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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 667 records · Page 37
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Demonstration of <2 ns timing resolution for neutrino interaction in the MicroBooNE detector

The MicroBooNE detector, located in the Booster Neutrino Beamline (BNB) at Fermilab, collected data from 2015 to 2021. MicroBooNE’s Liquid Argon Time Projection Chamber is accompanied by a Photon Detection System consisting of 32 PMTs used to measure the argon scintillation light and determine the timing of the neutrino interactions. This work employs improved analysis techniques combining light signals and reconstructed tracks achieving neutrino interaction timing resolution <2 ns. The result obtained allows MicroBooNE to access the 2 ns neutrino pulse structure of the BNB for the first time. The timing resolution achieved enables significant enhancement of cosmic background rejection for all neutrino analyses. Furthermore, the ns timing resolution opens the door for searching new long-lived-particles (e.g. Heavy Neutral Leptons, Higgs Portal Scalars) in MicroBooNE, as well in future large LArTPC experiments, namely SBN and DUNE.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2025

Implications of Aerosol Physicochemical Properties Including Ice Nucleation at ARM Mega Sites for Improved Understanding of Microphysical Atmospheric Cloud Processes (Final Technical Report)

Continuous, long-term measurements of atmospheric ice-nucleating particles (INPs) that influence clouds and precipitation were conducted to investigate the abundance and variability of ground-level INPs across the world. Three field campaigns were organized by the DOE Atmospheric Radiation Measurement (ARM) program, including Examining INP from Southern Great Plains (ExINP-SGP, 2019), Examining INP from Eastern North Atlantic (ExINP-ENA, 2020 – 2021), and Examining INP from North Slope of Alaska (ExINP-NSA, 2021 – 2024). Additional small-scale supporting field experiments were performed in 2019 and 2021 to collect airborne particulate matter at SGP for complementary laboratory characterization of the particles’ physical and chemical properties [Aerosol-Ice Formation Closure Pilot Study (AEROICESTUDY), 2019; ExINP-SGP II, 2021]. In these studies, the PI’s team measured INP concentration with both real-time and laboratory measurements in a wide range of freezing temperatures ($T$ from 0 °C to about –30 °C). This project elucidated spatial variability and seasonality in the abundance of immersion mode active INPs across three ARM sites using a single instrument, a Portable Ice Nucleation Experiment (PINE) chamber version 03 (PINE-03 hereafter). Collocated aerosol and meteorological data were analyzed to assess the correlation between ambient INP abundance, air mass origin region, and meteorological variability. Our findings suggest very high freezing efficiency of INPs at the NSA site across the measured temperatures (ice nucleation active surface site density, $n_s(T)$, $\approx 2 \times 10^{8} - 10^{10}$ m -2 for from –16 to –31 °C), which is a factor of 10 – 1000 times greater efficiency as compared to that found in the previous mid-latitude INP measurements in autumn using the same instrument; surprisingly high INP abundance ($\ge 1 \text{ L}^{-1}$ at –25 °C) for the examined temperatures throughout the year that PINE-03 did not measure at other sites; and high INP concentration in spring, possibly related to arctic haze episodes.

58 GEOSCIENCES↗
DOE OSTI2020

Quantum Information for Particle Theorists

Lectures given at the Theoretical Advanced Study Institute (TASI 2020), 1-26 June 2020. The topics covered include quantum circuits, entanglement, quantum teleportation, Bell inequalities, quantum entropy and decoherence, classical versus quantum measurement, the area law for entanglement entropy in quantum field theory, and simulating quantum field theory on a quantum computer. Along the way we confront the fundamental sloppiness of how we all learned (and some of us taught) quantum mechanics in college. Links to a Python notebook and Mathematica notebooks will allow the reader to reproduce and extend the calculations, as well as perform five experiments on a quantum simulator.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Search for exotic decays of the Higgs boson into $b\bar{b}$ and missing transverse momentum in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

A search for the exotic decay of the Higgs boson (H) into a $b\bar{b}$ resonance plus missing transverse momentum is described. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 fb -1 of pp collisions at $\sqrt{s}$ = 13 TeV. The search targets events from $ZH$ production in an NMSSM scenario where H → $\tilde{χ}^0_2\tilde{χ}^0_1$, with $\tilde{χ}^0_2$ → a$\tilde{χ}^0_1$, where a is a light pseudoscalar Higgs boson and $\tilde{χ}^0_{1,2}$ are the two lightest neutralinos. The decay of the a boson into a pair of b-quarks results in a peak in the dijet invariant mass distribution. The final-state signature consists of two leptons, two or more jets, at least one of which is identified as originating from a b-quark, and missing transverse momentum. Observations are consistent with Standard Model expectations and upper limits are set on the product of cross section times branching ratio for a three-dimensional scan of the masses of the $\tilde{χ}^0_2\tilde{χ}^0_1$ and a boson.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Study of e+e- → γΦJ/ψ from $\sqrt{s}$ = 4.600 to 4.951 GeV

Using data samples with an integrated luminosity of 6.4 fb -1 collected by the BESIII detector operating at the BEPCII storage ring, the process of e+e- → γΦJ/ψ is studied. The processes of e + e - → Φχc1,c2, χc1,c2 → γJ/ψ are observed with a significance of more than 10σ. The √s-dependent cross section of e + e - → Φχc1,c2 is measured between 4.600 and 4.951 GeV, and evidence of a resonance structure is found for the first time in the Φχc2 process. We also search for the processes of e + e - → γX(4140), γX(4274) and γX(4500) via the γΦJ/ψ final state, but no obvious structures are found. The upper limits on the production cross section times the branching fraction for these processes at the 90% confidence level are reported.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Study of ${\mathrm{B}}_{\mathrm{s}}^0$ → J/ψπ + π – K + K – decays

The decays ${\mathrm{B}}_{\mathrm{s}}^0$ → J/ψπ + π – K + K – are studied using a data set corresponding to an integrated luminosity of 9 fb –1 , collected with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The decays ${\mathrm{B}}_{\mathrm{s}}^0$ → $\mathrm{J}/{ψ \mathrm{K}}^{\ast 0}{\overline{\mathrm{K}}}^{\ast 0}$ and ${\mathrm{B}}_{\mathrm{s}}^0$ → χ c1 (3872)K + K – , where the K + K – pair does not originate from a Φ meson, are observed for the first time. Precise measurements of the ratios of branching fractions between intermediate χ c1 (3872)Φ, $\mathrm{J}/{ψ \mathrm{K}}^{\ast 0}{\overline{\mathrm{K}}}^{\ast 0}$, ψ(2S)Φ and χ c1 (3872)K + K – states are reported. A structure, denoted as X(4740), is observed in the J/ψΦ mass spectrum and, assuming a Breit-Wigner parameterisation, its mass and width are determined to be ${\displaystyle \begin{array}{c}{m}_{\mathrm{X}(4740)}=4741\pm 6\pm 6\kern0.5em \mathrm{MeV}/{c}^2,\\ {}{\Gamma}_{\mathrm{X}(4740)}=53\pm 15\pm 11\kern0.5em \mathrm{MeV},\end{array}}$ where the first uncertainty is statistical and the second is systematic. In addition, the most precise single measurement of the mass of the ${\mathrm{B}}_{\mathrm{s}}^0$ meson is performed and gives a value of ${m}_{{\mathrm{B}}_{\mathrm{s}}^0}=5366.98\pm 0.07\pm 0.13\kern0.5em \mathrm{MeV}/{c}^2.$

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Search for lepton flavour violating decays of a neutral heavy Higgs boson to $\mu\tau$ and e$\tau$ in proton-proton collisions at $\sqrt{s}=$ 13 TeV

A search for lepton flavour violating decays of a neutral non-standard-model Higgs boson in the μτ and eτ decay modes is presented. The search is based on proton-proton collisions at a center of mass energy $ \sqrt{s} $ = 13 TeV collected with the CMS detector in 2016, corresponding to an integrated luminosity of 35.9 fb$^{−1}$. The τ leptons are reconstructed in the leptonic and hadronic decay modes. No signal is observed in the mass range 200–900 GeV. At 95% confidence level, the observed (expected) upper limits on the production cross section multiplied by the branching fraction vary from 51.9 (57.4) fb to 1.6 (2.1) fb for the μτ and from 94.1 (91.6) fb to 2.3 (2.3) fb for the eτ decay modes.[graphic not available: see fulltext]

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Angular analysis of the decay B$^+$ $\to$ K$^*$(892)$^+\mu^+\mu^-$ in proton-proton collisions at $\sqrt{s} =$ 8 TeV

Angular distributions of the decay B$^{+}$→ K$^{∗}$(892)$^{+}$μ$^{+}$μ$^{−}$ are studied using events collected with the CMS detector in $ \sqrt{\mathrm{s}} $ = 8 TeV proton-proton collisions at the LHC, corresponding to an integrated luminosity of 20.0 fb$^{−1}$. The forward-backward asymmetry of the muons and the longitudinal polarization of the K$^{∗}$(892)$^{+}$ meson are determined as a function of the square of the dimuon invariant mass. These are the first results from this exclusive decay mode and are in agreement with a standard model prediction.[graphic not available: see fulltext]

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Measurement of b jet shapes in proton-proton collisions at $\sqrt{s} =$ 5.02 TeV

We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb$^{−1}$. To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.[graphic not available: see fulltext]

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Amplitude analysis and branching-fraction measurement of ${D}_s^{+}\to {K}_S^0{\pi}^{+}{\pi}^0$

By using 6.32 fb -1 of data collected with the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, we perform an amplitude analysis of the decay $D^+_s$→$K^0_Sπ^+π^0$ and determine the relative fractions and phase differences of different intermediate processes, which include $K^0_Sρ$(770) + ,$K^0_Sρ$(1450) + , $K^*$(892)$^0π^+$, $K^*$(892)$^+π^0$, and $K^*$(1410)$^0π^+$. With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be $\mathcal{B}$($D^+_s$→$K^0_Sπ^+π^0$)=(5.43±0.30 stat ±0.15 syst )×10 -3 .

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Search for supersymmetry in events with four or more charged leptons in 139 fb -1 of $\sqrt{s}$ = 13 TeV pp collisions with the ATLAS detector

A search for supersymmetry in events with four or more charged leptons (electrons, muons and $\tau$-leptons) is presented. The analysis uses a data sample corresponding to 139 fb -1 of proton-proton collisions delivered by the Large Hadron Collider at $\sqrt{s}$ =13 TeV and recorded by the ATLAS detector. Four-lepton signal regions with up to two hadronically decaying $\tau$-leptons are designed to target several supersymmetric models, while a general five-lepton signal region targets any new physics phenomena leading to a final state with five charged leptons. Data yields are consistent with Standard Model expectations and results are used to set upper limits on contributions from processes beyond the Standard Model. Exclusion limits are set at the 95% confidence level in simplified models of general gauge-mediated supersymmetry, excluding higgsino masses up to 540 GeV. In R-parity-violating simplified models with decays of the lightest supersymmetric particle to charged leptons, lower limits of 1.6 TeV, 1.2 TeV, and 2.5 TeV are placed on wino, slepton and gluino masses, respectively.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Study of the ψ 2 (3823) and χ c1 (3872) states in B + → (J/ψπ + π - )K + decays

The decays B + → J/ψπ + π – K + are studied using a data set corresponding to an integrated luminosity of 9 fb –1 collected with the LHCb detector in proton-proton collisions between 2011 and 2018. Precise measurements of the ratios of branching fractions with the intermediate ψ 2 (3823), χ c1 (3872) and ψ(2S) states are reported.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Measurements of the azimuthal anisotropy of prompt and nonprompt charmonia in PbPb collisions at $\sqrt{s_{\textrm{NN}}} $= 5.02 TeV

The second-order (v 2 ) and third-order (v 3 ) Fourier coefficients describing the azimuthal anisotropy of prompt and nonprompt (from b-hadron decays) J/ψ, as well as prompt ψ(2S) mesons are measured in lead-lead collisions at a center-of-mass energy per nucleon pair of $\sqrt {^{S}NN}$ = 5.02 TeV. The analysis uses a data set corresponding to an integrated luminosity of 1.61 nb –1 recorded with the CMS detector. The J/ψ and ψ(2S) mesons are reconstructed using their dimuon decay channel. The v 2 and v 3 coefficients are extracted using the scalar product method and studied as functions of meson transverse momentum and collision centrality. The measured v 2 values for prompt J/ψ mesons are found to be larger than those for nonprompt J/ψ mesons. The prompt J/ψ v 2 values at high p T are found to be underpredicted by a model incorporating only parton energy loss effects in a quark-gluon plasma medium. Prompt and nonprompt J/ψ meson v 3 and prompt ψ(2S) v 2 and v 3 values are also reported for the first time, providing new information about heavy quark interactions in the hot and dense medium created in heavy ion collisions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Did we hear the sound of the Universe boiling? Analysis using the full fluid velocity profiles and NANOGrav 15-year data

Abstract In this paper, we analyse sound waves arising from a cosmic phase transition where the full velocity profile is taken into account as an explanation for the gravitational wave spectrum observed by multiple pulsar timing array groups. Unlike the broken power law used in the literature, in this scenario the power law after the peak depends on the macroscopic properties of the phase transition, allowing for a better fit with pulsar timing array (PTA) data. We compare the best fit with that obtained using the usual broken power law and, unsurprisingly, find a better fit with the gravitational wave (GW) spectrum that utilizes the full velocity profile. Even more importantly, the thermal parameters that produce the best fit are quite different. We then discuss models that can produce the best-fit point and complementary probes using CMB experiments and searches for light particles in DUNE, IceCUBE-Gen2, neutrinoless doubleβ-decay, and forward physics facilities (FPF) at the LHC like FASERν, etc.

Astronomy & Astrophysics↗
DOE OSTI2022

Experimental and theoretical study of weakly coherent mode in I-mode edge plasmas in the EAST tokamak

The I-mode is a promising operation mode for fusion in the future, featuring high-temperature and low-density confinement, but the reason why the temperature and density are decoupled remains an important aspect to be explored. The experimental results from the experimental advanced superconducting tokamak (EAST) showed that the weakly coherent mode (WCM) is directly related to sustaining the I-mode and that the peak amplitude of the WCM is proportional to the temperature in the pedestal. Here, simulating the experimental data from EAST with the six-field model of BOUT++, we find a density perturbation close to the frequency of the WCM observed in the experiment. By testing all the physical terms in this model, we find that the density perturbation and particle transport are directly related to the drift Alfvén wave (DAW) mode. Additionally we use the SymPIC program (Xiao et al Plasma Sci. Technol. 20 110501; Phys. Plasmas 22 112504; Plasma Sci. Technol. 23 055102) to simulate the same experimental data and find that the frequency range of the WCM is close to both experimental and BOUT++ results. Therefore, the WCM of the I-mode can be considered to be driven by the DAW, which helps improve the transport of the I-mode.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2022

Machine learning on FPGA for event selection

Real-time data processing is a frontier field in experimental particle physics. The application of FPGAs at the trigger level is used by many current and planned experiments (CMS, LHCb, Belle2, PANDA). Usually they use conventional processing algorithms. LHCb has implemented Machine Learning (ML) elements for real-time data processing with a triggered readout system that runs most of the ML algorithms on a computer farm. The work described in this article aims to test the ML-FPGA algorithms for streaming data acquisition. Herein, there are many experiments working in this area and they have a lot in common, but there are many specific solutions for detector and accelerator parameters that are worth exploring further. This report describes the purpose of the work and progress in evaluating the ML-FPGA application.

47 OTHER INSTRUMENTATION↗
DOE OSTI2024

Saturation of Fishbone Instability by Self-Generated Zonal Flows in Tokamak Plasmas

Gyrokinetic simulations of the fishbone instability in DIII-D tokamak plasmas find that self-generated zonal flows can dominate the nonlinear saturation by preventing coherent structures from persisting or drifting in the energetic particle phase space when the mode frequency down-chirps. Results from the simulation with zonal flows agree quantitatively, for the first time, with experimental measurements of the fishbone saturation amplitude and energetic particle transport. Moreover, the fishbone-induced zonal flows are likely responsible for the formation of an internal transport barrier that was observed after fishbone bursts in this DIII-D experiment. Finally, gyrokinetic simulations of a related ITER baseline scenario show that the fishbone induces insignificant energetic particle redistribution and may enable high performance scenarios in ITER burning plasma experiments. Published by the American Physical Society 2024

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗