Present status on experimental search for pentaquarks

Abstract

It has been ten years since the first report for a positive strangeness pentaquark-like baryon state. However the existence of the pentaquark state is still controversial. Some contradictions between the experiments are unsolved. In this paper we review the experimental search for the pentaquark candidates Θ + , Θ ++ , Ξ −− , Θ 0 c and N * in details. We review the experiments with positive results and compare the experiments with similar conditions but opposite results.

Identifying Exotic Hidden-Charm Pentaquarks

“…In 2003, the LEPS Collaboration reported the evidence of the strange pentaquark state with the quark content uudd s and very narrow width [4]. Unfortunately this flavor exotic state was not confirmed by subsequent experiments [5,6]. In fact, the possible theoretical arguments for the non-existence of the stable strange pentaquarks were given in Refs.…”

Regge trajectories of exotic hadrons in the flux tube model

“…Initially, such states were observed as exotic baryons produced in different processes, 6 but with the improved experimental facilities, the experimental observation of these particles was first reported by Diakonov, Petrov, and Polyakov 7 in 1997. Since then many experiments have confirmed the existence of different pentaquark systems [8][9][10] and their properties are discussed in detail based on lattice calculations. 11 The analysis of many experimental data still need more careful attention to prove the existence of pentaquark configurations 12,13 however, there are number of investigations to confirm the existence of such states including the recent one at CERN and DIANA collaborations.…”

Exploration of charmed pentaquarks

“…Although the signal of Θ + (1540) was not confirmed in experiment, searching for pentaquark is still an important task [9]. Thus, we need to carry out further theoretical study of pentaquark, which can provide us more abundant information of possible pentaquark.…”