0000000000705857
AUTHOR
Yu-ping Guo
Direct production of χc1 at BESIII
The production of resonances in electron-positron annihilation has only been observed for states with quantum numbers JPC = 1−−, while C = +1 resonances appear only among the decay products. The direct production of the 1++ states could happen through two-photon or neutral current. Due to the smallness of the production rate, this process has never been verified experimentally. With the high luminosity and good performance of the BESIII experiment, a search of the direct production of the 1++ state in charmonium region, χc1, is undergoing with dedicated data samples around the χc1 mass. An overview of the data analysis will be presented.
Observation of the first iso-spin Charmonium-like State $Z_c(4020)$ }
In this paper, we present a new experimental progress in brief on the recent observation of the charged charmonium-like state Z_c(4020)^{+/-} states and its iso-spin partner Z_c(4020)^{0} in pi pi hc process at the BESIII experiment. The charged Z_{c}(4020) is its decay into \pi^{+/-} hc final state, and carries electric charge, thus it contains at least four quarks. The observation of both charge and neutral state makes Z_{c}(4020) the first iso-spin triplet Z_{c} state observed in experiment.
XYZ physics at BESIII
In this talk, we present the recent study on the charmonium-like states from the BESIII Collaboration based on large data samples above DD¯$D\overline D $ threshold. The observation of X(3872) from the Y(4260) radiative transition, the study of the Y states from the e+e− → π+π−hc process, and the observation of the charged Zc states are included.
LatestXYZresults frome+e−colliders
We present the recent progress on the charmonium-like states (or called XYZ states) from electron-positron colliders, including the results from BESIII, CLEO-c, BaBar and Belle. This talk covers the observation of X(3872) from radiative decay of the Y(4260), the updated results of Y states from initial state radiation (ISR) process of π + π − J/ψ and π + π − ψ(2S ) and also cross section measurement of e + e − → π + π − hc and e + e − → ωχc0, and the observation of charged and neutral charmonium-like states (Zcs).
Experimental review of e+e− →ππhcSupported by Joint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contracts No. U1332201, and National Natural Science Foundation of China (NSFC) under Contracts No. 11475207
We review the recent BESIII measurement of e+e− → ππhc in which its line shape is studied between the center-of-mass energies of 3.9 to 4.42 GeV and an iso-vector charmonium-like state Zc(4020) is observed in the invariant mass of πhc at the BESIII experiment. The charged Zc(4020)± is the second observed Zc state following Zc(3900), while the Zc(4020)0 is the first observed neutral Zc state. The line shape of σ(e+e− → ππhc) is also re-analyzed in view of searching for the Y state and the existence of the Y(4220) state is confirmed and compared with the previous work of the BESIII experiment.