No abstract

There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESIII and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESIII, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESIII during the remaining operation period of BEPCII. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCII to higher luminosity.

No abstract

We present a new limit on the production of a light dark-force mediator with the KLOE detector at DANE. This boson, called U, has been searched for in the decay φ → ηU, U → e+e−, analyzing the decay η → π0π0π0 in a data sample of 1.7 fb−1. No structures are observed in the e+e− invariant mass distribution over the background. This search is combined with a previous result obtained from the decay η → π + π − π 0 , increasing the sensitivity. We set an upper limit at 90% C.L. on the ratio between the U boson coupling constant and the fine structure constant of α′/α < 1.7 × 10−5 for 30 < MU < 400 MeV and α′/α 8 × 10−6 for the sub-region 50 < MU < 210 MeV. This result assumes the Vector Meson Dominance expectations for the φηγ∗ transition form factor. The dependence of this limit on the transition form factor has also been studied