Related papers: Are there S=-2 Pentaquarks?
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…
Recent evidence for pentaquark baryons is critically reviewed in the light of new high statistics data. The search of the WA89 experiment for the $\Xi^{--}(1860)$ is presented in detail and consequences of its non-observations are…
Experimental evidence for and against the existence of pentaquarks has accumulated rapidly in the last three years. If they exist, they would be dramatic examples of hadronic states beyond our well-tested and successful particle models. The…
Pentaquarks, namely baryons made by 4 quarks and one antiquark have been predicted and searched for since several decades without success. Theoretical and experimental advances in the last 2 years led to the observation of a number of…
Following Rosner [hep-ph/0312269], we consider B-decay production channels for the exotic I=0 and $I=3/2$ pentaquarks that have been recently reported. We also discuss new search channels for isovector pentaquarks, such as the $\Theta^{*++}…
Several experimental groups have reported evidence for baryons with flavor exotic quantum numbers that cannot be explained as $qqq$ bound states but require a minimum of five quarks -- $qqqq \bar q$. These pentaquark states include the…
The existence of an anti-decuplet of pentaquark particles has been predicted some year ago within the chiral soliton model. In the last year, several experimental groups have reported evidence for a S=+1 baryon resonance, with mass ranging…
Recently there has been revival of interest in exotic baryon spectroscopy triggered by experimental evidence for pentaquarks containing u,d,s and c-quarks. We report results of the searches for pentaquark states in decays to p K0S, Xi-…
I study the very recently discovered S=-2 resonance Xi--(1886) by the NA49 collaboration at the CERN SPS. This resonance was already predicted, with a mass close to 1.9 GeV, in a recent publication mostly dedicated to the S=1 resonance…
We study the possibility that four $\Xi$ resonances $(\Xi(1620)$, $\Xi(1690)$, $\Xi(1820)$, $\Xi(1950))$ could correspond to pentaquark states, in the form of meson-baryon bound systems. We also explore the possible existence of doubly…
Inspired by the recent evidence of $P_{cs}(4459)$ reported by LHCb, we continue to perform the investigation of hidden-charm molecular pentaquarks with double strangeness, which are composed of an $S$-wave charmed baryon…
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…
This paper is a continuation of our studies of multiquark hadrons. The anti-symmetrization of their wavefunctions required by Fermi statistics is nontivial, as it mixes orbital, color, spin and flavor structures. In our previous papers we…
Evidences for new baryon states with mass >1.8 GeV were obtained in the experiments of the SPHINX Collaboration in studying hyperon-kaon mass spectra in several proton diffractive reactions. The main result of these experiments is the…
Hidden-charm pentaquark states with double strangeness, $P_{css}$, have been predicted within the framework of unitary coupled-channel dynamics. In this work, we theoretically investigate the potential to observe these states in the decays…
Hidden-charm pentaquark-like $P_{\psi s}^\Lambda(4459)^0$ and $P_{\psi s}^\Lambda(4338)$ resonances are studied in a constituent quark model as molecular meson-baryon structures. Such states are found in the $J^P(I)=\frac{1}{2}^-(0)$…
Recent experimental evidence for the Theta^+(1540) has given rise to much theoretical interest in exotic baryons. The Theta^+ is a baryon that has strangeness S=+1, meaning that it contains an anti-strange quark. Thus it cannot be…
We review and discuss the experimental evidence on predicted baryonic states made by 4 quarks and one antiquark, called pentaquarks. Theoretical and experimental advances in the last few years led to the observation of pentaquark candidates…
Narrow Xi-pi+- and Xi-bar+pi+- resonances produced by quasi-real photons have been searched for by the COMPASS experiment at CERN. The study was stimulated by the recent observation of an exotic baryonic state decaying into Xi-pi-, at a…
The discovery of some baryon-antibaryon resonances has led us to consider 3q~3\bar{q} systems as possible candidates. We predict their spectrum in the framework of a constituent model, where the chromo-magnetic interaction plays the main…