TY - JOUR
T1 - Dark matter detection in two easy steps
AU - Pospelov, Maxim
AU - Weiner, Neal
AU - Yavin, Itay
PY - 2014/3/13
Y1 - 2014/3/13
N2 - Multicomponent dark matter particles may have a more intricate direct detection signal than simple elastic scattering on nuclei. In a broad class of well-motivated models, the inelastic excitation of dark matter particles is followed by de-excitation via γ decay. In experiments with fine energy resolution, such as many 0ν2β decay experiments, this motivates a highly model-independent search for the sidereal daily modulation of an unexpected γ line. Such a signal arises from a two-step weakly interacting massive particle (WIMP) interaction: the WIMP is first excited in the lead shielding and subsequently decays back to the ground state via the emission of a monochromatic γ within the detector volume. We explore this idea in detail by considering the model of magnetic inelastic WIMPs and take a sequence of CUORE-type detectors as an example. We find that under reasonable assumptions about detector performance it is possible to efficiently explore mass splittings of up to a few hundred keV for a WIMP of weak-scale mass and transitional magnetic moments. The modulation can be cheaply and easily enhanced by the presence of additional asymmetric lead shielding. We devise a toy simulation to show that a specially designed asymmetric shielding may result in up to 30% diurnal modulations of the two-step WIMP signal, leading to additional strong gains in sensitivity.
AB - Multicomponent dark matter particles may have a more intricate direct detection signal than simple elastic scattering on nuclei. In a broad class of well-motivated models, the inelastic excitation of dark matter particles is followed by de-excitation via γ decay. In experiments with fine energy resolution, such as many 0ν2β decay experiments, this motivates a highly model-independent search for the sidereal daily modulation of an unexpected γ line. Such a signal arises from a two-step weakly interacting massive particle (WIMP) interaction: the WIMP is first excited in the lead shielding and subsequently decays back to the ground state via the emission of a monochromatic γ within the detector volume. We explore this idea in detail by considering the model of magnetic inelastic WIMPs and take a sequence of CUORE-type detectors as an example. We find that under reasonable assumptions about detector performance it is possible to efficiently explore mass splittings of up to a few hundred keV for a WIMP of weak-scale mass and transitional magnetic moments. The modulation can be cheaply and easily enhanced by the presence of additional asymmetric lead shielding. We devise a toy simulation to show that a specially designed asymmetric shielding may result in up to 30% diurnal modulations of the two-step WIMP signal, leading to additional strong gains in sensitivity.
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U2 - 10.1103/PhysRevD.89.055008
DO - 10.1103/PhysRevD.89.055008
M3 - Article
AN - SCOPUS:84896954609
SN - 1550-7998
VL - 89
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 5
M1 - 055008
ER -