Therefore, as two color charges are separated, at some point it becomes energetically favorable for a new quark–antiquark pair to appear, rather than extending the tube further. As a result of this, when quarks are produced in particle accelerators, instead of seeing the individual quarks in detectors, scientists see " jets " of many color-neutral particles (mesons and baryons), clustered together. This process is called hadronization, fragmentation, or string breaking.