2018 Impact factor 4.843
Particles and Fields
Eur. Phys. J. C 7, 113-122
DOI 10.1007/s100529800956

Spin correlations in production and decay of charginos

G. Moortgat-Pick1 - H. Fraas1 - A. Bartl2 - W. Majerotto3

1 Institut für Theoretische Physik, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
2 Institut für Theoretische Physik, Universität Wien, Boltzmanngasse 5, A-1090 Wien, Austria
3 Institut für Hochenergiephysik, Österreichische Akademie der Wissenschaften, Nikolsdorfergasse 18, A-1050 Wien, Austria

Received: 28 April 1998 / Revised version: 18 June 1998 / Published online: 8 September 1998

Abstract
We study the production of charginos $e^+ e^- \to\tilde{\chi}^{+}_i\tilde{\chi}^{-}_j, (i,j=1,2)$ with polarized beams and the subsequent decays $\tilde{\chi}^{+}_{i} \to
 \tilde{\chi}^0_k
 \ell^{+}\nu_\ell$ and $\tilde{\chi}^{-}_{j} \to \tilde{\chi}^0_l \ell^{-}\bar{\nu}_\ell,
 (k,l=1,\ldots,4)$, including the complete spin correlations between production and decay. Analytical formulae are presented for the joint spin-density matrix of the charginos, for the chargino decay matrix and for the differential cross section of the combined processes of production and decays. We present numerical results for pair production of the lighter chargino with unpolarized beams and the leptonic decay of $\tilde{\chi}_1^-$ into the lightest neutralino $\tilde{\chi}^0_1$. The lepton angular distribution and the forward-backward asymmetry are studied in four representative scenarios for $\sqrt{s}=192$GeV and $\sqrt{s}=200$GeV.


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