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EDM4hep - The common event data model for the Key4hep project
No full textThe common and shared event data model EDM4hep is a core part of the Key4hep project. It is the component that is used to not only exchange data between the different software pieces, but it also serves as a common language for all the components that belong to Key4hep. Since it is such a central piece, EDM4hep has to offer an efficient implementation. On the other hand, EDM4hep has to be flexible enough in order to allow for new developments in detector technology and reconstruction. In order to meet these challenges EDM4hep is using the podio EDM toolkit to generate its implementation from a high level description. In this talk we give an overview of EDM4hep emphasizing the most recent developments that were tackled on the way to a first stable release. We use this opportunity to also highlight the latest developments in the podio toolkit that were required by the latest EDM4hep features. These include the introduction of type erased interface types, and a new generic RDataSource to support the full data model API in RDataFrame
The inner-shell ionization and fragmentation of selenophene at 120 eV
No full textThree-dimensional velocity-map imaging and covariance analysis were used to identify over 50 fragmentation channels produced following the inner-shell ionization of selenophene at 120 eV. The majority resulted in two or three 'heavy' products containing selenium or carbon, many of which had identical mass-to-charge ratios but different chemical compositions due to the degree of hydrogenation and the selenium isotope involved. Covariance analysis was used to isolate these reaction channels and to provide estimates of their relative yields. In combination with prior similar studies on thiophene and furan, the current results indicate that the nature of the heteroatom significantly influences the charge redistribution and bond cleavage dynamics induced by the Auger-Meitner process, and demonstrate the sensitivity of inner-shell ionization dynamics to the molecular and electronic structures of heterocyclic systems
Testing the ubiquitous presence of very high energy emission in gamma-ray bursts with the MAGIC telescopes
No full textGamma-ray bursts (GRBs) are the most powerful transient objects in the Universe, and they are a primary target for the MAGIC Collaboration. Recognizing the challenges of observing these elusive objects with Imaging Atmospheric Cherenkov Telescopes (IACTs), we implemented a dedicated observational strategy that included an automated procedure for rapid re-pointing to transient sources. Since 2013, this automated procedure has enabled MAGIC to observe GRBs at a rate of approximately ten per year, which led to the successful detection of two GRBs at very high energies (VHE; E > 100 GeV). We present a comprehensive analysis of 42 non-detected GRBs (4 short GRBs) observed by MAGIC from 2013 to 2019. We derived upper limits (ULs) on the observed energy flux as well as on the intrinsic energy flux corrected for absorption by the extragalactic background light (EBL) from the MAGIC observations in selected energy and time intervals. We conducted a comprehensive study of their properties to investigate the reasons for these non-detections, including the possible peculiar properties of TeV-detected GRBs. We find that strong EBL absorption significantly hinders TeV detection for the majority of GRBs in our sample. For a subset of 6 GRBs with redshift z < 2, we compared the UL on the intrinsic flux in the VHE domain with the simultaneous X-ray flux, which is observed to be at the same level in the current population of TeV-detected GRBs. Based on these inferred MAGIC ULs, we conclude that a VHE component with a luminosity comparable to the simultaneously observed X-ray luminosity cannot be ruled out for this sample.Key words: radiation mechanisms: non-thermal / gamma-ray burst: general / gamma rays: genera
Steering Pt Cluster Dimensionality via the Surface Oxidation State of CeO (111) Thin Films
No full textRefining Tau Identification with Domain Adaptation Techniques at CMS
No full textHadronically decaying tau leptons are a challenging signature to study given it can be mimicked by quark and gluon jets, electrons, or muons. The identification of this signature via a convolutional neural network performed by CMS during the LHC Run 2 brought a massive improvement with respect to previous strategies. To further improve the identification and reconstruction of hadronic decays of tau leptons, CMS has deployed, as of the start of Run 3, a new algorithm: DeepTau v2.5. This poster presents the performance resulting from these improvements in the network architecture using early Run 3 data and showcases the use of domain adaptation techniques to improve the modelling of data
All-sky Neutrino Point-source Search with IceCube Combined Track and Cascade Data
No full textDespite extensive efforts, discovery of high-energy astrophysical neutrino sources remains elusive. We present an event-level simultaneous maximum likelihood analysis of tracks and cascades using IceCube data collected from 2008 April 6 to 2022 May 23 to search the whole sky for neutrino sources, and using a source catalog, for coincidence of neutrino emission with gamma-ray emission. This is the first time a simultaneous fit of different detection channels is used to conduct a time-integrated all-sky scan with IceCube. Combining all-sky tracks, with superior pointing power and sensitivity in the northern sky, with all-sky cascades, with good energy resolution and sensitivity in the southern sky, we have developed the most sensitive point-source search to date by IceCube that targets the entire sky. The most significant point in the northern sky aligns with NGC 1068, a Seyfert II galaxy, which, from the catalog search, shows a 3.5σ excess over background after accounting for trials. The most significant point in the southern sky does not align with any source in the catalog and is not significant after accounting for trials. A search for the single most significant Gaussian flare at the locations of NGC 1068, PKS 1424+240, and the southern highest-significance point shows results consistent with expectations for steady emission. Notably, this is the first time that a flare shorter than four years has been excluded as being responsible for NGC 1068’s emergence as a neutrino source. Our results show that combining tracks and cascades when conducting neutrino source searches improves sensitivity and can lead to new discoveries
A first determination of the LHC neutrino fluxes from FASER data
No full textThe detection of TeV neutrinos from the LHC by the far-forward detectors FASER and SND@LHC enables a plethora of novel physics opportunities. Among these, the measurement of the flavour, energy, and rapidity dependence of the LHC forward neutrino fluxes provides unique constraints on theoretical predictions of forward particle production in hadronic collisions. We demonstrate that neutrino event yield measurements at FASER from Run 3 and at its HL-LHC upgrades enable a theory-agnostic extraction of the LHC forward neutrino fluxes. We exploit the equivalence of the problem with the determination of parton distributions from deep-inelastic structure functions to apply the NNPDF approach, based on machine learning regression and the Monte Carlo replica method, to LHC neutrino fluxes. The resulting NNνflux methodology is validated through closure tests and applied to a first extraction of the LHC muon neutrino flux from the FASER 2024 data. We show how NNνflux can discriminate between event generators of forward hadron production; scrutinize a possible intrinsic charm component in the proton; and constrain BSM scenarios with enhanced decays of neutral hadrons into neutrinos
Physics Considerations for a Plasma Booster Stage for the European XFEL
No full textThe linac of the European XFEL accelerates high-quality electron bunches up to a maximum of 17.5 GeV, which undergo free-electron lasing in undulators at photon energies of up to 30 keV. A plasma accelerator stage could be used to significantly increase the electron bunch energy of the European XFEL cheaply and over a short distance. Towards this end we have developed models and performed the first beamtimes at the European XFEL in order to understand whether a twin-bunch structure suitable for plasma acceleration can be generated at the photocathode, then be accelerated and shaped in the following linac sections and bunch compressors. Promising first results from these studies will be presented alongside first considerations of a suitable plasma source, which must be scalable to high average powers. The high current (~5 kA) of an XFEL-derived plasma accelerator driver generates challenges for such a source, for example from ion motion and beam-induced ionisation. These effects will be explored and mitigation strategies proposed. Potential use cases for a plasma booster stage at the European XFEL will be presented
