Polarization Measurements on the Recoil Proton from Pion (o) Photoproduction

Download or read book Polarization Measurements on the Recoil Proton from Pion (o) Photoproduction written by D. Lundquist and published by . This book was released on 1965 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The polarization of the recoil proton in pion(o) photoproduction off hydrogen has been measured for photons in the range 500-1000 MeV, using the Stanford Mark III linear accelerator. Protons were detected at an angle b and momentum analyzed using a 90 degree magnetic spectrometer. The scattered protons were detected by two counter telescopes placed symmetrically to left and right of the carbon target and making angles = C with respect to the direction of a proton emerging from the spectrometer. The measured asymmetry was obtained from the usual formula: e = L-R/L+R and the proton polarization P(b) was then obtained by substituting the known carbon analyzing power A(c) in the equation e(b, c) = (P(b) A(c). Using parity conservation it can be shown that P(b) = -P(b). Thus the running time was equally divided between measurements with the spectrometer at +b and -b. This technique enabled residual artificial asymmetries to be removed, since these do not change sign when b becomes -b. Preliminary results are presented and compared to existing data from various laboratories. (Author).