Related papers: Positive parity pentaquark towers in large Nc QCD
Recently, the 1/Nc expansion has been applied to the study of exotic baryons containing both quarks and antiquarks. We extend this approach to exotic states with mixed symmetric spin-flavor symmetry, which correspond in the quark model to…
The 1/N_c expansion for negative-parity heavy pentaquarks is developed using the formalism introduced for excited baryons in large N_c. Relations are found between the mass splittings of these pentaquarks and those of nonexotic baryons.
We present a very general argument that the analogue of a heavy pentaquark (a state with the quantum numbers of a baryon combined with an additional light quark and a heavy antiquark) must exist as a particle stable under strong…
We consider configuration mixing for the nonstrange positive parity excited baryons in the $[\mathbf{56'},0^+],[\mathbf{56},2^+], [\mathbf{70},0^+] $ and $[\mathbf{70},2^+]$ quark model $SU(6) \times O(3)$ multiplets contained in the $N=2$…
Assuming the two diquark structure for the pentaquark state as advocated in the Jaffe-Wilczek model, we study the strong decays of light and heavy parity-even pentaquark states using the light-front quark model in conjunction with the…
We have investigated negative-parity uudd\bar{s} pentaquarks by employing a quark model with the meson exchange and the effective gluon exchange as qq and q\bar{q} interactions. The system for the five quarks is dynamically solved; the…
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…
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…
The 1/N expansion for exotic baryons is developed, and applied to the masses, meson couplings and decay widths. Masses and widths of the 27 and 35 pentaquark states in the same tower as the Theta+ are related by spin-flavor symmetry. The 27…
We performed a complete analysis of the spectrum of all the states in the ${\cal N}=2$ quark model harmonic oscillator band with $N_f=3$ in the large $N_c$ limit including the often disregarded antisymmetric multiplet $[{\bf 20},1^+]$. We…
In the large Nc limit, the mass spectrum of the L=1 orbitally excited baryons N* has a very simple structure, with states degenerate in pairs of spins J=(1/2,3/2), (3/2,5/2), corresponding to irreducible representations (towers) of the…
We demonstrate that a five quark state of positive parity with an internal P-wave structure - usually pictured as a composite of an antiquark and two diquarks in a P-wave state - can couple to nucleons and Goldstone particles in a chirally…
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…
We discuss the mass splittings for the $S$-wave triply heavy pentaquark states with the $QQQq\bar{q}$ $(Q=b,c;q=u,d,s)$ configuration which is a mirror structure of $Q\bar{Q}qqq$. The latter configuration is related with the nature of…
The splittings between positive parity pentaquarks containing a single heavy (c,b) antiquark and four light (u,d) quarks are investigated in models having spin-dependent interactions generated by either effective Goldstone boson exchange or…
Motivated by the possible observation of the $\Theta^+(1530)$, we study the quark structure of pentaquark states in quenched lattice QCD. The complete set of 19 local sources that have the proper symmetry for positive or negative parity…
In the large $N_c$ limit, one can describe normal heavy baryons $Qqq$ and heavy pentaquarks $\bar Qqqqq$ as bound states of heavy mesons to chiral (anti)solitons. In this picture, the strong and electromagnetic decay parameters of these…
We discuss the compatibility between the quark-shell picture and the meson-nucleon scattering picture in large $N_c$ QCD for mixed symmetric $\ell$ = 1 states previously analyzed by using a simple Hamiltonian including operators up to order…
In a previous work we have studied the isospin 1/2 lowest positive and negative parity states of the pentaquark $uudc\overline{c}$, in a constituent quark model with a linear confinement and an SU(4) flavor-spin hyperfine interaction and we…
In a nonrelativistic potential quark model framework, we carry out a calculation of the mass spectrum for the low-lying $1S$ all-heavy pentaquark state by adopting the explicitly correlated Gaussian method. The obtained states are compact…