On the sbottom resonance in dark matter scattering

Understand

A resonance in the neutralino-nucleus elastic scattering cross section is usually purported when the neutralino-sbottom mass difference m_sbottom-m_chi is equal to the bottom quark mass m_b ~ 4 GeV.

• Such a scenario has been discussed as a viable model for light (~ 10 GeV) neutralino dark matter as explanation of possible DAMA and CoGeNT direct detection signals.
• Here we give physical and analytical arguments showing that the sbottom resonance may actually not be there.
• In particular, we show analytically that the one-loop gluon-neutralino scattering amplitude has no pole at m_sbottom=m_chi+m_b, while by analytic continuation to the regime m_sbottom<m_chi, it develops a pole at m_sbottom=m_chi-m_b.