“The theory community, myself included - became rather troubled about the particle.”
about the pentaquark, soon after its thought-to-be discovery in 2003, particle physicists found that the particle took about 100 times longer to decay into a neutron and meson than other particles did of the same mass, as quoted by by Maggie McKee, New Scientist, (April 20, 2005) http://www.newscientist.com/article/dn7287