2026-09-22T06:20:56Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/25851 2023-07-10 col_2142_8859 col_2142_5131 com_2142_8858 com_2142_234 com_2142_5130

Regge cuts Wyld, H.W. Miller, Robert Alan 2011-07-26T20:26:46Z 2011-07-26T20:26:46Z 10000-01-01 1970 We examine in some detail the numerical features of some absorptive Regge models of neutral pion photoproduction. We start be reviewing the formalism in a consistent notation. The formalism contains derivations of the two expressions commonly used to calculate absorbed scattering amplitudes and their relation to Regge cut parametrizations. The physical picture behind the derivations is that absorbed Regge scattering is the result of secondary scattering of the products of the pure Regge exchange so that particles are scattered into inelastic channels. The scattering of the particles which remain in the channel of interest is taken to be elastic scattering as measured experimentally. The oldest of the two absorptive expressions is the Gottfried-Jackson partial wave form; the newer expression involves an integral over the intermediate scattering angle. The integral absorption expression is used for most of the calculations in this work. Unitarity and factorization are discussed briefly regarding their relation to the calculations presented. Numerical results are obtained by choosing a specific parametrization for the Regge exchange and performing the required numerical integrations. We present graphs of the discontinuities across the Regge cut which is generated, the contribution to the s- and t-channel scattering amplitudes due to the cut, and the fit to the data which is obtained. The s dependence of the absorptive corrections is discussed. We find that the straightforward absorptive Regge model does not fit the data well. For this reason we examine the effects produced by the modifications of the straightforward model which have been used in several published fits. We find that the omission of the nonsense wrong-signature zero has a beneficial effect. We argue that, independent of the presence or absence of a nonsense wrong-signature zero, the effects of the cut calculated in the manner presented are too small, and that an arbitrary multiplication of the cut amplitude bya factor of about 2 is necessary in the types of absorptive Regge fits which have been tried. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-07-26T20:26:46Z No. of bitstreams: 1 1970_miller.pdf: 1481487 bytes, checksum: e277ef7ee651fa8787624d21b191ded2 (MD5) Made available in DSpace on 2011-07-26T20:26:46Z (GMT). No. of bitstreams: 1 1970_miller.pdf: 1481487 bytes, checksum: e277ef7ee651fa8787624d21b191ded2 (MD5) Previous issue date: 1970 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-07-26T20:26:46Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:32:56-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Thesis U of I Only 2167330 http://hdl.handle.net/2142/25851 en 1970 Robert Alan Miller numerical study absorption neutral pion photoproduction absorptive Regge models Numerical study of Regge cuts due to absorption in neutral pion photoproduction Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.