English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We calculate contributions of hadron resonances to two-photon exchangeeffects in electron-proton scattering. In addition to the nucleon and P33resonance, the following heavier resonances are included as intermediate statesin the two-photon exchange diagrams: D13, D33, P11, S11 and S31. We show thatthe corrections due to the heavier resonances are smaller that the dominantnucleon and P33 contributions. We also find that there is a partialcancellation between the contributions from the spin 1/2 and spin 3/2resonances, which results in a further suppression of their aggregatetwo-photon exchange effect.Comment: 6 pages, 1 figure; additional comparison with data, results  unchanged; to be published in Phys. Rev.

Contribution of spin 1/2 and 3/2 resonances to two-photon exchange effects in elastic electron-proton scattering