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Local-in-Time Conservative Binary Dynamics at Fifth Post-Minkowskian and First Self-Force Orders
No full textWe report the local-in-time conservative dynamics of nonspinning binary systems at fifth Post-Minkowskian (5PM) and first self-force (1SF) orders. This follows from an explicit calculation of the 5PM/1SF nonlocal-in-time tail-type contribution to the deflection angle via worldline effective field theory techniques. Proceeding as in [2403.04853], we subtract the nonlocal tail terms from the result in [2403.07781] and reconstruct a local-in-time Hamiltonian in isotropic gauge -- valid for generic orbits. For completeness, we reinstate the nonlocal terms relevant for elliptic-like motion up to 6PN/1SF in a small-eccentricity expansion. Via the connection between the (source) energy flux in [2210.05541] and tail effects, we also derive the SF-exact logarithmic-dependent part of the full 5PM bound Hamiltonian. Our results provide the most accurate description to date of the dynamics of bound compact objects within the framework of relativistic scattering computations
Structure of Supramers Formed by Glycolipid Analogues: SAXS Study
No full textSynthetic glycolipids and similar amphiphils with peptide and other head groups have been designed for labeling/modification of living cells under mild physiological conditions. Under-standing the mechanism of their penetration through the cellular glycocalyx and subsequent insertion into the plasma membrane opens up the prospect of improving the recently found anti-tumor properties of such constructs. In this work, we applied small-angle X-ray scattering (SAXS) technique to characterize structure of nanoparticles formed by self-assembly of synthetic glycolipid A (type 2)-Ad-DE and to estimate its dependence on the glycolipid concentration. The studies were performed at a range of SAXS-applicable concentrations. The obtained results indicate that self-assembly process leads to formation of monodisperse nanoparticles with micelle-like architecture, which is maintained regardless of concentration, indicating absence of the nanoparticle’s positive interaction with their glycopart. We applied ab initio modeling that showed a good agreement with experimental data, and found that the ellipsoid monodisperse nanoparticles have a size of about 14 nm. Quasi-atomic modeling visualised that glycan ligands are well accessed for biological recognition. This knowledge will facilitate further study of the formation of the supramolecular form(s) of A(type 2)-Ad-DE and other glycolipids within the glycocalyx and its further fate in new therapeutic strategies
Charge collection studies of MAPS in a 65 nm CMOS imaging process
No full textMonolithic Active Pixel Sensors (MAPS) are candidates to serve as vertex and tracking detectors in the future lepton colliders. This is due to the many advantages they provide compared to hybrid sensors, such as a reduced material budget and lower power consumption. The TANGERINE project aims for the development of the next generation of monolithic silicon pixel sensors produced in the 65 nm imaging process and investigates their possible use as vertex detectors in future lepton colliders. To investigate the 65 nm imaging process, simulations are implemented to reproduce the sensor response and thus save time and resources during the development phase. Technology Computer-Aided Design (TCAD) simulations permit the production of complex electric field profiles by the use of generic doping concentrations, a solution to the restricted access that commercial foundries implement in their fabrication process. A combination of Monte Carlo (MC) simulations using electrostatic TCAD fields was introduced to address the intensive computational requirements of using transient TCAD simulations. This allows the utilization of realistic electric fields combined with a high particle rate, resulting in simulations with high statistics. Furthermore, to include the effects that the electronics have on the signal produced by the silicon detector, Simulation Program with Integrated Circuit Emphasis (SPICE) is integrated into the simulation chain. The sensors used for the validation of the simulation chain are the ALICE Analogue Pixel Test Structure (APTS) are MAPS produced in a 65 nm CMOS imaging process designed at CERN for the CERN EP R&D program and are part of the studies for the ALICE ITS3 upgrade. In particular, the Analogue Pixel Test Structure Source Follower (APTS-SF) allows for the study of the different layouts and their effect on the signal due to several source follower stages used a simple electronic readout. This work showcases the results of a simulation approach combining TCAD, MC, and SPICE, a comparison of charge studies of these simulations with MAPS using a Fe-55 source for calibration and measurements taken at the DESY-II test beam facility using a 4 GeV electron beam. A discussion of the highlights and discrepancies between simulation and experimental data, and the possible reasons for these disagreements, is presented
Proof-of-principle experiment for the dark-field detection concept for measuring vacuum birefringence
No full textVacuum fluctuations give rise to effective nonlinear interactions between electromagnetic fields. These generically modify the characteristics of light traversing a strong-field region. X-ray free-electron lasers (XFELs) constitute a particularly promising probe, due to their brilliance, the possibility of precise control and favorable frequency scaling. However, the nonlinear vacuum response is very small even when probing a tightly focused high-intensity laser field with XFEL radiation and direct measurement of light-by-light scattering of real photons and the associated fundamental physics constants of the quantum vacuum has not been possible to date. Achieving a sufficiently good signal-to-background separation is key to a successful quantum vacuum experiment. To master this challenge, a dark-field detection concept has recently been proposed. Here we present the results of a proof-of-principle experiment validating this approach by demonstrating that using real-world x-ray optics the background signal can be suppressed sufficiently to measure the weak nonlinear response of the vacuum
Liquid metal embrittlement in solid-state welding of Mg/galvanized steel
No full textThe phenomenon of liquid metal embrittlement (LME) poses safety concerns for welded joints in themanufacturing field. In present study, LME was observed in refill friction stir spot welding (refill FSSW)of dissimilar magnesium (Mg) to galvanized steel. This marks the first reported proof of evidence ofLME in the field of solid-state welding. Microstructural characterization of cracks formed during thewelding process revealed typical characteristics of LME, specifically the penetration and enrichmentof Zn at the Mg alloy grain boundaries and the formation of a liquefied phase. Tensile tests of ZncoatedMg alloy were conducted at elevated temperatures to validate the LME phenomenon in refillFSSW and to identify the temperature range in which LME occurs. Based on these observations, amechanism of LME formation for the Mg-Zn system in refill FSSW is proposed. Additionally, strategiesto prevent LME are suggested and experimentally validated
Versatile Two-Photon Brain Imaging Using a Wavelength-Tunable, Fiber-Optic Dispersive Wave Generator
No full textFermion discretization effects in the two-flavor lattice Schwinger model: A study with matrix product states
No full textWe present a comprehensive tensor network study of staggered, Wilson, and twisted mass fermions in the Hamiltonian formulation, using the massive two-flavor Schwinger model as a benchmark. Particular emphasis is placed on twisted mass fermions, whose properties in this context have not been systematically explored before. We confirm the expected O(a) improvement in the free theory and observe that this improvement persists in the interacting case. By leveraging an electric-field-based method for mass renormalization, we reliably tune to maximal twist and establish the method’s applicability in the two-flavor model. Once mass renormalization is included, the pion mass exhibits rapid convergence to the continuum limit. Finite-volume effects are addressed using two complementary approaches: dispersion relation fits and finite-volume scaling. Our results show excellent agreement with semiclassical predictions and reveal a milder volume dependence for twisted mass fermions compared to staggered and Wilson discretizations. In addition, we observe clear isospin-breaking effects, suggesting intriguing parallels with lattice QCD. These findings highlight the advantages of twisted mass fermions for Hamiltonian simulations and motivate their further exploration—particularly in view of future applications to higher-dimensional lattice gauge theories
Measurement of the branching fraction and search for and decays at Belle
No full textWe present a study of the rare charm meson decays , , and using a 942 fb data set collected by the Belle detector at the KEKB asymmetric-energy collider. We use candidates identified by the charge of the pion in decays and normalize the branching fractions to decays. The branching fraction for decay is measured to be (39.6 4.5 (stat) 2.9 (syst)) , with the dielectron mass in the mass region MeV. We also search for () decays with the dielectron mass near the and resonances, and away from these resonances for the and modes. For these modes, we find no significant signals and set 90 confidence level upper limits on their branching fractions at the (10) level