相关论文: Study the exotic $\Theta^+$ in polarized photoprod…

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 carry out an analysis of the pentaquark $\Theta^+$ photoproduction with polarized photon beams. Kinematical and dynamical aspects are examined for the purpose of determining $\Theta^+$'s spin and parity. It shows that the polarized…

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…

The photoproduction processes of the exotic $\Theta^+(1540)$ baryon and the $\bar{K}^*$ meson from the nucleon targets, i.e., $\gamma n \to K^{*-} \Theta^+$ and $\gamma p \to \bar{K}^{*0} \Theta^+$, are investigated in a hadronic model. We…

We discuss the possibility of determining the parity of the $\Theta^+$ baryon from photoproduction $\gamma N\to K\Theta^+$ process near threshold. We utilize the conservation laws of parity and angular momentum for the analysis of angular…

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 compute cross sections of $\Theta^+$ production near threshold for a polarized proton reaction, $\vec p \vec p \to \Sigma^+ \Theta^+$ which was recently proposed to determine unambiguously the parity of $\Theta^+$. Within theoretical…

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 derive, in model independent way, the spin structure of the matrix element for the reaction of associative $\Theta^+$ pentaquark production, $\pi^{\pm}+D\to \Theta^+ +\Sigma^{\pm}, $ in the threshold region and in collinear kinematics.…

Spin structure of the reaction ${\vec p}{\vec n}\to {\vec \Lambda^0} {\vec \Theta}$ is analysed at the threshold in a model independent way under assumption that the $\Theta^+$ is an isosinglet. We found that the sign of the spin-spin…

The \gamma d \to K^+K^-pn reaction has been studied to search for the evidence of the \Theta^+ by detecting K^+K^- pairs at forward angles. The Fermi-motion corrected nK^+ invariant mass distribution shows a narrow peak at 1.524 +- 0.002 +…

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,…

We analyze the problem of how to determine the parity of the $\Theta^+$ pentaquark in the reaction $\gamma N\to K\Theta\to NK\bar{K}$, where $N=n,p$. Our model calculations indicate that the contribution of the non-resonant background of…

We present two possibilities to determine the P-parity of the pentaquark $\Theta^+$, in a model independent way, via the measurement of polarization observables in $p+p\to \Theta^+ +\Sigma^+$, or $n+p\to \Theta^+ +\Lambda^0$, in the near…

Angular distributions for production of the $\Theta^+$ pentaquark are calculated for the collisions of polarized protons with polarized target protons. We compare calculations based on different assumptions concerning spin and parity…

We examine cross sections for the processes $\gamma N\to NK\bar{K}$ in the framework of a phenomenological Lagrangian. We include contributions from $\Lambda$ and $\Sigma$ resonances up to spin 3/2, as well as those from an exotic…

A series of experiments have been carried out by using a linearly polarized photon beam at the SPring-8/LEPS facility from December 2000 to June 2001. The photon beam asymmetries and differential cross sections of the p(gamma,K+)Lambda and…

Using the symmetry properties of the strong interaction, such as the Pauli principle, the P-invariance, the conservation of the total angular momentum and isotopic invariance, we establish the spin structure of the threshold matrix elements…

We critically examine the possibility of determining the parity of the $\Theta^+(1540)$ from the reactions $NN\to \Theta^+Y$ ($Y$ = $\Lambda$, $\Sigma$) recently discussed in the literature. Specifically, we study the energy dependence of…

We study the $K^+p\to \pi^+K^+n$ reaction with some kinematics suited to the production of the $\Theta^+$ resonance recently observed and show that the measurement of cross sections and polarization observables can shed light on the…