Pentaquark searches at HERA

Faddeev calculation of the pentaquarkΘ+in the Nambu–Jona-Lasinio model-based diquark picture

“…Subsequently, the PDG in 2006 reduced the rating from three to one stars [4]. More recently, the ZEUS experiment at HERA [7] observed a signal for + in a high energy reaction, while H1 [7], SPHINX [8], and CLAS [9] did not see it. This disagreement between the LEPS [1] and other experiments could possibly originate from their differences of experimental setups and kinematical conditions.…”