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arXiv 0908.0446nucl-th
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中子光生K介子的Regge加共振预言

Regge-plus-resonance predictions for kaon photoproduction from the neutron

P. Vancraeyveld, L. De Cruz, J. Ryckebusch, T. Van Cauteren

摘要:

我们提出的预测n(伽马,K+)西格玛-微分截面和光子束的不对称性,并比较它们最近的LEPS数据。我们采用Regge加共振(RPR)模型描述光诱导和电诱导K介子生产质子。非共振对振幅的贡献用K+(494)和K*+(892)Regge轨迹交换来建模。该振幅补充了s通道共振图的选择。通过SU(2)同位旋的考虑,从拟合质子数据的参数导出了n(γ,K+)σ振幅的三个Regge模型参数。实现了对n(gamma,K+)Sigma-数据的公平描述,证明了Regge模型的鲁棒性和预测能力。从质子到中子的共振耦合的转换更具挑战性,因为它需要知道光耦合螺旋度振幅。我们说明了螺旋度振幅的不确定性如何传播,并严重限制了RPR和等压线模型的预测能力,为中子靶的K介子生产。

英文摘要:

We present predictions for n(gamma,K+)Sigma- differential cross sections and photon-beam asymmetries and compare them to recent LEPS data. We adapt a Regge-plus-resonance (RPR) model developed to describe photoinduced and electroinduced kaon production off protons. The non-resonant contributions to the amplitude are modelled in terms of K+(494) and K*+(892) Regge-trajectory exchange. This amplitude is supplemented with a selection of s-channel resonance diagrams. The three Regge-model parameters of the n(gamma,K+)Sigma- amplitude are derived from the ones fitted to proton data through SU(2) isospin considerations. A fair description of the n(gamma,K+)Sigma- data is realized, which demonstrates the Regge model's robustness and predictive power. Conversion of the resonances' couplings from the proton to the neutron is more challenging, as it requires knowledge of the photocoupling helicity amplitudes. We illustrate how the uncertainties of the helicity amplitudes propagate and heavily restrain the predictive power of the RPR and isobar models for kaon production off neutron targets.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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