Related papers: A Naturally Narrow Positive Parity Theta^+
In this article, we take the point of view that the pentaquark state $\Theta^+(1540)$ has negative parity, and choose the diquark-triquark type interpolating current to calculate the strong coupling constant $g_{\Theta NK}$ in the QCD sum…
Anti-decuplet penta-quark baryon is studied with the quenched anisotropic lattice QCD for accurate measurement of the correlator. Both the positive and negative parity states are studied using a non-NK type interpolating field with I=0 and…
LHCb Collaboration has recently announced the observation of a doubly charmed tetraquark $T_{cc \bar{u} \bar{d}}^+$ state with spin parity $J^P = 1^+$. This exotic state can be explained as a molecular state with small binding energy.…
Permutation groups are applied to analyze the symmetries of pentaquark states. All possible quark configurations of the color, flavor, spin and spatial degrees of freedom are worked out in the language of permutation groups, and the…
We investigate the mass spectra of $\Theta^+(udud\bar s)$ in quenched lattice QCD, with overlap and Wilson fermions respectively. Using three different interpolating operators, we measure their correlation matrix, and extract the mass…
We discuss a realisation of the pentaquark structure proposed by Jaffe and Wilczek within a simple quark model with colour-spin contact interactions and coloured harmonic confinement, which accurately describes the $\Delta-N$ splitting. In…
We carry out a systematic study of the $1S$-wave hidden and double charm-strange tetraquarks $cs\bar{c}\bar{s}$ and $cc\bar{s}\bar{s}$ in a nonrelativistic potential quark model framework with the explicitly correlated Gaussian method, and…
We present a generalization of the hyperspherical harmonic formalism to study systems made of quarks and antiquarks of the same flavor. This generalization is based on the symmetrization of the $N-$body wave function with respect to the…
Motivated by the recent experimental evidence of the exotic B = S = +1 baryonic state Theta(1540), we examine the older existing data on K+ N elastic scattering through the time delay method. We find positive peaks in time delay around…
We present an analysis of the Beam-Target double polarization asymmetry for the photoproduction of $\Theta^+$ in $\gamma n\to \Theta^+ K^-$. We show that this quantity can serve as a filter for the determination of the $\Theta^+$'s…
We study photoproduction and radiative decays of pentauqarks paying particular attention to the differences between spin-1/2 and spin-3/2, positive and negative parities of pentaquarks. Detailed study of these processes can not only give…
The recent experimental results of LHCb collaboration suggested the existence of pentaquark states with charmonium. To understand the structure of the states, a dynamical calculation of 5-quark systems with quantum numbers…
Evidence for the $\Theta^+$ pentaquark is still sketchy at the present time. This state, if it exists, has a small width and consequently a small production cross section. No single experiment has overwhelming evidence for the $\Theta^+$…
The continuous advancement of experimental techniques and investigations has led to observations of various exotic states in particle physics. Each addition to this family of states not only raises expectations for future discoveries but…
The wavefunctions of the lowest odd spin positive parity yrast states in the IBA are shown to be nearly pure multiple quadrupole-phonon excitations even outside the three dynamical symmetries. The empirical data for collective nuclei with…
We investigate three possible pentaquark candidates, one of which contains a single charm quark and the other two contain triple charm quarks in their substructure. To this end we apply QCD sum rule method and take into account both the…
We perform a QCD sum rule analysis for the pentaquark baryon Theta^+ with the non-interacting $KN$ contribution treated carefully. The coupling of the Theta^+ current to the $KN$ state is evaluated by applying the soft kaon theorem and…
In the Relativistic Mean Field Approximation three quarks in baryons from the lowest octet and the decuplet are bound by the self-consistent chiral field, and there are additional quark-antiquark pairs whose wave function also follows from…
In a diquark-diquark-antiquark picture of the pentaquark we study the decay $\Theta \to K^{+} n$ within the framework of QCD sum rules. After evaluation of the relevant three-point function, we extract the coupling $g_{\Theta nK}$ which is…
We discuss the spectroscopy of pentaquarks. The quantum numbers of the ground state depend on the interplay between spin-flavor and orbital contributions to the energy. The magnetic moments of the lowest pentaquark state with negative and…