Two different accelerators have found evidence for a particle that appears to contains four quarks, according to papers published in Physical Review Letters. Although particles with two and three quarks are common, this would be the first time that something containing four quarks has been spotted. Depending on the precise nature of the interactions among the quarks, this could be a discovery that keeps the theoreticians very busy.
via Ars Technica
Image: The Belle detector at Japan’s KEK facility. Karlsruhe Institute of Technology.