Nuclear transparency and effective kaon-nucleon cross section from the A ( e , e ′ K + ) reaction

• Published in: Physical review. C, Nuclear physics Nuclear physics, 2011-07, Vol.84 (1), Article 015210
• Main Authors: Nuruzzaman, Dutta, D., Arrington, J., Asaturyan, R., Benmokhtar, F., Boeglin, W., Bosted, P., Bruell, A., Clasie, B., Christy, M. E., Chudakov, E., Dalton, M. M., Daniel, A., Day, D., Fassi, L. El, Ent, R., Fenker, H. C., Ferrer, J., Fomin, N., Gao, H., Garrow, K., Gaskell, D., Gray, C., Horn, T., Huber, G. M., Jones, M. K., Kalantarians, N., Keppel, C. E., Kramer, K., Li, Y., Liang, Y., Lung, A. F., Malace, S., Markowitz, P., Matsumura, A., Meekins, D. G., Mertens, T., Miyoshi, T., Mkrtchyan, H., Monson, R., Navasardyan, T., Niculescu, G., Niculescu, I., Okayasu, Y., Opper, A. K., Perdrisat, C., Punjabi, V., Qian, X., Rauf, A. W., Rodriquez, V. M., Rohe, D., Seely, J., Segbefia, E., Smith, G. R., Sumihama, M., Tadevosyan, V., Tang, L., Tvaskis, V., Vulcan, W. F., Wesselmann, F. R., Wood, S. A., Yuan, L., Zheng, X. C.
• Format: Article
• Language: English
• Subjects: ATOMIC NUMBER; CEBAF ACCELERATOR; CROSS SECTIONS; DEUTERIUM; ELECTRONS; ELECTROPRODUCTION; FOUR MOMENTUM TRANSFER; KAONS; PARTICLE ACCELERATORS; SCATTERING; TARGETS
• ISSN: 0556-2813; 1089-490X
• DOI: 10.1103/PhysRevC.84.015210

We have determined the transparency of the nuclear medium to kaons from $A(e,e^{'} K^{+})$ measurements on $^{12}$C, $^{63}$Cu, and $^{197}$Au targets. The measurements were performed at the Jefferson Laboratory and span a range in four-momentum-transfer squared Q$^2$=1.1 -- 3.0 GeV$^2$. The nuclear transparency was defined as the ratio of measured kaon electroproduction cross sections with respect to deuterium, ($\sigma^{A}/\sigma^{D}$). We further extracted the atomic number ($A$) dependence of the transparency as parametrized by $T= (A/2)^{\alpha-1}$ and, within a simple model assumption, the in-medium effective kaon-nucleon cross sections. The effective cross sections extracted from the electroproduction data are found to be smaller than the free cross sections determined from kaon-nucleon scattering experiments, and the parameter $\alpha$ was found to be significantly larger than those obtained from kaon-nucleus scattering. We have included similar comparisons between pion- and proton-nucleon effective cross sections as determined from electron scattering experiments, and pion-nucleus and proton-nucleus scattering data.