DZERO Confirms The Y(4140) And Its Excitation !
I have reported about the studies of resonances in the decays of the B+ meson by CDF, CMS, and LHCb a few times in the recent past. The situation, in a nutshell, was the following until yesterday: CDF found a new particle, the Y(4140), as a resonant (J/ψ φ) intermediate state produced when B+ mesons decay into a J/ψ, a φ, and a positive kaon; CDF also saw some evidence for a further excitation of the same two-body system; CMS confirmed the CDF claims, finding observation-level significance for both states; and LHCb did not confirm either of the two. Furthermore Belle, a B-factory experiment studying electron-positron collisions, also found no evidence for the Y(4140) state. With two experiments seeing a signal and two denying it, the situation was controversial. read more