SEARCH · Engineering Papers
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.
Explore the source record for details and available documents.
Not provided.
The Muon $g-2$ experiment at Fermilab aims to measure the muon magnetic moment anomaly, $a_{\mu}=(g-2)/2$, with a final accuracy of 0.14 parts per million (ppm). The experiment’s first result was published in 2021, based on data collected in 2018, and in 2023 a new result was published based on two more years of data taking, 2019 and 2020. The combination of the two results from Fermilab and the previous one from Brookhaven National Laboratory brought the uncertainty on the experimental measurement of $a_{\mu}$ to the unprecedented value of 0.19 ppm. This paper will present details about the improvements of statistical and systematic uncertainties on $a_{\mu}$ since the 2021 result.
A detailed understanding of muon neutrino charged-current interactions on argon is crucial to the study of neutrino oscillations in current and future experiments using liquid argon time projection chambers. To help fill this need, MicroBooNE has produced a comprehensive set of cross section measurements which simultaneously probe the leptonic and hadronic systems by dividing the inclusive channel into final states with and without protons. Data-driven model validation utilizing the conditional constraint formalism is employed to detect mismodeling that may bias the nominal flux averaged cross section results, which are extracted with the Wiener-SVD unfolding method. The results are compared to widely used event generator predictions revealing significant mismodeling of final states without protons, possibly due to insufficient treatment of final state interactions. These are first differential muon neutrino-argon cross section measurements made simultaneously for final states with and without protons and provide novel information that will help stimulate the improvement of event generator modeling.
Registration and identification of muons and muon groups penetrating into the ocean depth, can be performed using a modular multilayer detector with high resolution bidimensional readout - deep underwater calorimeter (project NADIR). Laboratory testing of a prototype sensor cell with liquid scintillator in light-tight casing, testifies to the practicability of the full-scale experiment within reasonable expences.
The momentum measurement capability of the ATLAS muon spectrometer relies fundamentally on the intrinsic single-hit spatial resolution of the monitored drift tube precision tracking chambers. Optimal resolution is achieved with a dedicated calibration program that addresses the specific operating conditions of the 354 000 high-pressure drift tubes in the spectrometer. The calibrations consist of a set of timing offsets and drift time to drift distance transfer relations, and result in chamber resolution functions. This paper describes novel algorithms to obtain precision calibrations from data collected by ATLAS in LHC Run 2 and from a gas monitoring chamber, deployed in a dedicated gas facility. The algorithm output consists of a pair of correction constants per chamber which are applied to baseline calibrations, and determined to be valid for the entire ATLAS Run 2. The final single-hit spatial resolution, averaged over 1172 monitored drift tube chambers, is $81.7 \pm 2.2 \mu$m.
The six-dimensional ionization cooling is essential to design a bright muon source. A geometry constraint is a challenge issue in a compact helical cooling channel (HCC). Especially, the HCC requires a large bore helical magnet and a compact helical RF system to incorporate the RF into the magnet chamber. A new emittance evolution has been designed to mitigate the geometry constraint. The HCC was functionally separated into three parts sections. The lattice at the initial section provides a large transverse acceptance by using a strong helical focus magnet. Once the transverse beam size is small enough to get into the compact RF the HCC lattice in the middle section generates a large longitudinal beta tune to dominate the longitudinal cooling. Consequently, the longitudinal emittance becomes smaller than the transverse one at the end of middle section. In the final section, the magnetic field strength is gradually reduced to match out the helical channel to the straight solenoid. As a result, the emittance exchange takes place and the final transverse emittance becomes smaller than the longitudinal one. The new emittance evolution scenario will be discussed in this presentation.
In this work we carried out the disappearance analysis of muon neutrinos produced in the Fermilab Booster Neutrino Beam, using the data released to the public by the collaborations of the MiniBooNE and SciBooNE experiments. The calculations were made with programs in C and C++, implementing the ROOT libraries. From the analysis, using both the classical Pearson method and the Feldman and Cousins frequentist corrections, we obtained the 90\% C.L. limit for the oscillation parameters sin 2 2θ and Δm 2 in the region 0.1 ≤ Δm 2 ≤ 10 eV 2 using a two neutrino model. The result presented in this work is consistent with the official one, with small deviations ascribed to round-off errors in the format of the used data, as well as statistical fluctuations in the generation of fake experiments used in the Feldman and Cousins method. As the official one, our result is consistent with the null oscillation hypothesis. This work was carried out independently to the MiniBooNE and SciBooNE collaborations and its results are not official.
We use the NOvA near detector and the NuMI beam at Fermilab to study the neutrino- electron elastic scattering and the muon neutrino magnetic process beyond the Standard Model physics. The particle identications of neutrino on electron elastic scattering are trained by using the multi-layer neural networks. This thesis provides a general discussion of this technique and shows a good agreement between data and MC for the neutrino-electron elastic weak scattering. So that beneting from the precise cross-section of this channel, we are able to tune the neutrino beam ux simulation in the future. Giving the exposure of 3:62 1020 POT in the NOvA near detector, we report 1:58 10
we discuss a new facility for CLFV at Fermilab and its relation to the muon collider R&D
The Fermilab E989 Muon g-2 experiment aims to measure
Not Available
A study of the decays B s 0 → μ + μ – and B 0 → μ + μ – has been performed using 26.3 fb –1 of 13 TeV LHC proton-proton collision data collected with the ATLAS detector in 2015 and 2016. Since the detector resolution in μ + μ – invariant mass is comparable to the B s 0 -B 0 mass difference, a single fit determines the signal yields for both decay modes. This results in a measurement of the branching fraction B(B s 0 → μ + μ – ) = (3.2 +1.1 –1.0 ) × 10 –9 and an upper limit B(B 0 → μ + μ – ) < 4.3×10 –10 at 95% confidence level. The result is combined with the Run 1 ATLAS result, yielding B(B s 0 → μ + μ – ) = (2.8 +0.8 –0.7 ) × 10 –9 and B(B 0 → μ + μ – ) < 2.1 × 10 –10 at 95% confidence level. The combined result is consistent with the Standard Model prediction within 2.4 standard deviations in the B(B 0 → μ + μ – ) – B(B 0 s → μ + μ – ) plane.
The angular distributions of Drell-Yan charged lepton pairs in the vicinity of the Z-boson mass peak probe the underlying QCD dynamics of Z-boson production. This paper presents a measurement of the complete set of angular coefficients A 0–7 describing these distributions in the Z-boson Collins-Soper frame. The data analysed correspond to 20.3 fb –1 of pp collisions at √s = 8 TeV, collected by the ATLAS detector at the CERN LHC. The measurements are compared to the most precise fixed-order calculations currently available (O(α2s)) and with theoretical predictions embedded in Monte Carlo generators. The measurements are precise enough to probe QCD corrections beyond the formal accuracy of these calculations and to provide discrimination between different parton-shower models. A significant deviation from the (O(α 2 s )) predictions is observed for A 0 – A 2 . In conclusion, evidence is found for non-zero A 5,6,7 , consistent with expectations.
Not Available
Not provided.