Spin-Dependent WIMP Limits from a Bubble Chamber

Abstract

Bubble chambers were the dominant technology used for particle detection in accelerator experiments for several decades, eventually falling into disuse with the advent of other techniques. We report here on a new application for these devices. We operated an ultraclean, room-temperature bubble chamber containing 1.5 kilograms of superheated CF3I, a target maximally sensitive to spin-dependent and -independent weakly interacting massive particle (WIMP) couplings. An extreme intrinsic insensitivity to the backgrounds that commonly limit direct searches for dark matter was measured in this device under operating conditions leading to the detection of low-energy nuclear recoils like those expected from WIMPs. Improved limits on the spin-dependent WIMP-proton scattering cross section were extracted during our experiments, excluding this type of coupling as a possible explanation for a recent claim of particle dark-matter detection.

Global fits of the minimal universal extra dimensions scenario

“…The COUPP collaboration, for instance, has been operating an ultraclean, room-temperature bubble chamber containing 1.5 kilograms of superheated CF 3 I, that produced interesting limits on the spin-dependent coupling [62]. The plans for the future include the operation of a 60 kg chamber at Snolab, that could allow a substantial improvement in sensitivity.…”

Limits on a Muon Flux from Neutralino Annihilations in the Sun with the IceCube 22-String Detector

“…Planetary effects on the capture were neglected. Figure 4 shows the IceCube-22 limits on SD compared with other bounds [7,21,24,25], and the MSSM model space defined as for Fig. 3.…”

“…The shaded area represents MSSM models not disfavored by direct searches [21,22] based on SI . Also shown are the limits from CDMS [21], COUPP [25], KIMS [24], and Super-K [7].…”

Direct detection data and possible hints for low-mass WIMPs

“…Assuming that dark matter interacts with the proton spin one can therefore evade the bounds for DAMA, though no consistent explanation for CoGeNT is obtained in this way. However, there are sever bounds from experiments using a florine target, such as COUPP [20] or PICASSO [21], which exclude the DAMA region at 90% CL [22]. Moreover, in such a scenario neutrino constraints from the sun are tight [23], and under model dependent assumptions also collider constraints rule out such a solution, e.g.…”