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Differential Cross Section and Photon-Beam Asymmetry for the γp → π−Δ++(1232) Reaction at Forward π− Angles for Eγ=1.5–2.95 GeVстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 10 августа 2018 г.
- Авторы: Kohri H., Shiu S., Chang W.C., Yanai Y., Ahn D.S., Ahn J.K., Chen J., Daté S., Ejiri H., Fujimura H., Fujiwara M., Fukui S., Gohn W., Hicks K., Hosaka A., Hotta T., Hwang S.H., Imai K., Ishikawa T., Joo K., Kato Y., Kon Y., Lee H.S., Maeda Y., Mibe T., Miyabe M., Morino Y., Muramatsu N., Nakano T., Nakatsugawa Y., Nam S.i., Niiyama M., Noumi H., Ohashi Y., Ohta T., Oka M., Parker J.D., Rangacharyulu C., Ryu S.Y., Sawada T., Shimizu H., Strokovsky E.A., Sugaya Y., Sumihama M., Tsunemi T., Uchida M., Ungaro M., Wang S.Y., Yosoi M.
- Журнал: Physical Review Letters
- Том: 120
- Номер: 20
- Год издания: 2018
- Издательство: American Physical Society
- Местоположение издательства: United States
- Первая страница: 202004-1
- Последняя страница: 202004-6
- DOI: 10.1103/physrevlett.120.202004
- Аннотация: Differential cross sections and photon-beam asymmetries for the →γp→π−Δ++(1232) reaction have been measured for 0.7<cosθc.m.π<1 and Eγ=1.5–2.95 GeV at SPring-8/LEPS. The first-ever high statistics cross-section data are obtained in this kinematical region, and the asymmetry data for 1.5<Eγ(GeV)<2.8 are obtained for the first time. This reaction has a unique feature for studying the production mechanisms of a pure u¯u quark pair in the final state from the proton. Although there is no distinct peak structure in the cross sections, a non-negligible excess over the theoretical predictions is observed at Eγ=1.5–1.8 GeV. The asymmetries are found to be negative in most of the present kinematical regions, suggesting the dominance of π exchange in the t channel. The negative asymmetries at forward meson production angles are different from the asymmetries previously measured for the photoproduction reactions producing a d¯d or an s¯s quark pair in the final state. Advanced theoretical models introducing nucleon resonances and additional unnatural-parity exchanges are needed to reproduce the present data.
- Добавил в систему: Строковский Евгений Афанасьевич