Quark Bound States (image) Forschungszentrum Juelich Share Print E-Mail Caption For a long time, physicists were only able to reliably verify two different classes of hadrons: baryons and mesons. Experiments performed at Jülich's accelerator COSY have now shown that, in fact, another class of exotic particles made up of six quarks exists. Credit Source: Forschungszentrum Jülich/SeitenPlan (CC BY 4.0) Usage Restrictions CC BY 4.0 Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.