This Letter reports results from the partial wave analysis of the π - π - π + η final state in π - p collisions at 18GeV/c. Strong evidence is observed for production of two mesons with exotic quantum numbers of spin, parity and charge conjugation, J PC =1 -+ in the decay channel f 1 (1285)π - . The mass M=1709±24±41MeV/ c 2 and width Γ=403±80±115MeV/c 2 of the first state are consistent with the parameters of the previously observed π 1 (1600). The second resonance with mass M= 2001±30±92MeV/c 2 and width Γ= 333±52±49MeV/c 2 agrees very well with predictions from theoretical models. In addition, the presence of π 2 (1900) is confirmed with mass M=2003±88±148MeV/c 2 and width Γ=306±132±121MeV/c 2 and a new state, a 1 (2096), is observed with mass M=2096±17±121MeV/c 2 and width Γ=451±41±81MeV/c 2 . The decay properties of these last two states are consistent with flux tube model predictions for hybrid mesons with non-exotic quantum numbers.
|Original language||English (US)|
|Number of pages||9|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - Aug 12 2004|
ASJC Scopus subject areas
- Nuclear and High Energy Physics