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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Determination of the Σ + Timelike Electromagnetic Form Factors

Based on data samples collected with the BESIII detector at the BEPCII collider, the process e + e − → Σ + Σ ¯ − is studied at center-of-mass energies s = 2.3960 , 2.6454, and 2.9000 GeV. Using a fully differential angular description of the final state particles, both the relative magnitude and phase information of the Σ + electromagnetic form factors in the timelike region are extracted. The relative phase between the electric and magnetic form factors is determined to be sin Δ Φ = − 0.67 ± 0.29 ( stat ) ± 0.18 ( syst ) at s = 2.3960 GeV , Δ Φ = 55 ° ± 19 ° ( stat ) ± 14 ° ( syst ) at s = 2.6454 GeV , and 78 ° ± 22 ° ( stat ) ± 9 ° ( syst ) at s = 2.9000 GeV . For the first time, the phase of the hyperon electromagnetic form factors is explored in a wide range of four-momentum transfer. The evolution of the phase along with four-momentum transfer is an important input for understanding its asymptotic behavior and the dynamics of baryons. Published by the American Physical Society 2024

Physics↗
DOE OSTI2026

Characterization of nuclear breakup as a function of hard-scattering kinematics using dijets measured by ATLAS in p+Pb collisions

This Letter analyzes the sensitivity of event geometry estimators to the initial-state kinematics of hard scattering in proton–lead collisions. This analysis uses dijets as a proxy for the parton–parton scattering configuration, correlating it with event geometry estimators, namely the energy deposited in the Zero-Degree Calorimeter and the transverse energy recorded in the Forward Calorimeter in the Pb-going direction. The analysis uses data recorded by the ATLAS detector at the Large Hadron Collider with a nucleon–nucleon center-of-mass energy of 8.16 TeV, corresponding to an integrated luminosity of 56 nb − 1 . The jets are measured within the pseudorapidity interval −2.8 < η < 4.5, where positive η values correspond to the direction of the proton beam. Results are presented as a function of the Bjorken-x of the parton originating from the proton, xp . Both event geometry estimators are found to be dependent on xp , with the energy deposited in the Zero-Degree Calorimeter about six times less sensitive to xp compared with the transverse energy deposited in the Forward Calorimeter.

Aad, G↗
DOE OSTI2024

Measurement of e + e − → η J / ψ cross section from s = 3.808 GeV to 4.951 GeV

Using data samples with an integrated luminosity of 22.42 fb − 1 collected by the BESIII detector operating at the BEPCII storage ring, we measure the cross sections of the e + e − → η J / ψ process at center-of-mass energies from 3.808 to 4.951 GeV. Three structures are observed in the line shape of the measured cross sections. A maximum-likelihood fit with ψ ( 4040 ) , two additional resonances, and a nonresonant component are performed. The mass and width of the first additional state are ( 4219.7 ± 2.5 ± 4.5 ) MeV / c 2 and ( 80.7 ± 4.4 ± 1.4 ) MeV , respectively, consistent with the ψ ( 4230 ) . For the second state, the mass and width are ( 4386 ± 13 ± 17 ) MeV / c 2 and ( 177 ± 32 ± 13 ) MeV , respectively, consistent with the ψ ( 4360 ) . The first uncertainties are statistical, and the second ones are systematic. The statistical significance of ψ ( 4040 ) is 8.0 σ and those for ψ ( 4230 ) and ψ ( 4360 ) are more than 10.0 σ . Published by the American Physical Society 2024

Ablikim, M.↗
DOE OSTI2024

Solid-State Mixed-Potential Electrochemical Sensors for Natural Gas Leak Detection and Quality Control (Final Technical Report)

Mitigation of methane emissions are a critical factor to limiting the impact of the natural gas industry on global climate change. Throughout the period of 2020-2024, the University of New Mexico and its commercialization partner and subcontractor, SensorComm Technologies, Inc. (SCT), have worked together to develop a low-cost Artificial Intelligence (AI)-driven Internet of Things (IoT)-based multi-gas sensor platform for methane emissions detection. In the final year of the project, we extended this work to include hydrogen detection in support of a transition to a hydrogen economy where hydrogen could be transported through existing natural gas infrastructure. Mixed potential electrochemical sensors were first prototyped by ceramic additive manufacturing and then transitioned to conventional ceramic manufacturing tape casting and screen-printing technologies in preparation for mass production. Demonstrated limits of detection of 5 ppm of methane in natural gas and 1 ppm of hydrogen were measured. These limits of detection are among the lowest of solid-state electrochemical sensors that have been reported in the literature or available in the industry. Machine learning algorithms were developed to identify natural gas mixtures with > 98% accuracy level and quantify methane concentrations at 97% accuracy. The presence of hydrogen could also be identified, and its concentration quantified at these accuracy levels. These algorithms were optimized for running on portable computing hardware which enabled > 1 Hz processing rates. A portable packaged IoT system was integrated with the electrochemical sensor in collaboration with SCT. The package consists of readout electronics with < 1 mV resolution, sensor temperature control, and data transmission over cellular wireless and/or Wi-Fi networks. Field testing was performed in two rounds at Colorado State University’s Methane Emissions Technology Evaluation Center (CSU METEC). The first round of testing demonstrated successful measurements of methane from an underground natural gas leak of 20 standard liters per minute (SLPM), which agreed with previously published literature using more sophisticated and expensive analytical equipment. The second round of testing showed that an above ground leak of 2 SLPM of hydrogen could be detected at 32 ft. This project has resulted in six published peer reviewed journal articles, over ten presentations at professional conferences, and one full patent application filed in 2023. Future work on this project includes increased sensitivity, higher production yields, and applications in the hydrogen safety and flare emissions monitoring spaces.

03 NATURAL GAS↗
DOE OSTI2024

Measurement of absolute branching fractions of $$ {\textrm{D}}_{\textrm{s}}^{+} $$ hadronic decays

Abstract Usinge + e − collision data collected at the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV, corresponding to an integrated luminosity of 7.33 fb −1 , we determine the absolute branching fractions of fifteen hadronic$$ {D}_s^{+} $$ D s + decays with a double-tag technique. In particular, we make precise measurements of the branching fractions$$ \mathcal{B}\left({D}_s^{+}\to {K}^{+}{K}^{-}{\pi}^{+}\right)=\left(5.49\pm 0.04\pm 0.07\right)\% $$ B D s + → K + K − π + = 5.49 ± 0.04 ± 0.07 % ,$$ \mathcal{B}\left({D}_s^{+}\to {K}_S^0{K}^{+}\right)=\left(1.50\pm 0.01\pm 0.01\right)\% $$ B D s + → K S 0 K + = 1.50 ± 0.01 ± 0.01 % and$$ \mathcal{B}\left({D}_s^{+}\to {K}^{+}{K}^{-}{\pi}^{+}{\pi}^0\right)=\left(5.50\pm 0.05\pm 0.11\right)\% $$ B D s + → K + K − π + π 0 = 5.50 ± 0.05 ± 0.11 % , where the first uncertainties are statistical and the second ones are systematic. TheCPasymmetries in these decays are also measured and all are found to be compatible with zero.

Physics↗
DOE OSTI2024

Measurement of the absolute branching fraction of the three-body decay Λ c + → Ξ 0 K + π 0 and search for Λ c + → n K + π 0 , Σ 0 K + π 0 , and Λ K + π 0

The Cabbibo-favored decay Λ c + → Ξ 0 K + π 0 is studied for the first time using 6.1 fb − 1 of e + e − collision data at center-of-mass energies between 4.600 and 4.840 GeV, collected with the BESIII detector at the BEPCII collider. With a double-tag method, the branching fraction of the three-body decay Λ c + → Ξ 0 K + π 0 is measured to be ( 7.79 ± 1.46 ± 0.95 ) × 10 − 3 , where the first and second uncertainties are statistical and systematic, respectively. The branching fraction of the two-body decay Λ c + → Ξ ( 1530 ) 0 K + is ( 5.99 ± 1.04 ± 0.32 ) × 10 − 3 , which is consistent with the previous result of ( 5.02 ± 0.99 ± 0.31 ) × 10 − 3 . In addition, the upper limit on the branching fraction of the doubly Cabbibo-suppressed decay Λ c + → n K + π 0 is 7.1 × 10 − 4 at the 90% confidence level. The upper limits on the branching fractions of Λ c + → Σ 0 K + π 0 and Λ K + π 0 are also determined to be 1.8 × 10 − 3 and 2.0 × 10 − 3 , respectively. Published by the American Physical Society 2024

Ablikim, M.↗
DOE OSTI2025

Energy-efficient multimodal mobility networks in transportation digital twins: Strategies and optimization

The study proposes a comprehensive Transportation Mobility (TransitMo) framework covering conceptual design, model formulation, optimization, simulation, and impact analysis of the transportation mobility system. TransitMo is composed of a transportation digital twin developed in Simulation of Urban MObility (SUMO) and an Intelligent Traffic Management and Control Center (ITMCC) that identifies the best ways to improve the movement of people within urban areas using various modes of transportation. This study encompasses advanced modeling techniques, algorithms, and strategic testing to optimize energy efficiency and mobility in a multimodal shared mobility network. TransitMo’s practical applications are exemplified through a city-scaled simulation network in Chattanooga, TN, employing demographic data to analyze historical traffic patterns and forecast future demands. Central to this methodology are three models: the User Preference Model (UP), the Energy Consumption Model (EC), and the System Optimization Model (SO). These models work in concert to iteratively devise the optimal travel incentives and minimize the total system cost in a real-time manner. In conclusion, test results verified that the proposed adaptive incentive program and optimized bus scheduling can improve network performance by increasing public transit ridership.

42 ENGINEERING↗
DOE OSTI2024

Study of the Decay and Production Properties of D s 1 ( 2536 ) and D s 2 * ( 2573 )

The e + e − → D s + D s 1 ( 2536 ) − and e + e − → D s + D s 2 * ( 2573 ) − processes are studied using data samples collected with the BESIII detector at center-of-mass energies from 4.530 to 4.946 GeV. The absolute branching fractions of D s 1 ( 2536 ) − → D ¯ * 0 K − and D s 2 * ( 2573 ) − → D ¯ 0 K − are measured for the first time to be ( 35.9 ± 4.8 ± 3.5 ) % and ( 37.4 ± 3.1 ± 4.6 ) % , respectively. The e + e − → D s + D s 1 ( 2536 ) − and e + e − → D s + D s 2 * ( 2573 ) − cross sections are measured, and a resonant structure at around 4.6 GeV with a width of 50 MeV is observed in both processes with a statistical significance of 7.2 σ and 15 σ , respectively. The state is observed for the first time in e + e − → D s + D s 2 * ( 2573 ) − and could be the Y ( 4626 ) found by the Belle oration in the D s + D s 1 ( 2536 ) − final state, since they have similar masses and widths. There is also evidence for a structure at around 4.75 GeV in both processes. Published by the American Physical Society 2024

Ablikim, M.↗
DOE OSTI2024

First observation of Λ c + → Λ K + π 0 and evidence of Λ c + → Λ K + π + π −

We present the first observation of the singly Cabibbo-suppressed decay Λ c + → Λ K + π 0 with a significance of 5.7 σ and the first evidence of Λ c + → Λ K + π + π − decay with a significance of 3.1 σ , based on e + e − annihilation data recorded by the BESIII detector at the BEPCII collider. The data correspond to an integrated luminosity of 6.4 fb − 1 , in the center-of-mass energy range from 4.600 to 4.950 GeV. We determine the branching fractions of Λ c + → Λ K + π 0 and Λ c + → Λ K + π + π − relative to their Cabibbo-favored counterparts to be B ( Λ c + → Λ K + π 0 ) B ( Λ c + → Λ π + π 0 ) = ( 2.09 ± 0.3 9 stat ± 0.0 7 syst ) × 10 − 2 and B ( Λ c + → Λ K + π + π − ) B ( Λ c + → Λ π + π + π − ) = ( 1.13 ± 0.4 1 stat ± 0.0 6 syst ) × 10 − 2 , respectively. Moreover, by combining our measured result with the world average of B ( Λ c + → Λ π + π 0 ) , we obtain the branching fraction B ( Λ c + → Λ K + π 0 ) = ( 1.49 ± 0.2 7 stat ± 0.0 5 syst ± 0.0 8 ref ) × 10 − 3 . This result significantly departs from theoretical predictions based on quark S U ( 3 ) flavor symmetry, which is underpinned by the presumption of meson pair S -wave amplitude dominance. Published by the American Physical Society 2024

Astronomy & Astrophysics↗
DOE OSTI2024

Study of e + e − → π + π − π 0 at s from 2.00 to 3.08 GeV at BESIII

With the data samples taken at center-of-mass energies from 2.00 to 3.08 GeV with the BESIII detector at the BEPCII collider, a partial wave analysis on the e + e − → π + π − π 0 process is performed. The Born cross sections for e + e − → π + π − π 0 and its intermediate processes e + e − → ρ π and ρ ( 1450 ) π are measured as functions of s . The results for e + e − → π + π − π 0 are consistent with previous results measured with the initial state radiation method within one standard deviation, and improve the uncertainty by a factor of ten. By fitting the line shapes of the Born cross sections for the e + e − → ρ π and e + e − → ρ ( 1450 ) π , a structure with mass M = 2119 ± 11 ± 15 MeV / c 2 and width Γ = 69 ± 30 ± 5 MeV is observed with a significance of 5.9 σ , where the first uncertainties are statistical and the second ones are systematic. This structure can be interpreted as an excited ω state. Published by the American Physical Society 2024

Astronomy & Astrophysics↗
DOE OSTI2024

Search for low-mass resonances decaying into two jets and produced in association with a photon or a jet at √s = 13 TeV with the ATLAS detector

A search is performed for localized excesses in the low-mass dijet invariant mass distribution, targeting a hypothetical new particle decaying into two jets and produced in association with either a high transverse momentum photon or a jet. The search uses the full Run 2 data sample from LHC proton-proton collisions collected by the ATLAS experiment at a center-of-mass energy of 13 TeV during 2015–2018. Two variants of the search are presented for each type of initial-state radiation: one that makes no jet flavor requirements and one that requires both of the jets to have been identified as containing b-hadrons. No excess is observed relative to the Standard Model prediction, and the data are used to set upper limits on the production cross section for a benchmark Z' model and, separately, for generic, beyond the Standard Model scenarios which might produce a Gaussian-shaped contribution to dijet invariant mass distributions. The results extend the current constraints on dijet resonances to the mass range between 200 and 650 GeV.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Search for pair-produced vectorlike quarks coupling to light quarks in the lepton plus jets final state using 13 TeV p p collisions with the ATLAS detector

A search is presented for the pair production of heavy vectorlike quarks (VLQs) that each decay into a W boson and a light quark. This study focuses on events where one W boson decays into leptons and the other into hadrons. The search analyzed 140 fb -1 of pp collision data with $\sqrt{s}$ = 13 TeV, recorded by the ATLAS detector from 2015 to 2018 during run 2 of the Large Hadron Collider. The final state is characterized by a high-transverse-momentum isolated electron or muon, large missing transverse momentum, multiple small-radius jets, and a single large-radius jet identified as originating from the hadronic decay of a boosted W boson. With higher center-of-mass energy and integrated luminosity than in the run 1 search, and improved analysis tools, this analysis excludes VLQs (Q) with masses below 1530 GeV at 95% confidence level for the branching ratio $\mathscr{B}$⁡(Q →W⁢q) =1, an improvement of 840 GeV on the previous ATLAS limit.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Measurements of the suppression and correlations of dijets in Xe+Xe collisions at $\sqrt{s{NN}}$ = 5.44 TeV

Measurements of the suppression and correlations of dijets is performed using 3 µb –1 of Xe+Xe data at $\sqrt{s{NN}}$ = 5.44 TeV collected with the ATLAS detector at the CERN Large Hadron Collider. Dijets with jets reconstructed using the R = 0.4 anti- k t algorithm are measured differentially in jet p T over the range of 32 to 398 GeV and the centrality of the collisions. Significant dijet momentum imbalance is found in the most central Xe+Xe collisions, which decreases in more peripheral collisions. Results from the measurement of per-pair normalized and absolutely normalized dijet p T balance are compared with previous Pb + Pb measurements at $\sqrt{s{NN}}$ = 5.02 TeV. The differences between the dijet suppression in Xe+Xe and Pb + Pb are further quantified by the ratio of pair nuclear-modification factors. The results are found to be consistent with those measured in Pb + Pb data when compared in classes of the same event activity and when taking into account the difference between the center-of-mass energies of the initial parton scattering process in Xe+Xe and Pb + Pb collisions. These results should provide input for a better understanding of the role of energy density, system size, path length, and fluctuations in the parton energy loss.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Search for charginos and neutralinos in final states with two boosted hadronically decaying bosons and missing transverse momentum in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

A search for charginos and neutralinos at the Large Hadron Collider using fully hadronic final states and missing transverse momentum is reported. Pair-produced charginos or neutralinos are explored, each decaying into a high-p T Standard Model weak boson. Fully hadronic final states are studied to exploit the advantage of the large branching ratio, and the efficient rejection of backgrounds by identifying the high-p T bosons using large-radius jets and jet substructure information. An integrated luminosity of 139 fb -1 of proton-proton collision data collected by the ATLAS detector at a center-of-mass energy of 13 TeV is used. No significant excess is found beyond the Standard Model expectation. Exclusion limits at the 95% confidence level are set on wino or higgsino production with various assumptions about the decay branching ratios and the type of lightest supersymmetric particle. A wino (higgsino) mass up to 1060 (900) GeV is excluded when the lightest supersymmetry particle mass is below 400 (240) GeV and the mass splitting is larger than 400 (450) GeV. The sensitivity to high-mass winos and higgsinos is significantly extended relative to previous LHC searches using other final states.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Measurement of the e+e− → $$ {K}_S^0{K}_L^0 $$π0 cross sections from $$ \sqrt{s} $$ = 2.000 to 3.080 GeV

Abstract Based one + e − collision data collected at center-of-mass energies from 2.000 to 3.080 GeV by the BESIII detector at the BEPCII collider, a partial wave analysis is performed for the processe + e − →$$ {K}_S^0{K}_L^0 $$ K S 0 K L 0 π 0 . The results allow the Born cross sections of the processe + e − →$$ {K}_S^0{K}_L^0 $$ K S 0 K L 0 π 0 , as well as its subprocessese + e − →K ∗ (892) 0 $$ \overline{K} $$ K ¯ 0 and$$ {K}_2^{\ast } $$ K 2 ∗ (1430) 0 $$ \overline{K} $$ K ¯ 0 to be measured. The Born cross sections fore + e − →$$ {K}_S^0{K}_L^0 $$ K S 0 K L 0 π 0 are consistent with previous measurements by BaBar, but with substantially improved precision. The Born cross section lineshape of the processe + e − K ∗ (892) 0 $$ \overline{K} $$ K ¯ 0 is consistent with a vector meson state around 2.2 GeV with a significance of 3.2σ. A Breit-Wigner fit determines its mass asM Y = (2164.7±9.1±3.1) MeV/c 2 and its width as Γ Y = (32.4±21.0±1.8) MeV.

Physics↗
DOE OSTI2022

Search for Higgs boson decays into a pair of pseudoscalar particles in the $bbμμ$ final state with the ATLAS detector in pp collisions at $\sqrt{s} =$ 13 TeV

This paper presents a search for decays of the Higgs boson with a mass of 125 GeV into a pair of new pseudoscalar particles, $H→aa$, where one a-boson decays into a b-quark pair and the other into a muon pair. The search uses 139 fb -1 of proton-proton collision data at a center-of-mass energy of $\sqrt{s} =$ 13 TeV recorded between 2015 and 2018 by the ATLAS experiment at the LHC. A narrow dimuon resonance is searched for in the invariant mass spectrum between 16 GeV and 62 GeV. The largest excess of events above the Standard Model backgrounds is observed at a dimuon invariant mass of 52 GeV and corresponds to a local (global) significance of 3.3σ (1.7σ). Upper limits at 95% confidence level are placed on the branching ratio of the Higgs boson to the $bbμμ$ final state, $B(H→aa→bbμμ)$, and are in the range 0.2-4.0×10 -4 , depending on the signal mass hypothesis.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

Enabling Early Transient Discovery in LSST via Difference Imaging with DECam

We present SLIDE, a pipeline that enables transient discovery in data from the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST), using archival images from the Dark Energy Camera as templates for difference imaging. We apply this pipeline to the recently released Data Preview 1 (DP1; the first public release of Rubin commissioning data) and search for transients in the resulting difference images. The image subtraction, photometry extraction, and transient detection are all performed on the Rubin Science Platform. We demonstrate that SLIDE effectively extracts clean photometry by circumventing poor or missing LSST templates. We identified 29 previously unreported transients, 12 of which would not have been detected based on the DP1 DiaObject catalog. SLIDE will be especially useful for transient analysis in the early years of LSST, when template coverage will be largely incomplete or when templates may be contaminated by transients present at the time of acquisition. We present multiband light curves for a sample of known transients, along with new transient candidates identified through our search. Finally, we discuss the prospects of applying this pipeline during the main LSST survey. Our pipeline is broadly applicable and will support studies of all transients with slowly evolving phases.

Dong, Yize 一泽董 [Harvard-Smithsonian Center for Ast↗
DOE OSTI2025

Artificial intelligence for advanced functional materials: exploring current and future directions

This perspective addresses the topic of harnessing the tools of artificial intelligence (AI) for boosting innovation in functional materials design and engineering as well as discovering new materials for targeted applications in energy storage, biomedicine, composites, nanoelectronics or quantum technologies. It gives a current view of experts in the field, insisting on challenges and opportunities provided by the development of large materials databases, novel schemes for implementing AI into materials production and characterization as well as progress in the quest of simulating physical and chemical properties of realistic atomic models reaching the trillion atoms scale and with near ab initio accuracy.

36 MATERIALS SCIENCE↗