Precise Measurements Of Beam Spin Asymmetries In Semi-Inclusive Π0 Production,
2011
Old Dominion University
Precise Measurements Of Beam Spin Asymmetries In Semi-Inclusive Π0 Production, M. Aghasyan, H. Avakian, P. Rossi, E. De Sanctis, D. Hasch, M. Mirazita, D. Adikaram, M. J. Amaryan, M. Anghinolfi, H. Baghdasaryan, R. P. Bennett, S. Bültmann, G. E. Dodge, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, H. Seraydaryan, L. B. Weinstein
Physics Faculty Publications
We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial sin phi(h) amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle φh of the produced neutral pion. The dependence of this amplitude on Bjorken x and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations. (C) 2011 Elsevier B.V.
Evolution Of The Differential Transverse Momentum Correlation Function With Centrality In Au + Au Collisions At √Snn = 200 Gev,
2011
Old Dominion University
Evolution Of The Differential Transverse Momentum Correlation Function With Centrality In Au + Au Collisions At √Snn = 200 Gev, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arhipkin, G. S. Averichev, S. Bültmann, D. Plyku
Physics Faculty Publications
We present first measurements of the evolution of the differential transverse momentum correlation function, C, with collision centrality in Au + Au interactions at √sNN = 200 GeV. This observable exhibits a strong dependence on collision centrality that is qualitatively similar to that of number correlations previously reported. We use the observed longitudinal broadening of the near-side peak of C with increasing centrality to estimate the ratio of the shear viscosity to entropy density, η / s , of the matter formed in central Au + Au interactions. We obtain an upper limit estimate of η / s …
Two-Body Photodisintegration Of 3he Between 7 And 16 Mev,
2011
Old Dominion University
Two-Body Photodisintegration Of 3he Between 7 And 16 Mev, W. Tornow, H. J. Karwowski, J. H. Kelley, R. Raut, G. Rusev, S. C. Stave, A. P. Tonchev, A. Deltuva, A. C. Fonseca, L. E. Marcucci, R. Schiavilla
Physics Faculty Publications
A comprehensive data set is reported for the two-body photodisintegration cross section of 3He using mono-energetic photon beams at eleven energies between 7.0 and 16.0 MeV. A 3He + Xe high-pressure gas scintillator served as target and detector. Although our data are in much better agreement with our state-of-the-art theoretical calculations than the majority of the previous data, these calculations underpredict the new data by about 10%. This disagreement suggests an incomplete understanding of the dynamics of the three-nucleon system and its response to electromagnetic probes.
Experimental Results In Dis, Sidis And Des From Jefferson Lab,
2011
Old Dominion University
Experimental Results In Dis, Sidis And Des From Jefferson Lab, Sebastian E. Kuhn
Physics Faculty Publications
Jefferson Lab’s electron accelerator in its present incarnation, with a maximum beam energy slightly above 6 GeV, has already enabled a large number of experiments expanding our knowledge of nucleon and nuclear structure (especially in Deep Inelastic Scattering—DIS—at moderately high x, and in the resonance region). Several pioneering experiments have yielded first results on Deeply Virtual Compton Scattering (DVCS) and other Deep Exclusive Processes (DES), and the exploration of the rich landscape of transverse momentum‐dependent (TMD) structure functions using Semi‐Inclusive electron scattering (SIDIS) has begun. With the upgrade of CEBAF to 12 GeV now underway, a significantly larger kinematic …
Photoproduction Of The Φ(1020) Meson In Neutral Decay Mode Γp → Φp → K(S)K(L)P,
2011
Old Dominion University
Photoproduction Of The Φ(1020) Meson In Neutral Decay Mode Γp → Φp → K(S)K(L)P, Heghine Seraydaryan
Physics Theses & Dissertations
The Φ(1020) meson photoproduction cross sections in the neutral decay mode Φ → KSKL are measured for the first time. This work presents measurements of differential cross sections, dσ/dt, dσ/d cos θΦc.m.; Φ decay angular distributions, W(cos θ) and W(Φ), and spin-density matrix elements, ρ0, in the Helicity and Gottfried-Jackson frames, in the energy range 1.6 GeV < Eγ < 2.6 GeV. We analyzed the photoproduction data of the g11a experiment collected on an LH2 target using the CLAS detectector at Hall B, TJNAF. The measured cross sections show some differences from the charged decay mode Φ → K+ K−.
Anisotropic Response Of Nanosized Bismuth Films Upon Femtosecond Laser Excitation Monitored By Ultrafast Electron Diffraction,
2011
Old Dominion University
Anisotropic Response Of Nanosized Bismuth Films Upon Femtosecond Laser Excitation Monitored By Ultrafast Electron Diffraction, Ahmed R. Esmail, Hani E. Elsayed-Ali
Electrical & Computer Engineering Faculty Publications
The lattice response of 5 nm thick bismuth film to femtosecond laser excitation is probed by ultrafast electron diffraction. The transient decay time after laser excitation is greater for diffraction from (012) lattice planes compared to (110) planes and is reduced for both planes with the increased laser fluence. These results indicate that different energy coupling mechanisms to the lattice occur depending on the crystal direction. The behavior of the diffraction peak width indicates partial disorder of the film upon photoexcitation that increases together with the laser fluence. © 2011 American Institute of Physics. [doi:10.1063/1.3652919]
Polarization Observables In Deuteron Photodisintegration Below 360 Mev,
2011
Saint Mary's University
Polarization Observables In Deuteron Photodisintegration Below 360 Mev, J. Glister, G. Ron, B. W. Lee, R. Gilman, A. J. Sarty, S. Strauch, D. W. Higinbotham, E. Piasetzky, K. Allada, W. Armstrong, J. Arrington, H. Arenhövel, A. Beck, F. Benmokhtar, B. L. Berman, W. Boeglin, E. Brash, A. Camsonne, J. Calarco, J. P. Chen, S. Choi, E. Chudakov, L. Coman, B. Craver, F. Cusanno, J. Dumas, C. Dutta, R. Feuerbach, A. Freyberger, S. Frullani, F. Garibaldi, J. -O. Hansen, T. Holmstrom, C. E. Hyde, H. Ibrahim, Y. Ilieva, C. W. De Jager, X. Jiang, M. K. Jones, Hyekoo Kang, A. Kelleher, E. Khrosinkova, E. Kuchina, G. Kumbartzki, J. J. Lerose, R. Lindgren, P. Markowitz, S. May-Tal Beck, E. Mccullough, D. Meekins, M. Meziane, Z. -E. Meziani, R. Michaels, B. Moffit, B. E. Norum, Y. Oh, M. Olson, M. Paolone, K. Paschke, C. F. Perdrisat, M. Potokar, R. Pomatsalyuk, I. Pomerantz, A. Puckett, V. Punjabi, X. Qian, Y. Qiang, R. D. Ransome, M. Reyhan, J. Roche, Y. Rousseau, A. Saha, B. Sawatzky, E. Schulte, M. Schwamb, M. Shabestari, A. Shahinyan, R. Shneor, S. Širca, K. Slifer, P. Solvignon, J. Song, R. Sparks, R. Subedi, G. M. Urciuoli, K. Wang, B. Wojtsekhowski, X. Yan, H. Yao, X. Zhan, X. Zhu
Physics Faculty Publications
High precision measurements of induced and transferred recoil proton polarization in d(γ→,p→)n have been performed for photon energies of 277–357 MeV and θcm = 20°–120°. The measurements were motivated by a longstanding discrepancy between meson–baryon model calculations and data at higher energies. At the low energies of this experiment, theory continues to fail to reproduce the data, indicating that either something is missing in the calculations and/or there is a problem with the accuracy of the nucleon–nucleon potential being used.
Short-Distance Structure Of Nuclei,
2011
Thomas Jefferson National Accelerator Facility
Short-Distance Structure Of Nuclei, D. W. Higinbotham, E. Piasetzky, L. Weinstein, S. A. Wood
Physics Faculty Publications
One of Jefferson Lab's original missions was to further our understanding of the short-distance structure of nuclei, in particular, to understand what happens when two or more nucleons within a nucleus have strongly overlapping wave-functions – a phenomena commonly referred to as short-range correlations. Herein, we review the results of the (e, e'), (e, e'p) and (e, e'pN) reactions that have been used at Jefferson Lab to probe this short-distance structure as well as provide an outlook for future experiments.
Analysis Of Electrodeposited Nickel-Iron Alloy Film Composition Using Particle-Induced X-Ray Emission,
2011
Hope College
Analysis Of Electrodeposited Nickel-Iron Alloy Film Composition Using Particle-Induced X-Ray Emission, Alyssa Frey, Nicholas Wozniak, Timothy Nagi, Matthew Keller, J. Mark Lunderberg, Graham F. Peaslee, Paul Deyoung, Jennifer R. Hampton
Faculty Publications
The elemental composition of electrodeposited NiFe thin films was analyzed with particle-induced X-ray emission (PIXE). The thin films were electrodeposited on polycrystalline Au substrates from a 100mM NiSO4, 10 mM FeSO4, 0.5M H3BO3, and 1M Na2SO4 solution. PIXE spectra of these films were analyzed to obtain relative amounts of Ni and Fe as a function of deposition potential and deposition time. The results show that PIXE can measure the total deposited metal in a sample over at least four orders of magnitude with similar fractional uncertainties. The technique is …
Measurement Of Single- And Double-Spin Asymmetries In Deep Inelastic Pion Electroproduction With A Longitudinally Polarized Target,
2010
University of Richmond
Measurement Of Single- And Double-Spin Asymmetries In Deep Inelastic Pion Electroproduction With A Longitudinally Polarized Target, H. Avakian, Gerard P. Gilfoyle, Et. Al.
Physics Faculty Publications
We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes φ have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q2. A significant nonzero sin2φ single spin asymmetry was observed for the first time indicating strong spin-orbit …
Implementation Of The Clas12 Htcc Into Gemc,
2010
University of Connecticut - Storrs
Implementation Of The Clas12 Htcc Into Gemc, Nathan A. Harrison
Master's Theses
No abstract provided.
Speciation And Spectroscopy Of The Uranyl And Tetravalent Plutonium Nitrate Systems: Fundamental Studies And Applications To Used Fuel Reprocessing,
2010
University of Nevada, Las Vegas
Speciation And Spectroscopy Of The Uranyl And Tetravalent Plutonium Nitrate Systems: Fundamental Studies And Applications To Used Fuel Reprocessing, Nicholas A. Smith
UNLV Theses, Dissertations, Professional Papers, and Capstones
This dissertation explores the use of UV-Visible spectroscopy and Time Resolved Laser Induced Fluorescence spectroscopy as near real time process monitors of uranium and plutonium concentrations in aqueous reprocessing trains. The molar absorptivities and linear ranges of these metals were investigated under total nitrate and acid concentrations similar to those found in current reprocessing systems. Concurrent to this, a new multiple wavelength monitor was derived that is capable of determining the total nitrate concentration spectroscopically. This method uses the uranium absorbance spectrum to calculate the nitrate concentration in solution. When used as part of an Advanced Safeguard suite, this technique …
Tensor Correlations Measured In 3He(E,E',Pp)N,
2010
University of Richmond
Tensor Correlations Measured In 3He(E,E',Pp)N, H. Baghdasaryan, Gerard P. Gilfoyle, Et. Al.
Physics Faculty Publications
We have measured the 3He(e, e', pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum ptot. For pair relative momenta between 0.3 and 0:5 GeV / c, the ratio is very small at low ptot and rises to approximately 0.5 at large ptot. This …
Tensor Correlations Measured In 3he(E,E' Pp)N,
2010
Old Dominion University
Tensor Correlations Measured In 3he(E,E' Pp)N, H. Baghdasaryan, L. B. Weinstein, J. M. Laget, K. P. Adhikarii, M. Aghasyan, M. Amarian, M. Anghinolfi, H. Avakian, J. Ball, M. Battaglieri, R. P. Bennett, S. Bültmann, G. E. Dodge, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, C. Nepali, F. Sabatié, H. Seraydaryan, Z. W. Zhao
Physics Faculty Publications
We have measured the 3He(e,e' pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum ptot. For pair relative momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low ptot and rises to approximately 0.5 at large ptot. This shows the dominance of tensor over …
Two-Loop Soft Anomalous Dimensions For Single Top Quark Associated Production With A W- Or H-,
2010
Kennesaw State University
Two-Loop Soft Anomalous Dimensions For Single Top Quark Associated Production With A W- Or H-, Nikolaos Kidonakis
Faculty Articles
I present results for the two-loop soft anomalous dimensions for associated production of a single top quark with a W boson or a charged Higgs boson. The calculation uses expressions for the massive cusp anomalous dimension, which are presented in different forms, and it allows soft-gluon resummation at next-to-next-to-leading-logarithm (NNLL) accuracy. From the NNLL resummed cross section I derive approximate NNLO cross sections for bg→tW- and bg→tH- at LHC energies of 7, 10, and 14 TeV.
Absorption Of The Ω And Φ Mesons In Nuclei,
2010
University of Richmond
Absorption Of The Ω And Φ Mesons In Nuclei, M. Wood, Gerard P. Gilfoyle, Et. Al.
Physics Faculty Publications
Because of their long lifetimes, the ω and φ mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from 2H, C, Ti, Fe, and Pb targets. This Letter reports the first measurement of the ratio of nuclear transparencies for the e+e- channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the ω meson is stronger than that …
Differential Cross Sections And Recoil Polarizations For The Reaction Γp→K+Σ0,
2010
University of Richmond
Differential Cross Sections And Recoil Polarizations For The Reaction Γp→K+Σ0, B. Dey, Gerard P. Gilfoyle, Et. Al.
Physics Faculty Publications
High-statistics measurements of differential cross sections and recoil polarizations for the reaction γp → K+Σ0 have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (√s) from 1.69 to 2.84 GeV, with an extensive coverage in the K+ production angle. Independent measurements were made using the K+pπ−(γ) and K+p(π−, γ ) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR, and LEPS results, while offering better statistical precision and …
Differential Cross Sections And Recoil Polarizations For The Reaction Γp→K+Σ0,
2010
University of Richmond
Differential Cross Sections And Recoil Polarizations For The Reaction Γp→K+Σ0, B. Dey, Gerard P. Gilfoyle, Et. Al.
Physics Faculty Publications
High-statistics measurements of differential cross sections and recoil polarizations for the reaction γp → K+Σ0 have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ( √s) from 1.69 to 2.84 GeV, with an extensive coverage in the K+ production angle. Independent measurements were made using the K+pπ−(γ) and K+p(π−, γ) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR, and LEPS results, while offering better …
Neutron Flux And Energy Characterization Of A Plutonium-Beryllium Isotopic Neutron Source By Monte Carlo Simulation With Verification By Neutron Activation Analysis,
2010
University of Nevada, Las Vegas
Neutron Flux And Energy Characterization Of A Plutonium-Beryllium Isotopic Neutron Source By Monte Carlo Simulation With Verification By Neutron Activation Analysis, Zachary R. Harvey
UNLV Theses, Dissertations, Professional Papers, and Capstones
The purpose of this research was to characterize the neutron energy distribution and flux emitted from the UNLV plutonium-beryllium source, serial number MRC-N-W PuBe 453. This was accomplished through the use of the MCNPX/5 Monte-Carlo particle transport code to simulate radiation interactions within the physical environment of the source and its surroundings. The moderating drum currently containing the source as well as all of the sampling ports were accurately modeled in MCNPX/5. This geometry was then used to simulate the neutron interactions taking place in these geometries. The results of the simulations were then verified by the use of specifically …
Feasibility And Conceptual Design Of A C.W. Positron Source At Cebaf,
2010
Old Dominion University
Feasibility And Conceptual Design Of A C.W. Positron Source At Cebaf, Serkan Golge
Physics Theses & Dissertations
A feasibility study of a CW positron source for the 12 GeV upgrade at Jefferson Lab (JLAB) is provided. The proposed ≥ 100 nA Continuous Wave (CW) positron source at JLAB has several unique and challenging characteristics: high current incident electron beam at 126 MeV with a high beam power (up to a MW); CW e−beam and CW e+ production. The multiple scattering is a dominant process when creating e+ in a target, which results a large phase space area of the emitted positrons. An admittance study was done at CEBAF to find the maximum phase space area, which is …
