Scheme for the extraction of WIMP-nucleon scattering cross sections from total event rates

Abstract

We propose a scheme that allows to analytically determine the three elementary cross sections and connect the solutions to the relative sign between the proton and the neutron spin scattering amplitudes once the measurements of total event rate from three appropriate targets become available. In this way it is thus possible to extract the maximum information on the supersymmetric parameter space obtainable from direct detection experiments, in the case that the dark matter particle is the lightest neutralino. Our scheme is based on suitably normalized form of the isospin momentum dependent structure functions entering in the spin-dependent elastic neutralino-nucleus cross section. We compare these functions with the commonly used ones and discuss their advantages: in particular, these allow in the spin-dependent cross section to factorize the particle physics degrees of freedom from the momentum transfer dependent nuclear structure functions as it happens in the spin-independent cross section with the nuclear form factor. PACS numbers: 95.35.+d, 12.60.Jv

Complementarity of dark matter direct detection: the role of bolometric targets

“…The detection of WIMP DM in more than one target could provide more information about the nature of this particle [33,34,36,35]. First, the consistency of the energy spectra measured by experiments using different target nuclei would confirm that the events were due to WIMP scattering (rather than, for instance, neutron background) [40].…”

Theoretical direct WIMP detection rates for transitions to the first excited state inKr83

“…We should mention in passing that the nuclear matrix elements for 19 F are expected to be much more reliable [29,43]. Actually this problem will remain open until all the three nucleon cross sections (scalar, proton spin and neutron spin) can be determined along the lines previously suggested [50], after sufficient experimental information on at least three suitable targets becomes available. Anyway in the present work we will not commit ourselves to any particular model, but for orientation purposes we will use the value [41] of σ 1 (N ) ≈ 1.7 × 10 −38 cm −2 = 1.7 × 10 −2 pb.…”

Light WIMP Searches Involving Electron Scattering

“…Before proceeding further let us examine available information on 1 [35], which is summarized here: (a) supersymmetric models in which the LSP (lightest supersymmetric particle) communicates with the quarks via the exchange of the -boson [36]. In this case in the constrained minimal supersymmetric standard model one finds sizable spin induced cross sections [37,38], and as large as 10 −3 pb (the proton neutron representation was chosen, since the experiments are analyzed this way). If, however, the isoscalar contribution is negligible the proton and the neutron amplitudes are opposite and ≈ ≈ 1 .…”