Pulse shape discrimination performance of Inverted Coaxial Ge detectors

We report on the characterization of two inverted coaxial Ge detectors in the context of being employed in future $^{76}$Ge neutrinoless double beta ($0\nu\beta\beta$) decay experiments. It is an advantage that such detectors can be produced with bigger Ge mass as compared to the planar Broad Energy Ge detectors (BEGe) that are currently used in the GERDA $0\nu\beta\beta$ decay experiment. This will result in lower background for the search of $0\nu\beta\beta$ decay due to a reduction of cables, electronics and holders. The measured resolution near the $^{76}$Ge Q-value at 2039 keV is 2.5 keV and their pulse-shape characteristics are similar to BEGe-detectors. It is concluded that this type of Ge-detector is suitable for usage in $^{76}$Ge $0\nu\beta\beta$ decay experiments

Differential Scattering Cross-Sections for the Different Product Vibrational States in the Ion-Molecule Reaction Ar+ + N2

The charge transfer reaction Ar+ + N2 --> Ar + N2+ has been investigated in a crossed beam experiment in combination with three-dimensional velocity map imaging. Angular differential state-to-state cross sections were determined as a function of the collision energy. We found that scattering into the first excited vibrational level dominates as expected, but only for scattering in the forward direction. Higher vibrational excitations up to v'=6 have been observed for larger scattering angles. For decreasing collision energy, scattering into higher scattering angles becomes increasingly important for all kinematically allowed quantum states. Our detailed measurements indicate that a quantitative agreement between experiment and theory for this basic ion-molecule reaction now comes within reach.Comment: accepted to Phys. Rev. Let

The Tails of the Crossing Probability

The scaling of the tails of the probability of a system to percolate only in the horizontal direction $\pi_{hs}$ was investigated numerically for correlated site-bond percolation model for $q=1,2,3,4$.We have to demonstrate that the tails of the crossing probability far from the critical point have shape $\pi_{hs}(p) \simeq D \exp(c L[p-p_{c}]^{\nu})$ where $\nu$ is the correlation length index, $p=1-\exp(-\beta)$ is the probability of a bond to be closed. At criticality we observe crossover to another scaling $\pi_{hs}(p) \simeq A \exp (-b {L [p-p_{c}]^{\nu}}^{z})$. Here $z$ is a scaling index describing the central part of the crossing probability.Comment: 20 pages, 7 figures, v3:one fitting procedure is changed, grammatical change

Search for axion-like particles using a variable baseline photon regeneration technique

We report the first results of the GammeV experiment, a search for milli-eV mass particles with axion-like couplings to two photons. The search is performed using a "light shining through a wall" technique where incident photons oscillate into new weakly interacting particles that are able to pass through the wall and subsequently regenerate back into detectable photons. The oscillation baseline of the apparatus is variable, thus allowing probes of different values of particle mass. We find no excess of events above background and are able to constrain the two-photon couplings of possible new scalar (pseudoscalar) particles to be less than 3.1x10^{-7} GeV^{-1} (3.5x10^{-7} GeV^{-1}) in the limit of massless particles.Comment: 5 pages, 4 figures. This is the version accepted by PRL and includes updated limit

Formation of ultracold LiCs molecules

We present the first observation of ultracold LiCs molecules. The molecules are formed in a two-species magneto-optical trap and detected by two-photon ionization and time-of-flight mass spectrometry. The production rate coefficient is found to be in the range 10^{-18}\unit{cm^3s^{-1}} to 10^{-16}\unit{cm^3s^{-1}}, at least an order of magnitude smaller than for other heteronuclear diatomic molecules directly formed in a magneto-optical trap.Comment: 8 pages, 2 figure

Improving conversational dynamics with reactive speech synthesis

The active exchange of ideas and/or information is a crucial feature of human-human conversation. Yet it is a skill that present-day ‘conversational’ interfaces are lacking, which effectively hampers the dynamics of interaction and makes it feel artificial. In this paper, we present a reactive speech synthesis system that can handle user’s interruptions. Initial results of evaluation of our interactive experiment indicate that participants prefer a reactive system to a non-reactive one. Based on participants’ feedback, we suggest potential applications for reactive speech synthesis systems (i.e. interactive tutor and adventure game) and propose further interactive user experiments to evaluate them. We anticipate that the reactive system can offer more engaging and dynamic interaction and improve user experience by making it feel more like a natural human-human conversation