Related papers: Present status on experimental search for pentaqua…
I overview the physical picture of QCD at low energies that has led to the prediction of a narrow exotic baryon Theta^+ which cannot be made of three quarks. The very narrow width of the Theta^+ and a possible reason why it is seen in low-…
The discovery of hidden-charm pentaquarks and open-flavor tetraquarks motivates the search for even more exotic hadron configurations. In this work, we investigate genuinely exotic molecular pentaquark candidates comprising five different…
A large data set of proton-nucleus collisions at sqrt(s) =41.6 GeV has been searched for Theta+ and Xi(1862) pentaquark candidates. In 2x10**8 inelastic events we find no evidence for narrow signals (sigma=5 MeV/c**2) in the Theta+ --> pK0s…
The experimental evidence for pentaquarks is reviewed and compared with the experiments that do not see any sign of pentaquarks. This paper is based on a lecture given at the 33rd ITEP Winter School of Physics in the beginning of 2005.…
We consider hidden charm pentaquarks as hadroquarkonium states in a QCD inspired approach. Pentaquarks arise naturally as bound states of quarkonia excitations and ordinary baryons. The LHCb $P_c(4450)$ pentaquark is interpreted as a…
Possible existence of a molecular-type heavy-flavored strange pentaquark is considered. No narrow state of such a type is shown to exist.
Exotic multi-quark states are examined in the quark model and in QCD. Current status of theoretical studies of the pentaquark Theta^+ is reported. We show recent analyses of multi-quark components of baryons. A novel method to extract a…
Pentaquark states have been extensively investigated theoretically in the context of the constituent quark model. In this paper results of an experimental search for pentaquarks in the \Xim\pim, \Xim\pip, \Xip\pim and \Xip\pip invariant…
The existence of pentaquarks with strangeness content zero and one are major discoveries of the latest years in hadron physics. Most of these states can be understood as hadronic molecules and were predicted prior to their discovery within…
The PHENIX experiment at RHIC should be sensitive to decays of the the anti--pentaquark $\bar{\Theta}^-$ via the K$^-$ $\bar{n}$ channel. Charged kaons can be identified using the standard tracking and time of flight up to a momentum of 1.5…
We have searched for Theta+(1.54) -> K0,p decays using data from the 1999 run of the HyperCP experiment at Fermilab. We see no evidence for a narrow peak in the K0,p mass distribution near 1.54 GeV/c among 106,000 K0,p candidates, and…
We discuss certain general features of the pentaquark picture for the theta, its 10bar_F partner, Xi_{3/2}, and possible heavy quark analogues. Models employing spin-dependent interactions based on either effective Goldstone boson exchange…
The spectra of pentaquarks, some of them being observed recently, are discussed within topological soliton model and compared with simplified quark picture. Results obtained within chiral soliton model depend to some extent on the…
Experiments with electromagnetic probes are promising to search for baryon resonances that have been predicted by quark models but have not yet been observed. Data sets from different experiments show interesting resonance structures…
The possibility for an observation of a narrow penta-quark $Z^+$ baryon in $NN$ reactions is discussed. It is shown that the $pp{\to}n\Sigma^+K^+$ reaction at excess energies around 100 MeV above threshold provides optimal conditions for…
Starting from 2003, the discovery of a large amount of the so-called exotic hadronic states, i.e., the $XYZ$ states, the pentaquark states as well as the tetraquark states, have not only revived studies of hadron spectroscopy, but also…
The exotic baryon $\Theta^+$ (1540 MeV)$ is visualised as an expected (iso) rotational excitation in the Chiral Soliton Model. It is also argued as a Pentaquark baryon state in a constituent quark model with strong diquark correlations. I…
The problem of the long life time of the pentaquark $\Theta^+$ is investigated on the basis of the color molecular dynamics simulation. We find that it takes a long time (typically of 50-100 fm/c) for the initial pentaquark-state to…
This review deals with measurements and future experiments of light pentaquark searches using hadron beams.
We study the very recently discovered $\Theta^+$ (1540) at SPring-8, at ITEP and at CLAS-Thomas Jefferson Lab. We apply the same RGM techniques that already explained with success the repulsive hard core of nucleon-nucleon, kaon-nucleon…