Constraints on Supersymmetric Models from the Muon Anomalous Magnetic Moment

Abstract

We study the impact of present and future $(g-2)_μ$ measurements on supersymmetric models. The corrections to $(g-2)_μ$ become particularly relevant in the presence of light sleptons, charginos and neutralinos, especially in the large $\tanβ$ regime. For moderate or large values of $\tanβ$, it is possible to rule out scenarios in which charginos and sneutrinos are both light, but nevertheless escape detection at the LEP2 collider. Furthermore, models in which supersymmetry breaking is transferred to the observable sector through gauge interactions can be efficiently constrained by the $(g-2)_μ$ measurement.

Figures (4)

• Figure 1: Present experimental limit on the lightest chargino mass as a function of the sneutrino mass $m_{\tilde{\nu}}$ for $\tan\beta = 20$, and two values of $\mu$, $\mu =-500$ GeV (dark shaded region) and $\mu =-100$ GeV (light shaded region). Also displayed in the figure are the present limits coming from constraints on $\delta a_{\mu}$ for $\tan\beta=20$ and for $\mu = -500$ GeV and $\mu = 100$ GeV, respectively.
• Figure 2: Present limits on the gaugino mass parameter $M_2$ as a function of the Higgsino mass parameter $\mu$, in gauge mediated supersymmetry breaking models with $n=1$. The upper curve represents the limit for $\tan\beta = 60$, while the lower curve is the result for $\tan\beta = 10$.
• Figure 3: The same as fig. 2, but for $n=3$.
• Figure 4: Limits on the gluino and right-handed squark masses as a function of $\tan\beta$ for gauge-mediated supersymmetry-breaking models with $n=1$ (solid and dotted lines) and $n=3$ (dashed and dot-dashed lines), assuming that the future experimental sensitivity and the future theoretical estimates will allow to constraints new physics effects at the level $|\delta a_{\mu} |< 4 \times 10^{-4}$.