High Resolution Search for Exotic Pentaquark $\Theta^{++}$, and   $\Theta^+$ at Jefferson Lab
  Recent evidence for the existence of pentaquark $\Theta^+$ particle from several experiments at several different laboratories around the world has caused great excitement and raised many unanswered questions. We discuss a new proposal on a high resolution experiment searching for pentaquark states in Hall C at Jefferson Lab using an untagged bremsstrahlung photon beam employing both the hydrogen and the deuterium targets by studying the following processes: $\gamma p \to \Theta^{++} K^-$, and $\gamma n \to \Theta^+ K^-$. This new experiment will significantly improve our current knowledge of the mass, the width of the $\Theta^+$ particle if it is confirmed and provide unambiguous evidence for the existence or non-existence of the $\Theta^{++}$ particle from the \gamma p \to \Theta^{++} K^-$ process. 
Haiyan Gao and Wang Xu