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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 1,153 records · Page 64
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Coherent photoproduction of ρ0 vector mesons in ultra-peripheral Pb-Pb collisions at $ \sqrt{{\mathrm{s}}_{\mathrm{NN}}} $ = 5.02 TeV

Cross sections for the coherent photoproduction of ρ0 vector mesons in ultra-peripheral Pb-Pb collisions at $ \sqrt{{\mathrm{s}}_{\mathrm{NN}}} $ = 5.02 TeV are reported. The measurements, which rely on the π+π− decay channel, are presented in three regions of rapidity covering the range |y| < 0.8. For each rapidity interval, cross sections are shown for different nuclear-breakup classes defined according to the presence of neutrons measured in the zero-degree calorimeters. The results are compared with predictions based on different models of nuclear shadowing. Finally, the observation of a coherently produced resonance-like structure with a mass around 1.7 GeV/c2 and a width of about 140 MeV/c2 is reported and compared with similar observations from other experiments.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Measurement of the energy dependence of the e+e- → $ B\overline{B} $, $ B{\overline{B}}^{\ast } $ and $ {B}^{\ast }{\overline{B}}^{\ast } $ exclusive cross sections

We report the first measurement of the exclusive cross sections e + e - → $B\overline{B}$, e + e - → $B{\overline{B}}^{\ast }$, and e + e - → ${B}^{\ast }{\overline{B}}^{\ast }$ in the energy range from 10.63 GeV to 11.02 GeV. The B mesons are fully reconstructed in a large number of hadronic final states and the three channels are identified using a beam-constrained-mass variable. The shapes of the exclusive cross sections show oscillatory behavior with several maxima and minima. The results are obtained using data collected by the Belle experiment at the KEKB asymmetric-energy e + e - collider.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2023

A search for new resonances in multiple final states with a high transverse momentum Z boson in $\sqrt{s} $ = 13 TeV pp collisions with the ATLAS detector

A generic search for resonances is performed with events containing a Z boson with transverse momentum greater than 100 GeV, decaying into e + e – or μ + μ – . The analysed data collected with the ATLAS detector in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider correspond to an integrated luminosity of 139 fb –1 . Two invariant mass distributions are examined for a localised excess relative to the expected Standard Model background in six independent event categories (and their inclusive sum) to increase the sensitivity. No significant excess is observed. Exclusion limits at 95% confidence level are derived for two cases: a model-independent interpretation of Gaussian-shaped resonances with the mass width between 3% and 10% of the resonance mass, and a specific heavy vector triplet model with the decay mode W' → ZW → ℓℓqq.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Amplitude analysis of the $D^+$ → $π^-π^+π^+$ decay and measurement of the $π^-π^+$ S-wave amplitude

An amplitude analysis of the $D^+$ → $π^-π^+π^+$ decay is performed with a sample corresponding to 1.5 fb -1 of integrated luminosity of $pp$ collisions at a centre-of-mass energy $\sqrt{s}$ = 8 TeV collected by the LHCb detector in 2012. The sample contains approximately six hundred thousand candidates with a signal purity of 95%. The resonant structure is studied through a fit to the Dalitz plot where the $π^-π^+$ S-wave amplitude is extracted as a function of $π^-π^+$ mass, and spin-1 and spin-2 resonances are included coherently through an isobar model. The S-wave component is found to be dominant, followed by the $ρ(770)^0π^+$ and $f_2(1270)π^+$ components. A small contribution from the $ω$(782) → $π^-π^+$ decay is seen for the first time in the $D^+$ → $π^-π^+π^+$ decay.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Measurement of e + e – → $\mathrm{K^+K^–π^0}$ cross section and observation of a resonant structure

Based on collision data collected by the BESIII detector at the BEPCII collider at center-of-mass energies from 2.000 to 3.080 GeV, a partial-wave analysis is performed for the process $e^+e^–$→ $K^+K^–π^0$. The Born cross section of the process $e^+e^–$→ $K^+K^–π^0$ and its subprocesses $e^+e^–$ → $\phi π^0, K^{*+}$(892)$K^–$ and $K^{*+}_{2}$(1430)$K^–$ are measured. The results for $e^+e^–$→ $K^+K^–π^0$ and $\phi π^0$ are consistent with the BaBar measurements and with improved precision. By analyzing the cross sections of the subprocesses $e^+e^–$ → $K^{*+}$(892)$K^–$ and $K^{*+}_{2}$(1430)$K^–$ a structure with mass $M_R$ = (2190 ± 19 ± 37) MeV/c 2 and width $Γ_R$ = (191 ± 28 ± 60) MeV is observed with a combined statistical significance of 7.1σ. The measured resonance parameters suggest it can be identified as the $\phi$(2170), thus the results provide valuable input to understand the internal nature of this state.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Amplitude analysis and branching fraction measurement of $D_s^+$ →$K^–K^+π^+π^+π^–$

Using $e^+e^–$ annihilation data corresponding to a total integrated luminosity of 6.32 fb –1 collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay $D_s^+$ →$K^–K^+π^+π^+π^–$ and determine the relative fractions and phases of different intermediate processes. Absolute branching fraction of $D_s^+$ →$K^–K^+π^+π^+π^–$ decay is measured to be (6.60 ± 0.47 stat. ± 0.38 syst. ) x 10 –3 . The dominant intermediate process is $D_s^+$ → $a_1$(1260) + $\phi, \phi$ → $K^–K^+ a_1$(1260) + → $ρπ^+$, $ρ → π^+π^–$, with a branching fraction of (5.15 ± 0.41 stat. ± 0.32 syst. ) x 10 –3 .

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Cross section measurements of the processes $e^+e^–$ → $ωπ^0$ and $ωη$ at center-of-mass energies between 3.773 and 4.701 GeV

The Born cross sections of the processes $e^+e^–$ → $ωπ^0$ and $e^+e^–$ → $ωη$ are measured at center-of-mass energies between 3.773 and 4.701 GeV using a total integrated luminosity of 22.7 fb –1 collected with the BESIII detector operating at the BEPCII collider. A simple $s^{-n}$ dependence for the continuum process can describe the measured Born cross sections. No significant contributions from the ψ(4160), Y(4230), Y(4360), ψ(4415), Y(4660) resonances are found, which indicates relative small branching fractions for these resonances into the $ωπ^0$ and $ωη$ final states.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2023

Amplitude analysis of the ${D}_s^{+}$ → π - π + π + decay

A Dalitz plot analysis of the ${D}_s^{+}$ → π - π + π + decay is presented. The analysis is based on proton-proton collision data recorded by the LHCb experiment at a centre of-mass energy of 8 TeV and corresponding to an integrated luminosity of 1.5 fb -1 . The resonant structure of the decay is obtained using a quasi-model-independent partial-wave analysis, in which the π + π - S-wave amplitude is parameterised as a generic complex function determined by a fit to the data. The S-wave component is found to be dominant, followed by the contribution from spin-2 resonances and a small contribution from spin-1 resonances. The latter includes the first observation of the ${D}_s^{+}$ → ω(782)π + channel in the ${D}_s^{+}$ → π - π + π + decay. The resonant structures of the ${D}_s^{+}$ → π - π + π + and ${D}^{+}$ → π - π + π + decays are compared, providing information about the mechanisms for the hadron formation in these decays.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Amplitude analysis and branching fraction measurement of the decay $D_s^{+} → K^+π^+π^-$

Using 6.32 fb -1 of e + e - collision data collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay D$^+_s$ → K + π + π - and determine the amplitudes of the various intermediate states. The absolute branching fraction of D$^+_s$ → K + π + π - is measured to be (6.11 ± 0.18 stat. ± 0.11 syst. ) x 10 -3 . The branching fractions of the dominant intermediate processes D$^+_s$ → K + ρ 0 , ρ 0 → π + π - and D$^+_s$ → K*(892) 0 π + , K*(892) 0 → K + π - are determined to be (1.96 ± 0.19 stat . ± 0.23 syst. ) x 10 -3 and (1.85 ± 0.12 stat . ± 0.13 syst .) x 10 -3 , respectively. The intermediate resonances f 0 (500), f 0 (980), and f 0 (1370) are observed for the first time in this channel.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Amplitude analysis and branching fraction measurement of the decay $\mathrm{D}_s^+$ → $\mathrm{K}^+π^+π^-π^0$

The singly Cabibbo-suppressed decay D$^+_s$ → K + π + π - π 0 is observed by using a data set corresponding to an integrated luminosity of 6.32 fb -1 recorded by the BESIII detector at the centre-of-mass energies between 4.178 and 4.226 GeV. The first amplitude analysis of D$^+_s$ → K + π + π - π 0 reveals the sub-structures in this decay and determines the fractions and relative phases of different intermediate processes. The dominant intermediate process is D$^+_s$ → K *0 ρ + , with a fit fraction of (40.5 ± 2.8 stat. ± 1.5 syst. )%. With the detection efficiency based on our amplitude analysis, the absolute branching fraction for D$^+_s$ → K + π + π - π 0 is measured to be (9.75 ± 0.54 stat. ± 0.17 syst. ) x 10 -3 .

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2023

Amplitude analysis and branching fraction measurement of the decay D+ → ${\textrm{K}}_{\textrm{S}}^0$π + π 0 π 0

Using 2.93 fb-1 of e+e- collision data collected with the BESIII detector at the center-of-mass energy 3.773 GeV, we perform the first amplitude analysis of the decay D+ → ${K}^0_S$π + π 0 π 0 and determine the relative magnitudes and phases of different intermediate processes. The absolute branching fraction of D+ → ${K}^0_S$π + π 0 π 0 is measured to be (2.888 ± 0.058 stat. ± 0.069 syst. )%. The dominant intermediate processes are D+ → ${K}^0_S$a 1 (1260) + (→ ρ + π 0 ) and D+ → $\overline{K}$*0 ρ +, with branching fractions of (8.66 ± 1.04 stat. ± 1.39 syst. ) × 10 -3 and (9.70 ± 0.81 stat. ± 0.53 syst. ) × 10 -3 , respectively.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Search for pairs of scalar leptoquarks decaying into quarks and electrons or muons in $ \sqrt{s}$ = 13 TeV pp collisions with the ATLAS detector

A search for new-physics resonances decaying into a lepton and a jet performed by the ATLAS experiment is presented. Scalar leptoquarks pair-produced in pp collisions at s = 13 TeV at the Large Hadron Collider are considered using an integrated luminosity of 139 fb-1, corresponding to the full Run 2 dataset. They are searched for in events with two electrons or two muons and two or more jets, including jets identified as arising from the fragmentation of c- or b-quarks. The observed yield in each channel is consistent with the Standard Model background expectation. Leptoquarks with masses below 1.8 TeV and 1.7 TeV are excluded in the electron and muon channels, respectively, assuming a branching ratio into a charged lepton and a quark of 100%, with minimal dependence on the quark flavour. Upper limits on the aforementioned branching ratio are also given as a function of the leptoquark mass.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Observation of e + e - → ηψ(2S) at center-of-mass energies from 4.236 to 4.600 GeV

Using a total of 5 25 fb -1 of e + e - collision data with center-of-mass energies from 4.236 to 4.600 GeV, we report the first observation of the processe + e - → ηψ(2S) with a statistical significance of 4.9 standard deviations. The data sets were collected by the BESIII detector operating at the BEPCII storage ring. We measure the yield of events integrated over center-of-mass energies and also present the energy dependence of the measured cross section.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Search for periodic signals in the dielectron and diphoton invariant mass spectra using 139 fb -1 of $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

A search for physics beyond the Standard Model inducing periodic signals in the dielectron and diphoton invariant mass spectra is presented using 139 fb -1 of $\sqrt{s}$ = 13 TeV pp collision data collected by the ATLAS experiment at the LHC. Novel search techniques based on continuous wavelet transforms are used to infer the frequency of periodic signals from the invariant mass spectra and neural network classifiers are used to enhance the sensitivity to periodic resonances. In the absence of a signal, exclusion limits are placed at the 95% confidence level in the two-dimensional parameter space of the clock work gravity model. Model-independent searches for deviations from the background-only hypothesis are also performed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Search for heavy resonances in final states with four leptons and missing transverse momentum or jets in pp collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

A search for a new heavy boson produced via gluon-fusion in the four-lepton channel with missing transverse momentum or jets is performed. The search uses proton-proton collision data equivalent to an integrated luminosity of 139 fb -1 at a centre-of-mass energy of 13 TeV collected by the ATLAS detector between 2015 and 2018 at the Large Hadron Collider. This study explores the decays of heavy bosons: R → SH and A → ZH, where R is a CP-even boson, A is a CP-odd boson, H is a CP-even boson, and S is considered to decay into invisible particles that are candidates for dark matter. In these processes, S → invisible and H → ZZ. The Z boson associated with the heavy scalar boson H decays into all decay channels of the Z boson. The mass range under consideration is 390–1300 (320–1300) GeV for the R (A) boson and 220–1000 GeV for the H boson. No significant deviation from the Standard Model backgrounds is observed. The results are interpreted as upper limits at a 95% confidence level on the cross-section times the branching ratio of the heavy resonances.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

Measurement of the phase between strong and electromagnetic amplitudes in the decay J/ψ → ϕη

The first direct measurement of the relative phase between the strong and electromagnetic amplitudes for a J/ψ decaying into a vector-pseudoscalar final state is performed using 26 energy points of e + e − annihilation data between 3.00 GeV and 3.12 GeV. The data sets were collected by the BESIII detector with a total integrated luminosity of 452 pb −1 . By investigating the interference pattern in the cross section lineshape of e + e − → ϕη, the relative phase between the strong and electromagnetic amplitudes of J/ψ decay is determined to be within [133°, 228°] at 68% confidence level.

QCD↗
DOE OSTI2022

Observation of the decay ψ (3686) → $ {\Sigma}^{-}{\overline{\Sigma}}^{+} $ and measurement of its angular distribution

Using (448.1 ± 2.9) × 10 6 ψ(3686) events collected with the BESIII detector at the BEPCII collider, the decay ψ(3686) → Σ - $\overline{Σ}$ + is observed for the first time with a branching fraction of (2.82 ± 0.04 stat. ± 0.08 syst. ) × 10 -4 , and the angular parameter α Σ- is measured to be 0.96 ± 0.09 stat. ± 0.03 syst. .

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Extraction chromatography of 225 Ac and lanthanides on N,N-dioctyldiglycolamic acid /1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide solvent impregnated resin

The alpha-emitter 225 Ac (t 1/2 = 9.92 d) is currently under development for targeted alpha-particle therapy of cancer, and accelerator production of 225 Ac via proton irradiation of thorium targets requires robust separations of 225 Ac from chemically similar fission product lanthanides. Additionally, the lanthanide elements represent critical components in modern technologies, and radiolanthanides such as 140 Nd (t 1/2 = 3.37 d) also have potential application in the field of nuclear medicine. The ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim][NTf 2 ]), combined with the diglycolamide extractant, N,N-dioctyldiglycolamic acid (DODGAA), was adsorbed on macroporous resin support to produce a solvent impregnated resin (SIR) that was investigated for separations of 225 Ac and lanthanides. The equilibrium distribution coefficients (Kd) of the rare earth elements (Sc(III), Y(III), Ln(III)), 225 Ac(III), Th(IV), and U(VI) on the prepared DODGAA/[Bmim][NTf 2 ]-SIR were determined from batch adsorption experiments in HCl and HNO 3 media. The DODGAA/[Bmim][NTf2]-SIR exhibited preferential uptake of the heavier lanthanide elements while allowing for the separation of the lighter lanthanides. Column separations utilizing the DODGAA/[Bmim][NTf 2 ]-SIR were effective at separating the lighter lanthanides from each other, and separating 225 Ac from a mixture of lanthanides, 213 Bi, and 225 Ra without the need for additional complexing agents.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗