New Physics searches in a low threshold scintillating argon bubble chamber measuring coherent elastic neutrino-nucleus scattering in reactors

The sensitivity to New Physics of a low threshold scintillating argon bubble chamber measuring coherent elastic neutrino-nucleus scattering in reactors is reported. Namely, light scalar mediators, sterile neutrino oscillations, unitarity violation, and non-standard interactions are studied. The results indicate that this detector could be able to set stronger constraints than current limits set by the recent COHERENT measurements. Considering the best scenario, a 100 kg detector located 30 m from a 2000 MW$_{th}$ reactor, a sterile neutrino search would cover most of the space parameter allowed from the reactor anti-neutrino anomaly fit. Unitarity violation studies could set constraints on $\alpha_{11}$ more stringent than the current oscillation experiments fit. A low threshold argon detector with very low backgrounds has the potential to explore New Physics in different scenarios and set competitive constraints

A self-assembly based supramolecular bioink with hierarchical control As a new bioprinting tool

Tissue engineering aims to capture details of the extracellular matrix (ECM) that stimulate cell growth and tissue regeneration. Molecularly complex materials or advanced additive fabrication techniques are often used to capture aspects of the ECM. Promising biofabrication techniques often lack nano and molecular scale control, as well as materials that can recreate the natural ECM or selectively guide cell behaviour. On the other hand, complex biomaterials based on molecular self-assembly tend to lack reproducibility and order beyond the nanoscale. We propose a new material fabrication platform that integrates the benefits of bioprinting and molecular self-assembly to overcome the current major limitations. Our approach relies on the co-assembly of peptide amphiphiles (PAs) with biomolecules and/or proteins found in the ECM, whilst exploiting the droplet-on-demand (DoD) printing process. Taking advantage of the interfacial fluid forces during printing, it is possible to guide the self-assembly into aligned or disordered nanofibers, hydrogel structures of different geometries and sizes, surface topographies and higher-ordered structures made from multiple hydrogels. The co-assembly process can be performed during printing and in cell-friendly conditions, whilst exhibiting high cell viability (\u3e 88 %). Moreover, multiple cell types can be spatially distributed on the outside or embedded within the tuneable biomimetic scaffolds. The combination of self-assembly with 3D-bioprinting, provides a basis for a new biofabrication platform to create hydrogels of complex geometry, structural hierarchy and tuneable chemical composition. Please click Additional Files below to see the full abstract

Characterization of surface-states in a hollow core photonic crystal fiber

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSurface or edge states represent an important class of modes in various photonic crystal systems such as in dielectric topological insulators and in photonic crystal fibers. In the later, strong attenuation peaks in the transmission spectrum are attributed to coupling between surface and core-guided modes. Here, we explore a modified implementation of the spatial and spectral interference method to experimentally characterize surface modes in photonic crystal fibers. Using an external reference and a non-uniform Fourier transform windowing, the obtained spectrogram allows clear observation of anti-crossing behavior at wavelengths in which surface and core modes are strongly coupled. We also detect surface modes with different spatial symmetries, and give insight into mode families couple to the fundamental or high-order core modes, as well as the existence of uncoupled surface modes.26253255432564FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2013/20180-32015/04113-008/57857-2Sem informação574017/2008-

Dynamical polarization of the fermion parity in a nanowire Josephson junction

Josephson junctions in InAs nanowires proximitized with an Al shell can host gate-tunable Andreev bound states. Depending on the bound state occupation, the fermion parity of the junction can be even or odd. Coherent control of Andreev bound states has recently been achieved within each parity sector, but it is impeded by incoherent parity switches due to excess quasiparticles in the superconducting environment. Here, we show that we can polarize the fermion parity dynamically using microwave pulses by embedding the junction in a superconducting LC resonator. We demonstrate polarization up to 94% $\pm$ 1% (89% $\pm$ 1%) for the even (odd) parity as verified by single shot parity-readout. Finally, we apply this scheme to probe the flux-dependent transition spectrum of the even or odd parity sector selectively, without any post-processing or heralding

Investigation of the 6He cluster structures

The 4He+2n and t+t clustering of the 6He ground state were investigated by means of the transfer reaction 6He(p,t)4He at 25 MeV/nucleon. The experiment was performed in inverse kinematics at GANIL with the SPEG spectrometer coupled to the MUST array. Experimental data for the transfer reaction were analyzed by a DWBA calculation including the two neutrons and the triton transfer. The couplings to the 6He --> 4He + 2n breakup channels were taken into account with a polarization potential deduced from a coupled-discretized-continuum channels analysis of the 6He+1H elastic scattering measured at the same time. The influence on the calculations of the 4He+t exit potential and of the triton sequential transfer is discussed. The final calculation gives a spectroscopic factor close to one for the 4He+2n configuration as expected. The spectroscopic factor obtained for the t+t configuration is much smaller than the theoretical predictions.Comment: 10 pages, 11 figures, accepted in PR

Effects of drought ? altered seasonality and low rainfall ? in net ecosystem carbon exchange of three contrasting Mediterranean ecosystems

International audienceDroughts cause reductions in gross primary production (GPP) and also in net ecosystem exchange (NEE), contributing to most of the inter-annual variability in terrestrial carbon sequestration. In seasonally dry climates (Mediterranean) droughts result from reductions in annual rainfall and from changes in rain seasonality. In western Iberia, the hydrological-year (i.e., from October to September) of 2004?2005 was extremely dry, with precipitation 50% below the long-term mean (691 mm in 1961?1990), but 2005?2006 was normal. We compared the carbon fluxes measured by the eddy covariance technique from three contrasting ecosystems in southern Portugal: an evergreen oak woodland (savannah-like) with ca. 21% tree cover; a Mediterranean C3/C4 grassland; and a coppiced eucalyptus plantation. During the dry hydrological-year of 2004?2005, NEE was lowest, the highest sink strength was in the eucalypt plantation (NEE = ?399 g C m ?2 year?1) as compared to the oak woodland (NEE = ?88 g C m ?2 year?1), and the grassland (NEE = +49 g C m ?2 year ?1). The latter was a source of carbon dioxide. The NEE values of the dry year were, however, much lower than those for wetter years, e.g. NEE = ?861 g C m?2 year ?1 in 2002?2003 in the eucalypt plantation. The NEE of the grassland and the oak savannah in the 2005?2006 hydrological-year, with annual precipitation above the long term mean, were ?190 and ?120 g C m ?2 year?1, respectively. All ecosystems studied increased their rain-use efficiency (GPP per unit of rain volume) increased in dry years. In the case of annual vegetation ? grassland and low tree density woodland, however &ndash, rain-use efficiency decreased with severe drought. However, this was more pronounced in the eucalypt plantation due to greater GPP and the use of deep soil water resources. Although both calendar years of 2004 and 2005 had equally low rainfall, the effect of drought on the eucalypt plantation was delayed until the second dry year. This suggests that the effects of water deficits on Mediterranean forests are exacerbated by prolonged droughts when long-term soil water reserves are depleted. The grassland, however, was more vulnerable and responded faster to water deficits. This effect of drought was less pronounced in the oak woodland due to the sparse tree cover

Side-lobe level reduction in bio-inspired optical phased-array antennas

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQPhased arrays are expected to play a critical role in visible and infrared wireless systems. Their improved performance compared to single element antennas finds uses in communications, imaging, and sensing. However, fabrication of photonic antennas and their feeding network require long element separation, leading to the appearance of secondary radiation lobes and, consequently, crosstalk and interference. In this work, we experimentally show that by arranging the elements according to the Fermat's spiral, the side lobe level (SLL) can be reduced. This reduction is proved in a CMOS-compatible 8-element array, revealing a SLL decrement of 0.9 dB. Arrays with larger numbers of elements and inter-element spacing are demonstrated through a spatial light modulator (SLM) and an SLL drop of 6.9 dB is measured for a 64-element array. The reduced SLL, consequently, makes the proposed approach a promising candidate for applications in which antenna gain, power loss, or information security are key requirements.25243010530114COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSem informação08/57857-22013/20180-32015/04113-0574017/2008-9446746/2014-