相关论文: Polarization phenomena in open charm photoproducti…
The complete expression for the intensity in pseudo-scalar meson photoproduction with a polarized beam, target, and recoil baryon is derived using a density matrix approach that offers great economy of notation. A Cartesian basis with spins…
The polarization properties of the charmed Lambda^+_c baryon are investigated in weak non-leptonic four-body Lambda^+_c -> p + K^- + pi^+ + pi^0 decay. The probability of this decay and the angular distribution of the probability are…
We study the productions of charmed baryons ${\bar \Lambda}_c^- \Lambda_c^+$, ${\bar \Lambda}_c^- \Sigma_c^+$, and ${\bar \Sigma}^- \Sigma_c^+$ in the antiproton-proton collisions within an effective Lagrangian model that has only the…
We compute the recoil polarization of the lambda-hyperon and the photon asymmetry for the quasifree photoproduction of kaons in a relativistic impulse-approximation approach. Our motivation for studying polarization observables is…
We study the $\bar D D$ (${\bar D}^0 D^0$ and $D^-D^+$) charm meson pair production in antiproton (${\bar p}$) induced reactions on nuclei at beam energies ranging from threshold to several GeV. Our model is based on an effective Lagrangian…
General properties of the differential cross section and of the polarization observables are derived for the $e^++e^-\to N+\bar N$ reaction, in presence of two--photon exchange. Polarization effects are investigated for longitudinally…
The threshold region for processes of hadronic and nuclear interactions is very interesting for a theoretical as well as an experimental point of view. In this region one can apply different physical methods, starting from classical current…
We investigate near-threshold $J/\psi$ photoproduction off the nucleon, focusing on hadronic rescattering effects induced by open-charm meson-baryon intermediate states. Beyond the conventional Pomeron-exchange mechanism, the $\bar…
The model combined with unitarity and impact parameter picture provide a rather simple mechanism of hyperon polarization generation in collision of unpolarized hadrons. We concentrate on a particular problem of $\Lambda$-hyperon…
We consider the production of heavy-quark pairs in the collisions of polarized and unpolarized on-shell photons and present, in analytic form, the fully integrated total cross sections for total photon spins $J_z=0, \pm 2$ at…
We study the coherent photoproduction of pseudoscalar mesons---particularly of neutral pions---placing special emphasis on the various sources that put into question earlier nonrelativistic-impulse-approximation calculations. These include:…
The study of the charmed baryons is crucial for investigating the strong and weak interactions in the Standard Model and for gaining insights into the internal structure of baryons. In an $e^+e^-$ experiment the lightest charmed baryon,…
The cross section for the inclusive photoproduction of large-p_T D^*+- mesons is calculated at next-to-leading order, adopting different approaches to describe the fragmentation of charm quarks into D^*+- mesons. We treat the charm quark…
We study electric polarization and nonlinear optical effects in spin systems with broken inversion symmetry. We apply strong coupling expansion to the underlying electronic Hamiltonians, and systematically derive expressions for electric…
Photon-photon interactions mediated by the neutral hydrogen background can transform plane polarization into circular polarization, through completely forward processes, [gamma+gamma+atom-> gamma+ gamma+atom], in which only the photon…
We discuss charm production at LHC. The production of single $c \bar c$ pairs is calculated in the $k_t$-factorization approach. We use several unintegrated gluon distributions from the literature. The hadronization is included with the…
Positivity constraints have proved to be important for spin observables of exclusive reactions involving polarized initial and final particles. Attention is focused in this note on the photoproduction of pseudoscalar mesons from spin 1/2…
We propose a novel scheme to generate polarization entanglement from spatially-correlated photon pairs. We experimentally realized a scheme by means of a spatial correlation effect in a spontaneous parametric down-conversion and a modified…
Strange and charmed baryon productions from proton-antiproton collisions are studied in the effective Lagrangian and Regge approaches. We include only the $t$-channel dynamics which is dominant for the diffractive region that is relevant in…
Polarization phenomena are essential for the understanding of elementary processes, and are typically large in the threshold region. The selection rules with respect to P-parity, angular momentum, isotopic spin and the Pauli principle allow…