The story behind penguin diagrams
Penguin diagrams are Feynman diagrams showing certain particle decays that are important in searches for evidence of processes and particles not included in the Standard Model of Particle Physics.
The particle decays represented by penguin diagrams were first discussed in:
• A. Vainshtein, V. Zakharov, M. Shifman,
JETP Lett.
22 (1975) 55-56
The story behind the name, as recounted by John Ellis, is given on pages
x and xi of:
• M. Shifman, Foreward to ITEP Lectures on Particle Physics and
Field Theory (World Scientific, 1999)
and the paper in which the name was first used is:
• J. Ellis, M.K. Gaillard, D.V. Nanopoulos, S. Rudaz,
Nucl. Phys. B131 (1977) 285-307
