35006667
PS1-10afx at z= 1.388: Pan-STARRS1 Discovery of a New Type of Superluminous Supernova
We present the Pan-STARRS1 discovery of PS1-10afx, a unique hydrogen-deficient superluminous supernova (SLSN) at redshift z = 1.388. The light curve peaked at z P1 = 21.7 mag, making PS1-10afx comparable to the most luminous known SNe, with Mu = –22.3 mag. Our extensive optical and near-infrared observations indicate that the bolometric light curve of PS1-10afx rose on the unusually fast timescale of ~12 days to the extraordinary peak luminosity of 4.1 × 1044 erg s–1 (M bol = –22.8 mag) and subsequently faded rapidly. Equally important, the spectral energy distribution is unusually red for an SLSN, with a color temperature of ~6800 K near maximum light, in contrast to previous hydrogen-poor SLSNe, which are bright in the ultraviolet (UV). The spectra more closely resemble those of a normal SN Ic than any known SLSN, with a photospheric velocity of ~11, 000 km s–1 and evidence for line blanketing in the rest-frame UV. Despite the fast rise, these parameters imply a very large emitting radius ( 5 × 1015 cm). We demonstrate that no existing theoretical model can satisfactorily explain this combination of properties: (1) a nickel-powered light curve cannot match the combination of high peak luminosity with the fast timescale; (2) models powered by the spindown energy of a rapidly rotating magnetar predict significantly hotter and faster ejecta; and (3) models invoking shock breakout through a dense circumstellar medium cannot explain the observed spectra or color evolution. The host galaxy is well detected in pre-explosion imaging with a luminosity near L*, a star formation rate of ~15 M ☉ yr–1, and is fairly massive (~2 × 1010 M ☉), with a stellar population age of ~108 yr, also in contrast to the young dwarf hosts of known hydrogen-poor SLSNe. PS1-10afx is distinct from known examples of SLSNe in its spectra, colors, light-curve shape, and host galaxy properties, suggesting that it resulted from a different channel than other hydrogen-poor SLSNe.
7124426
Color and Variability Characteristics of Point Sources in the Faint Sky Variability Survey
We present an analysis of the color and variability characteristics for point sources in the Faint Sky Variability Survey (FSVS). The FSVS cataloged ~23 deg2 in BVI filters from ~16 to 24 mag to investigate variability in faint sources at moderate-to-high Galactic latitudes. Point-source completeness is found to be >83% for a selected representative sample (V = 17.5-22.0 mag, B - V = 0.0-1.5) containing both photometric B, V detections and 80% of the time-sampled V data available compared to a basic internal source completeness of 99%. Multiepoch (10-30) observations in V spanning minutes to years modeled by light-curve simulations reveal amplitude sensitivities to ~0.015-0.075 mag over a representative V = 18-22 mag range. Periodicity determinations appear viable to timescales of order 1 day or less using the most sampled fields (~30 epochs). The fraction of point sources is found to be generally variable at 5%-8% over V = 17.5-22.0 mag. For V brighter than 19 mag, the variable population is dominated by low-amplitude (<0.05 mag) and blue (B - V < 0.35) sources, possibly representing a population of γ Doradus stars. Overall, the dominant population of variable sources are bluer than B - V = 0.65 and have main-sequence colors, likely reflecting larger populations of RR Lyrae, SX Phe, γ Doradus, and W UMa variables.
11448200
The Faint Sky Variability Survey — I. Goals and data reduction process
The Faint Sky Variability Survey is aimed at finding photometric and/or astrometric variable objects in the brightness range between ∼16th and ∼24th mag on time-scales between tens of minutes and years with photometric precisions ranging from 3 millimag for the brightest to 0.2 mag for the faintest objects. An area of ∼23 deg 2 , located at mid and high Galactic latitudes, has been covered using the Wide Field Camera on the 2.5-m Isaac Newton Telescope on La Palma. Here we describe the main goals of the Faint Sky Variability Survey and the data reduction process.
56569059
Search for annual modulation in low-energy CDMS-II data
We report limits on annual modulation of the low-energy event rate from the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory. Such a modulation could be produced by interactions from Weakly Interacting Massive Particles (WIMPs) with masses ~10 GeV/c^2. We find no evidence for annual modulation in the event rate of veto-anticoincident single-detector interactions consistent with nuclear recoils, and constrain the magnitude of any modulation to 98% confidence. For events consistent with electron recoils, no significant modulation is observed for either single- or multiple-detector interactions in the 3.0-7.4 keVee range.
52245958
Revealing Bell’s nonlocality for unstable systems in high energy physics
Entanglement and its consequences—in particular the violation of Bell inequalities, which defies our concepts of realism and locality—have been proven to play key roles in Nature by many experiments for various quantum systems. Entanglement can also be found in systems not consisting of ordinary matter and light, i.e. in massive meson–antimeson systems. Bell inequalities have been discussed for these systems, but up to date no direct experimental test to conclusively exclude local realism was found. This mainly stems from the fact that one only has access to a restricted class of observables and that these systems are also decaying. In this Letter we put forward a Bell inequality for unstable systems which can be tested at accelerator facilities with current technology. Herewith, the long awaited proof that such systems at different energy scales can reveal the sophisticated “dynamical” nonlocal feature of Nature in a direct experiment gets feasible. Moreover, the role of entanglement and $\mathcal{CP}$ violation, an asymmetry between matter and antimatter, is explored, a special feature offered only by these meson–antimeson systems.
117986736
On two- and three-point functions of Landau gauge Yang-Mills theory
We present results for the gluon and ghost propagators and the ghost-gluon vertex obtained from Dyson-Schwinger equations. In the zero temperature case we elaborate on the role of the three-gluon vertex and discuss a model that can capture its qualitative features like its anomalous dimensions and a zero crossing of the dressing function. Our results compare well with lattice data. At non-zero temperature we calculated the ghost propagator which agrees rather well with lattice results already within our simple truncation. These results are used to obtain the temperature dependence of the ghost-gluon vertex. We also explain why the ghost propagator does not react to the phase transition despite its direct coupling to the chromoelectric gluon.
119438179
Central and noncentral components of the effective sd-shell interaction
The contributions of central as well as noncentral two-body interactions to the matrix elements of various effective interactions for the $\mathrm{sd}$ shell are studied in an SU(3) two-particle basis. The results show that their central parts agree rather well and exhibit an approximate SU(3) symmetry. However, large differences are found between the noncentral parts of microscopic and phenomenological interactions, respectively. The influence of noncentral components of the matrix elements of Glaudemans et al. on experimental data is investigated for the case of $^{28}\mathrm{Si}$, with the result that the $\mathrm{LS}$ component is very important to reproduce the correct ground state binding energy. Some effects introduced by higher order two-body interactions and many-body interactions are discussed.
15971982
Limits on spin-dependent WIMP-nucleon interactions from the Cryogenic Dark Matter Search
The Cryogenic Dark Matter Search (CDMS) is an experiment to detect weakly interacting massive particles (WIMPs), which may constitute the universe’s dark matter, based on their interactions with Ge and Si nuclei. We report the results of an analysis of data from the first two runs of CDMS at the Soudan Underground Laboratory in terms of spin-dependent WIMP-nucleon interactions on 73 Ge and 29 Si. These data exclude new regions of WIMP parameter space, including regions relevant to spin-dependent interpretations of the annual modulation signal reported by the DAMA/NaI experiment.