Search NASA⌕ Search

SEARCH · Search NASA

Results for “Exclusion”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Search for the Exclusive W Boson Hadronic Decays W ± → π ± γ, W ± → K ± γ and W ± → ρ ± γ with the ATLAS Detector

A search for the exclusive hadronic decays W ± → π ± γ, W ± → K ± γ, and W ± → ρ ± γ is performed using up to 140 fb -1 of proton-proton collisions recorded with the ATLAS detector at a center-of-mass energy of $\sqrt{s} =$ 13 TeV. If observed, these rare processes would provide a unique test bench for the quantum chromodynamics factorization formalism used to calculate cross sections at colliders. Additionally, at future colliders, these decays could offer a new way to measure the W boson mass through fully reconstructed decay products. The search results in the most stringent upper limits to date on the branching fractions B(W ± → π ± γ) < 1.9 × 10 -6 , B(W ± → K ± γ) < 1.7 × 10 -6 , B(W ± → ρ ± γ) < 5.2 × 10 -6 at 95% confidence level.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2026

Evidence of Spin-Interference Effects in Exclusive 𝐽/𝜓 → 𝑒 + ⁢𝑒 − Photoproduction in Ultraperipheral Heavy-Ion Collisions

Here, we report the first evidence of spin interference in exclusive 𝐽/𝜓 → 𝑒 + ⁢𝑒 − photoproduction in ultraperipheral heavy-ion collisions at STAR at $\sqrt{𝑠_{𝑁⁢𝑁}}$ = 200 GeV. In Au + Au collisions, a negative cos⁡(2⁢𝜙) modulation is found for 𝑝 𝑇 < 120 MeV/𝑐 with a significance of 3.2⁢𝜎, while the isobar data (Ru + Ru, Zr + Zr) show a consistent negative modulation with a significance of 1.9⁢𝜎, opposite in sign to that in 𝜌 0 → 𝜋 + ⁢𝜋 − photoproduction. This establishes for the first time that the interference sign is controlled by the spin structure of the final-state daughters, resolving the ambiguity present in the all-boson 𝜌 0 channel. The compact 𝐽/𝜓 probes gluon distributions at perturbative scales, resulting in a weaker modulation and providing stringent constraints on color glass condensate calculations. These findings demonstrate that spin-dependent interference in heavy vector mesons provides a new, experimentally accessible handle on gluon structure beyond traditional cross-section measurements.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

Criteria for projected discovery and exclusion sensitivities of counting experiments

Abstract The projected discovery and exclusion capabilities of particle physics and astrophysics/cosmology experiments are often quantified using the median expected p-value or its corresponding significance. We argue that this criterion leads to flawed results, which for example can counterintuitively project lessened sensitivities if the experiment takes more data or reduces its background. We discuss the merits of several alternatives to the median expected significance, both when the background is known and when it is subject to some uncertainty. We advocate for standard use of the “exact Asimov significance” $$Z^\mathrm{A}$$ Z A detailed in this paper.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2023

Searches for exclusive Higgs and Z boson decays into a vector quarkonium state and a photon using 139 fb$^{-1}$ of ATLAS $\sqrt{s}=13$ TeV proton–proton collision data

Searches for the exclusive decays of Higgs and Z bosons into a vector quarkonium state and a photon are performed in the μ + μ - γ final state with a proton– proton collision data sample corresponding to an integrated luminosity of 139 fb -1 collected at $\sqrt{s}=13$ TeV with the ATLAS detector at the CERN Large Hadron Collider. The observed data are compatible with the expected back grounds. The 95% confidence-level upper limits on the branching fractions of the Higgs boson decays into J/ψ γ , ψ(2S) γ , and $Υ$(1S, 2S, 3S) γ are found to be 2.0 × 10 -4 , 10.5×10 -4 , and (2.5, 4.2, 3.4)×10 -4 , respectively, assuming Standard Model production of the Higgs boson. The corresponding 95% CL upper limits on the branching fractions of the Z boson decays are 1.2 × 10 -6 , 2.4 × 10 -6 , and (1.1, 1.3, 2.4) × 10 -6 . An observed 95% CL interval of (-133, 175) is obtained for the κ c /κ γ ratio of Higgs boson coupling modifiers, and a 95% CL interval of (-37, 40) is obtained for κ b /κ γ .

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Simulation of the CBETA 4-pass FFAG ERL using field maps — exclusively

The Cornell-BNL Electron Test Accelerator (CBETA), a four-pass, 150 MeV energy recovery linac (ERL), is now in construction at Cornell. Commissioning commenced on March 2019. A particularity of CBETA is that a single channel loop recirculates the four energies (42, 78, 114 and 150 MeV). The return loop arcs are based on fixed-field alternating gradient (FFAG) optics. The loop is comprised of 107 quadrupole-doublet cells, built using Halbach permanent magnet technology. Spreader and combiner sections (4 independent beam lines each) connect the 36 MeV linac to the FFAG arcs. We introduce here a start-to-end simulation of the 4-pass ERL, based entirely, and exclusively, on the use of magnetic field maps to model the optical components.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Standard experimental paradigm designs and data exclusion practices in cognitive psychology can inadvertently introduce systematic “shadow” biases in participant samples

Abstract Standard cognitive psychology research practices can introduce inadvertent sampling biases that reduce the reliability and generalizability of the findings. Researchers commonly acknowledge and understand that any given study sample is not perfectly generalizable, especially when implementing typical experimental constraints (e.g., limiting recruitment to specific age ranges or to individuals with normal color vision). However, less obvious systematic sampling constraints, referred to here as “shadow” biases, can be unintentionally introduced and can easily go unnoticed. For example, many standard cognitive psychology study designs involve lengthy and tedious experiments with simple, repetitive stimuli. Such testing environments may 1) be aversive to some would-be participants (e.g., those high in certain neurodivergent symptoms) who may self-select not to enroll in such studies, or 2) contribute to participant attrition, both of which reduce the sample’s representativeness. Likewise, standard performance-based data exclusion efforts (e.g., minimum accuracy or response time) or attention checks can systematically remove data from participants from subsets of the population (e.g., those low in conscientiousness). This commentary focuses on the theoretical and practical issues behind these non-obvious and often unacknowledged “shadow” biases, offers a simple illustration with real data as a proof of concept of how applying attention checks can systematically skew latent/hidden variables in the included population, and then discusses the broader implications with suggestions for how to manage and reduce, or at a minimum acknowledge, the problem.

Siritzky, Emma M.↗
DOE OSTI2025

Data from a throughfall exclusion experiment: Fine root dynamics, morphology, chemistry, and AMF colonization across four lowland Panamanian forests

Fine roots regulate forest nutrient, carbon, and water cycling, yet their variation within and among tropical forests remains under-characterized. We quantified root productivity, disappearance, and stocks to 1 m using minirhizotron imaging, and we measured morphology, elemental composition [root carbon (C), root nitrogen (N), root phosphorus (P)], and arbuscular mycorrhizal fungi (AMF) colonization to 20 cm using ingrowth cores and sequential coring. Sampling took place in four distinct lowland Panamanian forests (32 plots; 8 per forest) from 2018 through 2022 under control and throughfall-exclusion (drought) treatments in the Panama Rainforest Changes with Experimental Drying (PARCHED) experiment.The dataset is presented as an Excel workbook with six tabs. The first tab is the data dictionary. Tab S1 contains ingrowth-core production and mortality, morphology and soil moisture. Tab S2 contains sequential-coring standing stocks with associated morphology and soil moisture. Tab S3 contains minirhizotron row data records to 1 m depth, including per-frame root length and diameter, normalized length metrics, and session timing. Tab S4 contains AMF colonization. Tab S5 contains fine-root chemistry at 0–10 cm, reporting %P, %C, %N, and C:N for samples collected via ingrowth cores and sequential-coring standing stocks. CSV mirrors for each tab are provided, and a KML file supplies coordinates for all 32 plots.Key variables span live and dead fine-root biomass (and coarse fractions where applicable), specific root length (SRL) and area (SRA), diameter, root tissue density (RTD), soil moisture, AMF colonization, root %N, %C, %P, and C:N, along with minirhizotron root length and diameter. Depth, season, treatment, and plot/site identifiers are included to support cross-tab integration and analysis from 0–100 cm (minirhizotron) and 0–20 cm (cores).Units are reported in-column and missing values are coded as NA. No special software is required to open or use the files (Excel, CSV, and KML compatible).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Neurotrophic Labs - Fish Exclusion Using a Floating Separator - Fish Protection Prize (Final Report)

In FY2020, the National Renewable Energy Laboratory (NREL) initiated a Prize competition with support from Pacific Northwest National Laboratory (PNNL), and sponsored by the U.S. Department of Energy Water Power Technologies Office (DOE WPTO), to support the development of innovative methods for excluding fish from water diversions and intakes: the Fish Protection Prize. Proposed solutions can include new ideas for addressing fish exclusion or improvements to existing technologies. Solutions can be applied to river and canal diversions, unscreened diversion pipes, or intakes at dams. In FY20 PNNL provided voucher support in the form of technical reviews and support, as well as graphics and presentation support, in helping the 9 finalists prepare for the Pitch Contest at the American Fisheries Society (AFS) virtual meeting. There were no subject inventions, patent applications, copyrights, and trademarks under this CRADA. The report herein provides an abstract of the presentation that the finalist presented at the American Fisheries Society virtual meeting in September 2020.

42 ENGINEERING↗
DOE OSTI2021

Team Hogan - Air Bubble Curtain for Physical Exclusion - Fish Protection Prize (Final Report)

In FY2020, the National Renewable Energy Laboratory (NREL) initiated a Prize competition with support from Pacific Northwest National Laboratory (PNNL), and sponsored by the U.S. Department of Energy Water Power Technologies Office (DOE WPTO), to support the development of innovative methods for excluding fish from water diversions and intakes: the Fish Protection Prize. Proposed solutions can include new ideas for addressing fish exclusion or improvements to existing technologies. Solutions can be applied to river and canal diversions, unscreened diversion pipes, or intakes at dams. In FY20 PNNL provided voucher support in the form of technical reviews and support, as well as graphics and presentation support, in helping the 9 finalists prepare for the Pitch Contest at the American Fisheries Society (AFS) virtual meeting. There were no subject inventions, patent applications, copyrights, and trademarks under this CRADA. The report herein provides an abstract of the presentation that the finalist presented at the American Fisheries Society virtual meeting in September 2020.

42 ENGINEERING↗
DOE OSTI2024

Dark SRF, a cavity-based search for the Dark Photon: new exclusion limit and path forward

The dark photon is a hypothesized particle in extension to the Standard Model (SM) that would weakly interact with ordinary SM photons. An effective way to search for hidden sector photons in a laboratory set up is through light-shining-through-wall (LSW) schemes.We present here the first results of Dark SRF, a LSW experiment that leverages ultra-high quality factor superconducting radio frequency (SRF) cavities to search for dark photons. The use of Nb SRF cavities combined with a strict calibration and measurement protocol increased sensitivity to dark photons by several orders of magnitude compared to other LSW experiments, as demonstrated by our new exclusion limit on the dark photon mixing angle.In addition to the results of the search conducted in liquid helium using 1.3GHz SRF cavities, we also present the first steps of the second phase of the experiment, which will take place in a dilution refrigerator using 2.6GHz SRF cavities.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Optical potential uncertainties on exclusive tens-of-MeV Ar cross sections

Large liquid argon time projection chamber (LArTPC) neutrino detectors, such as those planned for the Deep Underground Neutrino Experiment (DUNE), show considerable promise as a platform for next-generation measurements of supernova neutrinos. Thanks to the neutron excess in $^{40}$Ar as well as the detailed tracking possible with LArTPCs, these detectors are expected to be uniquely capable of measuring supernova electron neutrinos with high statistics and minimal backgrounds. However, these technological advantages come at the price of complexities in data interpretation; reconstruction of the incident energies of supernova neutrinos in a future LArTPC-based analysis will be subject to a variety of systematic uncertainties related to nuclear interaction modeling. In this talk, we present a study of a subset of these uncertainties as implemented in the MARLEY event generator used by DUNE and other LArTPC neutrino experiments. Variations to the optical potential used in the MARLEY nuclear de-excitation model are applied to the calculation of exclusive tens-of-MeV neutrino-nucleus cross sections for the first time, and the impact on observables of interest for supernova neutrino detection is examined. We also discuss prospects for quantifying other sources of uncertainty on the MARLEY neutrino interaction model.

El-Haj, Luca Abu↗
DOE OSTI2024

Cross Section Evaluation for Exclusive Channels of K+Λ and K+Σ0 Electroproduction off Protons Using CLAS Detector Data

In this work, a method for evaluating the cross sections of electroproduction of K+Λ0 and K+Σ0 off protons in the region of invariant masses of final hadrons MK + MY <W < 2.65 GeV (MK and MY being the masses of the kaon and hyperon, respectively) and squares of four-momentum transfers of virtual photons, i.e., photon virtualities 0 < Q2 < 5 GeV2, is developed based on experimental data of these exclusive channels’ cross sections measured by the CLAS detector in Hall B at Jefferson Lab. A set of algorithms has been implemented to evaluate the differential cross sections of these channels, along with their statistical and systematic uncertainties. A program was developed for the evaluation of differential cross sections and structure functions using C++ and Python libraries. An interactive website was created for working with the program, enabling the analysis of one-dimensional and two-dimensional dependences of structure functions and differential cross sections. The evaluation of differential cross sections for the K+Λ and K+Σ0 electroproduction channels is necessary for extracting the structure function σLT from the data on the polarization asymmetry of electroproduction reactions of these final states with longitudinally polarized electrons. The obtained results are also important for the development of realistic Monte Carlo event generators in planning future experiments and for evaluating the efficiency of detecting final particles when extracting reaction cross sections from experimental data.

Golda, A. V.↗
DOE OSTI2023

Throughfall exclusion and fertilization effects on tropical dry forest tree plantations, a large-scale experiment

Abstract. Across tropical ecosystems, global environmental change is causing drier climatic conditions and increased nutrient deposition. Such changes represent large uncertainties due to unknown interactions between drought and nutrient availability in controlling ecosystem net primary productivity (NPP). Using a large-scale manipulative experiment, we studied for 4 years whether nutrient availability affects the individual and integrated responses of aboveground and belowground ecosystem processes to throughfall exclusion in 30-year-old mixed plantations of tropical dry forest tree species in Guanacaste, Costa Rica. We used a factorial design with four treatments: control, fertilization (F), drought (D), and drought + fertilization (D + F). While we found that a 13 %–15 % reduction in soil moisture only led to weak effects in the studied ecosystem processes, NPP increased as a function of F and D + F. The relative contribution of each biomass flux to NPP varied depending on the treatment, with woody biomass being more important for F and root biomass for D + F and D. Moreover, the F treatment showed modest increases in maximum canopy cover. Plant functional type (i.e., N fixation or deciduousness) and not the experimental manipulations was the main source of variation in tree growth. Belowground processes also responded to experimental treatments, as we found a decrease in nodulation for F plots and an increase in microbial carbon use efficiency for F and D plots. Our results emphasize that nutrient availability, more so than modest reductions in soil moisture, limits ecosystem processes in tropical dry forests and that soil fertility interactions with other aspects of drought intensity (e.g., vapor pressure deficit) are yet to be explored.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Exclusive Four-pion Photoproduction in Ultra-peripheral Heavy-Ion Collisions at RHIC and LHC Energies

We study the photoproduction of exclusive 2π + 2 - mesons in ultraperipheral heavy-ion collisions at the RHIC and LHC energies. Predictions in photon–nucleus interactions are calculated for various resonances at central and forward rapidities. The recent H1 preliminary data are utilized to improve the description of the poorly known γp → 4π ± p process. We present the comparisons of our results to the available STAR data at RHIC, and made predictions for the LHC energies.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

From Elastic Scattering to Central Exclusive Production: Physics with Forward Protons at RHIC

In this work, we describe a physics program at the Relativistic Heavy Ion Collider (RHIC) with tagged forward protons. The program started with the proton-proton elastic scattering experiment (PP2PP), for which a set of Rosman Pot stations was built. The PP2PP experiment took data at RHIC as a dedicated experiment at the beginning of RHIC operations. To expand the physics program to include non-elastic channels with forward protons, like Central Exclusive Production (CEP), Central Production (CP) and Single Diffraction DIssociation (SD), the experiment with its equipment was merged with the STAR experiment at RHIC. Consequently the expanded program, which included both elastic and inelastic channels became part of the physics program and operations of the STAR experiment. In this paper we shall describe the physics results obtained by the PP2PP and STAR experiments to date.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS1968

User Manual for GERT EXCLUSIVE-OR Program

This report describes the procedures for using digital computer programs for analyzing GERT networks which contain nodes of the EXCLUSIVE-OR type and branches which have both a probability and a time associated with them. The time associated with a branch can be a random variable. The program calculates the probability, the expected time and the variance in the time to go from each source node of the GERT network to each sink node. Programs have been written in FORTRAN II and FORTRAN IV and have been exercised on the IBM 1130, GE 225 and CDC 3400 computers. This report details the operating procedures for using these programs. Four examples are included to illustrate the important facets involved in using the programs. Special options included in the program are: (1) printout of all loops and paths associated with the network; and (2) deletion of loops that have a probability of occurrence less than a value specified by the user. The program described in this report has been submitted to COSMIC.

Ishmael, Phillip C.↗