Helicity in proton–proton elastic scattering and the spin structure of the pomeron

We discuss different models for the spin structure of the nonperturbative pomeron: scalar, vector, and rank-2 symmetric tensor. The ratio of single-helicity-flip to helicity-conserving amplitudes in polarised high-energy proton–proton elastic scattering, known as the complex r5 parameter, is calcula...

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Bibliographic Details
Main Authors: Carlo Ewerz, Piotr Lebiedowicz, Otto Nachtmann, Antoni Szczurek
Format: Article
Language:English
Published: Elsevier 2016-12-01
Series:Physics Letters B
Online Access:http://www.sciencedirect.com/science/article/pii/S0370269316306359
Description
Summary:We discuss different models for the spin structure of the nonperturbative pomeron: scalar, vector, and rank-2 symmetric tensor. The ratio of single-helicity-flip to helicity-conserving amplitudes in polarised high-energy proton–proton elastic scattering, known as the complex r5 parameter, is calculated for these models. We compare our results to experimental data from the STAR experiment. We show that the spin-0 (scalar) pomeron model is clearly excluded by the data, while the vector pomeron is inconsistent with the rules of quantum field theory. The tensor pomeron is found to be perfectly consistent with the STAR data.
ISSN:0370-2693