Monday, April 27, 2009

How I came to love nuclear physics

About 18 months ago Gerard Milburn and Phil Stamp invited me to a small PITP workshop in Vancouver on Quantum Information and Many-body Physics. It was there that I met David Hinde and Nanda Dasgupta from Nuclear Physics at ANU (where I was an undergraduate). The talks given by David and Nanda were about a beautiful series of experiments that measure with incredibly high resolution the energy dependence of the cross section for nuclear fusion of two colliding complex nuclei. For fusion to occur quantum tunneling below the potential energy barrier between the nuclei must occur. This is found to be suppressed compared to what is expected for reasonable nuclear potentials and in a PRL with Gerard and a later theory paper with Alexis Diaz-Torres they suggest this suppression is because of decoherence arising from interaction of the relative motion of the nuclei with the internal degrees of freedom of the nuclei. I had been thinking a lot about quantum tunneling of protons in enzymes and reading the theory of quantum tunneling in the presence of a dissipative environment. What really got my attention was the quality of their data which extended over 8 orders of magnitude of the tunneling probability!


This should provide significant constraints on any theory for tunneling in the presence of decoherence. Nanda will give the physics colloquium at UQ this Friday.

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