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发帖数: 1828 | 1 Jumping the Gun April 4, 2011
Posted by gordonwatts in Uncategorized.
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The internet has come to physics. Well, I guess CERN invented the internet,
but, when it comes to science, our field usually moves at a reasonable pace
– not too fast, but not (I hope) too slow. That is changing, however, and I
fear some of the reactions in the field.
The first I heard about this phenomena was some results presented by the
PAMELA experiment. The results were very interesting – perhaps indicating
dark matter. The scientists showed a plot at a conference to show where they
were, but explicitly didn’t put the plot into any public web page or paper
to indicate they weren’t done analyzing the results or understanding their
systematic errors. A few days later a paper showed up on arXiv (which I
cannot locate) using a picture taken during the conference while the plot
was being shown. Of course, the obvious thing to do here is: not talk about
results before they are ready. I and most other people in the field looked
at that and thought that these guys were getting a crash course in how to
release results. The rule is: you don’t show anything until you are ready.
You keep it hidden. You don’t talk about it. You don’t even acknowledge
the existence of an analysis unless you are actually releasing results you
are ready for the world to get its hands on and play with it as it may.
I’m sure something like that has happened since, but I’ve not really
noticed it. But a paper out on the archives on April 1 (yes) seems to have
done it again. This is a paper on a Z’ set of models that might explain a
number of the small discrepancies at the Tevatron. A number of the results
they reference are released and endorsed by the collaborations. But there is
one source that isn’t – it is a thesis: Measurement of WW+WZ Production
Cross Section and Study of the Dijet Mass Spectrum in the l-nu + Jets Final
State at CDF (really big download). So here are a group of theorists,
basically, announcing a CDF result to the world. That makes a bit
uncomfortable. What is worse, however, is how they reference it:
In particular, the CDF collaboration has very recently reported the
observation of a 3.3 excess in their distribution of events with a
leptonically decaying W+- and a pair of jets [12].
I’ve not seen any paper released by the CDF collaboration yet – so that
above statement is definitely not true. I’ve heard rumors that the result
will soon be released, but they are rumors. And I have no idea what the
actual plot will look like once it has gone through the full CDF review
process. And neither do the theorists.
Large experiments like CDF, D0, ATLAS, CMS, etc. all have strict rules on
what you are allowed to show. If I’m working on a new result and it hasn’t
been approved, I am not allowed to even show my work to others in my
department except under a very constrained set of circumstances*. The point
is to prevent this sort of paper from happening. But a thesis, which was the
source here, is a different matter. All universities that I know of demand
that a thesis be public (as they should). And frequently a thesis will show
work that is in progress from the experiment’s point of view – so they are
a great way to look and see what is going on inside the experiment. However
, now with search engines one can do exactly the above with relative ease.
There are all sorts of potential for over-reaction here.
On the experiment’s side they may want to put restrictions on what can be
written in a thesis. This would be punishing the student for someone else’s
actions, which we can’t allow.
On the other hand, there has to be a code-of-standards that is followed by
people writing papers based on experimental results. If you can’t find the
plot on the experiment’s public results pages then you can’t claim that
the collaboration backs it. People scouring the theses for results (as you
can bet there will be more now) should get a better understanding of the
quality level of those results: sometimes they are exactly the plots that
will show up in a paper, other times they are an early version of the result.
Personally, I’d be quite happy if results found in theses would stimulate
conversation and models – and those could be published or submitted to the
archive – but then one would hold off making experimental comparisons until
the results were public by the collaboration.
The internet is here – and this information is now available much more
quickly than before. There is much less hiding-thru-obscurity than there has
been in the past, so we all have to adjust. Smile
* Exceptions are made for things like job interviews, students presenting at
national conventions, etc.
Update: CDF has released the paper… |
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