Search for exotic mesons at SLAC
The theoretical justification and results from recent experimental searches for backward-produced exotic mesons including two experiments carried out by the collaboration at SLAC are reviewed. The first experiment put upper limits of about 1 to 2 $mu$b for X$sup ++$ $Yields$ (2$pi$, 4$pi$, 6$pi$)$sup ++$ and anti pp$pi$$sup +$$pi$$sup +$ in the reaction $pi$$sup +$ + p $Yields$ X$sup ++$ + n/sub forward/ at 8.4 GeV/c studied with the SLAC 14 inch rapid cycling bubble chamber triggered by a downstream neutron detector. Also the important features of the recently completed second experiment with the SLAC streamer chamber to study the reaction $pi$$sup -$ + p $Yields$ X$sup --$ + p/sub forward/ at 14 GeV/c are discussed. (auth)
Search for exotics produced opposite a forward Λ in 15 GeV/c π+p interactions
We have carried out a search for exotic meson resonances produced in the reaction π+p→K++ + Λ (forward) at 15 GeV/c. We have found no evidence for the existence of resonance-like states in the K++ system, and have obtained 95% confidence level upper limits of 1.7 μb on their production with masses <2.8 GeV, and 2.6 μb with masses between 2.8 GeV and 4 GeV.
In search of exotic states
SummaryIt is argued that if exotic mesons exist at all, backward scattering is the most favourable reaction to search for them. In particular, for exotics with masses around (1.5÷2) GeV, their backward production in π- or K-nucleon collisions is expected to be comparable to the one observed for vector or tensor mesons.RiassuntoSi arguisce, che se i mesoni esotici esistono, lo scattering all’indietro è la reazione più favorevole per la loro ricerca. In particolare, per gli esotici con masse (1.5÷2) GeV, si prevede che la loro produzione all’indietro, nelle collisioni di π e K su nucleoni, è confrontabile con quella osservata per i mesoni vettoriali o tensoriali.РезюмеДоказывается, что если, вообще, экзотические мезоны существуют, то обратное рассеяние представляет наиболее благоприятную реакцию для поиска этих мезонов. В частности, для экзотических мезонов с массами около (1.5÷2) ГэВ ожидается, что их рождение при обратном рассеянии в π-или К-нуклонных соударениях сравнимо с наблюденным рождением векторных или тензорных мезонов.