Design and performance of the field cage for the XENONnT experiment

arXiv preprint arXiv:2403.14878

This paper details the first application of a software tagging algorithm to reduce radon-induced backgrounds in liquid noble element time projection chambers, such as XENON1T and XENONnT. The convection velocity field in XENON1T was mapped out using and events, and the root-mean-square convection speed was measured to be cm/s. Given this velocity field, background events can be tagged when they are followed by and decays, or preceded by decays. This was achieved by propagating a point cloud as directed by the velocity field, and searching for and decays or decays within a volume defined by the point cloud. In XENON1T, this tagging system achieved a background reduction of with an exposure loss of . The tagging algorithm was also used to produce a population of tagged events with a large enhancement in the fraction. We show that the performance can be improved in XENONnT, and that the performance of such a software-tagging approach can be expected to be further improved in a diffusion-limited scenario. Finally, a similar method might be useful to tag the cosmogenic background, which is relevant to the search for neutrinoless double-beta decay.

EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS

This paper presents a study of Z→ llγ decays with the ATLAS detector at the Large Hadron Collider. The analysis uses a proton–proton data sample corresponding to an integrated luminosity of 20.2 fb− 1 collected at a centre-of mass energy√ s= 8 TeV. Integrated fiducial cross-sections together with normalised differential fiducial cross-sections, sensitive to the kinematics of final-state QED radiation, are obtained. The results are found to be in agreement with state of-the-art predictions for final-state QED radiation. First measurements of Z→ llγ γ decays are also reported

Computing and Software for Big Science

The need for large-scale production of highly accurate simulated event samples for the extensive physics programme of the ATLAS experiment at the Large Hadron Collider motivates the development of new simulation techniques. Building on the recent success of deep learning algorithms, variational autoencoders and generative adversarial networks are investigated for modelling the response of the central region of the ATLAS electromagnetic calorimeter to photons of various energies. The properties of synthesised showers are compared with showers from a full detector simulation using geant4. Both variational autoencoders and generative adversarial networks are capable of quickly simulating electromagnetic showers with correct total energies and stochasticity, though the modelling of some shower shape distributions requires more refinement. This feasibility study demonstrates the potential of using such algorithms for ATLAS fast calorimeter simulation in the future and shows a possible way to complement current simulation techniques.

Physics Letters B

A search for non-resonant Higgs boson pair production, as predicted by the Standard Model, is presented, where one of the Higgs bosons decays via the H→ b b channel and the other via one of the H→ W W⁎/Z Z⁎/τ τ channels. The analysis selection requires events to have at least two b-tagged jets and exactly two leptons (electrons or muons) with opposite electric charge in the final state. Candidate events consistent with Higgs boson pair production are selected using a multi-class neural network discriminant. The analysis uses 139 fb− 1 of pp collision data recorded at a centre-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. An observed (expected) upper limit of 1.2 (0.9− 0.3+ 0.4) pb is set on the non-resonant Higgs boson pair production cross-section at 95% confidence level, which is equivalent to 40 (29− 9+ 14) times the value predicted in the Standard Model.

Lassa virus (LASV) outbreaks in West Africa pose a significant public health threat. We investigated the infection phenotype and transmission (horizontal and vertical) of LASV strain Ba366 in its natural host, Mastomys natalensis. Viral RNA levels in body fluids, virus titers in organs and antibody presence in blood were analyzed. In adults and 2-week-old animals, LASV caused transient infections with subsequent seroconversion. However, neonates and younger juveniles exhibited persistent infections lasting up to 16 months despite antibody presence. LASV was detected in various body fluids, organs, and cell types, primarily in lung, kidney, and gonadal epithelial cells. Despite the systemic virus presence, no pathological alterations in organs were observed. Infected individuals efficiently transmitted the virus throughout their lives. Our findings underscore the crucial role of persistently infected individuals, particularly infected females and their progeny, in LASV dissemination within the host population.

arXiv preprint arXiv:2403.14878

This paper details the first application of a software tagging algorithm to reduce radon-induced backgrounds in liquid noble element time projection chambers, such as XENON1T and XENONnT. The convection velocity field in XENON1T was mapped out using and events, and the root-mean-square convection speed was measured to be cm/s. Given this velocity field, background events can be tagged when they are followed by and decays, or preceded by decays. This was achieved by propagating a point cloud as directed by the velocity field, and searching for and decays or decays within a volume defined by the point cloud. In XENON1T, this tagging system achieved a background reduction of with an exposure loss of . The tagging algorithm was also used to produce a population of tagged events with a large enhancement in the fraction. We show that the performance can be improved in XENONnT, and that the performance of such a software-tagging approach can be expected to be further improved in a diffusion-limited scenario. Finally, a similar method might be useful to tag the cosmogenic background, which is relevant to the search for neutrinoless double-beta decay.

The Astronomical Journal

Firmamento (https://firmamento. hosting. nyu. edu) is a new-concept, web-based, and mobile-friendly data analysis tool dedicated to multifrequency/multimessenger emitters, as exemplified by blazars. Although initially intended to support a citizen researcher project at New York University–Abu Dhabi, Firmamento has evolved to be a valuable tool for professional researchers due to its broad accessibility to classical and contemporary multifrequency open data sets. From this perspective Firmamento facilitates the identification of new blazars and other multifrequency emitters in the localization uncertainty regions of sources detected by current and planned observatories such as Fermi-LAT, Swift, eROSITA, CTA, ASTRI Mini-Array, LHAASO, IceCube, KM3Net, SWGO, etc. The multiepoch and multiwavelength data that Firmamento retrieves from over 90 remote and local catalogs and databases can be used to …

The European Physical Journal C

Xenon dual-phase time projections chambers (TPCs) have proven to be a successful technology in studying physical phenomena that require low-background conditions. With of liquid xenon (LXe) in the TPC baseline design, DARWIN will have a high sensitivity for the detection of particle dark matter, neutrinoless double beta decay (\(0\upnu\upbeta\upbeta\)), and axion-like particles (ALPs). Although cosmic muons are a source of background that cannot be entirely eliminated, they may be greatly diminished by placing the detector deep underground. In this study, we used Monte Carlo simulations to model the cosmogenic background expected for the DARWIN observatory at four underground laboratories: Laboratori Nazionali del Gran Sasso (LNGS), Sanford Underground Research Facility (SURF), Laboratoire Souterrain de Modane (LSM) and SNOLAB. We present here the results of simulations performed to …

American Astronomical Society Meeting Abstracts

The Compton Spectrometer and Imager (COSI) is a NASA Small Explorer (SMEX) satellite mission scheduled for launch in 2027. COSI is a wide-field Compton telescope designed to survey the entire gamma-ray sky at 0.2-5 MeV with excellent energy resolution, providing powerful observations of sources with gamma-ray line emissions. COSI will provide key insights into the creation and evolution of the elements and the mysterious origin of Galactic positrons. In particular, COSI will reveal the core-collapse supernova activity in the Milky Way and determine the role of various stellar processes in massive stars by mapping the diffuse gamma-ray emission from 26 Al and 60 Fe in the Galaxy as a whole, and in individual star groups. It will uncover young and hidden supernova remnants by performing a survey of 44 Ti line emissions and probe the nuclear physics in the core of these supernovae through detailed …

arXiv preprint arXiv:2403.14878

This paper details the first application of a software tagging algorithm to reduce radon-induced backgrounds in liquid noble element time projection chambers, such as XENON1T and XENONnT. The convection velocity field in XENON1T was mapped out using and events, and the root-mean-square convection speed was measured to be cm/s. Given this velocity field, background events can be tagged when they are followed by and decays, or preceded by decays. This was achieved by propagating a point cloud as directed by the velocity field, and searching for and decays or decays within a volume defined by the point cloud. In XENON1T, this tagging system achieved a background reduction of with an exposure loss of . The tagging algorithm was also used to produce a population of tagged events with a large enhancement in the fraction. We show that the performance can be improved in XENONnT, and that the performance of such a software-tagging approach can be expected to be further improved in a diffusion-limited scenario. Finally, a similar method might be useful to tag the cosmogenic background, which is relevant to the search for neutrinoless double-beta decay.

Physical review letters

The first evidence for the Higgs boson decay to a Z boson and a photon is presented, with a statistical significance of 3.4 standard deviations. The result is derived from a combined analysis of the searches performed by the ATLAS and CMS Collaborations with proton-proton collision datasets collected at the CERN Large Hadron Collider (LHC) from 2015 to 2018. These correspond to integrated luminosities of around 140 fb− 1 for each experiment, at a center-of-mass energy of 13 TeV. The measured signal yield is 2.2±0.7 times the standard model prediction, and agrees with the theoretical expectation within 1.9 standard deviations.

arXiv preprint arXiv:2403.14878

This paper details the first application of a software tagging algorithm to reduce radon-induced backgrounds in liquid noble element time projection chambers, such as XENON1T and XENONnT. The convection velocity field in XENON1T was mapped out using and events, and the root-mean-square convection speed was measured to be cm/s. Given this velocity field, background events can be tagged when they are followed by and decays, or preceded by decays. This was achieved by propagating a point cloud as directed by the velocity field, and searching for and decays or decays within a volume defined by the point cloud. In XENON1T, this tagging system achieved a background reduction of with an exposure loss of . The tagging algorithm was also used to produce a population of tagged events with a large enhancement in the fraction. We show that the performance can be improved in XENONnT, and that the performance of such a software-tagging approach can be expected to be further improved in a diffusion-limited scenario. Finally, a similar method might be useful to tag the cosmogenic background, which is relevant to the search for neutrinoless double-beta decay.

Solid-State Electronics

Understanding trap dynamics and formation of localized temperature hot-spots due to self-heating is crucial for the design optimization of emerging vertical junctionless nanowire transistors (VNWFET). This work investigates the operation of an 18 nm VNWFET technology, for the first time, leveraging pulsed current–voltage measurements. Results indicate increased trap activity as well as electrothermal effects with increasing pulse width. Multiphysics simulations are then used to provide a deeper insight into the nanoscale transport of the VNWFETs. We then incorporated these effects into the SPICE-compatible VNWFET compact model and further investigated the behaviors of trapping and electrothermal effects in basic logic circuits based on the compact model simulation.

The European Physical Journal C

This work investigates static and dynamical quark star properties within a holographic model. We solve the Tolman–Oppenheimer–Volkoff equations for the quark matter equation of state obtained from the brane configuration. We determine the mass-radius diagram for a range of model parameters and compare with recent NICER observational data for the pulsars PSR J and PSR J Motivated by the GW170817 event detected by the LIGO-Virgo collaboration, we also calculate the tidal deformability parameter obtained for each component of the binary star system. We show that quark stars composed of flavor-independent quark matter derived from the holographic model are not able to satisfy simultaneously the LIGO-Virgo and NICER astrophysical bounds.

The European Physical Journal C

The inclusive Higgs boson production cross-section is measured in the di-photon and the decay channels using 31.4 and 29.0 fb of pp collision data respectively, collected with the ATLAS detector at a centre-of-mass energy of  . To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the channel’s detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are   fb, and   fb, in agreement with the corresponding Standard Model predictions of  fb and  fb. Assuming Standard Model acceptances and branching fractions for the two channels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of  pb and  pb at 13.6  from the di-photon and  …

The European Physical Journal C

Measurements of the differential production cross-sections of prompt and non-prompt and mesons with transverse momenta between 8 and 360 GeV and rapidity in the range are reported. Furthermore, measurements of the non-prompt fractions of and , and the prompt and non-prompt -to- production ratios, are presented. The analysis is performed using 140 fb of  TeV pp collision data recorded by the ATLAS detector at the LHC during the years 2015–2018.

The European Physical Journal C

A search for the production of single-top-quarks in association with missing energy is performed in proton–proton collisions at a centre-of-mass energy of with the ATLAS experiment at the large hadron collider using data collected in 2012, corresponding to an integrated luminosity of  fb. In this search, the boson from the top quark is required to decay into an electron or a muon and a neutrino. No deviation from the standard model prediction is observed, and upper limits are set on the production cross-section for resonant and non-resonant production of an invisible exotic state in association with a right-handed top quark. In the case of resonant production, for a spin- resonance with a mass of  GeV, an effective coupling strength above is excluded at 95 confidence level for the top quark and an invisible spin- state with mass between and  GeV. In the case of non-resonant production, an effective …

The European Physical Journal C

This paper presents for the first time a precise measurement of the production properties of the Z boson in the full phase space of the decay leptons. This is in contrast to the many previous precise unfolded measurements performed in the fiducial phase space of the decay leptons. The measurement is obtained from proton–proton collision data collected by the ATLAS experiment in 2012 at TeV at the LHC and corresponding to an integrated luminosity of 20.2 fb. The results, based on a total of 15.3 million Z-boson decays to electron and muon pairs, extend and improve a previous measurement of the full set of angular coefficients describing Z-boson decay. The double-differential cross-section distributions in Z-boson transverse momentum  and rapidity  are measured in the pole region, defined as GeV, over the range . The total uncertainty of the normalised cross-section measurements in the peak region of the …

The European Physical Journal C

The compatibility of W-boson mass measurements performed by the ATLAS, LHCb, CDF, and D0 experiments is studied using a coherent framework with theory uncertainty correlations. The measurements are combined using a number of recent sets of parton distribution functions (PDF), and are further combined with the average value of measurements from the Large Electron–Positron collider. The considered PDF sets generally have a low compatibility with a suite of global rapidity-sensitive Drell–Yan measurements. The most compatible set is CT18 due to its larger uncertainties. A combination of all measurements yields a value of  MeV with the CT18 set, but has a probability of compatibility of 0.5% and is therefore disfavoured. Combinations are performed removing each measurement individually, and a 91% probability of compatibility is obtained when the CDF measurement is removed. The …

The European Physical Journal C

The inclusive Higgs boson production cross-section is measured in the di-photon and the decay channels using 31.4 and 29.0 fb of pp collision data respectively, collected with the ATLAS detector at a centre-of-mass energy of  . To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the channel’s detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are   fb, and   fb, in agreement with the corresponding Standard Model predictions of  fb and  fb. Assuming Standard Model acceptances and branching fractions for the two channels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of  pb and  pb at 13.6  from the di-photon and  …

The European Physical Journal C

Measurements of the differential production cross-sections of prompt and non-prompt and mesons with transverse momenta between 8 and 360 GeV and rapidity in the range are reported. Furthermore, measurements of the non-prompt fractions of and , and the prompt and non-prompt -to- production ratios, are presented. The analysis is performed using 140 fb of  TeV pp collision data recorded by the ATLAS detector at the LHC during the years 2015–2018.

The European Physical Journal C

A search for the production of single-top-quarks in association with missing energy is performed in proton–proton collisions at a centre-of-mass energy of with the ATLAS experiment at the large hadron collider using data collected in 2012, corresponding to an integrated luminosity of  fb. In this search, the boson from the top quark is required to decay into an electron or a muon and a neutrino. No deviation from the standard model prediction is observed, and upper limits are set on the production cross-section for resonant and non-resonant production of an invisible exotic state in association with a right-handed top quark. In the case of resonant production, for a spin- resonance with a mass of  GeV, an effective coupling strength above is excluded at 95 confidence level for the top quark and an invisible spin- state with mass between and  GeV. In the case of non-resonant production, an effective …

The European Physical Journal C

This paper presents for the first time a precise measurement of the production properties of the Z boson in the full phase space of the decay leptons. This is in contrast to the many previous precise unfolded measurements performed in the fiducial phase space of the decay leptons. The measurement is obtained from proton–proton collision data collected by the ATLAS experiment in 2012 at TeV at the LHC and corresponding to an integrated luminosity of 20.2 fb. The results, based on a total of 15.3 million Z-boson decays to electron and muon pairs, extend and improve a previous measurement of the full set of angular coefficients describing Z-boson decay. The double-differential cross-section distributions in Z-boson transverse momentum  and rapidity  are measured in the pole region, defined as GeV, over the range . The total uncertainty of the normalised cross-section measurements in the peak region of the …

The European Physical Journal C

We explore a novel class of Yang–Baxter deformed backgrounds (J High Energy Phys 01:056, 2021) which exhibit a non-chaotic dynamics for (super)strings propagating over it. We explicitly use the Kovacic’s algorithm in order to establish non-chaotic dynamics of string models over these deformed backgrounds. This analysis is complemented with numerical techniques whereby we probe the classical phase space of these (semi)classical strings and calculate various chaos indicators, such as, the Poincaré sections and the Lyapunov exponents. We find compatibility between the two approaches. Nevertheless, our analysis does not ensure integrability; rather, it excludes the possibility of non-integrability for the given string embeddings.

The European Physical Journal C

The inclusive Higgs boson production cross-section is measured in the di-photon and the decay channels using 31.4 and 29.0 fb of pp collision data respectively, collected with the ATLAS detector at a centre-of-mass energy of  . To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the channel’s detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are   fb, and   fb, in agreement with the corresponding Standard Model predictions of  fb and  fb. Assuming Standard Model acceptances and branching fractions for the two channels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of  pb and  pb at 13.6  from the di-photon and  …

The European Physical Journal C

Measurements of the differential production cross-sections of prompt and non-prompt and mesons with transverse momenta between 8 and 360 GeV and rapidity in the range are reported. Furthermore, measurements of the non-prompt fractions of and , and the prompt and non-prompt -to- production ratios, are presented. The analysis is performed using 140 fb of  TeV pp collision data recorded by the ATLAS detector at the LHC during the years 2015–2018.

The European Physical Journal C

A search for the production of single-top-quarks in association with missing energy is performed in proton–proton collisions at a centre-of-mass energy of with the ATLAS experiment at the large hadron collider using data collected in 2012, corresponding to an integrated luminosity of  fb. In this search, the boson from the top quark is required to decay into an electron or a muon and a neutrino. No deviation from the standard model prediction is observed, and upper limits are set on the production cross-section for resonant and non-resonant production of an invisible exotic state in association with a right-handed top quark. In the case of resonant production, for a spin- resonance with a mass of  GeV, an effective coupling strength above is excluded at 95 confidence level for the top quark and an invisible spin- state with mass between and  GeV. In the case of non-resonant production, an effective …

The European Physical Journal C

This paper presents for the first time a precise measurement of the production properties of the Z boson in the full phase space of the decay leptons. This is in contrast to the many previous precise unfolded measurements performed in the fiducial phase space of the decay leptons. The measurement is obtained from proton–proton collision data collected by the ATLAS experiment in 2012 at TeV at the LHC and corresponding to an integrated luminosity of 20.2 fb. The results, based on a total of 15.3 million Z-boson decays to electron and muon pairs, extend and improve a previous measurement of the full set of angular coefficients describing Z-boson decay. The double-differential cross-section distributions in Z-boson transverse momentum  and rapidity  are measured in the pole region, defined as GeV, over the range . The total uncertainty of the normalised cross-section measurements in the peak region of the …

The European Physical Journal C

At the Large Hadron Collider (LHC), absolute luminosity calibrations obtained by the van der Meer (vdM) method are affected by the mutual electromagnetic interaction of the two beams. The colliding bunches experience relative orbit shifts, as well as optical distortions akin to the dynamic- effect, that both depend on the transverse beam separation and must therefore be corrected for when deriving the absolute luminosity scale. In the vdM regime, the beam–beam parameter is small enough that the orbit shift can be calculated analytically. The dynamic- corrections to the luminometer calibrations, however, had until the end of Run 2 been estimated in the linear approximation only. In this report, the influence of beam–beam effects on the vdM-based luminosity scale is quantified, together with the associated systematic uncertainties, by means of simulations that fully take into account the non-linearity of the beam …

The European Physical Journal C

We describe a method to generate scalar–tensor theories with Weyl symmetry, starting from arbitrary purely metric higher derivative gravity theories. The method consists in the definition of a conformally-invariant metric, that is a rank (0, 2)-tensor constructed out of the metric tensor and the scalar field. This new object has zero conformal weight and is given by, where is the conformal dimension of the scalar. As has conformal dimension of 2, the resulting tensor is trivially a conformal invariant. Then, the generated scalar–tensor theory, which we call the Weyl uplift of the original purely metric theory, is obtained by replacing the metric by in the action that defines the original theory. This prescription allowed us to define the Weyl uplift of theories with terms of higher order in the Riemannian curvature. Furthermore, the prescription for scalar–tensor theories coming from terms that have explicit …

The European Physical Journal C

We describe a method to generate scalar–tensor theories with Weyl symmetry, starting from arbitrary purely metric higher derivative gravity theories. The method consists in the definition of a conformally-invariant metric, that is a rank (0, 2)-tensor constructed out of the metric tensor and the scalar field. This new object has zero conformal weight and is given by, where is the conformal dimension of the scalar. As has conformal dimension of 2, the resulting tensor is trivially a conformal invariant. Then, the generated scalar–tensor theory, which we call the Weyl uplift of the original purely metric theory, is obtained by replacing the metric by in the action that defines the original theory. This prescription allowed us to define the Weyl uplift of theories with terms of higher order in the Riemannian curvature. Furthermore, the prescription for scalar–tensor theories coming from terms that have explicit …

The European Physical Journal C

The inclusive Higgs boson production cross-section is measured in the di-photon and the decay channels using 31.4 and 29.0 fb of pp collision data respectively, collected with the ATLAS detector at a centre-of-mass energy of  . To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the channel’s detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are   fb, and   fb, in agreement with the corresponding Standard Model predictions of  fb and  fb. Assuming Standard Model acceptances and branching fractions for the two channels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of  pb and  pb at 13.6  from the di-photon and  …

The European Physical Journal C

Measurements of the differential production cross-sections of prompt and non-prompt and mesons with transverse momenta between 8 and 360 GeV and rapidity in the range are reported. Furthermore, measurements of the non-prompt fractions of and , and the prompt and non-prompt -to- production ratios, are presented. The analysis is performed using 140 fb of  TeV pp collision data recorded by the ATLAS detector at the LHC during the years 2015–2018.