The start of a new week: Baha Balantekin + Ernesto Mane

We began the second week on the conference with neutrinos from Baha Balantekin, and laser spectroscopy from Ernesto Mane.

Prof. Balantekin gave one of the best review talks of he conference so far. He started with an historical introduction to neutrino astrophysics: Davis, Bahcal, the ancient solar neutrino problem. It turns out there's still life in it, arising from inconsistencies betwen observations in helioseismologic (the bubble behaviour of the sun) and the sun composition. It would require precision measurements of CNO neutrinos (precision+neutrino experiments: good luck with that!). The talk then flashed a bit too fast through neutrino experiments, but we were treated with pictures of SUPERKAMIOKANDE and some clasic experimental spectra: oscillation of atmospheric neutrinos, the few counts that made neutrino emissions from core collapse supernovae an experimental fact.

Theory was smartly introduces with slides written in "Comic Sans" font; it created a great illusion of simplicity for the derivations with Lagrangians and dimensional countings. Unfortunately, almost five six since my last classical mechanics class the difference between a Lagrangian and a Hamiltonian has long evaporated from my mind! From the derivations we arrived at the fact that a massive neutrino can be somewhat expressed in the simplest possible way within the standard model (exactly how was beyond me), so another of their properties is they obbey Ocham's razor. With the mass arrived their mixing angles (we'd ove to know theta13), and how all we ignore about neutrinos permeates everything from the matter-antimatter asymmetry to the electron fraction in the ejected material during core collapse supernovae.

A revolution is in the making in enormous underwater tanks and theorist's brains!


Then it was the turn of the local hero, Dr. Mane. He began explaining all things we can learn from shining lasers into radioactive ions, such as charge radii, magnetic moments, nuclear exited states. It followed with what I thought was a unnecessarily pessimistic picture of the experimental challenges in laser spectroscopic experiments... we need millions and millions of atoms! But it turns out he had a few cards to puled out of his sleeve and solve those problems with ion traps in the experimental setup!

The tricks: with a gas filled Pauli trap you can control bunch the beam (i.e. cotrol when you send the atoms out of the trap and into the light) and that reduces background greatly because you only listen to the detectors at that time. Fill the trap with gas and the atoms beam is restricted to smaller region of space, and has less spread in velocities (low low emitance). Thus better resolution. And finally just pump up the atoms when they're still in the trap (better efficiency!) and you can call yourself a laser spectroscopy magician.

In summary, I got the impression lasser spectroscopy is a field with a lot of activity (CERN, Finland, TRIUMF), and with more people jumping in the wagon soon (NSCL, ANL, one more), which promises lots of experimental results in the years to come.