Pentaquark
A pentaquark is a hypothetical subatomic particle consisting of four quarks and one antiquark bound together (compared to three quarks in normal baryons). As quarks have a baryon number of +1⁄3, and antiquarks of −1⁄3, it would have a total baryon number of 1, thus being classified as an exotic baryon. The existence of pentaquarks was originally hypothesized by Michał Praszałowicz in 1987.
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