2018 Impact factor 4.843
Particles and Fields
Eur. Phys. J. C 18, 379-391
DOI 10.1007/s100520000501

Impact of e+ and e- beam polarization on chargino
and neutralino production at a linear collider

G. Moortgat-Pick1 - A. Bartl2 - H. Fraas3 - W. Majerotto4

1 DESY, Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
2 Institut für Theoretische Physik, Universität Wien, 1090 Wien, Austria
3 Institut für Theoretische Physik, Universität Würzburg, 97074 Würzburg, Germany
4 Institut für Hochenergiephysik der Österreichischen Akademie der Wissenschaften, 1050 Wien, Austria

Received: 20 July 2000 / Published online: 27 November 2000 - © Springer-Verlag 2000

Abstract
We study the production processes $e^+ e^-\to \tilde{\chi}^+_i \tilde{\chi}^-_j$, i,j=1,2, and $e^+ e^-\to \tilde{\chi}^0_m \tilde{\chi}^0_n, m,n=$
$1,\ldots,4$, working out the advantages of polarizing both beams. For $e^+ e^-\to \tilde{\chi}^+_1 \tilde{\chi}^-_1$ with $\tilde{\chi}^-_1\to \tilde{\chi}^0_1 e^- \bar{\nu}$ and $e^+ e^-\to \tilde{\chi}^0_1 \tilde{\chi}^0_2$ with $\tilde{\chi}^0_2 \to \tilde{\chi}^0_1 e^+ e^-$ we perform a detailed analysis, including the complete spin correlations between production and decay. We analyze the forward-backward asymmetry of the decay electron for various beam polarizations. We also study polarization asymmetries in $e^+ e^-\to \tilde{\chi}^0_1 \tilde{\chi}^0_2$. These asymmetries strongly constrain the gaugino parameter M1 and the masses $m_{\tilde{e}_{\mathrm {L}}}$, $m_{\tilde{e}_{\mathrm {R}}}$, $m_{\tilde{\nu}}$ also if $m_{\tilde{e},\tilde{\nu}}\ge s^{1/2}/2$. We give numerical predictions for three scenarios for a linear collider with s1/2=500-1000GeV.


Copyright Società Italiana di Fisica, Springer-Verlag 2000