New! My Paper On Solving The Omega B Controversy
By Tommaso Dorigo | October 12th 2009 08:44 AM | 12 comments | Print | E-mail | Track Comments

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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The web site of the Cornell preprint archive, arxiv.org, says it best: successful submissions to the preprint archive are a source of considerable pride (darn it, the page with the exact statement is only available just after you submit a paper, so I cannot quote it literally here since my browser has by now forgotten it!).

I am indeed as proud as a first-timer, despite the fact that spires lists 416 papers with my name on the front page, a couple dozens of which as only author. The reason is that this morning, after ten days of work which I had expected to be three and which felt like a month, I was finally able to give the final touches and submit to the arxiv a paper which is has a special personal meaning: it is the first scientific article which is based on material I wrote on this blog. Well, what do I know. For sure the first one with my name on the front page!

I can imagine two different reactions from the reading of the above statements.
1) "He has gone nuts, and this is the final proof".
2) "He has reached the blogging nirvana, where whatever gets written in a blog bears fruit."
I think the truth is roughly in the middle. For sure it is a rather unconventional thing to work hard on a problem for the (at least initial) only goal of writing a blog post; and this I certainly did, although to be precise the blog posts were at least three. And for sure, being in the condition of reusing one's writing efforts for additional projects -scientific papers, newspaper articles, books, you name them- is a considerably effective way of using one's time.

Now, the paper. It is based on investigations I made in May this year (part I, part II, part III), when the CDF observation of the Omega_b baryon, a very fancy hadron made up by a bottom and two strange quarks, caused some confusion in the world of experimental particle physics (see the decay products of a $\Omega_b$or $\Xi_b$baryon in the figure on the right: the complicated decay chain results only in electrically charged tracks, which allow a full reconstruction of the originating baryon).

The very solid evidence of the particle flew in the face of a previous observation of the same particle by the antagonist experiment, D0, which had obtained a similarly solid signal one year before, but with quite different measured characteristics. In particular, the mass.

The two results are incompatible by 6.2 standard deviations, something that happens by chance only once in a billion times or so. Were CDF and D0 observing two different particles ? And if not, which of the two measurements was wrong ?

You can read my posts on the matter by following the links above; the more curious among you might however fancy downloading the original paper I submitted (ps file, pdf file): you will thus read it before anybody else, given that the Cornell preprint archive takes a couple of days to publish submitted material (maybe to have time to censor unwanted submissions, as was argued here). You might even just browse through the 14-page document and just concentrate on the figure pasted on the left, which summarizes my findings.

So, if you want to know why the D0 estimate of the probability that their signal is due to a statistical fluctuation was underestimated by a factor seventy, read my paper. I assure you it is quite readable and there is no hard physics in it. Below are title and abstract. Enjoy!

Type-I Error or Mass Bias ? An Investigation on the  $\Omega_b$Discovery
T.Dorigo

Abstract
The D0 and CDF collaborations recently published two independent analyses that both claim to represent the observation of the Omega_b particle, a baryon made up by a (bss) quark combination. Both signals are estimated to exceed the statistical significance of five standard deviations; however, the mass measurements derived from the candidates differ by over six standard deviations, accounting for estimated systematics. Measured rates also appear to differ, although they remain compatible within the large uncertainties.

In this paper the author recomputes the significance of the D0 result, showing that it was considerably overestimated in the original publication; he then investigates with a pseudoexperiment-based approach which, among different hypotheses, appears the most likely cause of the observed discrepancy between the D0 and CDF signals.

Congratulations to a successful submission! Paul Ginsparg was making fun of those who reach their intellectual limits when they learn how to create and upload a TeX/PDF file, but my congratulations to your achievement are genuine! ;-)
Well Lubos, thanks. Since you are so kind today, I will disclose that in fact I failed twice before the successful submission :) But I have a double justification: the first time, I had not read any instruction, assuming that the arxiv had evolved a bit since the last time and would accept a gzip of a .ps and a .pdf file. The second time, I did read all the information, but it turned out that a file had corrupted during a copy from linux to windows :(
Cheers,
T.
Dear Tommaso, indeed, being 1) arrogant enough not to listen to others, 2) assuming wrong things, 3) being corrupt, 4) using a communist would-be operation system ... sound like good enough justifications - given your standards. ;-)
Lol :)
Ok this was funny, especially calling linux communist. What did you use for your scientific work, may I ask ?
T.
For a few years, I was forced to use the Linux s*it, too. But it was under an immense pressure. ;-)
Nice graphics in the paper! Where are you sending it?

Here's some suggested changes (or possibly not, you decide):
"difference" -> ``difference''
hypothesize ? -> hypothesize? Or was this hypothesized?, I could have dropped a d.
intrinsic of the pseudoexperiments -> intrinsic to the pseudoexperiments
neglecting a trials factor -> neglecting a trial factor

Not sure about the "trials factor", but as a native English speaker, I would go for "trial factor". Can't say why. Do a google and check for abundance.

Getting people to read your papers and comment on them is difficult. I'm giving up on getting useful assistance on my spin paper and am going to send it in for reconsideration as is, after one more read through, maybe tomorrow.

Regarding arXiv quality control, check this one out:
http://arxiv.org/abs/0910.1641

You should have received an email from no-reply@arxiv.org, with title "Re: hput papername ...", with the exact formulation:

"Successful submission to the archives can be a significant source of pride and accomplishment. It entails many serious responsibilities: if you cannot check off on all of the items below, then you should replace your submission. (Note: *do not* resubmit, instead *replace*)"

HI Tommaso,

Congraulations on this publication.

I did a "Dorigo" search for ArXiv papers; 18 were listed. Numbers 5, 6, 7, 8, 9, 12 and 16 list a T Dorigo among the collaborators. Numbers 1, 10, 14, 17 and 18 list Tomamaso Dorigo alone, although the last two indicate collaboration.

Number 11 does not list any Dorigo as author, but has reference to a Marco Dorigo who is probably the M Dorigo of numbers 2, 3 and 4

An Alvise Dorigo is listed in number 13 and an A Dorigo in number 15.

Are these relatives?

Hi Doug,

look in spires, the link I point to quotes 416 papers. In the arxiv only few of the papers appeared, and indeed a few are from other Dorigos.

Cheers,
T.
I remember thinking, upon reading the third part of your "investigation", about in which way are your remarks going to be taken into account by the two experiments; I was expecting smth more like an internal publication or collaboration and being lazy I was expecting to be informed about the outcome in due time.
Now I am a bit surprised of the form the outcome took. Has there been any other kind of process between your blog posts and the arxiv post? (which the wider audience is permitted to know of, of course!) Which would be the "appropriate channel" for the continuation of this?

Hi Tulpoeid,

well, I asked D0 for a statement on their calculation of significance, they said they would get back to me, and then I lost patience and pressed the submit button. Maybe I should have waited for more time, because this is a result which is now 1.5 years old, and the information may not be so easy to trace back; but I thought that it was pretty clear what was the issue (1 or 2 dof), so any fellow in D0 could have answered that, not just the main author. I will be happy to discuss the issue with any of the members of the two collaboraitons, of course.

Cheers,
T.
I just did my first archive submission too, to viXra, now going to use it as my homepage for blog comment sections! Seriously how can Tony Smith not be allowed to add to his old E8 model papers on arXiv especially post-Lisi?