Related papers: Determining the $\Theta^+$ quantum numbers through…

We develop a model to study the $D^0 \to K^- \pi^+ \eta$ weak decay, starting with the color favored external emission and Cabibbo favored mode at the quark level. A less favored internal emission decay mode is also studied as a source of…

We provide a series of arguments which support the idea that the peak seen in the $\gamma p \to K^+ \Lambda$ reaction around 1920 MeV should correspond to the recently predicted state of $J^P=1/2^+$ as a bound state of $K \bar{K}N$ with a…

Polarization properties of strange baryons produced in pp reactions, p + p -> p + Lambda^0 + K^+ and p + p -> p + Sigma^0 + K^$, near thresholds of the final states (p Lambda^0 K^+) and (p Sigma^0 K^+) are analysed relative to polarizations…

The expressions for the differential cross section and of the polarization observables for the reaction $\bar p+p\rightarrow e^++e^-$ are given in terms of the nucleon electromagnetic form factors in the laboratory system. Radiative…

Fully constrained bubble chamber data on the pp -> pi+ pn and pp -> pi+ d reactions are used to investigate the ratio of the counting rates for the two processes as function of the pn excitation energy Q. Though it is important to include…

The pp -> ppK+K- reaction was measured below the phi threshold at a beam energy of 2.568 GeV using the COSY-ANKE magnetic spectrometer. By assuming that the four-body phase space is distorted only by the product of two-body final state…

We analyze the possibility of experimental investigation of new low-energy relations between the values of resonance masses in the meson form factors and the differential rate of radiative kaon decay $K^+\to \pi^+ e^+e^-(\mu^+\mu^- )$ at…

Results for the $\pi + N \to \Lambda, \Sigma + K$ reactions in nuclear matter of Ref. nucl-th/0004011 are presented. To evaluate the in-medium modification of the reaction amplitude as a function of the baryonic density we introduce…

The dependence of $K^+$ production on the nuclear equation of state is investigated in heavy ion collisions. An increase of the excitation function of $K^+$ multiplicities obtained in heavy ($Au+Au$) over light ($C+C$) systems when going…

Evidence for excitation of exotic S=+1 pentaquark degrees of freedom is presented by studying optical-potential fits to K^+ - nucleus total, reaction and elastic-differential cross section data at p(lab) = 500 - 700 MeV/c. Estimates of the…

Kaon production, in particular $K^+$ production in heavy ion collisions at intermediate energies is discussed. Main emphasis is put on the question if subthreshold $K^+$ production can serve as a suitable tool to test the high density phase…

The $\gamma p \to K^+ \pi^0 \Lambda$ and $\gamma p \to K^+ \pi \Sigma $ reactions are studied in the kinematic region where the $\pi^0 \Lambda$(1116) and $\pi\Sigma$(1192) pairs originate dominantly from the decay of the $\Sigma$(1385) and…

The reaction pp->p K0 pi+ Lambda has been studied with the ANKE spectrometer at COSY-Juelich at a beam momentum of 3.65 GeV/c in order to search for a possible signal of the pentaquark Theta+(1540), decaying into the p K0 system. By…

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…

We study the binding energy and the width of the $\Theta^+$ in nuclei, associated to the $K N$ and $ K \pi N$ components. The first one leads to negligible contributions while the second one leads to a sizeable attraction, enough to bind…

We analyze the possibility to produce an intermediate Theta^+ via a KN->\Theta+ formation process in gamma D-> pK^- X (X=nK^+,pK^0) reactions at some specific kinematical conditions, in which a pK^- pair is knocked out in the forward…

Extending the hadronic Lagrangians that we recently introduced for studying pentaquark $\Theta^+$ baryon production from meson-proton, proton-proton, and photon-proton reactions near threshold to include the anomalous interaction between…

We investigate the A$(\pi^+,K^+){_\Lambda}$A reaction within a covariant model. We consider those amplitudes which are described by creation, propagation and decay into relevant channel of $N^*$(1650), $N^*$(1710), and $N^*$(1720)…

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…

Cross sections for the $\gamma p \to K^+ \Lambda$ have been measured at backward angles using linearly polarized photons in the range 1.50 to 2.37 GeV. In addition, the beam asymmetry for this reaction has been measured for the first time…