The evidence for a pentaquark signal and kinematic reflections

Several recent experiments have reported evidence for a narrow baryon resonance with positive strangeness $\left({\Theta }^{+}\right)$ at a mass of $1.54\mathrm{GeV}{/c}^2.$ Baryons with $S=+1\mathrm{}$ cannot be conventional qqq states and the reports have thus generated much theoretical speculation about the nature of possible $S=+1\mathrm{}$ baryons, including a 5-quark, or pentaquark, interpretation. We show that narrow enhancements in the $K^{+}n$ effective mass spectrum can be generated as kinematic reflections resulting from the decay of mesons, such as the $f_2\mathrm{}\left(1275\right),$ the $a_2\mathrm{}\left(1320\right)\mathrm{}$ and the ${\rho }_3\mathrm{}\left(1690\right).$