K+-Meson Production inp−pCollisions at 2.5-3.0 GeV

Differential cross sections as a function of momentum are presented for the production of $K^{+}$ mesons in $p-p$ collisions at incident proton energies of 2.54, 2.88, and 3.03 GeV. The measurements were made at 20°, 30°, and 40° relative to the direction of the internal proton beam of the Princeton-Pennsylvania accelerator. At 2.54 GeV, the results follow closely the predictions from phase space (with 60% $K^{+}\Sigma N$ and 40% $K^{+}\Lambda p$ in the final state). At 2.88 and 3.03 GeV, however, there is a definite disagreement with phase space. The data are compared to the predictions of three models: (1) a model based on the assumption that $K\text{'}\mathrm{s}$ are produced via $p+p\to K^{+}+X^{+}$, where $X^{+}$ is a $B=2\mathrm{}$, $S=-1\mathrm{}$ resonance which decays into a nucleon+hyperon; (2) the isobar model; and (3) the one-pion-exchange model. Model (1) is found to be inconclusive, model (2) is inadequate, and model (3) is partly successful in predicting total cross sections, but not in interpreting the detailed experimental observations.