Polarization observables in the \(e^{+}e^{-} \rightarrow \bar{\Lambda}\Lambda\) reaction

Regular Article - Theoretical Physics

Abstract.

Cross-section, vector-polarization, and tensor-polarization distributions are calculated for the reactions \( e^{+}e^{-}\rightarrow\bar{p}p\) and \( e^{+}e^{-}\rightarrow \bar{\Lambda}\Lambda\). Each reaction requires six characteristic functions that are bilinear in the, possibly complex, electromagnetic form factors, denoted \( G_{E}(P^{2})\) and \( G_{M}(P^{2})\), of p and \( \Lambda\). For the hyperon reaction also the joint-decay distributions of \( \Lambda\) and \( \bar{\Lambda}\) are calculated. Their knowledge allows a complete determination of the hyperon electromagnetic form factors, without measuring hyperon spins. We explain how this is done in practice. For some tensor-polarization components our results are in conflict with previously repeatedly published distributions.

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Copyright information

© SIF, Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Department of physics and astronomyUppsala UniversityUppsalaSweden

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