5 is for pentaquarks, the exotic baryons that got discovered and then undiscovered!
Slides taken from Pat Burchat’s excellent talk on pentaquarks: https://www.stanford.edu/dept/physics/people/faculty/docs/burchatUCIseminar.pdf
Fake peak plot from paper by Torres and Oset: http://arxiv.org/abs/1012.2967
The Particle Data Group (PDG) review on pentaquarks (PDF documents) 2008, 2006, 2004.
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