First results from dark matter search experiment with LiF bolometer at Kamioka underground laboratory

Abstract

The Tokyo group has performed the first underground dark matter search experiment from 2001 through 2002 at Kamioka Observatory(2700m.w.e). The detector is eight LiF bolometers with a total mass of 168g and aims for the direct detection of WIMPs via spin-dependent interaction. With an exposure of 4.1 kg·days, we derived the limits in the a p − a n (WIMP-nucleon couplings) plane and excluded a large part of the parameter space allowed by the UKDMC experiment.

Limits on the WIMP–nucleon coupling coefficients from dark matter search experiment with NaF bolometer

“…Since 23 Na has a larger expectation value of the neutron spins than 7 Li as shown in Table 3, we were able to tighten the limits from the previous experiment [8] in the a p -a n plane.…”

“…As described in Ref. [8], we did not compare our results with the SD annual modulation allowed regions shown in Fig. 2 [5] because the DAMA group had not shown the results from 23 Na and 127 I independently.…”

“…[8], and set the new limits in the a p -a n plane. We compared our results with those of the UKDMC experiments [10,11], and tightened the UKDMC's limits that are close to the DAMA's SD allowed region in Ref.…”

Strangeness in the Nucleon, Cold Dark Matter in the Universe, and Neutrino Scattering off Liquid Argon

“…It is clear that the uncertainty in Ds is affecting the design of an optimal experiment for direct dark-matter detection. While the uncertainty persists, perhaps materials with unpaired both proton and neutron spins, such as the LiF bolometer used by the Tokyo group [14], have an advantage; however, the uncertainty still affects the interpretation of the results.…”

Pulse-shape discrimination of CaF2(Eu)

“…Several direct WIMP searches using 19 F-based detectors, such as bolometers [2,3], a bubble chamber [4], scintillators [5,6,7,8,9], a superheated droplet detector [10] and so on, have already been performed. In our group, a WIMP search experiment using a CaF 2 (Eu) scintillator is carried out at Kamioka observatory in 2005 [5].…”