by
Prof.Frederick A. Harris(UHM, Department of Physics and Astronomy)
→
Pacific/Honolulu
112 (Watanabe Hall)
112
Watanabe Hall
Description
One of the highlights of 2013, according to the editors of Physics, is
the evidence from the BESIII and Belle experiments for particles
containing four quarks, rather than the usual two or three. An
international team of scientists, which includes members of the High
Energy Physics Group in the Department of Physics and Astronomy at UH,
began studies in 2013 with the Beijing Electron Positron Spectrometer
(BESIII), aimed at understanding the anomalous ``Y(4260)'' particle.
The collaboration found early last year in the decays of the Y(4260) a
new, even more mysterious particle, the charged Z_c(3900), a four
quark candidate, which was almost immediately confirmed by the Belle
experiment. This was the first confirmed charged, charmonium-like
state and has sparked much theoretical interest.
In the meantime, the collaboration has found in other processes in
this energy region the Z_c(3885), Z_c(4020), and Z_c(4025). Although
some of these may well be the same particle, there are at least two
new four quark candidates. These results along with those from other
analyses of the data and from additional data will be very important
in the theoretical understanding of some of the mysterious XYZ
particles.