arXiv subjects

Yu-Bing Dong

Publications and source records attributed to Yu-Bing Dong.

42 records · Page 3Linked to original sources

arXiv2009

Two-photon Exchange Corrections to Single Spin Asymmetry of Neutron and $^3$He

In a simple hadronic model, the two-photon exchange contributions to the single spin asymmetries for the nucleon and the $^3$He are estimated. The results show that the elastic contributions of two-photon exchange to the the single spin asymmetries for the nucleon are rather small while those for the $^3$He are relatively large. Besides the strong angular dependence, the two-photon contributions to the single spin asymmetry for the $^3$He are very sensitive to the momentum transfer.

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arXiv2009

Nucleon Form Factors in a Light-Cone Quark Model with Two-Photon Exchange

We estimate the two-photon exchange corrections to both proton and neutron electromagnetic physical observables in a relativistic light cone quark model. At a fixed momentum transfer the corrections are found to be small in magnitudes, but with a strong angular dependence. Our results are comparable to those from simple hadronic model in a moderate momentum transfer region.

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arXiv2009

Form factors in RQM approaches: constraints from space-time translations, extension to constituents with spin-1/2 and unequal masses

Constraints related to transformations of currents under space-time translations have been considered for the relativistic quantum mechanics calculation of form factors of J=0 systems composed of scalar constituents with equal masses. Accounting for these constraints amounts to take into account many-body currents that restore the equality of the momentum transferred separately to the system and to the constituents, which holds in field-theory approaches but is not generally fulfilled in relativistic quantum mechanics ones. When this was done, discrepancies between results from different approaches could be found to vanish. The results are extended here to systems composed of spin-1/2 constituents with unequal masses. Moreover, as far as the equivalence of different approaches is concerned, some intermediate step could be skipped and the presentation of these results therefore slightly differs from the previous one. Due to the technical aspect of present results, this work is not aimed to be published but it could be useful for some applications like the form factors of the pion or kaon particles.

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arXiv2004

Magnetic moments and electromagnetic radii of nucleon and $Δ(1232)$ in an extended GBE model

We derive the exchange currents of pseudoscalar, vector, and scalar mesons from Feynman diagrams, and use them to calculate the magnetic form factors of nucleon and $Δ(1232)$. The magnetic moments and electromagnetic radii are obtained by using those form factors and the parameters determined from the masses of nucleon and $Δ(1232)$. We find the magnetic moments and electromagnetic radii of nucleon and $Δ(1232)$ can be produced very well in the extended Goldstone-boson-exchange model (GBE) in which all of pseudoscalar, vector and scalar meson nonet are included. The magnetic moments of $Δ(1232)$ are closer to experiment values and results from lattice calculation than the results obtained by the model without other mesons except for pion and sigma.

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arXiv2003

Negative Parity N* Resonances in an Extended GBE

In this paper, we calculate the masses and mixing angles of L=1 negative parity N* resonances in an extended GBE (Goldstone-boson-exchange model) with harmonic-oscillator wave functions. By using those mixing angles, we get their photoproduction amplitudes, and compare them with experimental data and the results of OPE (one-pion-exchange model), OPsE (only pseudoscalar meson exchange model), and OGE (one-gluon-exchange model). We find that the extended GBE gives right internal wave functions. It is essential to extend GBE to include not only pseudoscalar meson exchanges but also vector meson exchanges.

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arXiv2001

Extraction of Polarized Gluon Distributions from Large-pt Light Hadron Pair Production

We propose a new formula for extracting the polarized gluon distribution from the large-$p_T$ light hadron pair production for semi-inclusive processes in polarized deep inelastic scattering. In general, a large-$p_T$ hadron pair is produced via photon-gluon fusion(PGF) and QCD Compton at the lowest order of QCD. The PGF gives us a direct information on $Δg$ in the nucleon, while QCD Compton becomes background to the signal process for extracting $Δg$. We show that the contribution from this background, i.e. the QCD Compton process, can be removed by using symmetry relation among fragmentation functions and taking an appropriate combination of various light hadron pair production processes, and thus the double spin asymmetry can be described in terms of $Δg/g$ alone.

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