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ATLAS: update of the netbooting framework for SoC
No full textThe TDAQ System Administration team manages the installation and configuration of the Operating System (OS) of all the nodes of the ATLAS experiment and of the ATLAS TDAQ TestBed Laboratory in the CERN General Purpose Network. The currently supported OS is AlmaLinux 9 and it can be installed locally or via network. Some of the SoC devices (e.g Zynq MPSoc) can be booted with that supported OS and therefore the idea is to integrate those devices into the TDAQ System Administration “netbooting” infrastructure used to create and deploy the “standard” OS image. The capability to create the OS image to boot a SoC device via network will be overviewed, describing the more recents steps performed. Its management and deployment will be described
gauge bosons in beam dumps and supernovae
No full textWe study the phenomenology of a sub-GeV gauge boson. We find discrepancies with existing literature in sensitivity projections for the upcoming SHiP experiment and in the treatment of supernovae cooling constraints. We present a quantitative analysis of different production modes in beam dumps and compare our results to previous work. In the context of supernovae, we re-evaluate the standard supernova cooling bounds from SN1987A and analyze additional supernova-based probes: diffusive cooling, constraints from the existence of low-energy supernovae, and the absence of a high-energy neutrino signal from SN1987A
BuSca: A Buffer Scanner at HLT1 to detect LLPs beyond the SM at LHCb
No full textBuSca is a LHCb project prototype designed for long-lived parti cle searches in real-time, leveraging the enhanced parallelization capabilities of the new LHCb trigger scheme implemented on GPUs. BuSca algorithms are focused at present on downstream reconstructed tracks, which exclusively let hits in the UT and SciFi detectors. By projecting physics candidates onto 2D histograms of flight distance and mass hypotheses at 30 MHz rate, BuSca identifies hot spots indicative of potential candidates of new particles, thereby providing strategic guidance for the development of new trigger lines. Additionally, BuSca offers an Armenteros-Podolanski representation, providing insights into the mass hypotheses of the decay products associated with the new particle. The performance of BuSca, including the outcomes of its initial prototype on simulated and real data, will be elucidated in this manuscript
Investigating the Dark Sector with the ATLAS experiment: Search for Dark Photons decaying into Lepton-Jets
No full textMany extensions of the Standard Model predict a weakly coupled
Dark Sector, with the simplest case introducing a U (1) gauge group and a Dark
Photon. In the so-called Higgs portal models, Higgs bosons produced in proton-
proton collisions at the LHC are allowed to decay into Dark Sector particles, leading
to final states with two Dark Photons that decay into collimated Standard Model
particles. This work reports a search for Dark Photons with masses from 17 MeV to
20 GeV, promptly decaying into jets of collimated electrons and/or muons (lepton-
jets). The analysis uses the full Run-2 dataset of proton-proton collisions at 13 TeV
collected by the ATLAS experimen
ATLAS Tile calorimeter: Performance and upgrade for HL-LHC conditions
No full textThe Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS experiment, which measures energies in range from about 30 MeV to about 2 TeV. TileCal is a sampling calorimeter with steel as absorber and scintillators as active medium. The scintillators are read-out by wavelength shifting fibers coupled to photomultiplier tubes (PMTs). The analogue signals from the PMTs are amplified, shaped, digitized by sampling the signal every 25 ns and stored on pipelines on-detector until a trigger decision is received. Each stage of signal propagation is separately calibrated with an accuracy better than 1%: a Cs radioactive source excite the scintillating tiles directly, a laser light system directly tests the PMT response, and a charge injection system calibrates the front-end electronics. The performance of the calorimeter has been established with cosmic ray muons and the large sample of the proton proton collisions. The calorimeter’s electromagnetic scale is calibrated using isolated electrons and cross-checked with high-momentum isolated muons, whereas isolated hadrons are used to assess its hadronic response in beam tests. The timing resolution is determined through analyses of multijet events. To prepare the High-Luminosity phase of LHC (HL-LHC) starting in 2030, ATLAS will upgrade both the on- and off-detector TileCal electronics during the 2026–2030 shutdown. The new systems must support faster 1 MHz triggers while withstanding greater radiation and particle density. The upgraded system will digitize PMT signals from each TileCal cell and transmit them directly to back-end electronics for signal reconstruction, storage, and delivery to the Level-1 trigger system at 40 MHz. This will improve the precision of calorimeter signals available for triggering and enable implementation of more sophisticated trigger algorithms. The electronic upgrades will also contribute to the data integrity and system reliability. New electronics prototypes were tested in laboratories as well as in beam tests. Results of the calorimeter calibration and performance during LHC Run-3 are summarized, the main features and beam test results obtained with the new front-end electronics are also presented
The Miniball gamma-ray spectrometer
No full textThe Miniball gamma-ray spectrometer is an experimental setup at HIE-ISOLDE (High-Intensity and Energy project of ISOLDE). Miniball has been employed for the past two decades to study properties of radioactive nuclei, exploiting accelerated beams of radioactive ions provided by the HIE-ISOLDE facility
Keeping It Renormalizable: Minimal Baryogenesis induced Asymmetric Dark Matter
No full textMany asymmetric dark matter scenarios have been proposed to date. Among them, perhaps the most motivated ones are those in which the dark matter asymmetry is induced from the baryon/lepton asymmetries via chemical equilibration without any new sources of CP violation. However, most of the models put forward along these lines have been excluded by now and/or are based on complicated setups. In this letter, we present a new, simple, and viable scenario. It assumes only two new fields: a scalar singlet and an inert scalar doublet, and is based only on renormalizable interactions, that slowly generate the dark matter asymmetry from the Standard Model Higgs asymmetry. The model allows for the direct detection of dark matter in the upcoming generation of experiments, and the inert doublet is predicted to be light enough to be potentially produced and observed at the LHC and future colliders,