Constraints on light mediators: confronting dark matter searches with B physics

Understand

Light scalars appear in many well-motivated extensions of the Standard Model including supersymmetric models with additional gauge singlets.

• Such scalars could mediate the interactions between dark matter and nuclei, giving rise to the tentative signals observed by several dark matter direct detection experiments including CDMS-Si.
• In this letter, we derive strong new limits on light scalar mediators by using the LHCb, Belle and BaBar searches for rare $\Upsilon$ and B decays.
• These limits rule out significant parts of the parameter space favored by CDMS-Si.