Related papers: The narrow pentaquark
We study the interaction of the $\Theta^+$ pentaquark with nuclear matter associated to the $KN$ decay channels and to the two meson cloud. We find that the potential is attractive and could be strong enough to lead to the existence of…
We report on a study of the pentaquark Theta^+(1540), using a variety of different interpolating fields. We use Chirally Improved fermions in combination with Jacobi smeared quark sources to improve the signal and get reliable results even…
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…
Following a recent suggestion by Weinberg, we use the large-N expansion in QCD to discuss the decay amplitudes of tetraquarks into ordinary mesons as well as their mixing properties. We find that the flavor structure of the tetraquark is a…
We study the pentaquark $uudd\bar s$ with $J=3/2$ and I=1 ($\Theta^{++}$) in the QCD sum rule approach. We derive the QCD sum rules for positive and negative parity states of the pentaquark. The QCD sum rule predicts that there exists…
This paper intends to collect the various evidences observed by ATLAS and CMS within searches for heavy scalars and pseudocalars. These searches in tt, hZ, tautau and 2jets+W, obtain individual excesses in five channels, each at a modest…
Recent spectroscopy studies performed in high energy ep collisions by the H1 and ZEUS Collaborations are described. The status of the searches for the strange pentaquark, the Theta+, is presented as well as results on searches for further…
We study spin 1/2 isoscalar and isovector candidates in both parity channels for the recently discovered \Theta^+(1540) pentaquark particle in quenched lattice QCD. Our analysis takes into account all possible uncertainties, such as…
A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9 inverse pb collected by the CMS experiment at the LHC. Upper limits at the 95% confidence level (CL) are…
The masses of pentaquarks $uudd\bar s$ are calculated within the framework of a semirelativistic effective QCD Hamiltonian, using a diquark picture. This approximation allows a correct treatment of the confinement, assumed here to be…
The analysis of the sum rules (for two differentchoices of 5-quark currents) indicate that to explain experimental results it is necessary to have some one-particle lower state (and pentaquark is a reliable candidate to this state) while…
Building upon the discoveries of the $\Xi^{++}_{cc}(3621)$ and $T^{+}_{cc}(3875)$, we undertake a comprehensive investigation into the mass spectra, internal structures, and decay properties of doubly-charmed pentaquarks. By treating the…
The relativistic five-quark equations are found in the framework of the dispersion relation technique. The five-quark amplitude for the N(1688) resonance including u-, d- quarks is calculated. The pole of this amplitude determines the mass…
The LHCb Collaboration has recently reported strong evidences of the existence of pentaquark states in the hidden-charm baryon sector, the so-called $P_c(4380)^+$ and $P_c(4450)^+$ signals. Five-quark bound states in the hidden-charm sector…
The existence of the $J^p=1/2^+$ narrow resonance predicted by the chiral soliton model has been investigated by utilizing the new kaon photoproduction data. For this purpose, we have constructed two phenomenological models, which are able…
In this paper I review the history and geography of the pentaquark searches and discuss the current situation surrounding these searches performed at different facilities around the world. The possibility of the existence of multiquark…
We review the current status of the exotic pentaquark baryons. After a brief look at experiments of both positive and negative results, we discuss theoretical methods to study the structure and reactions for the pentaquarks. First we…
I present a concise review of the possible evidence for new physics at HERA and of the recent work towards a theoretical interpretation of the signal. It is not clear yet if the excess observed at large Q^2 is a resonance or a continuum…
States beyond those expected in the simple constituent quark model are now emerging. I focus on the scalar glueball and its mixing with states in the $q\bar{q}$ nonet, and also on correlations in Strong QCD that may form diquarks and seed…
We present a calculation of the $\gamma d \to K^+ K^- n p $ reaction with the aim of seeing if the experimental peak observed in the $K^+ n$ invariant mass around 1526 MeV, from where evidence for the existence of the $\Theta^+$ has been…