Dark Matter Detection in the Light of Recent Experimental Results

TL;DR

The paper surveys dark matter evidence and candidate particles, emphasizing WIMPs and the neutralino from SUSY as a natural DM candidate. It links early-universe relic density calculations to present-day direct-detection prospects, outlining both scalar (spin-independent) and axial (spin-dependent) interactions and their experimental implications. By analyzing supergravity, string-inspired, and M-theory frameworks, it maps how model assumptions (GUT vs intermediate scales, universal vs non-universal soft terms) shape the neutralino-nucleon cross section and the likelihood of detection. The work stresses current experimental tensions (e.g., DAMA vs CDMS/EDELWEISS/ZEPLIN) and concludes that upcoming experiments (GENIUS, GEDEON, CRESST, DRIFT) will critically probe substantial portions of SUSY parameter space relevant for neutralino dark matter.

Abstract

The existence of dark matter was suggested, using simple gravitational arguments, seventy years ago. Although we are now convinced that most of the mass in the Universe is indeed some non-luminous matter, we still do not know its composition. The problem of the dark matter in the Universe is reviewed here. Particle candidates for dark matter are discussed with particular emphasis on Weakly Interacting Massive Particles (WIMPs). Experiments searching for these relic particles, carried out by many groups around the world, are also reviewed, paying special attention to their direct detection by observing the elastic scattering on target nuclei through nuclear recoils. Finally, we concentrate on the theoretical models predicting WIMPs, and in particular on supersymmetric extensions of the standard model, where the leading candidate for WIMP, the neutralino, is present. There, we compute the cross section for the direct detection of neutralinos, and compare it with the sensitivity of detectors. We mainly discuss supergravity, superstring and M-theory scenarios.

Figures (29)

• Figure 1: Observed rotation curve of the nearby dwarf spiral galaxy M33, superimposed on its optical image.
• Figure 2: Feynman diagrams contributing to early-Universe neutralino ($\tilde{\chi}^0_1$) annihilation into fermions through neutral Higgses ($H\equiv H,h,A$) and squarks and sleptons ($\tilde{f}$).
• Figure 3: Elastic scattering of a dark matter particle with an atomic nucleus in a detector.
• Figure 4: Feynman diagrams contributing to neutralino-nucleon cross section through squark ($\tilde{q}$) exchange and CP-even light ($h$) and heavy ($H$) neutral Higgs exchange.
• Figure 5: Earth's motion around the Sun.