Implication of neutrino backgrounds on the reach of next generation dark matter direct detection experiments

Abstract

As direct dark matter experiments continue to increase in size, they will become sensitive to neutrinos from astrophysical sources. For experiments that do not have directional sensitivity, coherent neutrino scattering from several sources represents an important background to understand, as it can almost perfectly mimic an authentic weakly interacting massive particle (WIMP) signal. Here we explore in detail the effect of neutrino backgrounds on the discovery potential of WIMPs over the entire mass range of 500 MeV to 10 TeV. We show that, given the theoretical and measured uncertainties on the neutrino backgrounds, direct detection experiments lose sensitivity to light (∼ 10 GeV) and heavy (∼ 100 GeV) WIMPs with a spin-independent cross section below 10 −45 and 10 −49 cm 2 , respectively.

Blind spots for neutralino dark matter in the NMSSM

“…As expected, the largest cross-section is for ∂ 2 S f ≈ −µ corresponding to the maximal singlino-Higgsino mixing. Even in the region with ∂ 2 S f several times larger 6 As we explained in section 2, the sign of mχ is the same as that of the diagonal singlino entry, ∂ 2 S f , in the neutralino mass matrix. In the scale-invariant NMSSM and in our convention with λ > 0, the sign of the product µ ∂ 2 S f is the same as the sign of κ.…”

“…Nevertheless, there are points in the parameter space, so-called blind spots, for which the neutralino LSP spin-independent scattering cross-section (almost) vanishes at the tree level. In the vicinity of such blind spots the neutralino LSP is not only consistent with the LUX constraints but, due to the irreducible neutrino background [6], might be never detected in direct detection experiments sensitive only to the SI scattering crosssection. When comparing with the results of DM detection experiments we assume that the considered particle is the main component of DM with the relic density obtained by the Planck satellite [7] (otherwise the experimental bounds on the cross-sections should be re-scaled by the ratio Ω observed /Ω LSP ).…”

“…[4] and LZ [5] experiments. The colored areas at the bottom depict the neutrino background (NB) regions [6]. Upper panels: the solid lines show the LSP spindependent cross-section on neutrons (lower) and protons (upper) for positive (purple) and negative (cyan) values of parameter µ.…”

Cross Section Measurements for Supernova Neutrinos

“…Figure 1 shows some example recoil spectra. In addition to supernova relevance, neutrinos from steady-state sources (Sun, atmosphere, DSNB) represent a fundamental background for DM detectors, the so-called "neutrino floor" [23]. Although the CEvNS cross section is well predicted, it is highly desirable to measure it in order to determine detector response.…”

Analysis of the TeV-scale mirage mediation with heavy superparticles

“…These experiments will probe wide parameter space as long as the spin-independent cross section times the rescaling factor ξσ SI is on the so-called neutrino floor [96]. If ξσ SI is below the neutrino floor, the signals of the dark matter are buried under the neutrino background.…”