Nuclear Spin Longitudinal Response

这项为期三年的资助将支持一名教员、一名博士后、一名研究生和几名本科生在准自由（QF）峰激发区进行一系列自旋纵向核响应的测量。长期预测的纵向响应相对于横向响应的增强，基于基本假设，尚未观察到实验。测量将使用最近安装在印第安纳大学回旋加速器设施的印第安纳大学中子偏振计设备（INPOL）进行。将测量轻核体系2H、3He和4He中QF峰区的激发，并与先前由同一组从较重的体系12C、40Ca和208Pb中获得的数据进行比较。对轻核系统的研究可以与精确的法迪夫式计算进行比较，这在较重的核系统中是不可能的，从而可以深入了解差异的来源。使用INPOL的其他实验将提供40Ar， 59Co和127I目标的低洼伽莫夫-泰勒强度测量；这些信息对于正确校准在拟议的太阳中微子测量中测量到的中微子通量是必不可少的。俄亥俄大学小组还将负责为麻省理工学院贝茨设施的BLAST探测器建造中子飞行时间壁，并参与由CLAS合作在托马斯杰斐逊国家加速器设施进行的介子电产生的测量。

This three-year grant will support a faculty member, a post- doctoral fellow, a graduate student and several undergraduate students to perform a series of measurements of the spin longitudinal nuclear response in the quasi-free (QF) peak excitation region. A long predicted enhancement of the longitudinal response relative to the transverse response, based on fundamental assumptions, has yet to be observed experimentally. The measurements will be performed using the recently installed Indiana University Neutron Polarimeter Facility (INPOL) at the Indiana University Cyclotron Facility. Excitation of the QF peak region in the light nuclear systems 2H, 3He, and 4He will be measured, and compared with previously obtained data from the heavier systems 12C, 40Ca and 208Pb by the same group. The study of the light systems allows a comparison to exact Faddeev-type calculations, which are not possible with the heavier nuclear systems, which will thus provide insight into the source of the discrepancy. Other experiments using INPOL will provide measurements of low-lying Gamov-Teller Strength in 40Ar, 59Co, and 127I targets; such information is essential to properly calibrate measured neutrino fluxes in proposed solar neutrino measurements. The Ohio University group will also take responsibility for the construction of a neutron time-of flight wall for the BLAST detector at the MIT-Bates facility and participate in measurements of kaon electroproduction by the CLAS collaboration at the Thomas Jefferson National Accelerator Facility.