Search for the exotic Ξ--(1860) resonance in 340 GeV/c Σ- -nucleus interactions

We report on a high statistics search for the ${\ensuremath{\Xi}}^{\ensuremath{-}\ensuremath{-}}(1860)$ resonance in ${\ensuremath{\Sigma}}^{\ensuremath{-}}$-nucleus collisions at $340\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}∕c$. No evidence for this resonance is found in our data sample which contains 676000 ${\ensuremath{\Xi}}^{\ensuremath{-}}$ candidates above background. For the decay channel ${\ensuremath{\Xi}}^{\ensuremath{-}\ensuremath{-}}(1860)\ensuremath{\rightarrow}{\ensuremath{\Xi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}$ and the kinematic range $0.15l{x}_{F}l0.9$ we find a $3\ensuremath{\sigma}$ upper limit for the production cross section of 3.1 and $3.5\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{b}$ per nucleon for reactions with carbon and copper, respectively.