相关论文: Associative charm photoproduction with circularly …
We analyze polarization effects in associative photoproduction of pseudoscalar ($\bar{D}$) charmed mesons in exclusive processes $\gamma+ N\to Y_c +\bar{D}$, $Y_c=\Lambda_c^+$, $\Sigma_c$. Circularly polarized photons induce nonzero…
The spin structure of the matrix element for the reactions $\gamma+ N\to Y_c +{D}^*$, where $Y_c=\Lambda_c^+(2285)$, $\Sigma_c(2455)$ are charmed baryons with spin 1/2, and $D^*(2010)$ is the vector charmed meson, can be parametrized, in…
We suggest to measure the triple polarization correlations in the exclusive associative charm particle photoproduction, vector gamma + vector p --> vector Lambda_c^{++} bar{D^0} with linearly polarized photons, as a method to determine the…
The energy and the angular dependence of the associative vector charmed ${D^*}$-meson photoproduction, $\gamma+N\to {\cal B}_c+ \overline{D^*}$, with ${\cal B}_c=\Lambda_c$ or $\Sigma_c$, has been predicted in framework of pseudoscalar…
We calculate the cross section and the beam asymmetry for exclusive photoproduction of charmed particles near threshold ($\gamma+p\to \Lambda_c^+ +\bar{D^0}$), in the framework of an effective Lagrangian model. We discuss the sensitivity of…
We report measurements of the charm-anticharm production asymmetries for $\Lambda_c^+$, $\Sigma_c^{++}$, $\Sigma_c^0$, $\Sigma_c^{++*}$, $\Sigma_c^{0*}$, and $\Lambda_c^+(2625)$ baryons from the Fermilab photoproduction experiment FOCUS…
Charge asymmetries for the charm meson production ($D^{*+}$--$D^{*-}$, $D^{*0}$--$\bar D^{*0}$ and $D^+_s$--$\bar D^-_s$) have been estimated for the COMPASS kinematic conditions in the framework of perturbative recombination model. Mass…
We propose a two-component model involving the parton fusion mechanism and recombination of a $ud$ valence diquark with a sea $c$-quark of the incident proton to describe $\Lambda_c^+$ inclusive production in $pp$ collisions. We also study…
{We investigate the photoproduction process $ p \gamma \rightarrow \Lambda_{c}^{+} \overline{D^{0}}$ within the handbag approach, which we assume to be the dominant mechanism at energies well above the production threshold and in the…
We study the production asymmetry of charm versus anticharm mesons in photon-proton interactions. We consider photon gluon fusion plus higher order corrections in which light quarks through vector meson-proton interactions contribute to the…
We discuss some new aspects of charm production trigerred by recent observations of the LHCb collaboration. The LHCb collaboration measured small asymmetries in production of $D^+ D^-$ mesons as well as $D_s^+ D_s^-$ mesons. Is this related…
We show that coherent $\eta$ and $\etap$ photoproduction by means of the Primakoff Effect on the proton depends on the strange component of the neutral axial current coupling. We construct polarization asymmetries that are sensitive to this…
We suggest a method to determine the product of the coupling constants $g_{\rho\sigma\gamma}g_ {\sigma NN}$, in absolute value and relative sign, through the $t$-dependence of the two possible T-even asymmetries for the photoproduction of…
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…
Pair creation by a photon in an oriented crystal is considered in a frame of the quasiclassical operator method, which includes processes with polarized particles. Under some quite generic assumptions the general expression is derived for…
The asymmetries between charm and anticharm mesons observed in fixed-target photoproduction experiments are an order of magnitude larger than the asymmetries predicted by conventional perturbative QCD. We show that these charm meson…
We evaluate the cross sections for charmed hadron production from proton-proton reactions $pp\to\bar D^0p\Lambda_c^+$ and $pp\to\bar D^{*0}p\Lambda_c^+$ using a hadronic Lagrangian. With empirical coupling constants and cutoff parameters in…
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…
For $\pi^0\eta$-photoproduction on the nucleon formal expressions are developed for the five-fold differential cross section and the recoil polarization including beam and target polarizations. The polarization observables are described by…
Charm quarks are expected to be produced mainly by the photon-gluon fusion mechanism in photon-Nucleon interactions. However, a small part of the total charm cross section originates in similar processes to those appearing in charm…