Implications of muon anomalous magnetic moment for supersymmetric dark matter

Model-independent analysis of muon g(mu) - 2

We consider possible physics beyond the standard model that could account for the large recently reported [Muon g-2 Collaboration, H. N. Brown et al., Phys. Rev. Lett. 86, 2227 (2001)] effect in g(mu)-2. If the underlying theory can be treated perturbatively, then the only possibilities are models that contain particles that yield "direct" contributions, e.g., supersymmetric models, models with unexpectedly light leptoquarks, or with a rather exotic heavy vector boson. If the underlying theory involves strong interactions, as in technicolor models, then the discrepancy could be accounted for by a variety of mechanisms.

Upper limits on sparticle masses from g -- 2 and the possibility for discovery of supersymmetry at colliders and in dark matter searches

We analyze the implications of the new physics effect seen in the g -- 2 Brookhaven measurement and show that if the effect arises from supersymmetry, then the sign of the Higgs mixing parameter mu is determined to be positive in the standard sign convention. Further, analyses within the minimal supergravity model show that the Brookhaven result leads to upper limits on the universal gaugino and scalar masses of m(1/2) < or = 800 GeV and m(0) < or = 1.5 TeV for tan beta < or = 55. Our analysis strongly suggests that supersymmetry via production of sparticles must be found at the CERN Large Hadron Collider. Further, sgn(mu) positive is favorable for the discovery of supersymmetric cold dark matter.