be cosmic music resonating through this nirvana… through this 11 dimensional hyperspace—that would be the mind of God. We physicists are the only scientists who can say the word “God” and not blush.

    If you’re in New York and want to help him defeat a Cyborg Army on July 16th, see this.

  • As for me, I’m heading soon for Patagonia to try and see another eclipse. After that I’ll be traveling in South America for a couple weeks, won’t be able to help with the Cyborgs since I should be somewhere around Lake Titicaca on the 16th. Comments may get shutdown temporarily here for a while, partly because of the hundreds of spam comments coming in here each day, not all of which get caught by the spam filter, making some on-going maintenance necessary.
  • Posted in Uncategorized | 30 Comments

    Perelman Turns Down Millennium Prize

    The Clay Mathematics Institute today announced that Perelman has turned down the one million dollar Millennium prize:

    On June 8-9 CMI held a conference in Paris to celebrate the resolution of the Poincaré conjecture by Grigoriy Perelman. Dr. Perelman has subsequently informed us that he has decided not to accept the one million dollar prize. In the fall of 2010, CMI will make an announcement of how the prize money will be used to benefit mathematics.

    There are various media stories appearing about this, based on an AP report, with a bit more detail:

    Jim Carlson, institute president, said Perelman’s decision was not a complete surprise, since he had declined some previous math prizes.

    Carlson said Perelman had told him by telephone last week of his decision and gave no reason. But the Interfax news agency quoted Perelman as saying he believed the prize was unfair. Perelman told Interfax he considered his contribution to solving the Poincare conjecture no greater than that of Columbia University mathematician Richard Hamilton.

    “To put it short, the main reason is my disagreement with the organized mathematical community,” Perelman, 43, told Interfax. “I don’t like their decisions, I consider them unjust.”

    Carlson said institute officials will meet this fall to decide what to do with the prize money. “We have some ideas in mind,” he said. “We want to consider that carefully and make the best use possible of the money for the benefit of mathematics.”

    Posted in Uncategorized | 27 Comments

    LHC vs. Tevatron Update

    Over the weekend the LHC had a first successful physics run with nominal intensity beams, in 3 bunches. A peak luminosity of about 5 x 1029cm-2s-1 was achieved, and the total integrated luminosity per experiment is now around 30 nb-1. While this is quite a bit behind optimistic schedules of earlier this year, it may now be possible to much more quickly increase the LHC luminosity as the number of bunches is increased. The current plan foresees an integrated luminosity of about 1 pb-1 in July, and another 3 pb-1 in August.

    The report about this from BBC News has the LHC’s Mike Lamont trash-talking about the Tevatron:

    “It’s clear that the LHC is the new boy in town, but in two years running we’re going to put Fermilab out of business,” operation group leader Mike Lamont told BBC News.

    John Ellis is enthusiastic about the possibility of producing black holes:

    Professor Ellis added that as the luminosity increases, one of the things physicists at Cern will be looking for is a mini- black hole.

    “It would be absolutely, fantastically exciting if we produced black holes at the LHC,” he said.

    “Then we would test our ideas about gravity, quantum physics, string theory. This would be much more exciting than finding a… Higgs boson or even dark matter.”

    Meanwhile, over in Batavia, the Tevatron has been regularly operating at peak luminosities of 3-4 x 1032cm-2s-1, nearly a 1000 times that of the LHC, accumulating integrated luminosity of around 50 pb-1 a week. They’re getting the total number of collisions produced at the LHC this year about every couple of minutes. So far this year they are doing even better than planned, with over 2000 pb-1 of integrated luminosity in FY 2010. Last week, the Physics Advisory Committee met to consider plans to get in Mike Lamont’s face, and keep operating the Tevatron past its planned closing date of end FY 2011, possibly for another three years. This would take their total data set from about 10 fb-1 to possibly as much as 20 fb-1. With this amount of data they expect to be able to provide 3-sigma evidence for a Higgs over the entire expected mass range, as well as stay ahead of the LHC in several different measurements, including the sort of possible non-SM CP-violating effects that recently have been in the news.

    Update: More about CERN’s competition with the Tevatron here:

    The LHC now has to produce as many collisions as possible in the next two years in order for the various experiments at CERN to essentially prove their worth among other established particle physics laboratories.

    The past failures of the LHC weighed heavily on operations group leader Mike Lamont who talked about some of the criticism from the media.

    “The Americans in particular can be quite aggressive,” he told Deutsche Welle.

    “It’s quite clear that we’re competing with the States, and we’ve had setbacks, and you can see journalists occasionally being aggressive about that,” he said. “I mean ‘You’re spending taxpayers’ money, and you’re still messing up,’ which can be a fair comment.”

    Only if the experiments meet their goals for collected data by 2012, Lamont said, would CERN pull ahead of the research performed at the US-based Fermilab, a particle accelerator located near Chicago, Illinois that measures 6.3 kilometers in circumference.

    “We’ve got reach in energy, but they’re still sort of chasing at our heels,” Lamont said. “So if we can collect enough data in 2010 and 2011, we essentially put them out of business, then we can relax in 2012 and fix the [LHC] properly.”

    Update: The latest news (01:51) on the LHC Vistar doesn’t sound good: “soon access in US15 for fire brigade”. The beam was lost around 01:00, soon after beams had been ramped to 3.5 TeV. US15 is an underground service cavern next to the ATLAS detector.

    Update: Not clear what that was about, but as of 4:30 things are back to normal and they’re getting ready to inject another beam.

    Posted in Experimental HEP News | 10 Comments

    Summer School

    This is the time of the year when young particle physicists usually want to go to school, more precisely, a “summer school” held in some pleasant location. These typically have a series of survey lectures on the hot topics of the subject, aimed at the level of advanced graduate students and postdocs. These days, the lectures are often available on-line in some form, so anyone interested in learning some more about currently active research topics can do so, even if they have to miss the summer travel aspect of the school.

    Here’s a partial list of some of the larger such programs:

    Theoretical Advanced Studies Institute in Elementary Particle Physics: String theory and its applications, Boulder, Colorado June 1-25

    Summer school on structures in local quantum field theory, Les Houches, June 7-25

    50th Cracow School of Theoretical Physics, Zakopane, Poland June 9-19

    2010 European School of High-Energy Physics, Raseborg, Finland June 20 -July 3

    Summer School on Mathematical String Theory, Blacksburg June 21-July 2

    Cargese Summer School on String Theory: Formal Developments and Applications, Cargese, Corsica June 21-July 3

    PASI School on Quantum Gravity, Morelia, Mexico June 23-July 3

    Prospects in Theoretical Physics: Aspects of Supersymmetry, Princeton July 19 – July 30 (why Princeton as a location to travel to for the summer is a bit of a mystery…)

    Cargese Summer School on Physics at TeV Colliders, Cargese, Corsica July 19-July 30

    International School on Strings and Fundamental Physics, Munich July 25-August 6

    PSI Summer School on Particle Physics: Gearing up for LHC Physics, Zuoz, Switzerland, August 1-7

    SLAC Summer Institute on Neutrinos, Stanford, August 2-13

    Clifford Johnson is blogging from the quantum gravity school in Morelia, where he’s shocked to find the “totally bizarre” situation that the students there aren’t very enthusiastic about string theory. He attributes this to their ignorance:

    Here’s the really odd thing about all this … : While this is a school on Quantum Gravity, after talking with the students for a while one learns that in most cases the little they’ve heard about string theory is often essentially over 20 years out of date and almost always totally skewed to the negative, to the extent that many of them are under the impression that string theory has nothing to do with quantum gravity at all! It is totally bizarre, and I suspect it is largely a result of things that are said and passed around within their research community.. So there are a few students here and there who have some familiarity with strings, huddling together at times for warmth in a sea of miscommunication, misinformation, and strange preconceptions.

    I find it extremely hard to believe that the students at this school are ignorant of claims that string theory is a unified theory including quantum gravity, more likely they’re just unconvinced and more interested in other approaches.

    Lubos reacts to this by noting that Clifford is finally encountering reality:

    Clifford Johnson seems to be surprised that almost all the students have been brainwashed by various anti-stringy misconceptions. Clifford has clearly been living outside the reality at least for 4 years, and so have many other serious high-energy physicists.

    and then goes beyond Clifford, arguing that the problem is not just ignorance, but sub-normal intelligence:

    There’s no string theory group in Mexico – another fact that shouldn’t be shocking given Mexico’s average IQ around 85. The IQ increment needed to go from non-stringy quantum gravity to string theory is around 20.

    Posted in Uncategorized | 14 Comments

    String Theory Fan

    One of the weirder battles of the String Theory wars became known to some as “trackbackgate”, referring to arguments over the arXiv’s policy of not allowing trackbacks to this blog. I’ve mercifully forgotten the details of the story, other than that I wasted a lot of time arguing the issue with the authorities at the arXiv and Cornell, an argument that I finally lost. If you’re interested in the history, a couple blog entries you could start looking at would be this and this.

    At some point the arXiv’s policy changed, and some trackbacks to blog entries here started to appear, as well as trackbacks to all sorts of media stories that linked to the arXiv. A little bit of checking seemed to indicate that trackbacks would appear if I linked to papers not in hep-th, but wouldn’t appear when I linked to hep-th papers. A recent example would be this blog entry, which linked to and discussed this paper. This made me a bit curious about what the arXiv current trackback policy might be, but from past experience I figured that trying to contact them to find this out was unlikely to get me anywhere.

    One day recently it occurred to me that a way to find out something about this would be to start up another blog, write a posting linking to an hep-th paper and see what happened. It’s quite remarkable how little time it takes to start up a blog, so an hour or so later String Theory Fan was on the web, with an About section:

    This blog will be devoted to discussing the latest exciting developments in string theory, our best hope for a fundamental unified theory of particle physics and quantum gravity.

    The author is an academic actively studying this fascinating subject.

    a first blog entry spouting hype about string theory, the multiverse and how uninformed critics were, and a second one linking to and superficially summarizing a randomly chosen recent multiverse paper.

    Well, I still don’t know what the arXiv’s policy is about trackbacks to hep-th papers, but the data shows that while Not Even Wrong doesn’t seem to qualify, String Theory Fan does:

    Posted in Uncategorized | 30 Comments

    Various and Sundry

  • Last week’s symposium in Paris on Symmetry, Duality and Cinema now has talks available on-line. These include a very nice survey talk by Edward Frenkel, including some comments on his recent work with Langlands and Ngo that involves an analog of the trace formula in the geometric case. The symposium also included a showing of Frenkel’s film Rites d’amour et de maths, and the Huffington Post has an article about the film here.
  • Some notes from this year’s Talbot workshop on Twisted K-theory and Loop Groups have started to appear here.
  • For the last three weeks or so, the LHC has not been taking data, but instead working on commissioning the beam at higher intensity. This process should end soon, and the plan is to have physics runs this summer with up to 24 bunches/beam, getting an integrated luminosity of around 5 pb-1.
  • For an excellent article on the science job market in the US, see The Real Science Gap. The author quotes from this posting about 2009 particle theory hiring. Numbers for 2010 so far look similar.
  • The authors of the preprint that led to the “Five Higgs” world-wide hype-fest (see previous posting) have put out a revised version of their preprint. The first version gave as major motivation corroborating SM-violating data in another channel from earlier experiments, but this has gone away in recent CDF data. The new version removes most of the discussion of this, leaving one paragraph that seems odd to me, since it refers to the recent CDF data as “strengthening the case for physics beyond the SM”, although that data only disagrees with the SM at the .8 sigma level.
  • In Denmark it seems that they take their quantization of moduli spaces very seriously, with the Center for the Topology and Quantization of Moduli Spaces at Aarhus now joined by a new Center for Quantum Geometry of Moduli Spaces.
  • Posted in Uncategorized | 5 Comments

    God Particles Breeding Like Bosons

    Science news in the media today is full of stories about Fermilab finding no less than five Higgs particles: God Particles Breeding Like Bosons, The ‘God Particle’ may exist in five forms, Large Hadron Collider’s rival project finds, US experiment hints at ‘multiple God particles’, Fermilab Experiment Hints at Multiple Higgs Particles. The source of these stories can be traced back to this preprint, whose authors then appeared on this radio program, leading to this Symmetry Breaking story.

    On May 18 D0 claimed observation of CP violation in processes involving B-mesons of a sort that could not be explained by the SM, at a significance level of around 3 sigma. For an explanation, a good place to look is Resonaances. A violation of the SM is an extraordinary claim, so it requires some extraordinary evidence, and a 3-sigma result is not that extraordinary. The case for such a violation was strengthened by the fact that D0 and CDF had seen a 2-sigma violation of the SM in a similar CP-violating process. The May 23 theory theory preprint tries to explain these SM violations with a model involving two Higgs doublets. Two days later though, on May 25, CDF reported new results: with better data, their 2-sigma SM violation had gone away (now it is 0.8 sigma, completely consistent with the SM). Again, for a good explanation of this, see Resonaances. Somehow, the disappearance of one of the main reasons for taking all this seriously didn’t make it into the Symmetry Breaking story, or any of the flood of ridiculous stories that appeared today.

    Posted in Experimental HEP News, This Week's Hype | 9 Comments

    Predictions From David Gross

    Video of David Gross’s talk at the Physics at the LHC 2010 conference is now available. He devotes much of the talk to reviewing predictions he made back in 1993 of what would happen by 2008, and making new predictions for what will happen by 2020.

    The 1993 experimental predictions that didn’t work out could mostly be explained away by the SSC cancellation, which pushed investigation of TeV scale physics into the future at the LHC. In 1993 Gross predicted two light Higgs particle and superpartners (due to supersymmetry), new Z-mesons (i.e some new U(1) gauge fields) and “There will be cloudy evidence of superstrings.” His 1993 predictions about theoretical developments related to string theory didn’t work out very well:

    String field theory will begin to be a useful tool and will illuminate the underlying symmetries of the theory. (not at all, he admits)

    New mechanisms of string supersymmetry breaking will be discovered leading to new and definitive low energy models. (new maybe, certainly nothing definitive)

    The conceptual revolution arising from the nonperturbative formulation of string theory will be in full swing, revolutionizing the concepts of space-time geometry. (“on its way, but it hasn’t really revolutionized our concepts“)

    For 2020, Gross makes one striking non-scientific prediction: The US will join CERN and there will be a joint plan to build a linear collider at CERN.

    His experimental predictions include a repeat of the 1993 ones (superpartners, new Z-mesons, and the Higgs, although now he only mentions one Higgs), except that he has now given up on even “cloudy” evidence of superstrings showing up at the TeV scale. His theoretical predictions include a much scaled back version of the 1993 theoretical predictions about string theory: “If we’re lucky, string theory will start to be a theory with predictions (right now we don’t understand it)”.

    As far as supersymmetry goes, he says that he is “totally convinced that SUSY should be there, at the 50% level” and repeats his offer to take bets at 50/50 odds. One of the main motivations for this is the argument that SUSY can provide a suitable dark matter candidate, and he predicts observation of dark matter by 2020 at non-accelerator experiments.

    Finally, he ends up with an attack on the anthropic explanation of the CC, and predicts that a better one will be found by 2020.

    Update: See Lubos, who has a lot more energy than I do, for a transcription of Gross’s predictions.

    Posted in Uncategorized | 9 Comments

    Millennium Prize Update

    The Clay Mathematics Institute this past week sponsored a conference in Paris devoted to celebrating the proof of the Poincare Conjecture. This included a short ceremony on June 8th awarding the Millennium prize to Perelman, which included several laudations explaining his achievement.

    The question of what happens to the million dollars remains unresolved, with the following statement issued yesterday:

    The Clay Mathematics Institute has no plans for the Millennium Prize funds other than to respectfully wait for Dr. Perelman’s decision. No deadline has been fixed for his decision, and nothing has been said or will be said about the possible use of the funds. Please see the text and laudations below for what is truly important: Dr. Perelman’s great gift of a solution to the century-old conjecture of Henri Poincaré, and Thurston’s geometrization conjecture. Their solution was celebrated at a conference in Paris held June 8-9, 2010. Those present send their congratulations and best wishes to Dr. Perelman.

    Posted in Uncategorized | 30 Comments

    LHC Update

    See here for a new status report on the state of beam commissioning at the LHC. About two weeks ago a peak luminosity of about 2 x 1029cm-2s-1 was reached, using beams with 13 bunches, but each bunch relatively low intensity. Since that time, efforts have been directed at increasing the bunch intensity towards nominal values. During this process, there has been little new physics data gathered, although the plan has been to interleave physics runs on weekends with beam commissioning during the week.

    On Wednesday, this plan was changed, with the focus now completely devoted to commissioning beams with nominal bunch intensity. The hope is to have collisions of high intensity bunches in two weeks or so and then provide a 4 week period of stable running for physics during August, at luminosities an order of magnitude higher than now available. The limiting factor will be the stored energy in the beam, which is approaching Tevatron levels. To go higher will require much more testing of the beam protection systems.

    This week in Hamburg there was a conference people have been waiting a long time for, Physics at the LHC 2010, the first conference devoted to the presentation of LHC experimental results. So far the results are based on very low luminosities, so are only able to check that the machine is working and rediscover various well-known features of the Standard Model. As the luminosity increases, it will start to become possible to observe or rule out various exotic particles at masses not reachable by the Tevatron, as long as the cross-sections are high.

    Mostly such things are unmotivated and not expected to turn up, but one story to watch is that of supersymmetry, as the LHC becomes capable of observing strongly-interacting superpartners at masses beyond the Tevatron’s reach. The MSSM includes a huge number of unknown extra parameters, so the masses of these things are unknown. Given one motivation for supersymmetry, that it is supposed to stabilize the electroweak scale, one would expect superpartners to readily show up at the new mass ranges being investigated by the LHC. The problem with this is that it’s hard to understand why they haven’t already been seen at the Tevatron, or indirectly in other experiments through the effects of higher-order processes. Taking current non-observations into account, even if one has faith that superpartners exist at masses the LHC can probe, it doesn’t seem likely that the earliest LHC data will be able to see them (for more specific analysis along these lines, see for instance this talk).

    I’m quite dubious that the LHC will ever see superpartners, but many prominent theorists claim that this is likely to happen. It would be interesting to pin them down on what LHC luminosity is needed to see what they are expecting to see.

    Update: A particularly noteworthy talk is that of Mike Lamont, where he gives estimates of the progression of integrated luminosity this year. They’re significantly more pessimistic than similar estimates from early this year, with about 50 inverse pb this year instead of 200, but still on track for 1000 inverse pb by late 2011.

    Posted in Experimental HEP News | 3 Comments