Related papers: Theta++ from QCD sum rule
Exotic penta-quark baryon with strangeness +1, \Theta^+, is studied in the QCD sum rule approach. We derive sum rules for the positive and negative parity baryon states with J=1/2 and I=0. It is found that the standard values of the QCD…
We study $IJ^P=0{3/2}^\pm$ and $1{3/2}^\pm$ pentaquark states with $S=+1$ in the QCD sum rule approach. The QCD sum rule for positive parity states and that for negative parity are independently derived. The sum rule suggests that there…
The QCD sum rule for the pentaquark $\Theta^+$, first analyzed by Sugiyama, Doi and Oka, is reanalyzed with a phenomenological side that explicitly includes the contribution from the two-particle reducible kaon-nucleon intermediate state.…
We consider a $[ud]^2\bar{s}$ current, in the finite-density QCD sum rule approach, to investigate the scalar and vector self-energies of the recently observed pentaquark state $\Theta^+(1540)$, propagating in nuclear mater. We find that,…
In this work we investigate the consequences of the Jaffe and Wilczek diquark model in the framework of QCD sum rules. An analysis of the Theta^+(1540) as (ud)^2\bar{s} state shows that the mass of the pentaquark is compatible with the…
QCD sum rule is applied to the pentaquark spectroscopy. It is concluded that no positive parity state is seen in low energy region, while there may exist negative parity states at around 1.5 GeV. Choice of interpolating local operators and…
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…
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 QCD sum rule technique is employed to investigate pentaquark states with strangeness S = +1 and IJ^P = 0,1/2^\pm, 1,1/2^\pm, 0,3/2^\pm, 1,3/2^\pm. Throughout the calculation, emphasis is laid on the establishment of a valid Borel…
We construct QCD sum rules for the anti-charmed pentaquark $\Theta_c (3099)$, recently reported at HERA. The sum rules are constructed similarly with the $\Theta^+ (1540)$ sum rules using the anti-charmed analogue of the $\Theta^+$…
The pentaquark state of $\Theta^{+}(uudd\bar{s})$ has been observed to decay with two decay modes: $\Theta^+\to n K^+$ and $\Theta^+ \to p K^0$. The decay probability ratio of the two decay modes is studied with general symmetry…
We study pentaquark $\Theta^{+} (I=0,J=1/2)$ in the QCD sum rules emphasizing that we can not extract any properties of the pentaquark outside of the Borel window. To find the appropriate Borel window, we prepare a favorable set up of the…
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 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 this work we study the Theta(1540) in the framework of QCD sum rules based on (ud)^2\bar{s} diquark clustering as suggested by Jaffe and Wilczek. Within errors, the mass of the pentaquark is compatible with the experimentally measured…
In a diquark-diquark-antiquark picture of the pentaquark we study the decay $\Theta \rightarrow K^{+} n$ within the framework of QCD sum rules. After evaluation of the relevant three-point function, we extract the coupling $g_{\Theta nK}$…
We use QCD sum rules to study the possible existence of a \Theta c(3250) charmed pentaquark. We consider the contributions of condensates up to dimension-10 and work at leading order in \alpha_s. We obtain m(\Theta c) = (3.21 +/- 0.13) GeV,…
The QCD sum rule method is formulated for the strangeness +1 pentaquark baryon with isospin I=0 and spin-parity J^P = 3/2^\pm. The spin-3/2 states are considered to be narrower than the spin-1/2 ones, and thus may provide a natural…
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…
In this article, we study the $J^{PC}=0^{++}$ and $2^{++}$ $QQ\bar{Q}\bar{Q}$ tetraquark states with the QCD sum rules, and obtain the predictions $M_{X(cc\bar{c}\bar{c},0^{++})} =5.99\pm0.08\,\rm{GeV}$, $M_{X(cc\bar{c}\bar{c},2^{++})}…