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    Rumors About A Light Higgs
    By Tommaso Dorigo | July 8th 2010 02:59 PM | 102 comments | Print | E-mail | Track Comments
    About Tommaso

    I am an experimental particle physicist working with the CMS experiment at CERN. In my spare time I play chess, abuse the piano, and aim my dobson...

    View Tommaso's Profile
    UPDATE: if you came here to learn more details about the rumored Higgs signal, which media around the world are discussing and which Fermilab Today just dismiss-tweeted, please visit this other more recent post for more details. Below is the original post which apparently originated a lot of buzz.
    ---------------

    And for once, I feel totally free to speculate without the fear of being crucified. If you have followed my past blog adventures for long enough, you know that in at least a couple of occasions my posts have created some friction.

    Blogging can mean walking on a rope for particle physicists involved in large collaborations - the ways of the internet are infinite, really: you never know where trouble may come from! The chance to piss someone off forces bloggers to avoid making names even when they discuss humorous incidents; the internal rules of the experiments they participate in make bloggers wary of even discussing stuff that is approved for public distribution. A daily application of self-censoring review procedures before hitting the "submit" button must be enforced.

    But not this time. I am sure of one thing: I know nothing at all, so I can certainly talk about it without violating any rule! It so happens that I have heard voices about a possible new "three-sigma" Higgs effect, and I do not even know which experiment this comes from! Surely, no single experiment can get mad at me this time if I tell you what it is about, right ?

    ...Right. Well, I am not totally sure, but I am willing to declare that I have the right to express myself here, to some extent at least! So let me spill my guts. They are almost empty anyways...

    The Rumor

    It reached my ear, from two different, possibly independent sources, that an experiment at the Tevatron is about to release some evidence of a light Higgs boson signal. Some say a three-sigma effect, others do not make explicit claims but talk of a unexpected result. That the result comes from the Tevatron is for sure, since the LHC experiments do not have nearly enough data yet to search for that elusive particle, and other particle physics experiments in the world have not nearly enough energy to produce it. However, I am unable to understand whether the rumor comes from CDF or from D0.

    Lest you jump at conclusions too early, I need to explain something more: despite being a CDF author, I unfortunately do not follow actively the works of the Higgs Discovery Working Group within CDF, so a Higgs excess in CDF data could well have escaped me. In principle, if I now took on digging hard enough in the internal pages of the CDF experiment I might be able to find out if this signal is coming from there, and maybe learn more about it. But there are at least a dozen analyses to dig into! Too much work - while wild speculation is more fun!

    Reasoning On It

    So let us take a look at the latest Higgs boson limits, released jointly by CDF and D0 last November. The dozens of analyses combined for the global limit were based on a dataset amounting to anything between 2 and 5.4 inverse femtobarns of proton-antiproton collisions, while right now the experiments have probably in their hands over 50% more processed and analyzable data.

    The graph I choose to make a point is actually not one describing the limit on the Higgs boson cross section as a function of Higgs mass. Rather, let me pick the one showing, as a function of mass, a quantity that describes more clearly whether the data are background-like or signal-plus-background-like. The hatched black and red curves in the figure below show the value of the statistical estimator LLR (not going to explain you here what it is, but ask for it in the comments thread if you are interested) that the experiments would have globally observed, on average, if the higgs were there (red) or not (black). The farther the two curves are, the more sensitive the experiments are to a Higgs signal.



    Also note the green and yellow bands, drawn around the expected background curve: they denote the typical extent of one- and two-sigma fluctuations expected in the data. In other words, if the Higgs is NOT at 130 GeV, say, then the LLR is expected to be on average equal to 1, but 68% of the time we may expect to find it anywhere between -1 (lower edge of the green band at 130 GeV) and +2.6 (upper edge). This is the so-called "one-sigma" band.

    Now, look at the full black line. This shows the actual LLR value of the data, after the complicated analyses that sought the Higgs decay in dozens of different possible final states is processed. You notice several things.

    The first thing to note is that the curve stands more in the "signal-plus-background" region for masses below 145 GeV, then going up and following the "background-only" curve for higher values.

    The second thing to note is that while at 165 GeV the two LLR expectation curves are quite far apart (meaning that a Higgs boson might have produced a 3-sigma excess there, quite easily), at 120-140 GeV the curve of signal-plus-background stays on the border of the green band: the _expected sensitivity is there at most a one-sigma effect. In other words, a Higgs boson at 130 GeV would on average produce a 1-sigma deviation from the background-only curve, in the Tevatron data analyzed until November 2009. On average, though! The actual observed data, if it contained a Higgs boson, could produce larger signals, if the experiments got lucky.

    The third thing to note is that the black curve in the low-mass region stands even lower than the red hatched curve! That means that the data there is definitely more signal-like than background-only-like. But is this a significant observation ? Well, no: the curve is well-contained within the yellow band. A less-than-two-sigma effect.

    So, that was the situation last November. What should we expect now ? Could the black curve fall further down, hinting at a Higgs boson in the 115-140 GeV range ?

    It could. In my opinion, a further fluctuation of the data, and the addition of 50% more of it, could bring the black curve out of the yellow band, toward a three-sigma signal-like effect. Is this what the rumors are about ? I do not know, but one thing is sure: we will know soon... If you are coming to Paris for ICHEP, you are among the lucky ones who will get the information first-hand from the analyzers.


    An Appendix: Why Rumor Mongering ?

    Why am I doing this ? I know several "serious" physicists and colleagues who have questioned this care-free attitude of mine in the past. What good does it do to shout "Higgs" every second week ?

    It does a lot of good to particle physics, in my very humble, but not quite uninformed, opinion. I have made this point other times, and will not repeat it here. Suffices to say that, in a nutshell, keeping particle physics in the press with hints of possible discoveries that later die out is more important than speaking loud and clear once in ten years, when a groundbreaking discovery is actually really made, and keeping silent the rest of the time.

    And there is another reason why I find this kind of rumor-mongering entertaining: maybe some informed soul out there might comment anonymously and share some more gossip about the matter with us... ;-)

    Comments

    Amateur Astronomer
    I guess you are showing a Log Likelihood Ratio Test, with a null hypothesis Ho that there is no signal. There appears to be a 70% to 80% chance of finding a signal in the range 115 GeV to 140 GeV. Is 95% chance at the lower edge of the 2 sigma band the level of rejection for Ho? Are 50% more observations enough to decide if there is a signal in that interval, and could that much data have been collected in the past 6 months? I would have guessed that at least twice as many observations are be needed, or the team would need to be very lucky. Thanks for the preview.
    dorigo
    Hi Jerry, yes, it is a log-likelihood ratio. Dubbing H0 the null hypothesis is quite confusing, given that the particle's name is indeed H0 :) but I agree to calling the null H_0 and the alternate H_1.

    I do not understand how you can conclude that there's a 70% chance of finding a signal (if H_1) in the range 115-140 GeV: for us, "finding a signal" means observing it at 5-sigma. Instead, you are right about the rejection level: 95% is roughly where the edge of the two-sigma band lies.

    No, 50% more data won't discriminate the signal in any interval, but it might allow to exclude some ranges. The Tevatron will need of the order of 5 times more data than there is in the graph in order to exclude the full range of Higgs masses, but to find the particle at 5-sigma is simply not possible in the light-mass range.

    Best,
    T.
    Uh oh, Tommaso is taking aim at Resonaances for top HEP goss rag of the internet status! ;-))

    Of course, it's actually quite easy to find out what's happening in the Higgs working group if you have access to the CDF website; just look at recent talks and see what has been blessed recently. Wouldn't take long. But if you knew you wouldn't be free to talk about it :-)

    Good to hear, Tommaso, despite the 99.7% chance that rumors on your website are wrong.

    Despite your attempt at a justification, I do not understand why you're spreading such rumors. You are, in a nutshell, wasting other people's time. What do you think about other rumor-prone fields like, say, cancer research? How often did you have to read that we're oh-so-close to a cure for cancer, just to then never hear of it again. Don't you think they should keep their mouth shut until they have a scientific result and till then stick with the facts? Well, I think so. So, in my impression your premature rumor spreading is a disservice to science and one that you engage in merely to your own entertainment. Probably combined with the urge to have said it first. Go seek your navel. Take care,

    B.

    Dear B, if the media and communicators only informed the public at the moment when a five-sigma discovery of the Higgs boson caliber is first achieved, or "the" cure for cancer is first verified, there would be 1 report about particle physics in 40 years and 1 article about cancer research in 100 years.

    I've considered all previous Tommaso's rumors to be bogus, and all of them turned out to be bogus, indeed. But this one is different, and I think that the odds that such evidence will be claimed based on the data that were already collected are 50:50. It's simply a reasonable moment. With 10/fb, Fermilab has a 30% chance to find a 3-sigma and 70% chance to find a 2-sigma signal for a light Higgs - so why not? If he heard it...

    It's important to build on facts and solid arguments - but whoever is not excited by possible Higgs observations, and the chance that he could know these things before the rest of the world, doesn't have a scientific heart.

    Best wishes
    Lubos

    If the media wouldn't ticker around all sorts of nonsense and unconfirmed rumors that the blogosphere willingly feeds them who knows, they could actually fill their science sections with real science. You see, all the stuff that they now consider too boring. The stuff that could teach the general public a thing or two about this century's physics.

    It's one thing to be exited about being an insider and having the possibility to know first. It's another thing to go around and brag with that.

    Dear B, they wouldn't.

    If the media didn't have any inflow of sufficiently frequent exciting news of the Higgs-discovery scale, they would simply be choosing the exciting stuff from the realm of fantasy and pure garbage - which they're doing most of the time in the real world, anyway.

    You can't prevent these things. By their nature, the media are driven by excitement, not by boring textbook results. The maximum one can try to do is to make the excitement as correlated with the actual results and scientific developments as possible, and reporting on the daily hopes of the Tevatron is surely going in the positive, not negative, direction. It's an experiment that costs billions of dollars and I don't know why rumors about its hopes and daily life shouldn't be reported - or at least on a monthly basis. It's clear that a chance of a discovery or evidence for the God particle is more interesting news than another femtobarn of some boring old data.

    If Tommaso knows a real fact about the planned paper as one of the first people, then it's natural he brags. He has something to brag about. In fact, such things could be the *best* thing that Tommaso can brag about. It's hard for me to imagine something else he can brag about - of course, except for things like his kids.

    That's the point, they are already using fantasy and garbage - and they know there's sufficiently many people who dislike this. That's why they hold on to whatever somebody with a PhD is dumb enough to utter in the presence of a journalist, because a Dr title spreads authority. I'm not saying not to feed them, I'm saying feed them the stuff that the public should know. How many of them even have the faintest clue what a quantum field theory is? Oh, forget about the "quantum". Wait, forget about the "theory" as well. I'm certainly not going to prevent single-handedly the world from turning into a permanent overhype where nobody can tell and everybody has stopped caring what's real and what's made up. Yeah, sure, let's see it like this, there's this lab and it's cool if it's in the newspapers and all you need for that is an unconfirmed rumor from a blogger. I'll leave it to your imagination how much it takes till the rumors have become part of PR, or at least till the public suspects they are. Do some extrapolation. Science lives from accuracy and trust in its reliability. Trust is terribly easy to lose and hard to recover. Look what's happened to politics.

    And why won't this damned site let me unsubscribe from the comment notification? I already unchecked this box 3 times now.

    Dear B, you may feed the media whatever you want, but it's still true that those media that offer something that the readers or viewers don't find interesting will fade away and die.

    I completely agree with the rest of your criticism of the media and the direction where they help to push the society but I don't think that you have found a solution how to improve the situation. In fact, I think it is obvious that the media must be fed by the people who actually do find things such as QFT exciting, but also know lots about it, and controversies are the last ones that the media want to avoid if they want to survive. But there are interesting and justifiable controversies and rumors, too.

    "I'm saying feed them the stuff that the public should know," you say.

    Speaking as a science writer who distributes what I digest in journals and on sites like this to the general public in hopes of keeping up public interest and, in the end, public funding, I'd love to know what agency you recommend to be an arbiter of "stuff that the public should know."

    One of the things the public is sadly lacking is a grounding in critical thinking and a working knowledge of the process of scientific advancement. One of the thing that science is missing is popular interest and public support.

    A "walled garden" mentality, B, helps neither. It certainly doesn't help your funding.

    [*]

    dorigo
    Oh Lubos, thank you for defending me. But you misrepresent me - I can brag about a number of things. The first thing that comes to my mind: I can beat you, a 150+ IQ person, at chess, blindfolded. Oh, of course - my IQ is over 160 ;-)

    Cheers,
    T.
    Mine is 187. You would know it very well if you were watching CBS more carefully.

    By the way, if your IQ is above 130, as you claim, you should easily decode this picture:
    http://motls.blogspot.com/2010/07/secret-images-contest.html

    dorigo
    Thank you Lubos, but your site is not the only one offering IQ tests, nor do I have the time to play with these things. I am happy that your IQ is so high, however I am unhappy that you do not use your intelligence for the benefit of humanity. You could be a brilliant climate scientist, for instance ;-)

    Cheers,
    T.
    Dear Tommaso, it's curious that people like you never ask what the humanity has done for me.

    Concerning climate science, I am kind of satisfied for being the 23rd top sane climate scientist in the world according to Stephen Schneider et al. ;-)

    http://www.eecg.utoronto.ca/~prall/climate/skeptic_authors_table.html

    dorigo
    Hey Lubos, don't be melodramatic. If you listen to Bach or enjoy paintings in a museum or travel on an airplane or use the internet or take antibiotics or drink a good wine, remember that these things took a long effort to make, and the result is to make your life easier or more enjoyable.
    Best,
    T.
    But these things were not invented or produced by "humanity"; they were produced by individuals like me.

    hahaha! You tried to be superior to him in IQ, which failed, then in contribution, then failed that too and now are trying to pass it off as a win on your side.

    You failed twice in a row XD pwnt

    dorigo
    Methinks you wasted your time writing such a long, meaningless comment. Physics is not in everybody's attention as is cancer research. But I am wasting my time now.
    Best,
    T.
    Beware of announcements so close to ICHEP. There is a tendency to want to make an impact at what is always the most important biannual event in particle physics. Plus the simmering competition between CERN and Tevatron. Plus the memory of how LEP2 used tentative indications of Higgs-like events to try to justify a life-extension. Plus part of me finds the Higgs model too "cute" and pat and this fuels some scepticism on my part.
    But I welcome rumours about the possible discovery of theoretically well-founded particles. Anything is better than the stream of unmitigated hype coming from the String Theory crowd these last twenty years or so.

    Dear DB, it may turn that the LEP2's 115 GeV signal was due to the Higgs and your criticism of their pressure to extend the LEP lifetime may turn out to be indefensible pretty soon. It could have been very sensible to extend the lifetime, and I would have personally given them an extra year if I were deciding - simply because it's stupid to ignore the evidence that the sought-for particle could be just behind the corner. The LHC was delayed by many years, anyway - and the delay could have been equal even if the LEP continued.

    It's kind of amazing where does the certainty about the absence of the 115 GeV Higgs come from in the same brain that doesn't understand why the Higgs has to exist, as you admitted, and who even doesn't understand why string theory is the most robust and advanced discipline of contemporary science, as you admitted as well.

    You are completely right Lubos, string theory is by far the most robust and advanced discipline of contemporary science!

    In fact it's so robust and advanced as to be completely useless! But not in the bad way of course, it's useless in a good and progressive way, after all it has given work to many generations of brilliant young minds who would otherwise have to contribute meaningfully to the society! That has to count for something, right?

    And of course string theory have given us such towering figures of science as Lubos Motl himself, whose fame is dwarfed only by his failure to deliver scientific results, but I don't mean it in a bad way of course, I am your most devoted fan!

    All hail the glory of string theory!

    Dear DB,

    the purpose of string theory is not to be *useful* for wild monkeys or their human peers but to find out important things about the Universe that are *true*. This is a completely different adjective. If you want things that are *useful* for the likes of you, you will have to buy some heroine on the free markets. The retailers over there are very useful for the "society" such as yourself but sadly to inform you, they have nothing to with theoretical physics or anything else of any value, for that matter.

    [Lubos wrote: "It's kind of amazing where does the certainty about the absence of the 115 GeV Higgs come from"

    Now this is where you need to step back, take a refresher course in propositional calculus and study the semantics and etymology of the term "non sequitor".

    When you do this, the proposition you incorrectly attributed to me will dissolve along with the concomitant sense of amazement.

    DB, people at LEP were the first in being interested in the LHC. If some pushed for a longer run
    it was because the hints for a Higgs signal were pretty serious. And I for once agree with the little
    fascist and the Higgs is probably right there.

    Tommaso, you must abandon the obsolete concept that the Higgs has a unique mass. Otherwise you will never guess what the secret is.

    dorigo
    Interesting concept. A broad Higgs. Wow, that's indeed food for thought. Thanks for the lead, I will think it over...

    Cheers,
    T.
    Well, this is a SM Higgs analysis, so there's no broad Higgs at this range.
    Nothing agains BSM Higgses, though.

    Or, the comment by "Higgs masses" could be interpreted to mean that the rumor involves more than one Higgs.

    Or, this whole thing is just an excess of the usual boring variety that you would expect to happen when you are looking for lots of things in lots of bins, and therefore doesn't correspond to a fixed Higgs mass, just as you would expect for such boring excesses.

    Boy, some of you people have a lot of nerve!

    The Tevatron is a project of the United States government that is funded by taxpayer dollars -- well in excess of a billion of them.

    I am not aware of any other field (except for military and intelligence activities, or personal information like individual tax returns and criminal investigation materials) where anyone would be so presumptuous to claim a right to keep any information paid for by the government secret from the public for any length of time.

    That government employees actually claim some form of entitlement to do this, for their personal career benefit, is really quite outrageous.

    Not only does Tommaso in the right to publish these "rumors," but I have serious questions about whether it is even legal (see, e.g., Freedom of Information Act; U.S. Const. Am. 1) for the experiments to attempt to force employees to withhold scientific data from the public. I paid for that data, it belongs to me, and if I want to see the draft papers, Tomasso's rumor mongering, or even the raw data as it is being generated, who is anyone to tell me that I can't?

    People working at the experiments who don't like that, should go and work at a privately funded particle accelerator.

    Hank
    I think you are misunderstanding the difference between secrecy and not allowing misunderstood data to be published before it is accurate.   Tevatron publishes results every week, nothing secret about that.

    Would the FDA issue a report after a day of testing on a product and assume the public is well versed enough to realize it may not be accurate and they should not use it yet?  Of course not, even with rigor plenty of drugs get approved that are later harmful.  But they are as accurate as they can be.

    If you personally only need a 65% confidence interval than the Higgs has already been found - guaranteed.    It also means that your "well in excess of a billion of them" statement is accurate despite it being wrong by 60%.    But these groups want 5 standard deviations and claims before that is possible are not allowed because it would be irresponsible.
    dorigo
    Well summarized Hank.

    In principle Amos is right. Science should not be hidden. Openness is better than secrecy. But in reality, collaborations need to keep their internal workings private because of the need to work freely without the risk of being judged for incomplete, partial, not yet scrutinized results.

    Granted, the system is a bit twisted. While internal, private discussions, meetings, talks, slides, notes must be protected in order to prevent people from having to think twice at every other thing they do and say within their collaboration -this would harm the Science-, the rather paranoid way by means of which these collaborations operate, and their constitutions, are erring on the side of caution. Bordering the ridicule in some cases, when it gets demonstrasted that these strict rules just do not work, just as prohibitionism did not stop alcohol consumption in the early XXth century.

    I see no way to mend these shortcomings. Evolutionarily speaking, 2000+ -strong collaborations will have to lower the bar of their policy of what is private and what is not, as the system withstands larger and larger failures. The problem is Internet, and the problem is that men like to discuss outside of their offices. Which is just normal and healthy, and does not harm Sicence, quite the opposite.

    Cheers,
    T.
    I personally have no problem with rumours with a positive twist... But are three sigma worthy of all this fuss? Why don't we ask the octopus for the correct Higgs mass? ;)

    Hi Tulpoeid,
    The octopus is just telling you what IQ you need to guess in football. It did better than me anyway.
    As for the 3 sigma, aren't we talking about a 2-sigma effect?

    Hank
    And the octopus picked Germany, so he is 100% wrong.
    L O L! "The octopus is just telling you what IQ you need to guess in football"

    Hi Tommaso,

    Assume you had 50% more data and this data looked exactly like the one we already have, i.e., this data would also favour a Higgs boson at 120-140 GeV, etc.
    How would then the LLR plot look like? Is there some rule of thumb to guess the new plot in a quantitative way?
    Of course the dotted lines would move further appart, the 1 sigma bands would probably increase a bit, etc,
    but would the observed LLR manage to peep out of the yellow area at around 135 GeV? Probably at 115 GeV too?

    In a related question: what is the correlation between the different Higgs mases in the LLR plot? If the Higgs boson happend to be there at 115 GeV, what would we expect the black line to look like at 135 GeV?
    Of course, at 160 GeV it would not change a bit since we are looking at different channels.
    My point is, if the H was behind the corner at M_H < 145 GeV, should there be a correlation like the one we are getting between all the points in the LLR_{obs} curve?

    Bye,
    Federico

    By the way, if the rumor is right, my guess is that the Higgs was spotted right at those 115 GeV. See also

    http://www.science20.com/quantum_diaries_survivor/new_tevatron_higgs_lim...

    that Tommaso wrote in November 2009 but everyone forgot about it. For the 115 GeV Higgs, one had a 1.7 sigma excess from LEP2 and a 2-sigma excess from November's Tevatron. When combined, via a Pythagorean theorem, this gave 2.6 sigma already at that time.

    And the very light Higgs, as light as possible, given other exclusions, is the most likely one, after all, because of precision measurements and the way how SUSY works.

    Tommaso, I assume that rumors will be solved in the paper "Combined upper limits on standard model Higgs boson production at D0 in ppbar collisions at sqrt(s)=1.96 TeV," where results of Higgs searches up to 6.8 /fb will be published in ICHEP2010.

    dorigo
    Hi Francis,
    maybe so, or maybe in another talk. But first CDF and DZERO will present their new results at a wine and cheese seminar on July 16th at FNAL.

    Cheers,
    T.
    Finally, FNAL's "wine & cheese" has been FNAL's "salt & pepper." Maybe the combined CDF+DZero results on Higgs will be presented in ICHEP.

    If the 115 GeV fluctuation (seen so far by LEP2) will grow and if I were L. Majani (so far CERN DG ) which did not allow
    LEP experiments to collect data for one more year..... I would not sleep very well.

    dorigo
    THe decision to stop LEP2 was quite sound P. Some of the LEP people were quite vocal back then, even claiming they had 3 sigma. ALEPH in particular -ah, always ALEPH... But the truth was that the "evidence" was a mere 1.7 standard deviations. Maiani did excellently, not well, to stop LEP II, regardless of whether there is a Higgs, four Higgses, or no Higgs there.

    Best,
    T.
    Tommaso, here I disagree. The main reasons to stop LEP were more political than scientific
    (look at the LEPC recommendation...), not to "disturb" LHC that had to be ready in a five year
    time (but we know the story). You have indication of a signal, you know the next machine
    of your Lab will have many difficulties in covering that mass range, you know the competitor lab
    has a reasonable chance to find it if it is there, and you simply destroy the best machine ever
    built in the world....
    Is it a scientific argument?
    SM fits prefer light Higgs, so the chance (I could say Bayesian probability) of having a signal at 115 was high.

    For the story: a little afterwords we knew that CERN budget to accomplish LHC was not sufficient.
    If it is at 115 I think somebody should excuse for his choices. Of course it will never happen.

    P.

    dorigo
    Nobody questions that the decision was due to the need to build the LHC! But the "indication of a signal" was anyway not really strong, the analyzers had got the chance of a fluke wrong by over an order of magnitude (1.7 sigma happens once in ten times, 3 sigma once in 300), and it looked too much like a rant of the boy whose toy is taken apart.

    Anyway saying "the best machine ever built in the world" says it all - you are certainly not objectively looking at the matter :)

    Cheers,
    T.
    Given the known facts, the decision to stop LEP(2) was irrational. Even with 1.7-sigma, it's 91% confidence level. It makes the discovery 10 times more likely than without the signal. Correspondingly, the number of discovery per invested dollar increases by an order of magnitude or so. It was just a bad moment to stop it, instead of giving it a year or two.

    dorigo
    Lubos, "it makes the discovery 10 times more likely than without the signal" is a rather imprecise statement, but after thinking it over I understood that you meant "it makes the discovery of a Higgs at 115 GeV 10 times more likely than without the observed data".

    In that case I agree. But since we do not know what is the prior probability of the signal at 115 GeV, the statement has little effect for decision theory, which is what is used in these occasions.
    If the CERN management played the game of giving the Higgs a uniform prior in mass, and assumed that the SM is correct and that the Higgs exists, they must have concluded that there was indeed a sizable chance of missing a discovery. Nevertheless, one also has to cope with investment profiles, the need to start construction of the LHC or risk the whole project, etcetera. They did the right thing.

    Cheers,
    T.
    Dear Tommaso, you wrote:

    "But since we do not know what is the prior probability of the signal at 115 GeV..."

    Is that a joke? The very purpose of the construction of colliders such as the LEP or the Tevatron or the LHC is to find new physics, i.e. they're based on the assumption that there's a significant prior probability of new physics at the accessible energy scales - up to, say, 120 GeV of the Higgs mass for LEP2.

    If it were unknown whether the "prior probability" is sufficiently high to justify the construction and running of LEP, then it may become unreasonable to build the LEP in the first place. So your "argument" is not against a continuation of LEP beyond 2000; it's an argument against the construction of particle colliders.

    The prior was whatever it was - but the 1.7-sigma signal increased this prior around the accessible 115 GeV interval for the Higgs, and the discovery-rate per dollar of extra running, by an order of magnitude. So if the collider was a good idea to start with and run it for a few years, it was 10 times better idea to continue the running. This is just about a simple inequality: if LEP was good before, it was even better afterwards. Don't tell me that you don't understand this conclusion.

    People may act irrationally for all kinds of reasons but delaying the construction of the LHC by 1-2 years because of a sizable chance to get a key discovery much earlier would surely be a great idea. And you know, if LEP managed to detect the new physics around 115 GeV before the LHC and people decided that it was enough, then indeed, one could have saved money for the LHC.

    In reality, it's clear that a discovery of a 115 GeV Higgs would, on the contrary, energized attempts to build bigger colliders because certain things would still remain hard to get by LEP and the curiosity would grow markedly.

    Your logic is upside down. It's not really logic according to my definition of logic - it's an irrational noise meant to make logic and science suffocate in fog.

    Cheers
    Lubos

    Tommaso,

    To my knowledge, the current thinking is that pairs of top and bottom quarks provide the dominant contribution for light Higgs decays. For this reason, gluon-gluon fusion reactions gg -> H are considered favorable for Higgs detection because they include heavy quarks in the loop. But is the physics of heavy quarks well understood to allow accurate computations of the statistical estimator? How confident are we that the background in these channels can be reliably suppressed?

    Cheers,

    Ervin

    dorigo
    Hi Ervin,

    the loop diagram gg->H through a top or W loop is easy to compute. There is nothing about the physics of heavy quarks that enter in the calculation, because the top quarks in the loop are virtual particles that do not have the time to act as confined objects. So the calculation of the cross section is quite reliable.

    As for the backgrounds, there are many, but they are all studied with the data, and measured separately in other final states. For example, we have now very precise measurements of the diboson production processes WW,  WZ, ZZ in proton-antiproton collisions. There can be no big surprises there.

    Cheers,
    T.
    Tommaso,

    Are you then saying that calculation of the cross section in the loop diagram discards from the outset any possible non-perturbative contributions because of the short time scale involved?

    Cheers,

    Ervin

    dorigo
    Ervin, it is better and more natural to think of it as a matter of Q^2, rather than time scale. At high Q^2 QCD is perturbatively calculable because of the smallness of alpha_s. The Q^2 of Higgs production is typically of the order of M_H^2.

    Best,
    T.
    Tommaso, thanks for your reply.

    Indeed, our current understanding of perturbative QCD is that it becomes asymptotically free at high Q^2. Looking from the perspective of effective field theory, new heavy and strongly-coupled flavors might very well show up as we probe the UV region. These hidden fields may very well destabilize the aymptotic freedom of perturbative QCD. In fact, QCD is presumed to lose its asymptotic freedom when the number of flavors reaches or exceeds about Nf=14.

    It remains to be seen if LHC will uncover the presence of such novel non-perturbative effects. If (and when) it will happen, it is likely that the 3 sigma Higgs signal will not survive. Another signature may be a deviation from anomaly cancellation that works well at the level of full SM Lagrangian.

    We'll hopefully find out soon.

    Regards,

    Ervin

    dorigo
    Dear Ervin,

    The three-sigma excess, if any, that the Tevatron could show would have nothing to do with theoretical cross section calculations of the Higgs. It would be an excess in the data, period. So I do not quite understand your comment.

    In any case the running of alpha_s is measured, not just computed. If there were additional flavours, their mass would be important. High-mass new quarks would modify the value of alpha_s for Q^2 values above their masses squared. We do know such quarks do not exist when relevant for M_H^2 values, so the perturbativity of the calculation is not at stake. However, if new quarks existed, the Higgs cross section would increase sizably, because those new quarks would give a constant increment to the gg->H diagram.

    Best,
    T.
    Dear Tommaso,

    I apologize for my insistence but there is something that is not quite clear to me here. Let me rephrase my question in a different form:

    Could the 3 sigma observation be related not to Higgs but to different physical process or processes, possibly related to some yet undiscovered channels involving heavy quarks, among other things?

    Best,

    Ervin

    Amateur Astronomer
    Tommaso Speaking of Q^2 can you give an opinion about how the experimental data compares to predictions of Quantum Triviality in the Standard Model referenced to the Higgs boson? Has Quantum Triviality been discredited by the observations, or is it still in the running?
    Tim Quin
    Stop including yourself in your posts. Learn how to write about the subject instead of your lame self.
    There is so much expectation surrounding the Higgs it is inevitable that some will suggest it has been sighted. I suspect what has been sighted is a nascent particle- that is a particle which is about to be formed- perhaps a nascent muon.

    The hard truth is that the Higgs is not needed, the explanation for mass already exists. The funamental origin of mass depends on the energy of Planck's constant, this equates to mass using the standard formula E=mc2. The fundamenrtal quantum of Nature would be the vibrational energy of Planck's constant translated into simple harmonic motion. The fundamental quantum is thus termed "harmonic quintessence".

    This energy would also explain the energy inherent in space-time the "dark energy".This way using Planck's constant quantum mecanics and qauntum gravity are merged and we get advanced qauntum gravity, QED.

    Available form the American Institute of Physics www.aip.org

    1. String quintessence and the formulation of advanced quantum gravity. Physics Essays 22: 364-377. http://dx.doi.org/10.4006/1.3182733.

    2. The formulation of harmonic quintessence and a fundamental energy equivalence equation. Physics Essays 23: 311-319 http://dx.doi.org/10.4006/1.3392799

    In response to your comment,

    It is important to recall that there are many Higgs-less formulations of electroweak symmetry breaking and physics of the Terascale sector. Replacing the Higgs mechanism with something else is highly non-trivial because of:

    a) consistency conditions that lie at the foundation of Quantum Field Theory. These impose enormuous constraints on what Higgs-less models are realistic and match existing experimental evidence. For example, introducing a nonlocal theory obstructs the requirement of Lorentz invariance and may be in contradiction with observations.

    b) the need to coherently explain part or all of open questions surrounding the Standard Model (the origin of free parameters, the number of fermion families, chiral symmetry breaking, the origin of neutrino oscillation and masses, anomaly cancellation, the true source of CP symmetry breaking, the origin of anomalous magnetic moment of leptons, the gauge hierarchy problem, the spectrum of hadron masses in QCD and so on).

    c) the need to indicate a sensible route to understanding all or part of the open problems unrelated to the Standard Model but pertaining to cosmology and astrophysics (dark matter, dark energy, cosmological constant problem, baryogenesis, inflation)

    Best,

    Ervin

    Thankyou Erwin,

    I agree,

    As ever, there is more that we do not know, than we do know. Certainly I can say the 2 papers I quoted do go some way to answering the questions you asked.

    Those grouped in paragraph c). Specifically dark matter, dark energy and quantum gravity are at least in part answered in the paper on advanced quantum gravity.

    Those gouped in paragraph a). are at least in part answerd by the paper on harmonic quintessence.

    Those grouped in paragraph b). are more difficult and something that is a work in progress. These wiil include constants like the mass and charge of the electron, the fine structure constant, the accurate masses of the baryons and mesons as well as those things you have already mentioned.

    I should perhaps cautiously state that, whilst the Higgs may explain some of these things- and is certainly non trivial - but that it is unlikely to exist. And I say this cautiously because the hard truth is we already have an explanation for mass, and that derives from Planck's constant, as stated above. What I perhaps do not sufficiently stress is that to realise this -that is consider the quantum at the Planck' energy scale you have to go a lot smaller than is currently realised.

    That scale is 20 magnitudes smaller than the electron - then QM can be far more readily understood and the eqautions of quantum physics can be derived from first principles. These also apply consitency conditions to QM that make it a lot more deterministic, although Heisenberg still applies.

    Perhaps it is not surprising that in order to understand quantum phyiscs you have to go to the almost unimaginably small.

    Available online
    1. String quintessence and the formulation of advanced quantum gravity. Physics Essays 22: 364-377. http://dx.doi.org/10.4006/1.3182733

    2. The formulation of harmonic quintessence and a fundamental energy equivalence equation. Physics Essays 23: 311-319 http://dx.doi.org/10.4006/1.3392799

    I hate to sound negative but your reply has made me skeptical of your arguments. Some of your claims are either in contradiction with observations or highly questionable. For example:

    1) You say that your theory derives universal constants such as electron mass and electric charge from physics of the Planck region. Both parameters are not universal constants, they vary with the energy scale at which experiments are performed.
    2) It is unclear how far quantum theory (as we know it) will survive in the deep ultraviolet region that we are just beginning to probe at the LHC. To state that you need to explain quantum phenomena appealing to a scale some 20 times smaller than the electron mass is, in my view, speculative and un-testable.

    Regards,

    Ervin

    Hank
    Both New Scientist and the Telegraph have made a lot more of this than you do.   The Scienceblogs writers who covered this instead linked to your cross-posted ICHEP blog version, of course - probably because we don't pay them for advertising.   :)
    Dear Tommaso, be sure that you *will* be crucified if this turns out to be one of your typical rubbish pieces. The Telegraph, Nude Socialist, Pop Sci, and even the Reference Frame with all the links are summarized

    http://motls.blogspot.com/2010/07/rumor-3-sigma-light-higgs-at-d0-or-cdf...

    not to speak about Twitter that produces several Higgs rumors each minute now, which produces hundreds or thousands of readers of your rumor per minute:

    http://twitter.com/#search?q=Higgs%20boson

    Hank
    The good news about Twitter is that no one actually clinks links.   I can see all the traffic coming into the site and Twitter is non-existent even if a person with 250K followers links it.

    Had it been on Digg or reddit or slashdot it would get a lot of new readers but twitter is mostly people in small circles retweeting each other. So one person says something obvious, like, 'it will need more than 3-sigmas' (NO SHIT??) and they all retweet each other and look increasingly stupid.
    Hank
    From Discovery News - "Carroll also urged caution about Dorigo's dramatic blog post: "I would be inclined to wait until there was some actual announcement, rather than just rumors on the internet, before taking it seriously."

    Article where Sean was quoted despite not being an experimental physicist - on the Internet.  Where Sean blogs - on the Internet. 

    The very first section of the article says this may be nothing - the article says 3 sigma, when everyone knows 5-sigma is the standard.   But they keep writing like it is some secret they just  unearthed.

    I get that the media are going to be clueless but are these guys at science publications not science journalists?
    Modesty should be exhibited in the final results, but I see nothing wrong with getting excited. Indeed, particle physics is on the cusp of fantastic discoveries. Excitement seems obvious, if not an understatement.

    Of course there is no harm discussing these things - it makes for good debate.

    The debate wiil be far hotter when the Higgs doesn't turn up though - then science will really have to start looking for a theory that explains particle phyiscs from first principles.

    Hi, Prof. Dorigo ;-)
    for what it's worth, here is a reaction from "Fermilab Today" on twitter: http://twitter.com/FermilabToday/status/18396561721

    Hank
    A writer at Popular Science says, "as a respected scientific institution there's little incentive for it to jump the gun and fuel the rumor cycle before it's got the hard data written up and ready to publish. But New Scientists speculates the lab might be waiting to present at the International Conference on High Energy Physics in Paris in a few weeks."

    Reasonable.
    I have just received striking new details about the rumor:

    http://motls.blogspot.com/2010/07/detailed-rumor-gluonb-goes-to-bhiggs.html

    Ahoj Luboš,
    Quemadmoeum gladis nemeinum occidit, occidentis telum est.
    I am positively surprised by your consistent argumentation skills.
    Stats of your IQ appear good enough for me.
    Somehow, I cannot stop wondering: are your intelligence test results reproducible?
    Many times, these results are nothing more than relics from our past, when
    you (or me) as children got bonus points just for being young.
    As a matter of fact, I would still not mind seeing you for a
    superficial discussion of the spreading of your genes.
    Straightly speaking, I would like to mate a man with at least an IQ approaching mine.
    Regards,
    Lena.

    http://www.telegraph.co.uk/science/large-hadron-collider/7888012/Higgs-b...

    Tevatron are already saying this is a false rumor.

    Hank
    When a rumor becomes true, it is not a rumor so saying a rumor is false is a little redundant.    ICHEP is bound to have plenty of good stuff so if there is no 3-sigma data, that is fine.    But the discussion of the Tevatron being extended will really kick into high gear if something does come up in the next year.  The combined experiments are doing terrific work so it would not be a surprise if "More data are needed for that" becomes 'we have the data' at some point, maybe before the LHC.
    Good point. However, the fact that Tevatron is specifically named and they've come out and stated that it's false pretty much settles it. I DO hope they get some good data and get extended. We need more minds working on this, not less.

    "Let's settle this: the rumors spread by one fame-seeking blogger are just rumors. That's it."
    FermilabToday -

    sorry this has gone this way bro.

    Hank
    His first paragraph is "And for once, I feel totally free to speculate without the fear of being crucified. If you have followed my past blog adventures for long enough, you know that in at least a couple of occasions my posts have created some friction"  so why some anonymous talking head on twitter is criticizing Tommaso, and getting paid to do it, is up for speculation.

    Hey, Fermi talking head, Tommaso just got you more publicity in 3 days than your press release will get you in 3 months.   The worst thing that could happen to Tevatron is irrelevance.
    dorigo
    Thanks for the support Hank. Here is what I gave to a science reporter as a quote for inclusion in his piece, just minutes ago:

    "The interesting thing is that there is still people around who really won't understand or acknowledge that, if twenty newspapers and online media sites discuss the Higgs boson because some 'blogger in search of fame' tells about a coffee break conversation, this actually helps science. They will never learn."

    Cheers,
    T.
    Amateur Astronomer
    Already Tommaso told us that 3 sigmas will need 5 times more data than in the November graph. Also the 5 sigmas are probably not achievable with sensitivity at Tevatron. The new data is only 50% more than in the November 2009 graph. An important milestone of 2 sigmas could be achieved with the available data. If that happens it would mean that the null hypothesis H_0 can be rejected. ICHEP could confirm discovery of a signal in the interval 115 GeV to 140 GeV with 95% probability of being correct. Probability of being right is 95.4% at 2 sigmas in a double sided standard normal distribution, 99.7% at 3 sigmas, and 99.99994% at 5 sigmas. The November graph has a double sided distribution, but not enough data points to support a standard distribution. Fortunately the alternative standard t test gives nearly the same results with the available degrees of freedom. So the percentages are still about right. Proof of a signal in the interval doesn’t prove it is a Higgs boson. That’s what the additional sigmas are for. Other people have predicted heavy mesons in the same interval. If Tommaso had not written his article, a lot of people wouldn’t know anything about Higgs or ICHEP.
    As pointed out by colleagues from the CDF Higgs Discovery group, a 2 sigma excess have been found in a couple of channels (lepton+neutrino+2jets & 3 b-jets) but these have already been shown at the conferences some time ago. It still could be a fluctuation, systematic effect or a software bug.

    dorigo
    Hi Yuri! How nice to hear from you here!

    Yes, a fluctuation is a good explanation of any 3-sigma bump, and a systematic underestimation of backgrounds is an even better one. Which is not too different from a bug in the analysis after all...

    Cheers and regards to your family,
    T.
    Grazie, Tommaso

    Same to you. I hope the broad interest to your post would help to raise support to extend the collider program here at Fermilab. One of the key points for this decision would be the estimate of survival of both trackers which has not been completed yet.

    dorigo
    The point that even bad publiciy is publicity has already been made in this thread, and I do not even think this is _bad_ publicity after all... Actually I think that the more the word "Higgs" and "Tevatron" are spelt together in a page will help the lab, and grow the interest in HEP! That is the twisted way communication works nowadays...

    I do hope that the trackers will survive. You guys did a great job, they have taken a lot of heat and are still going strong!

    Cheers,
    T.
    dorigo
    Hi Jerry,

    please see my latest posting of today. If the rumored signal is a MSSM Higgs, the Tevatron MIGHT see it at 5-sigma with the current data, because such a signal would have a much larger cross section (and quite different phenomenology).

    Cheers,
    T.
    Hank
    ha ha ... a "Lisa Zyga" at a press release site got creative to try and milk some google traffic out of your piece, writing ... "A rumor that Fermilab’s Tevatron may have discovered evidence of a light Higgs boson wouldn't be the first unsupported speculation from Tommaso Dorigo..."

    PhysOrg should stick to posting google link bait and paying marketers to be the on the front page of digg.
    Cool!

    .

    Hi Dear Tommaso Dorigo,
    It is a Holy Grail of Physics, Higgs Boson :God Particle" may be found in Fermi Lab or in CERN's LHC chamber.
    I think it may be a rummer at the moment,but dark matter or anti-matter may be discovered within this decades.
    It is unique to find some lovely story in the Science corridor or in coffee parlor.

    Nice to read the story.
    David

    David, you might want to check your sources. Antimatter is pretty well known, experimentally. We produce it regularly, and in fact the Tevatron runs on two beams: one made of protons and one of antiprotons. There is no way to discover something that is as established experimentally as any quark or lepton.

    Ahoj Luboš,
    Quemadmoeum gladis nemeinum occidit, occidentis telum est.
    I am positively surprised by your consistent argumentation skills.
    Stats of your IQ appear good enough for me.
    Somehow, I cannot stop wondering: are your intelligence test results reproducible?
    Many times, these results are nothing more than relics from our past, when
    you (or me) as children got bonus points just for being young.
    As a matter of fact, I would still not mind seeing you for a
    superficial discussion of the spreading of your genes.
    Straightly speaking, I would like to mate a man with at least an IQ approaching mine.
    Regards,
    Lena.

    What's the point of all this hype and attention if it's just a quick blip on the personal radar and then it's gone again? You're not educating or raising awareness, you're not creating lifelong physics supporters. It's shameless self promotion that has little to gain and seriously affects the perceived integrity of the subject. The boy who cried wolf etc etc. Keep saying "we've found it" and people will ignore you far more than before you started this silly hype. Finding an actual value for mass is a far better guarantor of funding and support, not this silly rumormill. Being an attention fiend probably has more negative long term implications than positive ones. If you're right, no harm no foul. The hype was lived up to. But if you're wrong, you've caused more problems than you've solved. The average person is not going to understand the Grey areas your article resides in. They're going to take this as "we've found it!" and if you don't deliver, you might have lost more support than you gained.

    Hank
    The average person does not read this site, it's the larger media who try to drum up pageviews and use statistical terminology (99.7%, which sounds significant) that is confusing to their readers.

    I suppose in a world of CNN shock news and such, people thinking about fundamental physics is not so bad.
    Regardless of what you think about the modern media, people expect you to deliver. You make bold claims and self promotions, then say "I can't understand why people are hyping this, damn mainstream journalism". For your sake, something good better be presented at the ICHEP. I feel there are far better ways to raise the profile of physics without compromising its perceived integrity.

    Bonny Bonobo alias Brat
    You haven't really read what has been written here, otherwise you wouldn't make these unsupported claims and criticisms. Hopefully this is 'just a quick blip' on your personal radar and then you too are gone again.
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    I'm not making unsupported claims, it's very obvious that people are misinterpreting this article and giving others the wrong idea. And this was by intention, as the entire stated purpose of this article is to create buzz about particle physics in general. The hype was accomplished by exploiting a grey area of speculation and rumors and letting people stew. Tommaso knew the media would take this and run with it, that's why he's able to sit back and say "well look what everyone else is doing, why are they taking all this out of context"

    Furthermore, this is a pitiful attempt to steal LHC's thunder.

    Hank
    The LHC was 3 years behind schedule and wildly overbudget and funded entirely based on hype about what it would accomplish - and it immediately broke.

    But your argument makes even less sense, since Tommaso works for both projects and would be 'stealing' his own thunder.
    Tommaso, I left the comment below at Bee's Backreaction post. The latter challenged the prudence of spreading scientific "rumors" around. I defend doing so when fairly identified and barring other flaws:

    "The important thing is that Tommaso called the post "Rumors about ..." so he wasn't pretending the rumors were more than that. I think it's newsworthy that such thoughts are floating around and it can stimulate thought. As long as things are well framed and accurately assessed (to the rough sense possible in such cases) there is IMHO little to complain about about per se (that is, other than any specific complaints about this or that detail, as usual re any piece.)"

    dorigo
    Thanks for the support Neil! I had not seen Bee's post yet.
    Cheers,
    T.
    I think I know why the Higg's Bison is showing up at a little higher energy than expected, and for unusual lightness as well. Like the Photon requiring a certain Quantum energy (charge) to jump to the next level, the Higg's requires extra energy to re-hide itself in those extra dimensions of string theory, and its mass expressions change with charge and spin perhaps? The spin is what stuffs it "around the corner." Just a thought. I may inaccurate, but I thought I'd put in an observational suggestion.

    Hank
    String theory needs a Higgs too?   It's like a Spider-Man/Superman  teamup.  Sure, it has been done, but it doesn't feel quite right.
    Wow, very interesting article. Reading this post Was pleasure for me :)