Experimental confirmation of the 1100 structure and first observation of the leptonic decay of the ρ′(1250)

Summary We have extended our survey of the reaction γ+p→p+$ e^{+} $+$ e^{−} $ by collecting 20 000 additional $ e^{+} %$ e^{−} $ pairs in the invariant-mass region 900<m<1500 MeV. The measured interference pattern shows two enhancements at mass values of 1097 and 1266 MeV. The parameters of th...
Ausführliche Beschreibung

Summary We have extended our survey of the reaction γ+p→p+$ e^{+} $+$ e^{−} $ by collecting 20 000 additional $ e^{+} %$ e^{−} $ pairs in the invariant-mass region 900<m<1500 MeV. The measured interference pattern shows two enhancements at mass values of 1097 and 1266 MeV. The parameters of those structure, when interpreted as vector mesons in the VDM framework, are given. Ausführliche Beschreibung