Lenslet-coupled antenna arrays have been used in CMB experiments and are the baseline technology for the next-generation satellite missions such as LiteBIRD and PICO. Lenslets are small hemispherical ...lenses mounted on the focal plane that couple light to the detectors and are typically made of silicon or alumina due to their high focusing power and low absorption loss. To minimize reflection at the vacuum-dielectric interface, lenslets require anti-reflection (AR) coatings. Metamaterials have been used in large microwave optical components because they avoid any mismatch on the thermal expansion between the lens and its coating, but so far they have only been machined on surfaces of comparatively large radius of curvature. As a first step to understand the feasibility of machining metamaterial AR layers in lenslets through laser-etching for the LiteBIRD mission, a model in ANSYS HFSS was developed. The goal of the simulation was to optimize transmission in three frequency bands while meeting assumed laser machinability constraints and optical requirements. Simulation results from flat silicon show that an AR metamaterial coating made under the assumed conditions is feasible, and the baseline parameters for further curved-surface studies are provided.
We present the first measurement of cross-correlation between the lensing potential, reconstructed from cosmic microwave background (CMB) polarization data, and the cosmic shear field from galaxy ...shapes. This measurement is made using data from the Polarbear CMB experiment and the Subaru Hyper Suprime-Cam (HSC) survey. By analyzing an 11 deg2 overlapping region, we reject the null hypothesis at 3.5 and constrain the amplitude of the cross-spectrum to , where is the amplitude normalized with respect to the Planck 2018 prediction, based on the flat Λ cold dark matter cosmology. The first measurement of this cross-spectrum without relying on CMB temperature measurements is possible owing to the deep Polarbear map with a noise level of ∼6 K arcmin, as well as the deep HSC data with a high galaxy number density of . We present a detailed study of the systematics budget to show that residual systematics in our results are negligibly small, which demonstrates the future potential of this cross-correlation technique.
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•Method proposal to couple energy efficiency strategies for windows in hot climates.•Combination of five hybrid ventilation setpoints and five electrochromic controls.•Parametric ...simulations and Pareto front were used to obtain sub-optimal scenarios.•Incident solar radiation in the façade and external illuminance was more relevant.
Many studies were conducted to reduce energy demand and consumption in buildings related to HVAC systems, mainly in warm and hot climates, where heat gain from the envelope is relevant. In this context, the window is the component that demands more attention as it usually shows a low thermal performance and represents the weakest component in the building envelope. This work proposes a method to evaluate window performance considering operation strategies regarding dynamic solar control and passive cooling in commercial buildings in subtropical and tropical climates. Parametric simulations were run for three Brazilian cities testing three windows compositions – laminated, insulated, and electrochromic glazing – with hybrid ventilation. Personalized codes were developed to establish rules for window control and prioritize actions to meet energy-saving and thermal comfort for five electrochromic and five hybrid ventilation controls. It was proposed the Pareto-optimal frontier to obtain the optimal set of solutions. The results showed that electrochromic windows reached an energy saving of up to 6.1% to 8.6% in the studied cities. The most influential variables were solar radiation incidence, external illuminance level, and outdoor air temperature. The method is adequate to establish guidelines for window controlling in warm and hot climates, especially coupling different techniques.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A comprehensive study of the atmospheric neutrino flux in the energy region from sub-GeV up to several TeV using the Super-Kamiokande (SK) water Cherenkov detector is presented in this paper. The ...energy and azimuthal spectra, and variation over time, of the atmospheric νe+ν¯e and νμ+ν¯μ fluxes are measured. The energy spectra are obtained using an iterative unfolding method by combining various event topologies with differing energy responses. The azimuthal spectra depending on energy and zenith angle, and their modulation by geomagnetic effects, are also studied. A predicted east-west asymmetry is observed in both the νe and νμ samples at 8.0σ and 6.0σ significance, respectively, and an indication that the asymmetry dipole angle changes depending on the zenith angle was seen at the 2.2σ level. The measured energy and azimuthal spectra are consistent with the current flux models within the estimated systematic uncertainties. A study of the long-term correlation between the atmospheric neutrino flux and the solar magnetic activity cycle is performed, and a weak preference for a correlation was seen at the 1.1σ level, using SK-I–SK-IV data spanning a 20-year period. For several particularly strong solar activity periods, corresponding to Forbush decrease events, no theoretical prediction is available but a deviation below the typical neutrino event rate is seen at the 2.4σ level. The seasonal modulation of the neutrino flux is also examined, but the change in flux at the SK site is predicted to be negligible, and, as expected, no evidence for a seasonal correlation is seen.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The charge-conjugation and parity-reversal (CP) symmetry of fundamental particles is a symmetry between matter and antimatter. Violation of this CP symmetry was first observed in 1964
, and CP ...violation in the weak interactions of quarks was soon established
. Sakharov proposed
that CP violation is necessary to explain the observed imbalance of matter and antimatter abundance in the Universe. However, CP violation in quarks is too small to support this explanation. So far, CP violation has not been observed in non-quark elementary particle systems. It has been shown that CP violation in leptons could generate the matter-antimatter disparity through a process called leptogenesis
. Leptonic mixing, which appears in the standard model's charged current interactions
, provides a potential source of CP violation through a complex phase δ
, which is required by some theoretical models of leptogenesis
. This CP violation can be measured in muon neutrino to electron neutrino oscillations and the corresponding antineutrino oscillations, which are experimentally accessible using accelerator-produced beams as established by the Tokai-to-Kamioka (T2K) and NOvA experiments
. Until now, the value of δ
has not been substantially constrained by neutrino oscillation experiments. Here we report a measurement using long-baseline neutrino and antineutrino oscillations observed by the T2K experiment that shows a large increase in the neutrino oscillation probability, excluding values of δ
that result in a large increase in the observed antineutrino oscillation probability at three standard deviations (3σ). The 3σ confidence interval for δ
, which is cyclic and repeats every 2π, is -3.41, -0.03 for the so-called normal mass ordering and -2.54, -0.32 for the inverted mass ordering. Our results indicate CP violation in leptons and our method enables sensitive searches for matter-antimatter asymmetry in neutrino oscillations using accelerator-produced neutrino beams. Future measurements with larger datasets will test whether leptonic CP violation is larger than the CP violation in quarks.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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