Search for $\hat{I}{˜}^{+}(1540)$ pentaquark in high statistics measurement of ${\hat{I}}^{3}p\to {\bar{K}}^0{K}^{+}n$ at CLAS

Abstract

The exclusive reaction ${\hat{I}}^{3}p\to {\bar{K}}^0{K}^{+}n$ was studied in the photon energy range between 1.6-3.8 GeV searching for evidence of the exotic baryon $\hat{I}{˜}^{+}(1540)\to n{K}^{+}$. The decay to $n{K}^{+}$ requires the assignment of strangeness $S=+1$ to any observed resonance. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility corresponding to an integrated luminosity of 70 $p{b}^{-1}$. No evidence for the $\hat{I}{˜}^{+}$ pentaquark was found. Upper limits were set on the production cross section as function of center-of-mass angle and $n{K}^{+}$ mass. The 95% CL upper limit on the total cross section for a narrow resonance at 1540 MeV was found to be 0.8 nb.

Submitted to Physical Review Letters