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Machine Learning Assisted Reconstruction of Hadron-Collider Events using Mini-Jets
No full textReconstructing impactful physical observables from hadron collider data represents challenges due to combinatorial ambiguities and experimental effects. We propose a novel approach using mini-jets (R=0.1) as the sole reconstructed objects, employing a deep neural network for observable determination. This method condenses full event information into a manageable size, demonstrating superior efficiency and generality compared to classical algorithms for future LHC analyses
Single-Shot electro-optic detection of broadband THz at EuXFEL and FLASH using diversity scheme with advanced reconstruction algorithms
No full textWe present novels methods aiming at recording THz waveforms in single-shot and high repetition rates, with high temporal resolution. This work is performed in the PhLAM-DESY collaboration framework, aiming at developing real-time diagnostics for THz sources, as well as monitoring the shapes of relativistic electron bunches in accelerators. While electro-optic probing with chirped laser probes is efficient for high repetition rate operations, it suffers from resolution and fidelity limitations, particularly for extended recording windows. To address these issues, we explore solutions based on the diversity concept, employing a multi-output electro-optic measurement system. This approach, combined with advanced reconstruction algorithms, enables faithful retrieval of the measured electric field. We have developed a new algorithm that "adapts" to laser chirp imperfections (high-order dispersion), enabling high-resolution single-shot broadband THz measurements over a long temporal window. We present the method's principle, numerical results, and the status of experimental developments at European XFEL and FLASH, demonstrating a significant advancement in high-resolution, long-duration of broadband THz characterization
Transient quasiperiodic oscillations of Fermi-LAT blazars under the curved jet model
No full textContext. This study explores transient quasiperiodic oscillations (QPOs) in the γ-ray emission of two blazars, PMN J0531−4827 and PKS 1502+106, using over a decade of Fermi Large Area Telescope observations.Aims. The analysis focuses on identifying QPO signatures in their long-term light curves and interpreting the variability through a curved jet model, which predicts multiplicative oscillations with exponentially decaying amplitudes.Methods. We developed an analysis methodology to characterize the QPOs and the specific properties of the amplitudes of such QPOs.Results. The findings offer insights into the dynamic processes driving relativistic jet evolution and their potential connections to underlying mechanisms, such as binary systems or other phenomena influencing the observed characteristics of these blazars.Key words: methods: statistical / techniques: photometric / astronomical databases: miscellaneous / galaxies: active / BL Lacertae objects: genera
dCache project status and update
No full textThe dCache project delivers an open-source, massively scalable, distributed storage system deployed internationally to satisfy today’s scientists’ ever-demanding storage requirements. Its multifaceted approach supports different use cases with the same storage, from high throughput data ingest, data sharing over wide area networks, efficient access from HPC clusters, and longterm data persistence on tertiary storage. Even though dCache was initially developed for HEP experiments, today, it is used by various scientific communities, including astrophysics, biomed, and life science, each with their specific requirements. To match the needs of these new communities and keep up with the scaling demands of existing experiments, dCache is permanently evolving. With this contribution, we would like to highlight the recent developments in dCache regarding integration with CERN Tape Archive (CTA), advanced metadata handling, token-based authorization support, bulk API for QoS transitions, REST API to control interaction with the tape system, and future development directions
High-Resolution Mapping of the Human Olfactory Bulb Using X-Ray Phase Contrast Tomography and Virtual Surface Unfolding
No full textThe human olfactory bulb (OB) is a complex neural structure critical for odor processing and oneof the earliest sites of pathology in a number of neurodegenerative diseases. We used X–ray phase–contrast tomography (XPCT) to obtain high–quality 3D images of OB tissue from postmortem patients,allowing detailed visualization of soft tissue microarchitecture, including the olfactory glomeruli. Toimprove spatial analysis, we developed a computational unfolding method that transforms the curvedsurface of the OB into a 2D map. This transformation preserves anatomical relationships, allowingaccurate quantification of glomeruli by number, size, shape, and distribution. The unfoldedrepresentations of OB image support in–depth statistical analysis and are compatible with machinelearning tools for automated detection and classification of OB morphological structures. This methodprovides a powerful framework for studying olfactory function and identifying early structural changesin diseases such as Parkinson's disease, Alzheimer's disease, and COVID–19–associated anosmia. Byintegrating XPCT with virtual unfolding, we offer a new approach to mapping OB morphologicalfeatures with increased clarity and diagnostic accuracy.Key words: human olfactory bulb, X–ray phase contrast tomography, virtual unrolling.Citation: Bukreeva I, Cedola A, Fratini M, Junemann O. High–Resolution Mapping of theHuman Olfactory Bulb Using X–Ray Phase Contrast Tomography and Virtual Surface Unfolding
Full-field x-ray fluorescence imaging based on coded aperture ghost imaging
No full textWe demonstrate an approach to record spectrally resolved images of x-ray fluorescence emission under full-field illumination with a monochromatic synchrotron beam. We achieve this by combining coded aperture and ghost imaging. Specifically, we record signals of two detection devices: an x-ray camera without energy resolution and a spectrometer without spatial resolution. By joint analysis of these complementary signals, we reconstruct images for each spectral emission line. We compare the performance of this technique with a previously demonstrated computational ghost imaging scheme based on coding only the illumination. Finally, we explore the depth resolution of this approach in view of future single-shot volumetric reconstructions
