jump to navigation

More on the 1992 top controversy November 21, 2006

Posted by dorigo in physics, politics, science.
trackback

In the post I wrote two days ago about a new single top production measurement by CDF, Tony Smith left a very informative comment that I wish to make available directly as an individual post. It somehow puts a few things in their right place… Or at least it gives some perspective into the affair.

The facts mentioned in Tony’s comment are not new to me, since I had started working on CDF just in that very same year -and I remember that one of the very first articles I read was the limit on top quark production where the famous dilepton ttbar candidate was mentioned. An event that is indeed most likely the first clear top-antitop decay detected in a particle physics experiment. 

Anyway, back to Tony’s comment.

I met Richard Dalitz at a meeting in Waco, Texas, in 2002.
He told me that he had written a letter to the New Scientist expressing his concerns about the events around 1992, but that “nobody ever read it”.
When I told him that I was at least one counterexample who had read his letter, we had extensive conversation about it. He made it clear to me that he was very unhappy with the personal conflicts that had arisen, and that he felt that the conflict was primarily due to irresponsible journalism by the New Scientist writer William Bown.
Unfortunately, Richard Dalitz is now deceased. So that his views might get a wider audience, here is a copy of his letter to the New Scientist (15 August 1992, page 47) regarding the matter, captioned “Top quark”:

“With regard to William Bown’s article on the so-called discovery of a top quark (This Week, 27 June), when I spoke with him I did not claim to have found the top quark.
That is a job for an experimenter, whereas I am a theoretical physicist.
The “earlier paper” he mentions gave a speculative analysis of an event already published by the collider detector (CDF) group at Fermilab, but there was no claim that this event was due to top-antitop production and decay.
We were completely open and told Bown the current situation in this research, and even sent him copies of our three papers on top-antitop event analysis.
The CDF group at Fermilab is not blocking the publication of any paper of ours.
I should note here that we would never publish data from any group,
unless it has given us formal permission to do so or has already published it itself. We have never done so in the past, and will not do so in the future.
When Bown asked me what, supposing that a top quark were found now,
would be the effect on the Tevatron Main Injector project, I told him that this upgrading programme would then have the highest priority, since the Tevatron would be the only accelerator capable of top quark studies before the next century. His statement in the last paragraph that money spent on the Tevatron upgrade would be wasted is opposite to what I said.
Richard Dalitz
Department of theoretical physics
University of Oxford”.

I should mention that, back in 1992, I was interested in the Sliwa – Goldstein – Dalitz analysis because it seemed to support my theoretical calculation of Tquark mass.

When the book mentioned by Andrea, “The Evidence for the Top Quark: Objectivity and Bias in Collaborative Experimentation”, by Kent Staley, appeared, I noticed that it mentioned the Sliwa – Goldstein – Dalitz situation, and I had some e-mail correspondence with Kent Staley, who said:
“… Krys Sliwa … certainly was skeptical of the standard CDF
interpretation of the data, even after the 1995 Observation of Top
Quark paper (PRL 74(14): 2626), in particular suggesting that, even if
the top quark was contributing to the excess, there might be something
more there as well. I did not get specifics from him, however (he would
not agree to be interviewed in person, but only to answer by letter
questions that I submitted to him). …”.

I also had e-mail discussion with Krzysztof Sliwa, in which he said that he “… always felt that the “official” interpretation of the CDF top candidate
events in Run-I could be too simplistic …”.

That line of thought seems to be in the epilogue of Staley’s book, which says:
“… Sliwa struck a hopeful note with regard to just those things in the data that threaten our current understanding. Even when experimenters find that they have achieved experimenter’s success, they look more closely to see the interesting flaw in their achievement – the discrepancy that will mean, not failure necessarily, but the possibility of some new success to strive for. Just as the prelude to discovery should not be seen in terms of a monotonic preparation for the discovery that occurs, so the aftermath of discovery should not be seen as the straightforward unfolding of the consequences of the knowledge thus gained. CDF and D-zero went to great lengths to establish that they now know some things about the world that were previously unknown. Just as important is the probing of this new realm of information to find out just what it is that we do not yet know. …”.

Tony Smith
http://www.valdostamuseum.org/hamsmith/

Comments

1. Tony Smith - November 22, 2006

I sort of apologize for being the first commenter on an entry about what I wrote, but it seems to me to be a good idea to quote from the New Scientist (27 June 1992) article by William Bown about which Richard Dalitz was unhappy.
Here are some relevant excerpts from the article (I think they give an accurate picture of its flavor) by William Bown. entitled “Transatlantic row keeps top quark hidden”:

“… A CLAIM that the top quark has been found is being suppressed by scientists at the Fermilab particle physics centre near Chicago. …
The researchers are blocking publication of a paper by a rival group which reanalyses results generated by the Fermilab’s Tevatron particle collider. The rival group includes Richard Dalitz … and uses analytical methods he developed. Gary Goldstein …[is]… one of Dalitz’s collaborators …
Dalitz and Goldstein were given details of all the collisions by Kris Sliwa …
Alvin Tollestrup, also a member of the [CDF] team, says: “The two people who are not members of CDF should not have had access to the data.” …
Physicists at Fermilab have been unable to find conclusive evidence for the top quark. Dalitz, who used a different technique for analysing the patterns, believes he has identified it. …
If Dalitz turns out to be correct, the $68 million spent on upgrading the Tevatron will have been wasted; and the main credit for finding the particle will go to Dalitz, a scientist outside Fermilab. “.

The article is inaccurate, confrontational and sensational. For example:

1 – It claims that the results of Dalitz et al were “being suppressed by scientists at … Fermilab”.
In fact, the paper of Dalitz and Goldstein was received on 22 May 1992 (well before the 27 June 1992 New Scientist article) by Physics Letters B and was published as Phys. Lett. B 287 (1992) 225-230.

2 – It describes Richard Dalitz as a member of “a rival group” to CDF.
In fact, anyone who ever had any personal contact with Richard Dalitz knows that he was a quintessential Oxford gentleman, and that the concept of hostile rivalry in the science of physics was totally absent from his character.

3 – It describes Dalitz as “believ[ing] he has identified it [the top quark].
In fact, Dalitz told Bown that he “did not claim to have found the top quark”.

4 – It says that if Dalitz had found the top quark, then “the $68 million spent on upgrading the Tevatron will have been wasted”.
In fact, Dalitz told Bown the opposite, that the upgrade would in that event have the highest priority.
This inaccuracy may have been crucial in poisoning the personal-level conflct, because at the time Fermilab was lobbying for the upgrade and the funding outcome was then uncertain. Bown’s article was probably perceived by people at Fermilab as an attack on Fermilab’s lifeblood funding, and that probably accounted for at least some of the hostility manifested by Tollestrup and other Fermilab powers-that-were-then.

5 – It says that if the Dalitz analysis holds, ” the main credit for finding the particle will go to Dalitz, a scientist outside Fermilab “.
That is the most absurd inaccuracy in the Bown article, and it doubtless inflamed passions at Fermilab.
In fact,
no matter who (inside or outside Fermilab) does any analysis by any technique (in-house or outside), THE ANALYSIS DOES NOT DISCOVER THE PARTICLE.
THE DISCOVERY IS ENTIRELY DUE TO THE EXPERIMENTERS WHO RUN THE EXPERIMENT AND PRODUCE THE DATA.
Whether analytical team A sees an event in the data before it is seen by analytical team B is irrelevant. It is the lab that produced the data of the discovery event, and therefore it is the lab that discovered the particle.

Tony Smith
http://www.valdostamuseum.org/hamsmith/

2. dorigo - November 22, 2006

Hi Tony,

I had read that article long ago, and forgotten most of it… Thanks for posting it.
Of course I totally agree with all your conclusions. Especially your bottom line about discoveries in particle physics. A punctualization, though, is in order -to make the case clear, an exception is always useful.

I think that the trend set by D0, who years after finishing the analyses on their Run I dataset made available their data to everybody, should be followed by all other big experiments, in line with what astronomers have been doing for a long time now.
In that case, if -once data is published- somebody comes out with a bold idea, and reconstructs a new particle signal, which is then confirmed by independent analyses elsewhere, then the credit can jolly well go to the analyzer alone.

Cheers,
T.

3. Alejandro Rivero - November 23, 2006

Another person who is waiting for clarification of the 174 Gev events is Alan R. White with his “sextet quark physics”. The most detailed review is in his Phys. Rev. D 72, 036007 (2005). Note particularly figure 24, the jet excess at large T, which is about 1-2 sigma out from predictions but with a very very large sigma. Would Run II narrow the errors, it could be a claim for slowing of the running of the strong coupling (and what about asymtotic freedom, then?).

Sextet quarks are usually discarded because we should see their mesons; still I am not sure if the same argument that rules out top mesons can rule out the existence of sextet-quark mesons.

In page 120 of hep-ph/0610012 it is mentioned that White’s model should give a very spectacular signal in the WW channel of LHC.

Marginally I am interested in the sextet physics because of my count of degrees of freedom of the standard model mesons and diquarks as I described in hep-ph/0512065. And of course, any condensate model could help with the Z0 mistery pointed out earlied in this blog🙂

4. dorigo - November 23, 2006

Hi Alejandro,

thanks for pointing that out -I was unaware of the model. I am now reading the QCD TeV4LHC report you mention, will then look at the PRD… Will update later (now I am at the Atlas-CMS workshop),

Cheers,
T.

5. gordonwatts - December 18, 2006

Holy cow. I remember this mess from when I was a graduate student. I dont’ remember the details (indeed, already I can feel things shifting in my memory as I read this account). it was pretty ugly, however.

6. dorigo - December 18, 2006

Yes there was this air of suspicion around in 1992… As if somebody had committed Heresy!
T.

7. Cómo nos enteraremos del descubrimiento del bosón de Higgs « Francis (th)E mule Science's News - August 16, 2009

[…] Bueno, algo parecido pasó con el quark top (cima), como nos cuenta brevemente Tommaso en “More on the 1992 top controversy,” y muchos otros, como Tony Smith, “1984-1992 Truth Quark History.” En 1984 el […]


Sorry comments are closed for this entry

%d bloggers like this: