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Results for “measurement precision”

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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Hadron Structure in Electroweak Precision Measurements

Precision measurements offer important, low-energy tests of the Standard Model. The Qweak and (proposed) MOLLER experiments at Jefferson Lab are two such measurements. Since the interpretation of the experimental results depends on the precision of the theory prediction, radiative corrections need to be properly accounted for. In this thesis we examine the γZ box correction to the the weak charge of the proton.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems

Interest in the production of printed electronics using a roll-to-roll system has gradually increased due to its low mass-production costs and compatibility with flexible substrate. To improve the accuracy of roll-to-roll manufacturing systems, the movement of the web needs to be measured precisely in advance. In this paper, a novel measurement method is developed to measure the displacement and velocity of the web precisely and directly. The proposed algorithm is based on the traditional single field encoder principle, and the scale grating has been replaced with a printed grating on the web. Because a printed grating cannot be as accurate as a scale grating in a traditional encoder, there will inevitably be variations in pitch and line-width, and the motion of the web should be measured even though there are variations in pitch and line-width in the printed grating patterns. For this reason, the developed algorithm includes a precise method of estimating the variations in pitch. In addtion, a method of correcting the Lissajous curve is presented for precision phase interpolation to improve measurement accuracy by correcting Lissajous circle to unit circle. The performance of the developed method is evaluated by simulation and experiment. In the experiment, the displacement error was less than 2.5 μm and the velocity error of 1σ was about 0.25%, while the grating scale moved 30 mm.

36 MATERIALS SCIENCE↗
DOE OSTI2013

High precision measurement of the proton charge radius: The PRad experiment

The recent high precision measurements of the proton charge radius performed at PSI from muonic hydrogen Lamb shift puzzled the hadronic physics community. A value of 0.8418 ± 0.0007 fm was extracted which is 7σ smaller than the previous determinations obtained from electron-proton scattering experiments and based on precision spectroscopy of electronic hydrogen. An additional extraction of the proton charge radius from electron scattering at Mainz is also in good agreement with these 'electronic' determinations. An independent measurement of the proton charge radius from unpolarized elastic ep scattering using a magnetic spectrometer free method was proposed and fully approved at Jefferson Laboratory in June 2012. This novel technique uses the high precision calorimeter HyCal and a windowless hydrogen gas target which makes possible the extraction of the charge radius at very forward angles and thus very low momentum transfer Q{sup 2} up to 10{sup −4} (GeV/c){sup 2} with an unprecedented sub-percent precision for this type of experiment. In this paper, after a review of the recent progress on the proton charge radius extraction and the new high precision experiment PRad will be presented.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2012

Precise measurement of the CP violation parameter sin 2Φ 1 in B 0 → (c$\bar{c}$)K 0 decays

We present a precise measurement of the CP violation parameter sin2$\phi$ 1 and the direct CP violation parameter $A$ f using the final data sample of 772×10 6 $B\overline{B}$ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e + e - collider. One neutral B meson is reconstructed in a J/ψK$0\atop{S}$, ψ(2S)K$0\atop{S}$, χc1K$0\atop{S}$, or J/ψK$0\atop{L}$ CP eigenstate and its flavor is identified from the decay products of the accompanying B meson. From the distribution of proper-time intervals between the two B decays, we obtain the following CP violation parameters: sin2 $\phi$ 1 =0.667±0.023(stat)±0.012(syst) and $A$ f =0.006±0.016(stat)±0.012(syst).

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2013

Correlated, precision measurements of θ 23 and δ using only the electron neutrino appearance experiments

Precision measurement of the leptonic CP violating phase δ will suffer from the, then surviving, large uncertainty of sin 2 θ 23 of 10–20% in the experimentally interesting region near maximal mixing of θ 23 . We advocate a new method for determination of both θ 23 and δ at the same time using only the ν e and ν̄ e appearance channels and show that sin 2 θ 23 can be determined automatically with much higher accuracy, approximately a factor of six, than sinδ. In this method, we identify a new degeneracy for the simultaneous determination of θ 23 and δ, the θ 23 intrinsic degeneracy, which must be resolved in order to achieve precision measurement of these two parameters. Spectral information around the vacuum oscillation maxima is shown to be the best way to resolve this degeneracy.

Minakata, Hisakazu↗
DOE OSTI2013

Precision Measurement of Charged Pion and Kaon Differential Cross Sections in e + e - Annihilation at s = 10.52 GeV

Measurements of inclusive differential cross sections for charged pion and kaon production in e + e - annihilation have been carried out at a center-of-mass energy of s = 10.52 GeV . The measurements were performed with the Belle detector at the KEKB e + e - collider using a data sample containing 113 × 10 6 e + e - → q q ¯ events, where q = { u , d , s , c } . We present charge-integrated differential cross sections d σ h ± / d z for h ± = { π ± , K ± } as a function of the relative hadron energy z = 2 E h / s from 0.2 to 0.98. The combined statistical and systematic uncertainties for π ± ( K ± ) are 4% (4%) at z ~ 0.6 and 15% (24%) at z ~ 0.9 . The cross sections are the first measurements of the z dependence of pion and kaon production for z > 0.7 as well as the first precision cross section measurements at a center-of-mass energy far below the Z 0 resonance used by the experiments at LEP and SLC.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Precision measurement of the top-quark mass in lepton+jets final states

We measure the mass of the top quark in lepton$+$jets final states using the full sample of $p\bar{p}$ collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at $\sqrt s=1.96 $TeV, corresponding to $9.7 {\rm fb}^{-1}$ of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from $t\bar t$ production or background. The overall jet energy scale is constrained in situ by the mass of the $W$ boson. We measure $m_t=174.98\pm0.76$ GeV. In conclusion, this constitutes the most precise single measurement of the top-quark mass.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Dynamic Differential Image Circle Diameter Measurement Precision Assessment: Application to Burning Droplets

Dynamic measurement precision assessment has been achieved for a differential circle measurement application. Differential circle diameter measurement, in image analysis, typically requires fitting a circle model that optimizes for image distortions, defects or occlusions. The differential task occurs when precise measurements of diameter change are required given object size variation with time. An automated system was designed to provide diameter measurements and associated measurement precision of images of a fuel droplet undergoing combustion in zero gravity for the FLEX-2 dataset. An image gradient-based, least-squares boundary point fitting method to a circle or ellipse model is used for diameter measurement. The presence of soot aggregates poses significant challenges for diameter measurements when it occludes part of the droplet boundary. The precision of the diameter measurements depends upon the image quality. Using synthetic image simulations that model the soot behavior, we developed a model based on image quality measures that assesses the measurement precision for each individual diameter measurement. Thus, diameter measurements with precision assessments were made available for follow-up scientific analysis. As a result, the algorithm's success rate for measurable runs was 98%. In cases of limited occlusion, a measurement precision of ±0.2 pixels for the FLEX-2 dataset was achieved.

42 ENGINEERING↗