Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “GeV”

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 901 records · Page 50

A Heavy Ion Fireball freeze-out Dipion Cocktail for Au-Au Collisions at $\sqrt{S_{NN}}$ = 200 GeV $p_t$ dependence (Part 3)

In this paper we use methods developed in Part 1 of The Dipion Cocktail, to fit the $p_t$ dependence of dipions for mid-central Au-Au collisions at $\sqrt{S_{NN}}$=200 GeV. For the minijet fragmentation part we use PYTHIA fragmentation as described in Part 1. For the thermal resonance production we use an exponential growth behavior. The interference between the direct production of dipion pairs from non-resonance minijet fragmentation and re-scattering through resonance states gives a measure of the size of the re-scattering region. This size is contain in the α parameter of Part1. We assumed a relationship between the α parameter and the mass shift of the ρ resonance. The data used for the fits comes from the RHIC collider as measured in the STAR experiment.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Measurement of the Parity-Violating Asymmetry in Deep Inelastic Scattering at JLab 6 GeV

The parity-violating asymmetry in deep inelastic scattering (PVDIS) offers us a useful tool to study the weak neutral couplings and the hadronic structure of the nucleon, and provides high precision tests on the Standard Model. During the 6 GeV PVDIS experiment at the Thomas Jefferson National Accelerator Facility, the parity-violating asymmetries A{sub PV} of a polarized electron beam scattering off an unpolarized deuteron target in the deep inelastic scattering region were precisely measured at two Q 2 values of 1.1 and 1.9 (GeV/c) 2 . The asymmetry at Q 2 =1.9 (GeV/c) 2 can be used to extract the weak coupling combination 2C 2u - C 2d , assuming the higher twist effect is small. The extracted result from this measurement is in good agreement with the Standard Model prediction, and improves the precision by a factor of five over previous data. In addition, combining the asymmetries at both Q 2 values provides us extra knowledge on the higher twist effects. The parity violation asymmetries in the resonance region were also measured during this experiment. These results are the first A PV data in the resonance region beyond the Δ (1232). They provide evidence that the quark hadron duality works for A PV at the (10-15)% level, and set constraints on nucleon resonance models that are commonly used for background calculations to other parity-violating electron scattering measurements.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Measurement of the Muon Neutrino Double-Differential Charged Current Quasi-Elastic Like Cross Section on a Hydrocarbon Target at E v ~ 3.5 GeV

The MINERvA Experiment (Main Injector Experiment v ₋ A interaction) [1] is a highly segmented detector of neutrinos, able to record events with high precision (over than thirteen million event in a four year run), using the NuMI Beam (Neutrino Main Injector) at the Fermi National Accelerator Laboratory [2]. This thesis presents a measurement of the Charged Current Quasi-Elastic Like1 vμ interaction on polystyrene scintillator (CH) in the MINERvA experiment with neutrino energies between 1.5 and 10 GeV. We use data taken between2 March 2010 and April 2012. The interactions were selected by requiring a negative muon, a reconstructed and identified proton, no michel electrons in the final state (in order to get rid of soft pions decaying) and a low calorimetric recoil energy away from the interaction vertex. The analysis is performed on 66,214 quasi-elastic like event candidates in the detectors tracker region with an estimated purity of 74%. The final measurement reported is a double differential cross sections in terms of the muon longitudinal and transversal momentum observables.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Measurement of Muon Neutrino Quasi-Elastic-Like Scattering on a Hydrocarbon Target at ${\bf E_{\nu}} \sim $ 6 GeV

The MINERA Experiment (Main Injector Experiment $\nu$ -A interaction) is a highly segmented detector of neutrinos, able to record events with high precision using the NuMI Beam (Neutrino Main Injector) at the Fermi National Accelerator Laboratory. In this thesis, we present the rst measurement of the charged current quasi-elastic-like interaction on polystyrene scintillator (CH) in the MINERA detector at neutrino energies around 6 GeV. The dataset used was taken between 2013 and 2014 with a total of 1:17 x $10^{21}$ protons on target. The interactions were selected by requiring a negative muon, a reconstructed and identied proton, no michel electrons in the nal state (in order to get rid of soft pions decaying) and a low calorimetric recoil energy away from the interaction vertex. The nal measurement reported is a dierential cross section in terms of the muon quadratic transfered energy $Q^{2}$.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

PHENIX results on centrality dependence of yields and correlations in d plus Au collisions at root s(NN)=200 GeV

PHENIX has measured the transverse momentum (pT) spectra and two particle angular correlations for high pT particles in d+Au collisions at psNN=200 GeV using the RHIC Year-2008 run data. The azimuthal angle correlations for two particles with a large rapidity gap exhibit a ridge-like structure. Using the pi-0s reconstructed in the EMCal, we have successfully extended the pT reach of the correlation up to 8 GeV/c. We find that the azimuthal anisotropy of hadrons found at low pT persists up to 6 GeV/c with a significant centrality and pT dependence, similar to what was observed in A+A collisions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Parton Dynamics Inferred from High-Mass Drell-Yan Dimuons Induced by 120 GeV p+D Interactions

Fermilab Experiment 906/SeaQuest (E906/SeaQuest) is the latest in a well established tradition of studying leptoproduction from the annihilation of a quark and anti-quark, known as the Drell-Yan process. The broad goal of E906/SeaQuest is measuring various properties of nucleon structure in order to learn more about quarks and Quantum Chromodynamics (QCD), the mathematical description of the strong force. The present work investigated violations of the Lam-Tung relation between virtual photon polarization and quark and lepton angular momentum. The violation of Lam-Tung can be explained as the signature of quark-nucleon spin-orbit coupling through the use of the Transverse-Momentum-Dependent (TMD) framework, which assumes that the initial transverse momentum of quarks is smaller than the hard scattering scale, but also non-negligible. An analysis of the angular moments in Drell-Yan collected by E906/SeaQuest was performed with four different configurations in order to estimate the systematic errors attributed to each correction. After correction for background and error propagation, the final extraction of the azimuthal moment excluding contributions from the trigger was ν = 0.151 ± 0.88(stat.) ± 0.346(syst.) at an average transverse momentum of 0.87 ± 0.50 GeV/c and an average dimuon mass of 5.48 ± 0.70 GeV. In the future, the magnitude of the systematic errors on the extraction could potentially be reduced by improving the quality of the trigger efficiency calculation, improving the intensity dependent event reconstruction efficiency, considering the changes in acceptance due to a beam shift relative to the E906/SeaQuest spectrometer, and improving the modeling of background.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Measurement of Neutrino Absolute Deep Inelastic Scattering Cross Section in Iron, Lead, Carbon, and Plastic Using MINERvA Detector at $E_{\nu} = 6$ \GeV

A deep inelastic sample is selected from the nuclear charged current inclusive analysis, by requiring reconstructed $Q^{2} \geq 1.0$ (GeV/c)$^{2}$ and $W \geq 2.0$ GeV/c$^{2}$. The neutrino energy range of $5 < E_{\nu} < 50$ previously applied to this analysis in the Low Energy (LE) analysis is removed and the energy range cut is imposed on the muon energy from $2 < E_{\mu} < 50$ GeV. Machine learning vertexing is used to improve the track-based vertexing resulting in higher purity and efficiency of the sample. A local sideband method is utilized to remove the plastic background for the events reconstructed in the target. After plastic backgrounds and non-DIS backgrounds are subtracted, the reconstructed neutrino energy and Bjorken-x are unsmeared to their true quantities via Bayesian unfolding. The unfolded distributions of carbon, iron, lead, and plastic are efficiency corrected and then divided by the flux and the number of nucleons in the target to produce the absolute cr oss section as a function of $E_{\nu}$ and differential cross section as function of $x_{bj}$. The results of the analysis show good agreement between data and MC for $E_{\nu}$ and $x_{bj}$ (see Figures \ref{fig:xsecEnuC} through \ref{fig:xsecXCH}). None of the distributions displayed significant differences with the theoretical models underlying MINERvAs MC.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

First Measurements of Inclusive Muon Neutrino Charged Current Differential Cross Sections on Argon at 0.8 GeV Average Neutrino Energy with the MicroBooNE Detector

Current and next-generation precision neutrino oscillation experiments aim to determine the neutrino mass ordering, to measure the extent of CP violation in the lepton sector and to probe beyond Standard Model physics, such as sterile neutrinos. These experiments rely on models for neutrino interactions with matter that are complicated by nuclear effects and final state interactions. To date, these effects cannot be modelled precisely, especially for heavy target nuclei, typically used in modern neutrino experiments. Many future experiments will employ detectors based on the liquid argon time projection chamber technology. As a consequence, neutrino-argon cross-section measurements are of the outmost importance, especially given the relative scarcity of neutrino-argon data, due to the novelty of the technology. This thesis presents the first measurement of muon-neutrino charged-current inclusive cross section on argon at a mean neutrino energy of 0.8 GeV. Data were collected using the MicroBooNE liquid argon time projection chamber in the Fermilab Booster neutrino beam during a period of six months, corresponding to an exposure of $1.6 \times 10^{20}$ protons on target. The measured cross section is presented as a function of the outgoing muon momentum, using multiple Coulomb scattering as a measurement technique, as well as the muon angle with respect to the beam direction. A comparison of the measured cross section obtained with two different configurations of the \textsc{Genie} neutrino event generator is performed, and better agreement is found when using nuclear-effect modelling in the theoretical calculations. Additionally, the total flux integrated cross section is measured to be $0.693 \pm 0.010 \, (\text{stat.}) \pm 0.165 \, (\text{syst.}) \times 10^{-38} \, \text{cm}^{2}$.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

SBN-BD: O(10 GeV) Proton Beam Dump at Fermilab’s PIP-II Linac

Proton beam dumps are prolific sources of mesons enabling a powerful technique to search for vector mediator coupling of dark matter to neutral pion and higher mass meson decays. By the end of the decade the PIP-II linac will be delivering up to 1 MW of proton power to the FNAL campus. This includes a significant increase of power to the Booster Neutrino Beamline (BNB) which delivers 8 GeV protons to the Short Baseline Neutrino (SBN) detectors. By building a new dedicated beam dump target station, and using the SBN detectors, a greater than an order of magnitude increase in search sensitivity for dark matter relative to the recent MiniBooNE beam dump search can be achieved. This modest cost upgrade to the BNB would begin testing models of the highly motivated relic density limit predictions and provide novel ways to test explanations of the anomalous excess of low energy events seen by MiniBooNE.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

SBN-BD: $\mathcal{O}$(10 GeV) Proton Beam Dump at Fermilab&#x27;s PIP-II Linac

Proton beam dumps are prolific sources of mesons enabling a powerful technique to search for vector mediator coupling of dark matter to neutral pion and higher mass meson decays. By the end of the decade the PIP-II linac will be delivering up to 1 MW of proton power to the FNAL campus. This includes a significant increase of power to the Booster Neutrino Beamline (BNB) which delivers 8 GeV protons to the Short Baseline Neutrino (SBN) detectors. By building a new dedicated beam dump target station, and using the SBN detectors, a greater than an order of magnitude increase in search sensitivity for dark matter relative to the recent MiniBooNE beam dump search can be achieved. This modest cost upgrade to the BNB would begin testing models of the highly motivated relic density limit predictions and provide novel ways to test explanations of the anomalous excess of low energy events seen by MiniBooNE.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

PIP2-BD: GeV Proton Beam Dump at Fermilab's PIP-II Linac

The PIP-II superconducting RF linac is currently under construction at Fermilab and is expected to be completed by the end of 2028. PIP-II is capable of operating in a continuous-wave mode and can concurrently supply 800 MeV protons to a mega-watt, GeV-scale beam dump facility and to LBNF/DUNE. Designs for proton accumulator rings are being studied to bunch the PIP-II protons into the short pulses needed for neutrino and low-mass dark matter experiments. PIP2-BD is a proposed 100-ton LAr scintillation-only experiment, whose detector design is inspired by CENNS-10 and CCM, that would have world-leading sensitivities to BSM physics, including low-mass dark matter produced in the PIP-II proton beam dump.

42 ENGINEERING↗

System Downtime Management at 12 GeV CEBAF

Jefferson Lab?s Accelerator Division uses two independent web based applications for Beam Time Accounting and System Downtime tracking. The Beam Time Accounting application acts as the accelerator time clock, while the Downtime Manager application monitors individual system performance. Accelerator system health is important to quantify in order to effectively and efficiently utilize limited resources for performance improvements. Jefferson Lab?s Accelerator Operability Group has historically tracked System Downtime by gathering failure data via Operator input. A recent overhaul of that process has been implemented which includes failure guidelines, a new web based application/reporting application, and Operator training. The new process was implemented at the start of CEBAF?s 12 GeV Commissioning to document system failures during commissioning, identify ?infant mortality? failures, and improve the Downtime Manager application prior to production running. This discussion will focus on the journey of implementing the modified system downtime process and the vision of future improvements for CEBAF operations.

Michaud, Randy↗

Study of TMDs with SoLID at 12-GeV Jefferson Lab

Solenoidal Large Intensity Device (SoLID) was proposed at JLab to take the full advantage of the 12-GeV upgrade. SoLID is designed to handle high luminosities with large acceptance, which is ideal for measuring transverse momentum depended parton distribution functions (TMDs). Currently there is a highly-rated approved program focusing on the study of TMDs using semi-inclusive deep inelastic scattering (SIDIS) with longitudinal/transversely polarized 3He target and a transversely polarized proton target. These experiments will provide a comprehensive set of data on proton and neutron (effective) in a wide range of kinematics, allowing us to perform precise 4-d (x, Q^2, P_T, z) mapping of leading-twist TMDs related spin asymmetries. The future SoLID data will allow for a precise extraction of nucleon tensor charge, and important TMDs such as Sivers, pretzelosity and worm-gear functions in the valence quark region. In this talk we will present the impact of future SoLID data on the extraction of tensor charge and Sivers function of u and d-quarks.

Allada, Kalyan↗

Spin Structure with JLab 6 and 12 GeV

Selected results from JLab spin experiments were presented with focus on the moments of the spin structure functions, including GDH, Bjorken and B-C sum rules, polarizabilities and Color Lorentz Force. Planned spin program with 12 GeV JLab is also discussed.

Chen, Jian-Ping↗