Radiative corrections to the direct detection of the Higgsino- and wino-like neutralino dark matter: Spin-dependent interactions

Abstract

The lightest neutralino (χ˜10) is a promising dark matter (DM) candidate in the R-parity conserving minimal supersymmetric standard model. In this work, we focus on dominantly Higgsino-like and wino-like χ˜10 DM, with small admixtures of gauginos and Higgsinos, respectively. In particular, we explore large one-loop corrections to the χ˜10χ˜10Z vertex, which can significantly affect the estimation of the spin-dependent χ˜10-nucleon scattering cross section in the regions where such DM candidates are viable. We have used the on-shell renormalization scheme to estimate the relevant counterterm contributions. In the parameter region where χ˜10 is dominantly Higgsino-like, the radiative corrections (including the contributions from the respective counterterms) are substantial and can enhance the χ˜10χ˜10Z vertex by up to ∼120% for the benchmark scenarios we have considered. Further, for an almost pure wino-like χ˜10, the increment in the χ˜10χ˜10Z vertex is up to 15%. The corresponding cross sections with the proton and the neutron can be changed by up to about 50%. In addition, including the electroweak box diagrams, the cross sections can be significantly enhanced, in particular, for the wino-like χ˜10. Published by the American Physical Society 2025