Advantages of Al based GEM detector aimed at plasma soft-semi hard X-ray radiation imaging

Development of gaseous detectors, more specifically Gas Electron Multiplier (GEM) based detectors, for application at tokamak plasma radiation monitoring/imaging in Soft−Semi Hard X-ray (S−SH) region is an ongoing research activity aiming to deliver valuable information on plasma shape, magnetic configuration, non-axisymmetry phenomena of the plasma, etc. Wide radiation range and brightness of plasma radiation impose some restrictions on choice of materials in the detecting chamber, as their interaction with the incident radiation may disrupt original signals. This work proposes usage of aluminum as GEM foils electrodes for the first time. The detector based on these foils was constructed and examined. The operational characteristics and spectral capabilities of such detector were compared with the ones based on the standard (commonly used) copper GEM foils. The laboratory tests were performed using X-ray tube and 55Fe sources to examine detectors’ capabilities in energy-resolved imaging. Additionally, simulations of origin and number of the generated electrons, which determine the detector signal, were performed for Al and Cu GEM foils for a wide energy range of incident photons. The experimental and modelling data demonstrated that Cu based GEM detector produces higher parasitic signal than Al one necessitating total elimination of copper from detector’s chamber

Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Measurement of the ratios of branching fractions R(D∗)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

The ratios of branching fractions $\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu})$ and $\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu})$ are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb${ }^{-1}$ of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}$. The measured values are $\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024$ and $\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066$, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is $\rho=-0.43$. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

Feasibility tests of RoCE for the cluster-based event building in LHCb

This paper evaluates the utilization of RDMA over Converged Ethernet (RoCE) for the Run3 LHCb event building at CERN. The acquisition system of the detector will collect partial data from approximately 1000 separate detector streams. Total estimated throughput equals 40 terabits per second. Full events will be assembled for subsequent processing and data selection in the filtering farm of the online trigger. As a result, inter-node large-throughput transmissions with a combination of 100 and 25 Gigabit-per-second will be essential features of the system. Therefore, the data exchange mechanism of the cluster must utilize memory-lightweight data transmission protocols. In this work, the RoCE high-throughput kernel bypass Ethernet-based protocol is benchmarked as an applicable technology for the event building network. CPU and memory bandwidth utilization for RoCE-based data transmissions is investigated and discussed. A comparison of RoCE with InfiniBand protocol is presented. Preliminary performance results are discussed with the selected network hardware supporting the protocol. Relevant utilization and interoperability issues are detailed along with lessons learned along the road

25th International Conference on Computing in High Energy & Nuclear Physics

This paper evaluates the real-time distribution of data over Ethernet for the upgraded LHCb data acquisition cluster at CERN. The total estimated throughput of the system is 32 Terabits per second. After the events are assembled, they must be distributed for further data selection to the filtering farm of the online trigger. High-throughput and very low overhead transmissions will be an essential feature of such a system. In this work RoCE high-throughput Ethernet protocol and Ethernet flow control algorithms have been used to implement lossless events distribution. To generate LHCb-like traffic, a custom benchmark has been implemented. It was used to stress-test the selected Ethernet networks and to check resilience to uneven workload distribution. Performance tests were made with selected evaluation clusters. 100 Gb/s and 25 Gb/s links were used. Performance results and overall evaluation of this Ethernet-based approach are discussed

Feasibility tests of RoCE for the cluster-based event building in LHCb

This paper evaluates the utilization of RDMA over Converged Ethernet (RoCE) for the Run3 LHCb event building at CERN. The acquisition system of the detector will collect partial data from approximately 1000 separate detector streams. Total estimated throughput equals 40 terabits per second. Full events will be assembled for subsequent processing and data selection in the filtering farm of the online trigger. As a result, inter-node large-throughput transmissions with a combination of 100 and 25 Gigabit-per-second will be essential features of the system. Therefore, the data exchange mechanism of the cluster must utilize memory-lightweight data transmission protocols. In this work, the RoCE high-throughput kernel bypass Ethernet-based protocol is benchmarked as an applicable technology for the event building network. CPU and memory bandwidth utilization for RoCE-based data transmissions is investigated and discussed. A comparison of RoCE with InfiniBand protocol is presented. Preliminary performance results are discussed with the selected network hardware supporting the protocol. Relevant utilization and interoperability issues are detailed along with lessons learned along the road

Network simulation of a 40 MHz event building system for the LHCb experiment

The LHCb experiment will be upgraded in 2021 and a new trigger-less readout system will be implemented. In the upgraded system, both event building (EB) and event selection will be performed in software for every collision produced in every bunch-crossing of the LHC. In order to transport the full data rate of 32 Tb/s we will use state of the art off-the-shelf network technologies, e.g. InfiniBand EDR. The full event building system will require around 500 nodes interconnected together via a non blocking topology, because of the size of the system it very difficult to test at production scale, before the actual procurement. We resort therefore to network simulations as a powerful tool for finding the optimal configuration. We developed an accurate low level description of an InfiniBand based network with event building like traffic. We will present a full scale simulation of a possible implementation of the LHCb EB network

Changing patterns of urologic emergency visits and admissions during the COVID-19 pandemic: a retrospective, multicenter, nationwide study

IntroductionWe aimed to examine the change in the number and severity of visits to the emergency departments (EDs) and subsequent admissions for urgent urologic conditions in the early stage of the coronavirus disease 2019 (COVID-19) pandemic in Poland.Material and methodsWe evaluated data from 13 urologic centers in Poland and compared the number of visits to the EDs and subsequent admissions before and after the advent of COVID-19 in 2020, and before and after the escalating national restrictions. Furthermore, data on types of urologic complaints, crucial laboratory parameters, and post-admission procedures were analyzed.ResultsIn total 1,696 and 2,187 urologic visits (22.45% decrease) and 387 and 439 urologic urgent admissions (11.85% decrease) were reported in given periods in 2020 and 2019, respectively. The year-over-year difference in daily mean visits was clear (36.1 vs. 46.5; p &lt; 0.001). Declines were seen in all complaints but device malfunction. In 2020 daily mean visits and admissions decreased from 40.9 and 9.6 before lockdowns to 30.9 (p &lt; 0.001) and 6.9 (p = 0.001) after severe restrictions, respectively. There was a trend towards more negative laboratory parameter profiles in 2020, with patients who visited the EDs after severe restrictions having twice as high median levels of C-reactive protein (15.39 vs. 7.84, p = 0.03).ConclusionsThe observed declines in ED visits and admissions were apparent with the significant effect of national lockdowns. Our results indicate that some of the patients requiring urgent medical help did not appear at the ED or came later than they would have done before the pandemic, presenting with more severe complaints.</jats:sec