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production in pp collisions at TeV
No full textInternational audienceThe measurement of production in pp collisions at TeV is presented. The measurement is performed at midrapidity in both minimum-bias and high-multiplicity pp collisions at TeV. The is reconstructed via its weak-decay topology in the decay channel with . In a novel approach, the neutral pion is reconstructed by combining photons that convert in the detector material with photons measured in the calorimeters. The transverse-momentum () distributions of the and its rapidity densities ddy in both event classes are reported. The spectrum in minimum-bias collisions is compared to QCD-inspired event generators. The ratio of to previously measured baryons is in good agreement with calculations from the Statistical Hadronization Model. The high efficiency and purity of the novel reconstruction method for presented here will enable future studies of the interaction of with protons in the context of femtoscopic measurements, which could be crucial for understanding the equation of state of neutron stars
Does privacy regulation harm content providers? A longitudinal analysis of the impact of the GDPR
No full textFNEGE 1*, ABS 4*International audienceConcerns that the European General Data Protection Regulation (GDPR) would adversely affect the ability of news and media websites to create new quality content have not been thoroughly investigated in the literature. We construct a longitudinal data set of European Union (EU) and U.S. news and media websites to study how online content providers responded to the GDPR over time and whether potential restrictions on online tracking enforced by the regulation affected their downstream outcomes. We find robust evidence that both EU and U.S. news and media websites responded to the regulation by altering their data collection practices, but did so differently, with EU websites reducing tracking and implementing consent mechanisms at higher rates than their U.S. counterparts. Although we detect a reduction in average page views per user on EU relative to U.S. websites, we do not find evidence of negative impacts, in both the short and long term, on EU websites’ provision of new content or on several proxies for quality of that content, such as social media engagement metrics, various traffic measures, and articles’ text analytics. We also find no evidence of differences in survival rates across EU and U.S. news and media websites, and no evidence that monetization strategies changed at higher rates on EU relative to U.S. websites. The analysis suggests that EU online content providers did implement changes to their data collection practices in response to the GDPR but were able to use data minimization and consent mechanism strategies that allowed them to keep producing content and engage audiences at degrees on par with their U.S. counterparts
Harnessing ecological niche modeling of Listeria monocytogenes for biopreservation system engineering
No full textInternational audienceBiopreservation is a microbiome engineering technology based on the use of microorganisms as protective cultures and/or their metabolites, which can be used to mitigate the presence of pathogens in food. This study explores the potential of ecological niche modeling to guide the selection of biopreservation candidates. A luminescent strain of Listeria monocytogenes was utilized in a multivariate high-throughput competition assay, assessing a combination of abiotic factors (i.e. glucose, NaCl, pH in a factorial design) and biotic variables (i.e. various competing microorganisms). The resulting data were analyzed using two parallel methods: k-means clustering and Response Surface Modeling (RSM). Integrating the outputs of these approaches allowed for grouping competitors based on both inhibition strength and niche modeling characteristics. Competitors were categorized into five groups, distinguished by their inhibition levels against L. monocytogenes and the shape of their response surfaces, with some groups displaying complementary features. Weighted Niche Reduction (WNR) calculations derived from model predictions identified the strain combination Carnobacterium maltaromaticum CP14 and Leuconostoc pseudomesenteroides PTF6 as having enhanced inhibitory properties. This study highlights promising possibilities for the bottom-up engineering of synthetic communities for biopreservation applications
Preliminary design and simulation for CEPC fast luminosity monitor detector based on 4H-SiC
No full textInternational audienceThe Circular Electron-Positron Collider (CEPC), a next-generation high-luminosity collider, employs a crab waist scheme to achieve ultrahigh luminosity at Higgs mode. Owing to the extremely small beam size, the luminosity is highly sensitive to the stability of final focusing elements, where mechanical vibrations (e.g. ground motion) may induce beam offsets and luminosity degradation. To address this, a luminosity-driven dithering system is implemented for horizontal beam stabilization. In this work, we develop an optimized 4H-SiC fast luminosity detector scheme using an array of radiation detectors with picosecond time resolution positioned at critical locations. By using self-development software RAdiation SEmiconductoR (RASER), we optimize the active area of the detector to achieve 2% relative precision at 1~kHz. Furthermore, the Total Sample Current (TSC) exhibits a near-linear correlation with luminosity attenuation, enabling real-time luminosity monitoring
Hypernuclei with Neural Network Quantum States
No full textInternational audienceLeveraging complementary machine-learning-based approaches, we compute properties of - and -shell hypernuclei - including binding energies, single-particle densities, and radii - starting from the individual interactions among their constituents. These interactions are modeled using an improved leading-order pionless effective field theory expansion, with coefficients determined via a Gaussian Process framework anchored on virtually exact few-body techniques. We solve the many-body Schrödinger equation using a variational Monte Carlo method based on neural network quantum states, extending it for the first time to include particles alongside protons and neutrons. The predicted binding energies show remarkably good agreement with experimental results, given the simplicity of the input Hamiltonian. We also confirm the experimentally observed shrinkage of the proton radius in Li compared to its parent nucleus, Li. This work paves the way for an ab initio description of medium-mass and heavy hypernuclei, as well as for understanding the onset of strange degrees of freedom in the core of neutron stars
Cryogenic light detectors with thermal signal amplification for search experiments
No full textInternational audienceAs a step towards the realization of cryogenic-detector experiments to search for neutrinoless double-beta decay (such as CROSS, BINGO, and CUPID), we investigated a batch of 10 Ge light detectors (LDs) assisted by Neganov-Trofimov-Luke (NTL) signal amplification. Each LD was assembled with a large cubic light-emitting crystal (45 mm side) using the recently developed CROSS mechanical structure. The detector array was operated at milli-Kelvin temperatures in a pulse-tube cryostat at the Canfranc underground laboratory in Spain. We achieved good performance with scintillating bolometers from CROSS, made of LiMoO crystals and used as reference detectors of the setup, and with all LDs tested (except for a single device that encountered an electronics issue). No leakage current was observed for 8 LDs with an electrode bias up to 100 V. Operating the LDs at an 80 V electrode bias applied in parallel, we obtained a gain of around 9 in the signal-to-noise ratio of these devices, allowing us to achieve a baseline noise RMS of (10 eV). Thanks to the strong current polarization of the temperature sensors, the time response of the devices was reduced to around half a millisecond in rise time. The achieved performance of the LDs was extrapolated via simulations of pile-up rejection capability for several configurations of the CUPID detector structure. Despite the sub-optimal noise conditions of the LDs (particularly at high frequencies), we demonstrated that the NTL technology provides a viable solution for background reduction in CUPID
Sensitivity of the Hyper-Kamiokande experiment to neutrino oscillation parameters using acceleration neutrinos
No full textInternational audienceThis paper describes the analysis to estimate the sensitivity of the Hyper-Kamiokande experiment to long-baseline neutrino oscillation parameters using accelerator (anti)neutrinos. Results are presented for the CPV discovery sensitivity and precision measurements of the oscillation parameters , , and . With the assumed Hyper-Kamiokande running plan, a CPV discovery is possible in less than three years in the case of maximal CPV and known MO.In the absence of external constraints on the MO, considering the MO sensitivity of the Hyper-Kamiokande measurement using atmospheric neutrinos, the time for a CPV discovery could be estimated to be around six years. Using the nominal final exposure of protons on target, corresponding to 10 years, with a ratio of 1:3 in neutrino to antineutrino beam mode, we expect to select approximately 10000 charged current, quasi-elastic-like, muon neutrino events, and a similar number of muon anti-neutrino events. In the electron (anti)neutrino appearance channels, we expect approximately 2000 charged current, quasi-elastic-like electron neutrino events and 800 electron antineutrino events. These larges event samples will allow Hyper-Kamiokande to exclude CP conservation at the significance level for over 60% of the possible true values of
The High Voltage Splitter board for the JUNO SPMT system
No full textInternational audienceThe Jiangmen Underground Neutrino Observatory (JUNO) in southern China is designed to study neutrinos from nuclear reactors and natural sources to address fundamental questions in neutrino physics. Achieving its goals requires continuous operation over a 20-year period. The small photomultiplier tube (small PMT or SPMT) system is a subsystem within the experiment composed of 25600 3-inch PMTs and their associated readout electronics. The High Voltage Splitter (HVS) is the first board on the readout chain of the SPMT system and services the PMTs by providing high voltage for biasing and by decoupling the generated physics signal from the high-voltage bias for readout, which is then fed to the front-end board. The necessity to handle high voltage, manage a large channel count, and operate stably for 20 years imposes significant constraints on the physical design of the HVS. This paper serves as a comprehensive documentation of the HVS board: its role in the SPMT readout system, the challenges in its design, performance and reliability metrics, and the methods employed for production and quality control
Redshift Assessment Infrastructure Layers (RAIL): Rubin-era photometric redshift stress-testing and at-scale production
No full textInternational audienceVirtually all extragalactic use cases of the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) require the use of galaxy redshift information, yet the vast majority of its sample of tens of billions of galaxies will lack high-fidelity spectroscopic measurements thereof, instead relying on photometric redshifts (photo-) subject to systematic imprecision and inaccuracy best encapsulated by photo- probability density functions (PDFs). We present the version 1 release of Redshift Assessment Infrastructure Layers (RAIL), an open source Python library for at-scale probabilistic photo- estimation, initiated by the LSST Dark Energy Science Collaboration (DESC) with contributions from the LSST Interdisciplinary Network for Collaboration and Computing (LINCC) Frameworks team. RAIL's three subpackages provide modular tools for end-to-end stress-testing, including a forward modeling suite to generate realistically complex photometry, a unified API for estimating per-galaxy and ensemble redshift PDFs by an extensible set of algorithms, and built-in metrics of both photo- PDFs and point estimates. RAIL serves as a flexible toolkit enabling the derivation and optimization of photo- data products at scale for a variety of science goals and is not specific to LSST data. We thus describe to the extragalactic science community, including and beyond Rubin the design and functionality of the RAIL software library so that any researcher may have access to its wide array of photo- characterization and assessment tools
Euclid preparation. The impact of redshift interlopers on the two-point correlation function analysis
No full textInternational audienceThe Euclid survey aims to measure the spectroscopic redshift of emission-line galaxies by identifying the H line in their slitless spectra. This method is sensitive to the signal-to-noise ratio of the line, as noise fluctuations or other strong emission lines can be misidentified as H, depending on redshift. These effects lead to catastrophic redshift errors and the inclusion of interlopers in the sample. We forecast the impact of such redshift errors on galaxy clustering measurements. In particular, we study the effect of interloper contamination on the two-point correlation function (2PCF), the growth rate of structures, and the Alcock-Paczynski (AP) parameters. We analyze 1000 synthetic spectroscopic catalogues, the EuclidLargeMocks, designed to match the area and selection function of the Data Release 1 (DR1) sample. We estimate the 2PCF of the contaminated catalogues, isolating contributions from correctly identified galaxies and from interlopers. We explore different models with increasing complexity to describe the measured 2PCF at fixed cosmology. Finally, we perform a cosmological inference and evaluate the systematic error on the inferred , and values associated with different models. Our results demonstrate that a minimal modelling approach, which only accounts for an attenuation of the clustering signal regardless of the type of contaminants, is sufficient to recover the correct values of , , and at DR1. The accuracy and precision of the estimated AP parameters are largely insensitive to the presence of interlopers. The adoption of a minimal model induces a 1%-3% systematic error on the growth rate of structure estimation, depending on the redshift. However, this error remains smaller than the statistical error expected for the Euclid DR1 analysis