η介子3He的光产生
核实验
2009-11-10 v3
摘要
利用美因茨微子加速器设施MAMI上的TAPS量热计，研究了η介子3He的光产生。测量了从阈值到820 MeV光子能量范围内γ+3He→η+X反应的全包含总截面。提取了高达745 MeV能量的总相干η截面和角微分相干η截面。在η产生阈值附近观察到一个具有各向同性角分布的类共振结构，表明存在共振准束缚态。对此类准束缚η介子核衰变为π^0+p+X的竞争衰变道的研究支持了这一结论。对于3He中的准束缚η介子态，推导出其结合能为(-4.4±4.2) MeV，宽度为(25.6±6.1) MeV。
引用
@article{arxiv.nucl-ex/0312011,
title = {Photoproduction of eta-mesic 3He},
author = {M. Pfeiffer and J. Ahrens and J. R. M. Annand and R. Beck and G. Caselotti and S. Cherepnya and K. Föhl and L. S. Fog and D. Hornidge and S. Janssen and V. Kashevarov and R. Kondratiev and M. Kotulla and B. Krusche and J. C. McGeorge and I. J. D. MacGregor and K. Mengel and J. G. Messchendorp and V. Metag and R. Novotny and M. Rost and S. Sack and R. Sanderson and S. Schadmand and A. Thomas and D. P. Watts},
journal= {arXiv preprint arXiv:nucl-ex/0312011},
year = {2009}
}
备注
v1: 4 pages, 4 figures, submitted to PRL; v2: minor revisions and corrections, new figure added, 4 pages, 5 figs; v3: minor changes