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Semi-leptonic four-fermion final states in polarised γγreactions: Exact results vs an improved narrow width approximation

M. Baillargeon·G. Bélanger·F. Boudjema
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Abstract

We calculate the process $γγ\rightarrow e^- \barν_e u \bar{d}$ with the full set of Feynman diagrams. We consider different implementations of the $W$ width and different combinations of the photon polarisations. The results of an improved narrow width approximation based on $γγ\rightarrow W^+ W^-$ with full spin-correlations that takes into account different angular cuts as well as cuts on the invariant masses are compared to those of the complete calculation.

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M. Baillargeon, G. Bélanger, F. Boudjema. 1997-01-24. Semi-leptonic four-fermion final states in polarised γγreactions: Exact results vs an improved narrow width approximation. https://doi.org/10.1016/s0370-2693(97)00496-6

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