Sunday, 1 April 2012

April Fools '12: Higgs or loose cable?!

These days CERN is going through turbulent times. Last week a prominent physicist had to quit his post after an embarrassing error was discovered in the neutrino speed measurement by CERN's OPERA experiment. Soon there will be more heads rolling. As soon as it became clear that the apparent superluminal propagation of neutrinos in OPERA was caused by a loose cable, CERN's director general ordered an inspection of all detectors so as to make sure a similar problem is not affecting other experiments. The conclusions of this internal inspection were reported yesterday evening at a closed meeting at CERN. The news reaching me are quite sensational: spokesperson of the ATLAS collaboration admitted that a faulty cable had been identified in their detector; moreover, that issue may have significantly distorted the results of the Higgs boson searches!

From what I could gather, the issue is with a cable connecting two modules of the electromagnetic calorimeter. It was discovered that this particular cable had a short-circuit, as a result of which it was repeatedly sending pulses with similar characteristics as those expected from a 125 GeV Higgs boson decaying to a pair of photons. Recall that the tantalizing hints of the Higgs boson reported last year by the ATLAS and CMS collaborations were almost entirely based on the observations of a bump in the diphoton mass spectrum, see the graph on the right. It now appears that at least a part of that bump can be blamed on the loose cable. Meanwhile, the CMS collaboration also reported a problem yesterday. From what I could understand, in this case it is not a hardware problem but a software bug originating due to the American and European parts of CMS using different units of mass (kilograms vs pounds). It is not yet clear if this issue affects the Higgs searches, but it is not unlikely that, when the data analysis is corrected, the bump in the diphoton spectrum will shift to a different location or completely disappear.

In the end, it is probable that the Higgs searches at the LHC will have to be redone from scratch during the 2012 run. In that case the LHC may lose its place in the queue, and the glory may go to the Tevatron who recently reported a signal of the Higgs boson decaying to a pair of bottom quarks.

An official statement from CERN is expected on Monday morning. Stay tuned as the story unfolds.

Update: Obviously, this story is an April Fools joke. If you forgot what date it was, you could easily realize this was not a true story because of the following inaccuracies:
  • OPERA is not a CERN experiment, CERN only provides the neutrino beam for that collaboration (although, because of some awkward politics, CERN assumed in the eyes of the world a certain moral responsibility for OPERA).
  • There's no way a loose cable can fake the Higgs signal; thousands things can but not this one.
  • On both sides of the Atlantic the elementary particle masses are measured in GeV.
  • The ATLAS and CMS detectors thousands cables, so if one of them went loose we probably would never know ;-)

25 comments:

Anonymous said...

Incredible!

wellinformed said...

I heard ATLAS and CMS spokespersons resigned

Anonymous said...

What amateurs!!! All these people should be fired!!!

Anonymous said...

Nice April Fool. Almost got me.

Anonymous said...

It seems a secret cable was found connecting Atlas and CMS computing farms, which was producing resonaances at a mass value around 124 GeV

beanfeast said...

I'm going to wait for confirmation of this story from other sources on a date other an April 1st.

Anonymous said...

As long as it doesn't call the new gluino evidence into question.

Anonymous said...

If only every theorist with a loose cable had to resign...

Anonymous said...

Well .... are you serious?

Today is April Fools' Day!

Tom Weidig said...

I heard that the origin of the loose cable was in the Resonaances' brain and due to cultural information he has stored through his interaction with his social environment through the years.

Vladimir Kalitvianski said...

Shortcut is a 1-rst April joke, of course. However you must know that self-action in Theoretical Physics is like connecting an amplifier outlet to its inlet with a positive feedback. Such a theoretical construction generates funny mass corrections removed later by hand (renormalizations). The corresponding substantiation (known as "bare particle physics") has nothing to do with reality and it is not a joke.

TINA ΝΑΝΤΣΟΥ said...

What a joke!! Bravo!

SC's Blog said...

Well done! I like this post.

Anonymous said...

Happy Birthday Sidd Finch.

http://www.newsday.com/sports/baseball/mets/it-s-april-fools-happy-birthday-sidd-finch-1.3635480

Anonymous said...

Should have re-run "BEH Boson" post also.

chris said...

a nice one, really ^_^

Anonymous said...

Nice joke :DDDD

Rhys said...

Haha, very good!

Anonymous said...

You almosy had me

Anonymous said...

It got me until the second paragraph
;)

fp

Sanhita said...

:D

Anonymous said...

I'm unsure of the first inaccuracy you list: OPERA *is* a CERN experiment, classified as CNGS1 in the SPS programme.

Jester said...

Yep, I should have been more precise. Of course, CERN is involved as it provides the beam (and a lot of money has gone down the drain too...) But the experimental collaboration that performed the data analysis is independent of CERN, unlike that of ATLAS, CMS, ALPHA, CAST, etc.

Anonymous said...

It is a CERN experiments when there are hints of a new scientific result, when there is a world wide webinar to run in the main auditorium.
It is not a CERN experiment when the results disappear.

tulpoeid said...

Cute, but *nothing* will ever beat your last year's story...