GlueX Finds Y(2240) at 5σ and X(1830) While Missing Sought-After Y(2175)
Updated
Updated · Interesting Engineering · Aug 23
GlueX Finds Y(2240) at 5σ and X(1830) While Missing Sought-After Y(2175)
2 articles · Updated · Interesting Engineering · Aug 23
Summary
Jefferson Lab’s GlueX Collaboration reported a 5σ signal for Y(2240) at about 2.24 GeV and a weaker 3σ hint for X(1830) near 1.82 GeV.
The structures emerged during a photon-beam search for Y(2175), which did not appear where expected, giving researchers an upper limit on how often that state is produced in photon collisions.
GlueX used CEBAF electrons converted by a diamond wafer into a high-intensity polarized photon beam, then reconstructed proton-collision debris in a large spectrometer.
Y(2240) meets particle physics’ usual observation threshold, while X(1830) still needs more evidence to determine whether it is an exotic quark-gluon state or another composite configuration.
The result adds fresh targets for theorists studying the strong force and suggests more exotic hadrons could emerge as GlueX analyzes its remaining data.