Implications for relic neutralinos of the theoretical uncertainties in the neutralino-nucleon cross-section
A. Bottino, F. Donato, N. Fornengo, S. Scopel
TL;DR
This paper analyzes how present uncertainties in the pion–nucleon sigma term, the strange-quark content of the nucleon, and the light-quto-heavy quark mass ratio propagate into the neutralino–nucleon spin-independent cross-section and, consequently, into the inferred relic density for neutralino dark matter. Using MSSM parameter scans and hadronic input sets, the authors show that the DAMA annual modulation signal remains compatible with a neutralino comprising a substantial fraction of dark matter, and that larger hadronic inputs can widen this compatibility into the cosmologically interesting region $0.01 \\leq \\Omega_{\\chi} h^2 \\leq 0.7$. The study highlights a strong anticorrelation between $\\sigma_{\\rm scalar}^{(\\rm nucleon)}$ and $\\Omega_{\\chi} h^2$, and demonstrates that uncertainties in $\\sigma_{\\pi N}$, $y$, and $r$ can shift the allowed regions by factors of a few, affecting both direct and indirect detection interpretations. Overall, the work emphasizes the crucial role of hadron physics uncertainties in translating WIMP direct-detection results into robust cosmological implications, and it calls for a coherent, cross-validated determination of $\\sigma_{\\pi N}$, $y$, and $r$ to tighten these connections.
Abstract
We discuss the effect induced on the neutralino-nucleon cross-section by the present uncertainties in the values of the quark masses and of the quark scalar densities in the nucleon. We examine the implications of this aspect on the determination of the neutralino cosmological properties, as derived from measurements of WIMP direct detection. We show that, within current theoretical uncertainties, the DAMA annual modulation data are compatible with a neutralino as a major dark matter component, to an extent which is even larger than the one previously derived. We also comment on implications of the mentioned uncertainties for experiments of indirect dark matter detection.