High Energy Physics With Polarized Beams Proceedings Of The Summer Study U S Atomic Energy Commission

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ISBN 13 :
Total Pages : 56 pages
Book Rating : 4.:/5 (893 download)

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Download or read book High-Energy-Physics Experiments with Polarized Targets written by and published by . This book was released on 1966 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: If we are to do a workmanlike job of studying the strong interactions it is imperative that we have knowledge of the spin dependence of the forces. This implies that polarization experiments are essential. Already Bareyre, Bricman, Stirling and Villet have shown that pion-proton polarization experiments should be interpreted as indicating two new resonances not previously seen by other methods. The present-day approach to determining detailed pion-proton scattering amplitudes is to use measured differential cross sections, polarization measurements, dispersion relations, and isospin conservation rules. Further assumptions are unitarity of the S matrix and the short-range nature of strong interactions. In the more distant future I hope we may see the day when the scattering experiments will be sufficiently detailed that the dispersion relations will not be necessary to the interpretation of results. Then the dispersion relations may themselves be checked experimentally, rather than being assumed. I see, then, an early period of polarization experiments followed by a later period in which more extensive experimental results will be called for. For the pion-proton system the first period seems well progressed, based on measurements of differential cross section and P, the polarization. In the second period more complex experiments should be required, such as measurements of the parameters R and A . In R and A measurements, the protons have a known polarization before the collision takes place. After the pion scatters on the proton, one asks how much residual polarization the proton has. The nucleon-nucleon (N-N) system is susceptible to similar analysis, but there are more amplitudes to be determined, so more experiments must be performed. The N-N system is less well analyzed at present than the [pi]-N system.