1966/07/29 by J. Peter Berge, Philippe Eberhard, John P. Hubbard +8 · 3 citations
Physics and Astronomy · #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #High-Energy Particle Collisions Research
paper · doi:10.1103/physrev.147.945
The production of cascade hyperons by incident K^\ensuremath- on hydrogen has been studied from threshold (1.05 BeV/c) to 1.7 BeV/c. A sample of 1004 \ensuremathΞ^\ensuremath- and 206 \ensuremathΞ0 was obtained. Production cross sections rise over this momentum range, reaching about 150 \ensuremathμb for \ensuremathΞ^\ensuremath-K+ production and about 100 \ensuremathμb each for \ensuremathΞ0K0 and \ensuremathΞ\ensuremathπK. Production of the \ensuremathΞ*(1530) near threshold is observed, and the assignment I=(1)/(2) for this resonance is confirmed. The \ensuremathΞ decay analysis yields weak evidence for J_\ensuremathΞ=(1)/(2). For J_\ensuremathΞ=(1)/(2), our decay-parameter results are \ensuremathα_\ensuremathΞ^\ensuremath-=\ensuremath-0.368\ifmmode±\else\textpm\fi0.057 and \ensuremathΦ_\ensuremathΞ^\ensuremath-=invtan(\frac\ensuremathβ\ensuremathγ)_\ensuremathΞ=0.008\ifmmode±\else\textpm\fi0.186 rad. The final-state \ensuremathπ\ensuremathΛ phase difference is then (\ensuremathδP\ensuremath-\ensuremathδS)=invtan(\frac\ensuremathβ\ensuremathα)_\ensuremathΞ=179\ifmmode±\else\textpm\fi26 deg. No significant violation of the \ensuremathΔI=(1)/(2) rule was observed. The upper limit on the leptonic decay rate, \frac(\ensuremathΞ^\ensuremath-\ensuremath→\ensuremathΛe^\ensuremath-\ensuremathν)(\ensuremathΞ^\ensuremath-\ensuremath→\ensuremathΛ\ensuremathπ^\ensuremath-), was found to be 0.5%.