质子上的 ω 介子光生反应
核实验
2019-08-14 v1 高能物理 - 实验
摘要
利用 CBELSA/TAPS 实验装置，测量了反应 γp → pω 在从反应阈能至 2.5 GeV 初始光子能量范围内的微分截面和非极化自旋密度矩阵元。这些可观测量通过 ω 介子的辐射衰变 ω → π⁰γ 测得。截面覆盖了全角度范围，并显示出 t 道前向抬升的全貌。微分截面和非极化自旋密度矩阵元的角分布整体形状与先前数据基本吻合。此外，首次利用能量范围在 1150 MeV 至 1650 MeV 的线极化标记光子束提取了极化自旋密度矩阵元。这些数据被纳入 Bonn-Gatchina 分波分析（PWA）中。研究发现，在阈能附近，ω 光生反应的主要贡献来自 3/2⁺ 分波，这主要归因于亚阈共振态 N(1720) 3/2⁺。在更高能量下，坡密子交换占主导地位，而 π 交换仍然很小。为了描述整个数据集，这些 t 道贡献以及来自核子共振态的进一步贡献都是必要的：1/2⁻、3/2⁻ 和 5/2⁺ 分波也被发现具有显著贡献。
引用
@article{arxiv.1508.01483,
title = {Photoproduction of {\omega} Mesons off the Proton},
author = {A. Wilson and V. Crede and A. V. Anisovich and J. C. S. Bacelar and B. Bantes and O. Bartholomy and D. Bayadilov and R. Beck and Y. A. Beloglazov and K. T. Brinkmann and R. Castelijns and H. Dutz and D. Elsner and R. Ewald and F. Frommberger and M. Fuchs and Chr. Funke and R. Gregor and A. Gridnev and E. Gutz and J. Hannappel and W. Hillert and P. Hoffmeister and I. Horn and I. Jaegle and T. Jude and J. Junkersfeld and H. Kalinowsky and V. Kleber and Frank Klein and Friedrich Klein and E. Klempt and M. Kotulla and B. Krusche and M. Lang and H. Löhner and I. V. Lopatin and S. Lugert and T. Mertens and J. G. Messchendorp and V. Metag and M. Nanova and V. A. Nikonov and D. Novinski and R. Novotny and M. Ostrick and L. M. Pant and H. van Pee and M. Pfeiffer and A. Roy and A. V. Sarantsev and C. Schmidt and H. Schmieden and S. Shende and V. Sokhoyan and N. Sparks and A. Süle and V. V. Sumachev and T. Szczepanek and U. Thoma and D. Trnka and R. Varma and D. Walther and Ch. Wendel and U. Wiedner},
journal= {arXiv preprint arXiv:1508.01483},
year = {2019}
}
备注
8 pages, 5 figures, accepted for publication in Physics Letters B