Warped penguin diagrams

“….one evening, after working at CERN, I stopped on my way back to my apartment to visit some friends living in Meyrin where I smoked some illegal substance. Later, when I got back to my apartment and continued working on our paper, I had a sudden flash that the famous diagrams look like penguins. So we put the name into our paper, and the rest, as they say, is history.”

The speaker is John Ellis, FRS, currently Clerk Maxwell Professor of Theoretical Physics at King’s College London, and he is describing a crucial stage in the origin of Penguin Diagrams back in 1977. (details here, page 7)

More than thirty years have passed since their inception, but now there’s a new twist – the Warped Penguin Diagram. They are described in a new paper from professor Csaba Csáki, and colleagues at the Institute for High Energy Phenomenology, Newman Laboratory of Elementary Particle Physics, Cornell University, NY, and they assist in the visualisation of loop-induced magnetic dipole operators in the Randall-Sundrum model of a warped extra dimension with anarchic bulk fermions and an IR brane-localized Higgs.
For full details see:Warped Penguins, published on April 1st , 2011 in Physical Review D , Volume 83 , Issue 7,


1) For more background on the genesis of the original penguin diagrams, and the parts played by Melissa Franklin, (now Mallinckrodt Professor of Physics; and Chair, Department of Physics, at Harvard) and a dartboard, see the Quantum Diaries Survivor blog.

2) The illustration shows a ‘traditional’ penguin diagram [top] and a ‘warped’ penguin diagram [below] which, for comparison, Improbable has overlayed onto an image of a real penguin (photo courtesy NASA).

3) The paper also introduces the Yin-Yang and Double Rainbow topologies of two-loop diagrams.

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