Radiative Corrections to Aid the Direct Detection of the Higgsino-like Neutralino Dark Matter: Spin-Independent Interactions

The lightest neutralino ($\tilde{\chi}_1^0$) is a good Dark Matter (DM) candidate in the R-parity conserving Minimal Supersymmetric Standard Model (MSSM). In this work, we consider the light higgsino-like neutralino as the Lightest Stable Particle (LSP), thanks to rather small higgsino mass parameter $\mu$. We then estimate the prominent radiative corrections to the neutralino-neutralino-Higgs boson vertices. We show that for higgsino-like $\tilde{\chi}_1^0$, these corrections can significantly influence the spin-independent direct detection cross-section, even contributing close to 100\% in certain regions of the parameter space. These corrections, therefore, play an important role in deducing constraints on the mass of the higgsino-like lightest neutralino DM, and thus the $\mu$ parameter.