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تسجيل مستخدم جديدSpin effects in hard exclusive electroproduction of mesons
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تأليف
P. Kroll
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In this talk various spin effects in hard exclusive electroproduction of mesons are briefly reviewed. The data are discussed in the light of recent theoretical calculations within the frame work of the handbag approach.
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It is reported on an analysis of electroproduction of light mesons at small Bjorken-x within the handbag approach. The partonic subprocesses, meson electroproduction off quarks or gluons, are calculated within the modified perturbative approach in wh
ich quark transverse momenta are retained. The soft hadronic matrix elements, generalized parton distributions, are constructed by means of double distributions. The constraints from parton distributions and sum rules are taken into account. Various moments of these generalized parton distributions are compared to recent results from lattice gauge theories.
It is reported on a global analysis of hard vector-meson electroproduction which is based on the handbag factorization. The generalized parton distributions are constructed from their forward limits with the help of double distributions and the parto
nic subprocesses are calculated within the modified perturbative approach.
We report on an attempt to describe hard exclusive photoproduction of $J/Psi$ mesons, i.e. the reaction $gamma p to J/Psi p$, by means of a modified version of the hard-scattering approach, in which the proton is treated as a quark-diquark rather tha
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