相关论文: Photon and nucleon induced production of Theta^+
We investigate Theta^+ production via gamma N and NN reactions in order to obtain information on the structure of Theta^+, especially its parity. We observe that the positive parity. Theta^+production provides about ten times total cross…
We investigate the photoproduction of the $\Theta^+(1540)$ on a nucleon ($\gamma n \to K^- \Theta^+$, $\gamma p \to \bar{K}^0 \Theta^+$) and the pion-induced $\Theta^+$ production reaction on the proton ($\pi^- p \to K^- \Theta^+$). The…
We estimate the reaction mechanisms for the photoproduction of the Theta^+(1540) resonance on the nucleon, through K and K^* Regge exchanges. We compare the size of the cross sections for the gamma n -> K^- Theta^+ and gamma p -> K^0 bar…
Based on the hadronic model with the gauge prescription suggested by Ohta and Haberzettl, we investigate the possibility of determining the parity state of the $\Theta^+$ baryon using photon induced processes, $\gamma n\to K^- \Theta^+$ and…
We investigate the production of the pentaquark $\Theta^+$ baryon via the $\gamma n\to K^-\Theta^+$ and $\gamma p\to \bar{K}^0 \Theta^+$ processes, focusing on the parity of the $\Theta^+$. Using the effective Lagrangians, we calculate the…
We study $\Theta^+(1540)$ productions in kaon-nucleon ($KN$) and nucleon-nucleon ($NN$) interactions by assuming that the $\Theta^+$ is an isosinglet with $J^P = \frac12^+$. Possible $t$-channel diagrams with $K^*$ exchange are considered…
We present results on the production of bound states of $\Theta^+$ in nuclei using the $(K^+,\pi^+)$ reaction. By taking into account the states obtained within a wide range of strength of the $\Theta^+$ nucleus optical potential, plus the…
We study properties of the pentaquark particle Theta+ with emphasis on the role of chiral symmetry. It is shown that when chiral force is sufficiently strong, the positive parity Theta+ may be realized with a lower mass relative to the…
Photoproduction of the pentaquark particle Theta^+ on the nucleon has been studied by using an isobar and a Regge model. Using the isobar model, total cross sections around 100 nb for the gamma n --> K- Theta+ channel and 400 nb for the…
It is demonstrated that measurements of photon asymmetry in the $\gamma n \to K^- K^+ n$ reaction, can most likely determine the parity of the newly discovered $\Theta^+$ pentaquark. We predict that if the parity of $\Theta^+$ is positive,…
We discuss model independent methods to measure the $P$-parity of the $\Theta^+$-pentaquark, in the simplest processes of photoproduction, $\gamma+N\to \bar{K}+\Theta^+$, using definite relations between T-even polarization observables,…
The cross section for $\Theta^+$ production from the reaction $\gamma p\to\pi^+K^-\Theta^+$, which was observed in the CLAS experiment at the Jefferson National Laboratory, is evaluated in a hadronic model that includes couplings of…
We investigate the photoproduction of Theta^+ from the proton and neutron, gamma N -> Kbar Theta^+. Assuming that spin and parity of Theta^+ are J^P = 3/2^(+,-), it is shown that the production from the proton is strongly suppressed as…
Spin observables in the photoproduction of the $\Theta^+$ are explored for the purpose of determining the parity of the $\Theta^+$. Based on reflection symmetry in the scattering plane, we show that certain spin observables in the…
We analyse Theta+ production in the gamma+D -> \Lambda+n+K+ reaction and study the dependence of the gamma+D -> \Lambda+n+K+ differential cross section on the nK+ invariant mass and on the momentum of the final neutron p_n. We examine the…
We study $np\to \Lambda\Theta^{+}$ and $np\to \Sigma^{0}\Theta^{+}$ processes for both of the positive and negative parities of the $\Theta^{+}$. Employing the effective chiral Lagrangians for the $KNY$ and $K^*NY$ interactions, we…
We analyze an effect of the coherent $\Theta^+\Lambda(1520)$ photoproduction in $\gamma D$ interaction near the threshold. We demonstrate that the coherence effect becomes manifest in a comparison of the $nK^+$ invariant mass distribution…
Photoproduction of eta mesons from nucleons can provide valuable information about the excitation spectrum of the nucleons. The angular dependence of photoproduction in the photon-induced reaction is investigated in the multi-source thermal…
We study photoproduction reactions for Theta^+, which was recently observed as a candidate of an exotic five quark state uudd(bar s). We employ effective lagrangian interactions in the linear and non-linear formalism of chiral symmetry and…
We study determination of the parity of the pentaquark baryons in two different processes. First, we investigate the Theta^+ production via the vec{p} vec{p} -> Sigma^+ Theta^+ reaction process which was proposed to determine unambiguously…