Abstract
We consider the prospects for testing the dark matter interpretation of the DAMA/LIBRA signal with the Super-Kamiokande experiment. The DAMA/LIBRA signal favors dark matter with low mass and high scattering cross section. We show that these characteristics imply that the scattering cross section that enters the DAMA/LIBRA event rate determines the annihilation rate probed by Super-Kamiokande. Current limits from Super-Kamiokande through-going events do not test the DAMA/LIBRA favored region. We show, however, that upcoming analyses including fully-contained events with sensitivity to dark matter masses from 5 to 10 GeV may corroborate the DAMA/LIBRA signal. We conclude by considering three specific dark matter candidates, neutralinos, WIMPless dark matter, and mirror dark matter, which illustrate the various model-dependent assumptions entering our analysis.
Highlights
Have been proposed to explain DAMA: neutralinos [19], WIMPless dark matter [12, 21, 22], and mirror dark matter [23]
In the low-mass region of interest, the dominant contribution to neutrino production via dark matter annihilation is from the Sun [28], and we will focus on the Sun below, the Earth may provide an interesting signal
It has been shown [28,29,30] that if σv ∼ 10−26 cm3 s−1, as required for the thermal relic density of dark matter to be in the observed range, for the range of parameters used in this work the Sun is in equilibrium, and
Summary
Super-K may indirectly detect dark matter by finding evidence for dark matter annihilation in the Sun or Earth’s core to standard model (SM) particles that decay to neutrinos. √ where C is the capture rate, τ ≃ 4.5 Gyr is the age of the solar system, and a = σv /(4 2V ), with σ the total dark matter annihilation cross section and V the effective volume of WIMPs in the Sun (V = 5.7 × 1030 cm3(1 GeV/mX )3/2 [27, 28, 31]) It has been shown [28,29,30] that if σv ∼ 10−26 cm s−1, as required for the thermal relic density of dark matter to be in the observed range, for the range of parameters used in this work the Sun is in equilibrium Super-K bounds the νμ-flux from dark matter annihilation in the Sun. Since the total annihilation rate is equal to the capture rate, this permits Super-K to bound the dark matter-nucleon scattering cross section using eq (2.2), assuming ρX = 0.3 GeV cm−3 and a Maxwellian velocity distribution with v ∼ 220 km/s. We will see that consideration of the full Super-K event sample may provide marked improvements, and extend Super-K’s sensitivity to low masses and the DAMA regions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
