PHOTOPRODUCTION OF K$sup +$ MESONS AND POLARIZATION OF $lambda$$sup 0$ HYPERONS IN THE 1-GeV RANGE.
PHOTOPRODUCTION OF K$sup +$ MESONS AND POLARIZATION OF $lambda$$sup 0$ HYPERONS IN THE 1-GeV RANGE.
复制标题
K$sup $ 介子的照片制作和 1-GeV 范围内 $lambda$$sup 0$ 超子的极化。
DOI：
10.1103/physrevd.2.439
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发表时间：
1970
期刊：
影响因子：
--
通讯作者：
S. Iwata
中科院分区：
文献类型：
--
作者：
T. Fujii;A. Imanishi;S. Iwata
在入射光子能量为1054、1100和1160 MeV时，测量了K+介子质心角分别为45、70和90 °时的Λ超子极化和γ+ p→ K++ Λ反应的微分截面。用磁谱仪和基于能量损失和飞行时间的速度选择系统检测了K+介子。通过测量衰变Λ→ p π−中质子相对于产生面的上下不对称性来确定Λ的极化。结果表明，在第三共振区，极化对sin θ K* 的依赖性占主导地位，这与质量约为1700 MeV的P11共振的贡献是一致的.
Polarization of Λ hyperons and differential cross sections for the reaction γ+ p→ K++ Λ were measured at the K+-meson center-of-mass angles around 45, 70, and 90 for the incident photon energies of 1054, 1100, and 1160 MeV. The K+ mesons were detected with a magnetic spectrometer and a velocity-selection system based on the energy loss and the time of flight. The polarization of Λ was determined by measuring the up-down asymmetry of protons in the decay Λ→ p π− with respect to the production plane. The results show a dominant sin θ K* dependence of the polarization at the region of the third resonance and are consistent with a contribution of the P 11 resonance with a mass of about 1700 MeV.