Thursday, July 12, 2012

Cabibbo what?

I recently came across an old report from Nordita, the years 1957-1982. It's in Swedish and for all I can tell it covers the mission, organization and the research areas that were pursued back then, atomic and nuclear physics, condensed matter and astrophysics. Somewhere in the middle of the little booklet one finds this photo

The photo has no caption and I have no clue who the people are. I suspect it was taken sometime in the 70s.  The woman in the photo is the only female face that appears in the whole booklet. Wondering what a caption might have read, I thought it looks like "Cabibbo what? Forget about that, how about tonight?" while the guy on the far right clearly feels like slapping his forehead ;o)

Anyway, Stefan and I couldn't really figure out what the multiplet is they have on the blackboard there, the one with the two L's and the N in the middle. Anybody has a good guess? Or does anybody actually know who's on the photo? Seeing that they look pretty young, they might actually still be alive. Or maybe you have a suggestion for an alternative caption...

Update: Somebody on FB indeed recognized people on the photo! So the person the the very right is Finn Ravndal and the woman's name Cecilia Jarlskog.


  1. Hi Bee,

    Not certain who they are or what they are considering yet it appears many of them had already adopted the John S. Bell look. Then again I suppose we could attribute the fashion to a few other physicists at the time :-)



    P.S. Grateful the mysterious female is not also sporting a beard, yet delighted to find she does have her love beads on :-)

  2. It's spelled "nucular", not "nucelar"!


  3. The guy on the right can't work out what they've written on the blackboard either.

  4. The guy to the right is Finn Ravndal (Oslo), my old MSc supervisor, retiring from our department this summer. He did his PhD with Feynman. The woman is Cecilia Jarlskog (Lund), retired a few years back, and was on the NORDITA board until 2010 I think. The pic is from the 70ies, and I'm sure Hans Hansson can tell you who the others are. No:2 from the left looks a bit like Petter Minnhagen (who still wears this type of beard, last time I saw him anyway) but probably it's not him..

  5. The chap with the seaman's beard reminds me of Bengt Gustafsson, who AFAIK has always worn a seaman's beard. However, while he does know a huge amount about a lot of subjects, he's primarily an astrophysicist (stellar atmospheres), so I don't think that's him.

  6. The triplet is a lepton triplet - positively charged lepton, neutrino, and negatively charged lepton. Homework exercise: what's wrong with this model?

  7. Well, there's no such triplet in the SM. Without a Lagrangian it's hard to tell though exactly what would go wrong. Probably violates some symmetry/conservation law.

  8. What Cecilia Jarlskog was thinking about in 1971:


    Muon decay, without requiring conservation of the lepton charge, is examined. The coupling constants occuring in the terms of the interaction Hamiltonian which can give rise to a pair of identical neutrinos (or antineutrinos) are reffered to as the lepton-charge-violating coupling constants. Using the predicted V-A values for four decay parameters (which are close to the experimental values) we show that only four coupling constants, viz., gV and gA of the ordinary theory and (View the MathML source) and (View the MathML source) of the lepton-charge violating interactions remain undertermined. Further, only the combination (View the MathML source) can be measured. The further assumption of the two-component theory for one of the decay neutrinos gives uniquely the V-A theory (View the MathML source). Allowing for the experimental uncertainties, lepton-charge-violating scalar and pseudoscalar interactions of about the same order of magnitude as the usual scalar and pseudoscalar interactions cannot be excluded. The significance of future measurements of η′, one of the decay parameters for radiative muon decay, for finding upper limits to the scalar, pseudoscalar and tensor interactions is also discussed.

  9. I asked Cecilia Jarlskog what she remembers about the occasion. She is talking to Matts Roos from Helsinki, and the subject, she thinks, seems to have been weak interaction (her field of expertise), the Cabibbo theory and its extension due to the charm quark.

  10. Its my grandma Cecilia Jarlskog :)


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