The 450-GeV Quark That Wouldn't Go Away
    By Tommaso Dorigo | May 6th 2010 05:08 PM | 44 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...

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    Two years ago I discussed the results of a very interesting search performed by the CDF experiment in its dataset of 2-TeV proton-antiproton collisions, provided by the Tevatron accelerator at Fermilab.

    The search focused on the hypothesis that a massive fourth-generation quark was produced in the collisions. What was assumed was that the quark was heavy -otherwise previous searches would have found it already-, and that it behaved similarly to the sixth quark, the top, which is by now a well-known animal of the particle zoo.

    Top quarks have been sought by the CDF experiment since the late eighties, and studied ever since their discovery in 1995. A brother of the top quark would hardly have escaped detection if its mass had been similar to that of the top quark, but a significantly heavier body would have been hidden by its smaller production rate.

    The reason of the small rate is that the heavier a particle is, the harder it is to produce it at a hadron collider. The production process involves the transformation of kinetic energy of the colliding quarks or gluons contained in the proton and antiproton into mass: and quarks and gluons are increasingly hard to find with large enough energy.

    The search I reported on in 2008 found an intriguing excess of events compatible with the decay of a 450-GeV t' quark. The significance of such excess was of merely two point something standard deviations -roughly the chance that you walk in a Casino and win 35 times your stake with a single bet on a number at the roulette. But it was interesting, and exciting.

    So much so, that I could not wait for more data to be thrown in, to see whether the excess would disappear -a sign that it was due to a background fluctuation- or become more solid -a sign that it might be due to a new particle signal!... or to a systematic underestimation of backgrounds.

    Now the analysis has been carried out, with as much as 4.6 inverse femtobarns worth of proton-antiproton collisions: exactly twice as much data as that used in the previous search. And the result is...

    No, I am not going to give it away so easily. You will have to deliberately scroll down to satiate your curiosity. The more polite among you will instead stay with me for a minute more. Their prize will be to learn a couple of details about the new analysis.

    The analysis has not changed significantly from the previous instantiation - a good idea, given the need to investigate the early fluctuation at 450 GeV (on the right you get to see a t' candidate seen by CDF -it belongs to the dataset searched in 2008). The heavy t' quark is assumed to behave as any other standard-model quark, e.g. decay via weak interactions through a charged current W boson. For heavy objects, whose mass is larger than the sum of the masses of W boson and daughter quark, the emitted W boson is a real one, i.e. it carries its regular 80.4 GeV of mass -if we omit to discuss its natural width, that is. That would be a useful but derailing explanation which I will leave to some other article.

    If t' quarks are produced by strong interactions just like any other known quark, we should observe pairs of them: in other words, if they are standard model quarks they must carry a unit of "T'-ness" which strong interactions cannot produce out of the blue. So t' -anti-t' quark pairs are produced together, such that the final T'-ness of the system is still zero (+1 for the quark, and -1 for the antiquark).

    The above observations drive CDF to focus to a very specific final state: the same which has proven successful to discover, and later collect and study, the top-quark-pair samples produced at the Tevatron. This final state includes the signal of a leptonically-decaying W boson, which provides sufficient characterization to allow the efficient triggering of the events: a high-momentum electron or muon.

    Two words about data collection

    I think that many among you do not know well enough the importance of the trigger in a hadron collider experiment, so I will spend a paragraph or two describing what is going on there. You must bear in mind that the Tevatron produces collisions three million times per second in the core of the CDF detector, and there is simply no way to read out and store with such a rate the information collected by the hundreds of thousands of electronic channels to which the sensitive detecting elements report their findings. Instead, the trigger makes a choice: it selects the very few events deserving to be kept and later studied offline.

    Of course, this is a critical decision! Among three million interactions per second, only about 100 (a hundred, yes, you read correctly) are saved; the rest are lost forever. And the fact that the decision is taken "on the fly" by hardware processors should send a shiver down your spine: there is no turning back. But that is exactly what is done by CDF; and D0, and CMS, and ATLAS for that matter!

    To collect events containing a leptonically-decaying W boson -ones among which hide top pair events, as well as Higgs events- an electron or muon of high momentum must be observed by the online data acquisition system, such that in the matter of a microsecond or so the event is flagged as potentially good by the "first level" trigger; in the matter of some twenty microseconds it is reconstructed in detail, to decide that the lepton signal is a genuine one, by the "second level" trigger; and finally, in few milliseconds it is handled by software algorithms performing a full reconstruction at the "third level" trigger.

    Every time I think about the working of the data acquisition system of CDF my mind cannot help picturing a grand concert. Particles hit each other at light speed in the core of the detector; other particles are created and emitted in all directions; they leave electronic signals in the active devices. These signals travel through meters of cables, get interpreted by hardware boards, the information is collated and signals are sent to other boards that enable the collection of more detailed information by the detector components. Then the more complete event information goes to other electronic boards; and so on, until the distilled result of a single lucky collision chosen among thirty thousand gets written to a storage medium. And all this goes on at a lightning rate.

    It is, in earnest, mind-boggling. And I am sorry if my description was incomplete and approximative: the more you know about the system, the lower your jaw is bound to fall.

    The analysis, finally

    Okay, I think I attended my duty with science outreach enough above. Now let me tell you in short about the analysis -if I did it in more detail, I fear I would not do a much better job than the one of the relative public web page anyway.

    The selection is the one typically used to collect top-quark pairs: a well-identified, high-momentum electron or muon must be present together with significant missing transverse energy. The latter is the result of the escape of a energetic neutrino, which the leptonic W decay produced together with the triggering charged lepton.

    Four hadronic jets are also required. These nominally correspond to the four energetic quarks emitted by t'-anti t' pairs: two from the other W boson, which must therefore have decayed hadronically; and two from the down-type quark that t' quarks must have turned into. Mind you: these are not necessarily b-quarks, since we assume to know nothing of the way these fourth-generation up-type quarks couple to b, s, or d-quarks. Unlike top quarks, that decay 99.9% of the times to a b-quark, t' quarks might in principle all yield down quarks!

    The above should tell you that b-tagging is of course not used, as is instead the case in most top quark searches. Standard model backgrounds are thus larger than in the typical top quark analyses (b-tagging is a powerful background rejecting tool), but not overly so. They are due to real top quark pairs -of course!, since yesterday's signal is today's background- and to W production events accompanied by radiation of additional jets.

    A further small background is due to non-W events: ones for which the leptonic W signature was faked; this is rare, since you must get both a jet passing as an electron or muon, and a large imbalance in the detected energy in the calorimeters, which mimics the effect of an escaping neutrino.

    The authors reconstruct the putative mass of the new heavy quark with a fit technique which is identical to that of regular top mass measurement, save for the lack of any b-tagging information. This complicates matters, because if one does not have b-tags to indicate which jets come from the W decay and which ones do not, there are many different ways (12, if you are curious) to assign jets to the partons originated in the decay chain t't'bar -> W q W q -> (lnq)(qqq).

    Below is shown how the fit reconstructs the mass of t' events (blue histogram, where the t' mass is simulated at 400 GeV), top events (red histogram -it clusters at about the true top mass as it should) and the main background (empty black histogram). On the top left panel you see all 12 solutions together; on the right you see the fit solution with the correct matching of the jets to final state partons (which we know since these are simulated events!). Reality is what you get on the left, but even there, there still is plenty of discrimination between top quarks and a heavier partner.

    The reconstructed quark mass is then used together with another discriminating variable: the so-called Ht, which is the sum of transverse energies of all objects in the event, including the inferred neutrino. The t' mass and the Ht are fit together using a likelihood technique. This allows to extract an upper limit on the cross section for the new physics process. It is reported synthetically in the figure below.

    In the figure you see the t' mass on the horizontal axis. As a function of it, the purple curve describes the theoretical guess for the rate of t' production at the Tevatron, in picobarns (one picobarn is about a hundredth of a billionth of the total collision rate). As you see, the predicted rate decreases with the hypothetical particle mass, an effect of the rarity of more energetic collisions, as I mentioned above.

    Next is the blue band: it describes the rate limit that CDF expected to set, using the analysis and the size of data it analyzed, and it spans from minus two to plus two standard deviations -97% of the expected reality, in other words. The red curve shows instead the actual limit computed with the data actually observed. The crossing between purple and red line indicates that all t' masses below 335 GeV are excluded: if the t' had been that light, its predicted rate would far exceed the lower limit set by the red curve. Instead, for masses above that value, the data cannot exclude the t'.

    But wait, that is not all. The data does not just "not exclude" a t' heavier than 335 GeV: if you look closely, you see that the red curve departs significantly from the blue band. The observed limit, for a 450 GeV t', is significantly weaker than expected! What is going on ?

    What is going on is that there is still an excess -a two-sigmaish one, apparently- of t'-like quarks with a mass of about 450 GeV, with respect to the standard model expectation. So the same effect seen with half the data, and a quite similar analysis, remains!

    Let us look at the mass distributions for the data and the sum of backgrounds. They are shown below. The black points are data, the three main backgrounds are shown with different blue shadings. On the left the data is interpreted as the sum of backgrounds only; on the right, a 450 GeV t' is thrown in to see how well it fits the data. The lower parts of the figure show the difference between data and sums of backgrounds: judge by yourself if the yellow t' contribution is needed or not...

    So, to conclude, the doubling of the data has not yielded a conclusive answer to the question thrown in by the result of the 2008 analysis: a 450-GeV t'-like quark is not excluded. And the rate of similar events in CDF is higher than expectations by over two standard deviations. One more fluctuation to keep a look at. Or rather, one fluctuation you cannot yet take your eyes off from!

    It only remains for me to congratulate with the main authors (J. Conway, D. Cox, R. Erbacher, W. Johnson, A. Ivanov, T. Schwarz, and A. Lister), of this new CDF analysis, and I hope they will three-peat it when they get 7 or 8 inverse femtobarns of available collisions to analyze... Way to go, folks!

    For more detailed reading on the analysis, please consult the relative public document recently produced, which contains a nice introduction on the theoretical motivation for the search.


    very nice post. Is it true that LHC will be able to exclude (or find!) a 450GeV t' by the end of the first run (i.e. with factor 5 less than luminosity but a factor 3.5 more in energy)?

    Hi Anon,

    I am not sure, I need to look it up. However I would say so by just considering that 450 GeV < 3x175 GeV, and 7 TeV > 3x2 TeV. It should follow that, given that strong interactions are not sensitive to flavour, a 450 GeV t' quark should be produced at least as frequently at the LHC than the top quark at the Tevatron. And the Tevatron needed only 100 inverse picobarns to discover top...

    Two sigma excess? That's huge. You may finally publish the discovery of the heavy quark in a Journal of Climate Change. ;-)
    Since I assume climate science researchers in East Anglia are not reading this column, I will go ahead and say 'ouch' for them.
    You speak like that because you are a renegade theorist Lubos. Real theorists drool at two-sigma excesses!

    This is complete bullshit, Tommaso. Garden-variety *phenomenologists* may drool at such stuff - because that's what their work is often composed of, and they want a lot of it - but no *real theorist* I have ever met would be excited by two-sigma excesses. I think you have never met any *real theorists* in your life....

    It's still true that no *phenomenologist* would ever claim that a two-sigma excess is a proof of anything, or a good way to decide about future decisions or policies. You must be a *climate scientist* to do so.

    The hierarchical differences between the required confidence levels talk about the very essence of these occupations. 

    Theoretical physicists - real theorists - work with principles that are valid up to huge accuracies - often experimentally checked at the 10^{-15} precision or so - and they even care about bigger accuracy that can't be experimentally verified at this moment. 

    The foundations are extremely robust and have to be robust. Theorists don't care much whether experimenters managed to already verify something, but if they could have - which is pretty much necessary for us to know the right answer - it's extremely likely that the actual knowledge is much more accurate, so the facts are known at N-sigma level where N is almost arbitrarily huge.

    Phenomenologists are more eager to change their opinions because of random data. They always focus on the things and resolutions that are close to the available experimental limits. They almost never trust extrapolated principles - or any principles, for that matter. Instead of studying which assumptions may be extrapolated and which of them can't (because of mathematical limitations), they always assume that nothing can be extrapolated beyond the level known to experiments at the moment. So they're routinely affected by two-sigma bumps. Two-sigma bumps are the "winds" that determine their life. They always suspect that a new dragon is right behind the corner but they realize that most of the two-sigma dragons turn out to be flukes.

    Climate scientists live out of one-sigma and two-sigma bumps that they view as the required unquestionable holy proof, sent directly from God, that must be carefully cherry-picked and that are showing that the debate is over and the world economy and the capitalist have to be brought down to its knees. 
    If your kid has strong symptoms of a serious disease do you wait for a 99.99999% certainty diagnosis before springing for her treatment?
    Probably no, but in the case of "climate disease", sane people who have studied these issues know that there is a 99.999999% certainty that no such serious "disease" exists.
    If you consider less serious diseases that might exist, one must consider the costs and benefits of treatment as well as non-treatment, and once again, except for killers and complete idiots, no parent would allow his "baby Earth" to be used for such a treatment in this case.
    Oh Jebus, now you've got Lubos started again....

    What are we going to name it if the t' DOES exist? We have to start thinking about this now before the British get a chance to put their pretentious designs on things and try to call it "beauty" or some stuffy crap like that again! I propose "sexy".

    LOL Blake! ;-)
    there are already names for them, as I detailed in a former post. Audio and Video quarks.

    Hi Lubos.
    A real scientist need theoretcical constructions, but also a lot of sensitiveness. You have forgotten the latter.

    Hi cheap annoying troll, 
    the correct spelling of "theoretcical" is "theoretical" and the correct English word for "sensitiveness" is sensitivity. The latter has nothing whatsoever to do with science; did you really mean emotional sensitivity? 

    I am a very sensitive person but science is about completely different things, and trolls like you need to be kicked into their obnoxious arses every day so that they become genuinely sensitive.

    Cheers, LM
    What is it with you? I am astonished.
    I will not make this into some language question, so stop with that, please.

    By sensitiveness I mean not emotional, although You SEEM to lack also that. I mean ability to reflect and respond, also to tiny things. Also that is important in sciense just as Tommaso showed. Maybe there are some lessons to learn too.

    I think you would need some kick too, maybe a kind person would show up. I am a very kind person :) Definitely no troll. Shame on you.

    Ulla, you would not argue with a skunk right ? Lubos is like that -you can appreciate him only after you have managed to handle him (don't plunge in the link unless you are willing to follow a few more, such that you get a full picture of that particular affair). But I do not think this is for everybody :)

    Dear Tommaso, you clearly enjoy not only to discuss with stinky skunks but to have an intercourse with them, too.
    Yes, I'll admit that. And apparently you enjoyed being the receiving end, too! :D
    Well, I thought to give a lecture about Damasios thoughts of what emotions really mean for us. In fact, Lubos you react very emotionally ;) You also talk so very much about IQ, but EQ is shown to be much more sophisticated. But all depends on what emotions are shown :)

    I don't know why, but you make me very aggressive sometimes :) I think it depends on your arrogancy and narrow thinking. Still you are very brilliant sometimes.

    Sensitiveness has high priority for predictivity. Sorry if I said something bad. It was not my aim.

    If there does turn out to be a fourth generation of heavy quarks, I propose to call them euphoria (t') and dysphoria (d'), with abbreviations u4 and d4.

    I guess you mean u' and d'. Interesting and witty suggestion though... It makes sense.
    Is this some kindergarten contest for nouns that come in pairs?
    Male (f, for father) and female (m, for mother) quark? Yin (y) and jang (j)? Heaven (H) and hell (h)? I(ntegratino) and D(derivative)?

    Why don't you actually ask some children in the kindergarten to help you solve your "physics" problems?
    I must point out that jang is a linguistic misnomer. It should be Yang, so the pair is Y/Y ? Usually full/empty.
    Also You, my Lubos...

    As one of the authors of the search, let me make a few comments... Firstly, I personally spent a very large portion of my research from last summer until March of this year working on getting the statistics of our results correct. With earlier, less sophisticated techniques, we were seeing that the excess had a much larger apparent excess. But it was only apparent - the true statistical significance of this excess has never been large, and still isn't.

    Secondly, whatever the excess is, it is not a new 450 GeV quark. The excess events are all at very high total energy (HT) and spread out in apparent t' mass. This is not what we would expect to see, really, from a fourth generation quark. Also, the production rate for an "ordinary" fourth generation quark of such a mass is not large enough to account for the excess. And if the excess is not from t' we are at a loss to characterize jsut how significant the excess is, since we are observing it a posteriori.

    Nevertheless the events are there, and show no signs of being some detector effect or misreconstruction. If there is a standard model background we have neglected we don't know what it is or we would have included it. We see 8 events in the highest HT bin where we expect about 2-3. No matter what it's not statistically significant, and as Tommaso points out we have seen such excesses before.

    Is it interesting theoretically? Well, if some theorist out there thinks they have a model that we can test, particularly by looking at some other channel or variables we have not studied, we are all ears! There is nothing wrong with thinking about what our 8 events might be if they are not SM background or a t'. And we have had a few suggestions from some excellent, and quite real, theorists.

    Hi John,

    thanks for stopping by, and for the information!

    I agree, the few events of excess are not very significant. However, since we could not exclude a t' quark above 335 GeV, I think it is wrong to say that what we see (or at least part of the events we see) cannot be a t' quark at 400, or 450 GeV.

    But I acknowledge that other models might fit the data better!

    Tommaso, your reading and thinking skills are just incredibly bad....

    John kindly comes to your blog and as a co-author of the research you described, he explains why the events can't be due to a 4th-generation quark. 

    The total mass of the new particle is measured as fuzzy and the total energy is large which wouldn't happen for the 4th generation quark. Moreover, 4th generation quark theories couldn't predict enough of a signal to explain this data. And a few more inconsistencies.

    You *completely* ignore every single observation above - and many of them may be known at much higher a confidence level than 2 sigma (which is enough for you to start to believe something as long as it is compatible with your severely limited mental skills) - and you conclude that "it is wrong to say that we cannot see a t' quark". Do you have a brain tumor? It is almost certainly not wrong to say that we cannot be seeing a t' quark.

    Then you add that "you acknowledge that other models might fit the data better". But as John explains, there are no known models that would fit this data. But whether or not we have better models, it's still possible to falsify one particular model - of a 4th-generation quark - which is what has taken place here, despite your ostrich's head being hidden a foot beneath the sand.

    More generally, I am shocked by your obsession with an idea as cheap, as unimaginative, and as mostly excluded as a 4th-generation quark. Even if this could exist, that would be the kind of "new physics" that wouldn't be "too new", surely not intellectually.

    Lubos, sometimes I get bored to have to teach you stuff. What does the reconstructed mass have of "fuzzy" ? There is one Monte Carlo plot above, and it shows that the detector resolution is roughly 10% for that particle (40 GeV for 400 of mass). What's more, on the data plot you get to see how the t' signal at 450 GeV would distribute (the yellow stuff, which is reported on the lower panel along with the data-fit). The two panels show exactly what you negate: that a t' quark with 450 GeV mass (right) fits the data better than the null hypothesis (left).

    Among the rest, one thing is speculative: that we know the t' cross section (we know the cross section that a Q=2/3 quark would have under SM hypotheses, that is all).

    One thing you mention is ludicrously wrong (that a 450 GeV t' quark would have little energy). Of course the opposite is true. But you are confusing things: Ht is total transverse energy of all measured (and unmeasured) objects. Ht is high for high-mass decays -it was in fact one of the variables we used to select the first top quarks (John himself has another analysis where he did precisely that, measuring the tt cross section). John correctly points out that the excess has all high Ht, which is not too characteristic of a t'. But this is not sufficient to claim something.
    Since I believe that you are not below the average theorist as far as your understanding of experimental physics goes (despite the many pitfalls you experienced by being quick-mouthed), I am seriously concerned with the fact that I should lower the bar a bit here, and discuss things more at your reach.

    Dear Tommaso, your writing is just pure rubbish. ...

    The 450-GeV new quark is instantly falsified by the observed data - even this very data. The fact that you can draw one picture or calculate one "statistic" for which the 450-GeV quark would be slightly better than "nothing" doesn't change anything about the non-existence of the quark simply because yours is a wrong "statistic". 

    In it, you are just cherry-picking the quantities that agree with your (wrong) hypothesis, and ignore/deny all others that disagree. John Conway wrote you very clearly what you should actually have looked at, i.e. the more relevant quantities that enter the proper statistic deciding about the fate of the new-quark model, and when it is looked at properly, the conclusion is that the 450-GeV hypothesis explaining this bump is ruled out experimentally.

    The cross section predicted by the new quark is simply not enough to account for the bump, and this fact itself is enough to falsify the hypothesis. But John mentioned three others. Another them is the distribution of Ht. When you write

    "John correctly points out that the excess has all high Ht, which is not too characteristic of a t'. But this is not sufficient to claim something."

    you are just giving another proof that you are an irrational bigot. Really? A two-sigma bump at a random place is enough for you to claim the evidence for a fourth generation - but a wrong distribution of Ht that disagrees with your theory - probably at a higher confidence level than 2 sigma - is "not sufficient to claim something".

    In other words, any 2-sigma or 1-sigma bump in any randomly chosen quantity is enough for you to scream that you have evidence for your crackpot delusions, but no evidence, not even 5 sigma evidence, is "sufficient to claim something", if this evidence disproves your delusions. You're an irrational bigot.

    John Conway is telling you pretty much the same content, but because he doesn't emphasize that you're an imbecile, you choose to completely ignore 100% of what he is saying. I am fed up with this kind of communication between silent people who know something and vocal idiots who prefer not to listen.

    Lubos, I am not claiming anything, as is clear to anybody with a grain of salt in the brain. Instead, you are just trolling today, and I will ignore you because I have better things to do.

    You are delusional in your attempts at playing the experimental physicist. Let the matter to people who know better. I will explain you the look-elsewhere effect (the thing you were clumsily attempting to mention above) in another post, but for a starter you can read about it here.

    Dear Tommaso, you're not claiming anything, are you? You have written several dumb articles on your blog, claiming that you have some evidence supporting a 450-GeV quark. John Conway and I have explained you the detailed technical reasons - here and elsewhere - why there exists no such evidence. You just choose not to listen why because you don't like the conclusion.
    I am not criticizing you for a look-elsewhere supernatural effect that you have advocated in other delusional texts of yours. I am criticizing you for your inability or lack of will to falsify wrong hypotheses after they're shown to disagree with the experimental evidence. This inability of yours is lethal both for theorists as well as experimenters, so whether you try to call others names - such as "experimenters" - is completely irrelevant for this point.
    Lubos, sometimes I get bored to have to teach you stuff. 
    We never get bored reading him, though.   He always makes interesting points, he just has a very blunt style.   You have been to Czech Republic, you have eaten that food - it would make anyone irritable.

    Whether or not he is right I cannot say because the subject gets a bit deep but I always feel like I learn something new reading the articles and then again in the comments.   The comments I usually wait until some time passes though.    Like serial television programs, I want them all at once.
    Dear Hank,...

    you can look at your comment and the unstoppable racism in it. My today's lunch was Roast Beef in Gypsy Sauce with Rice (cikánská hovězí pečeně s rýží) and it was OK. Too bad that the gypsies can't actually make it these days.

    But when you look at the genuine typical Czech cuisine, it's perfectly pleasing and universally eatable by adults as well as infants. That starts with the candle sauce (svíčková) with dumplings, fruit dumplings (the best thing about Czechoslovakia for many Mormon missionaries from Utah), all kinds of kolaches (koláče) as the Czech wedding cakes, and lots of foods we share with the Germans and other adjacent nations who are not irritable at all.

    There is a whole song dedicated to the psychological impact of the difference between the Czech food and Italian food. It was recorded by "Triky&Povery", a well-known Czech pop band, and the title is "The Italian chap doesn't know the miracle". See

    There are at least two songs, the food song begins at 1:45. (The first one is "Oh Women Women" about the Czech women who want to live in Milan while the Czech male capitalists prefer the concrete blocks in Prosek, a part of Prague. The last song is about the bohemization of the Italian hits in general: there's no love and Sun in them any more, just pickaxes and excavators.)

    It says that the Italian guy eats spaghetti and pasta all the day which is why his body is decaying. Together with his sister, the only other survivor, they have buried the family. He doesn't know the miracle, dumplings, pork, cabbage, and beer - the typical "Czech national food". It describes the tough life of a poor Italian guy who just became the director of the Fiat brand because he applied to become one. A hard life without dumplings and beer, indeed.

    The superiority of the Czech food is partly why we, the Czechs, are so restful, peaceful, tolerant, liberal (ask anyone!) - and why we have so much patience to deal with the hysterical hormonal Italian alternative physicists on the Internet, among many other unlikely parties to co-exist with.

    Best wishes

    you can look at your comment and the unstoppable racism in it. 
    ha ha ... I can't be racist.  I love Czechs!  I keep two in the freezer ... for special occasions.
    Needless to say, I also love Californians. After having spent 1 year in CA, I prefer to make love to them with metallic sticks. ;-) Unless, of course, the Californians are Austrian oaks, in which case they must be burned by the hot love.
    But let's not get excessively distracted about the content of this thread.

    It is about a paper "Why the 450 GeV signal has just gone away" by John Conway et al. Tommaso Dorigo popularized this paper under the new name "The 450-GeV quark that wouldn't go away" and he got very irritated when I pointed out that he turned the conclusion upside down.
    Secondly, whatever the excess is, it is not a new 450 GeV quark.

    Phew! Thank God! A t' quark at 400, or 450 GeV is more than my poor feeble brain could handle!
    Dear Eric, just to be sure, if you refer to my comments about John's remarks, I said, on the contrary, that a new 400-450 GeV quark is at the maximum that the minds like yours or Tommaso's *can* understand (so it is *less* than your brains can handle), which is why Tommaso favors them so much, despite the huge evidence against them.
    Dear Lubos, I don't favor them. And they are more than my feeble brain can handle. ;-)
    Dear Eric, you may be far too modest - and maybe, it's because you're trying to flatter Tommaso. ;-)
    Dear Lubos, If you have read some of my comments, then you would know that I am not the type of individual to "flatter" anyone. Quite the contrary, I tend to be a misanthropic SOB! ;-)
    Why is this Luboš Motl allowed to insult everybody here with his rude comments. Is there a way to censor him? He hardly brings anything relevant to the discussion.

    I have brought more to this blog than the official Italian blogger at this blog - for example, I helped to explain why the 450-GeV new quark is not supported by any data, a fact that Dorigo tried to mask. 

    And unlike the anonymous pile of aggressive garbage that is you, the owner of this server seems to realize this not-so-subtle fact which is why nasty, boring, annoying, and dishonest censors of your type are not the kings over here.

    You sure sound like a crackpot and not someone that actually understands anything about physics.

    Hank, couldn't you please block this kind of anonymous human waste that only brings hatred and lies to these threads?
    I was about to but so that I would have a justification for censorship (inflammatory language) I went to the Reference Frame and searched for how many times you called someone a 'crackpot'.

    I think I broke Google because it ran for a long time just to tabulate the 2010 results for your blog.  :)  2009 is still running.  Poor Bee.  She must think you believe 'crackpot' is her actual name.
    Hi Lubos,

    Anand is a world chess champion, and with all due respect, you are human waste in comparison!