Search for hidden-photon dark matter with the FUNK experiment

Many extensions of the Standard Model of particle physics predict a parallel sector of a new U(1) symmetry, giving rise to hidden photons. These hidden photons are candidate particles for cold dark matter. They are expected to kinetically mix with regular photons, which leads to a tiny oscillating electric-field component accompanying dark matter particles. A conducting surface can convert such dark matter particles into photons which are emitted almost perpendicularly to the surface. The corresponding photon frequency follows from the mass of the hidden photons. In this contribution we present a preliminary result on a hidden photon search in the visible and near-UV wavelength range that was done with a large, 14 m2 spherical metallic mirror and discuss future dark matter searches in the eV and sub-eV range by application of different detectors for electromagnetic radiation.Comment: Contribution to the 35th International Cosmic Ray Conference ICRC2017, 10 to 20 July, 2017, Bexco, Busan, Korea. arXiv admin note: text overlap with arXiv:1711.0296

A Network Analysis of Control-Value Appraisals and Class-room-Related Enjoyment, Boredom, and Pride

Control-Value Theory (CVT) proposes that discrete emotions arise from combinations of control-value appraisals of learning activities and outcomes. Studies have supported this proposition using factor analytic, and latent profile, analyses. Network analysis (NA), however, has not been widely used within the field of educational psychology or to investigate the propositions of CVT. In the present study we set out to examine how control-value appraisals related to three commonly experienced classroom emotions: enjoyment, boredom, and pride, using network analysis. In addition, we included positive and negative facets of value. The sample comprised 170 students (53.5% female) in the first year of secondary education who responded to survey items in a cross-sectional design. NA shows a two-dimensional graphical network of items (edges) and the relations between them (edges). In addition, statistical indices can be used to identify those nodes that show numerous or strong links to others or that bridge clusters (communities) of nodes. The NA showed that emotions and value (positive and negative) but not control cohered into distinct communities. Many, but not all edges, were in support of CVT; positive links between control/positive value and enjoyment and pride, and negative links for boredom; negative links between negative value and enjoyment and pride, and positive links for boredom. Three control-value nodes were particular influential, that lessons are important/valuable (positively) and that work requires too much time (negatively). Interventions and classroom instructional strategies that build value/importance and reduce perceptions of time cost may be particularly effective in facilitating positive emotions and reducing negative emotions

Search for dark matter in the hidden-photon sector with a large spherical mirror

If dark matter consists of hidden-sector photons which kinetically mix with regular photons, a tiny oscillating electric-field component is present wherever we have dark matter. In the surface of conducting materials this induces a small probability to emit single photons almost perpendicular to the surface, with the corresponding photon frequency matching the mass of the hidden photons. We report on a construction of an experimental setup with a large ~14 m2 spherical metallic mirror that will allow for searches of hidden-photon dark matter in the eV and sub-eV range by application of different electromagnetic radiation detectors. We discuss sensitivity and accessible regions in the dark matter parameter space.Comment: 9 pages, proceeding of the 34th International Cosmic Ray Conference (ICRC), July 30 - August 6, 2015, The Hague, The Netherland

Search for dark photons as candidates for Dark Matter with FUNK

An additional U(1) symmetry predicted in theories beyond the Standard Model of particle physics can give rise to hidden (dark) photons. Depending on the mass and density of these hidden photons, they could account for a large fraction of the Dark Matter observed in the Universe. When passing through an interface of materials with different dielectric properties, hidden photons are expected to produce a tiny flux of photons. The wavelength of these photons is directly related to the mass of the hidden photons. In this contribution we report on measurements covering the visible and near-UV spectrum, corresponding to a dark photon mass in the eV range. The data were taken with the FUNK experiment using a spherical mirror of ~14m2 total area built up of 36 aluminum segments

Large scale cosmic-ray anisotropy with KASCADE

The results of an analysis of the large scale anisotropy of cosmic rays in the PeV range are presented. The Rayleigh formalism is applied to the right ascension distribution of extensive air showers measured by the KASCADE experiment.The data set contains about 10^8 extensive air showers in the energy range from 0.7 to 6 PeV. No hints for anisotropy are visible in the right ascension distributions in this energy range. This accounts for all showers as well as for subsets containing showers induced by predominantly light respectively heavy primary particles. Upper flux limits for Rayleigh amplitudes are determined to be between 10^-3 at 0.7 PeV and 10^-2 at 6 PeV primary energy.Comment: accepted by The Astrophysical Journa

On noise treatment in radio measurements of cosmic ray air showers

Precise measurements of the radio emission by cosmic ray air showers require an adequate treatment of noise. Unlike to usual experiments in particle physics, where noise always adds to the signal, radio noise can in principle decrease or increase the signal if it interferes by chance destructively or constructively. Consequently, noise cannot simply be subtracted from the signal, and its influence on amplitude and time measurement of radio pulses must be studied with care. First, noise has to be determined consistently with the definition of the radio signal which typically is the maximum field strength of the radio pulse. Second, the average impact of noise on radio pulse measurements at individual antennas is studied for LOPES. It is shown that a correct treatment of noise is especially important at low signal-to-noise ratios: noise can be the dominant source of uncertainty for pulse height and time measurements, and it can systematically flatten the slope of lateral distributions. The presented method can also be transfered to other experiments in radio and acoustic detection of cosmic rays and neutrinos.Comment: 4 pages, 6 figures, submitted to NIM A, Proceedings of ARENA 2010, Nantes, Franc