Exploring the interaction between handedness and body parts ownership by means of the Implicit Association Test

The experience of owning a body is built upon the integration of exteroceptive, interoceptive, and proprioceptive signals. Recently, it has been suggested that motor signals could be particularly important in producing the feeling of body part ownership. One thus may hypothesize that the strength of this feeling may not be spatially uniform; rather, it could vary as a function of the degree by which different body parts are involved in motor behavior. Given that our dominant hand plays a leading role in our motor behavior, we hypothesized that it could be more strongly associated with one’s self compared to its non-dominant counterpart. To explore whether this possible asymmetry manifests as a stronger implicit association of the right hand (vs left hand) with the self, we administered the Implicit Association Test to a group of 70 healthy individuals. To control whether this asymmetric association is human-body specific, we further tested whether a similar asymmetry characterizes the association between a right (vs left) animal body part with the concept of self, in an independent sample of subjects (N = 70, 140 subjects total). Our results revealed a linear relationship between the magnitude of the implicit association between the right hand with the self and the subject’s handedness. In detail, the strength of this association increased as a function of hand preference. Critically, the handedness score did not predict the association of the right-animal body part with the self. These findings suggest that, in healthy individuals, the dominant and non-dominant hands are differently perceived at an implicit level as belonging to the self. We argue that such asymmetry may stem from the different roles that the two hands play in our adaptive motor behavior

A comprehensive analysis of the dark matter direct detection experiments in the mirror dark matter framework

Mirror dark matter offers a framework to explain the existing dark matter direct detection experiments. Here we confront this theory with the most recent experimental data, paying attention to the various known systematic uncertainties, in quenching factor, detector resolution, galactic rotational velocity and velocity dispersion. We perform a detailed analysis of the DAMA and CoGeNT experiments assuming a negligible channeling fraction and find that the data can be fully explained within the mirror dark matter framework. We also show that the mirror dark matter candidate can explain recent data from the CDMS/Ge, EdelweissII and CRESSTII experiments and we point out ways in which the theory can be further tested in the near future.Comment: about 30 page

Intense beam of metastable Muonium

Precision spectroscopy of the Muonium Lamb shift and fine structure requires a robust source of 2S Muonium. To date, the beam-foil technique is the only demonstrated method for creating such a beam in vacuum. Previous experiments using this technique were statistics limited, and new measurements would benefit tremendously from the efficient 2S production at a low energy muon ($<20$ keV) facility. Such a source of abundant low energy $\mathrm{\mu^+}$ has only become available in recent years, e.g. at the Low-Energy Muon beamline at the Paul Scherrer Institute. Using this source, we report on the successful creation of an intense, directed beam of metastable Muonium. We find that even though the theoretical Muonium fraction is maximal in the low energy range of $2-5$ keV, scattering by the foil and transport characteristics of the beamline favor slightly higher $\mathrm{\mu^+}$ energies of $7-10$ keV. We estimate that an event detection rate of a few events per second for a future Lamb shift measurement is feasible, enabling an increase in precision by two orders of magnitude over previous determinations

Timing with resonant gravitational wave detectors: An experimental test

We measure the time of arrival ${t}_{0}$ of a force signal acting on a room temperature gravitational wave antenna. The antenna has a noise spectral density whose shape is a rescaled replica of that predicted for the two subkelvin antennas located in Italy, once at their sensitivity goal. ${t}_{0}$ is expressed as {t}_{0}{=t}_{\ensuremath{\varphi}}{+kT}_{0} where ${T}_{0}$ is half the natural period of oscillation of the antenna, |{t}_{\ensuremath{\varphi}}|l~{T}_{0}/2, and $k$ is an integer. We measure the phase part {t}_{\ensuremath{\varphi}} with an accuracy of {\ensuremath{\sigma}}_{{t}_{\ensuremath{\varphi}}}\ensuremath{\approx}174\mathrm{\ensuremath{\mu}}\mathrm{s}/\mathrm{S}\mathrm{N}\mathrm{R}, where SNR is the signal to noise ratio for the signal amplitude. We also find that, for $\mathrm{SNR}g~20,$ the error on $k$ is \ensuremath{\delta}k\ensuremath{\ll}1 so that the total statistical error on the arrival time reduces to the phase error {\ensuremath{\sigma}}_{{t}_{\ensuremath{\varphi}}}. We discuss how this last result can be achieved even for smaller values of the SNR, by better tuning the modes of the antenna. We finally discuss the relevance of these results for source location and spuria events rejection with the two subkelvin detectors above