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Full-Text Articles in Physics

Quantum Logic Control And Precision Measurements Of Molecular Ions In A Ring Trap: An Approach For Testing Fundamental Symmetries, Yan Zhou, Joshua O. Island, Matt Grau Jan 2024

Quantum Logic Control And Precision Measurements Of Molecular Ions In A Ring Trap: An Approach For Testing Fundamental Symmetries, Yan Zhou, Joshua O. Island, Matt Grau

Physics Faculty Publications

This paper presents an experimental platform designed to facilitate quantum logic control of polar molecular ions in a segmented ring ion trap, paving the way for precision measurements. This approach focuses on achieving near-unity state preparation and detection, as well as long spin-precession coherence. A distinctive aspect lies in separating state preparation and detection conducted in a static frame from parity-selective spin precession in a rotating frame. Moreover, the method is designed to support spatially and temporally coincident measurements on multiple ions prepared in states with different sensitivity to the new physics of interest. This provides powerful techniques to probe …


Application Of Image Processing Programs In Color Analysis Of Wood Photodegradation, Gabriel Joseph D. Plata, Ramon M. Delos Santos Jan 2022

Application Of Image Processing Programs In Color Analysis Of Wood Photodegradation, Gabriel Joseph D. Plata, Ramon M. Delos Santos

Physics Faculty Publications

In general, polymer photodegradation is an important aspect of polymer science that is of great interest to chemistry, materials science, biology, and physics students who engage in this field of research. Wood consists of three main polymers, which makes it a good candidate for such photodegradation studies. Aside from structural changes based on chemical analysis, color change assessment can also be employed to check any extent of degradation on wood without the need for sophisticated analytical equipment. This study presents the application of two image processing programs in color analysis of wood photodegradation: ImageJ and Colormath library, which are Java-based …


Coupled Dynamics Of Spin Qubits In Optical Dipole Microtraps: Application To The Error Analysis Of A Rydberg-Blockade Gate, L. V. Gerasimov, R. R. Yusupov, A. D. Moiseevsky, I. Vybornyi, K. S. Tikhonov, S. P. Kulik, S. S. Straupe, Charles I. Sukenik, D. V. Kupriyanov Jan 2022

Coupled Dynamics Of Spin Qubits In Optical Dipole Microtraps: Application To The Error Analysis Of A Rydberg-Blockade Gate, L. V. Gerasimov, R. R. Yusupov, A. D. Moiseevsky, I. Vybornyi, K. S. Tikhonov, S. P. Kulik, S. S. Straupe, Charles I. Sukenik, D. V. Kupriyanov

Physics Faculty Publications

Single atoms in dipole microtraps or optical tweezers have recently become a promising platform for quantum computing and simulation. Here we report a detailed theoretical analysis of the physics underlying an implementation of a Rydberg two-qubit gate in such a system—a cornerstone protocol in quantum computing with single atoms. We focus on a blockade-type entangling gate and consider various decoherence processes limiting its performance in a real system. We provide numerical estimates for the limits on fidelity of the maximally entangled states and predict the full process matrix corresponding to the noisy two-qubit gate. We consider different excitation geometries and …


One-Dimensional Lateral Force Anisotropy At The Atomic Scale In Sliding Single Molecules On A Surface, Yuan Zhang, Daniel J. Trainer, Badri Narayanan, Yang Li, Anh T. Ngo, Sushila Khadka, Arnab Neogi, Brandon Fisher, Larry A. Curtiss, Subramanian K.R.S. Sankaranarayanan, Saw Wai Hla Jan 2021

One-Dimensional Lateral Force Anisotropy At The Atomic Scale In Sliding Single Molecules On A Surface, Yuan Zhang, Daniel J. Trainer, Badri Narayanan, Yang Li, Anh T. Ngo, Sushila Khadka, Arnab Neogi, Brandon Fisher, Larry A. Curtiss, Subramanian K.R.S. Sankaranarayanan, Saw Wai Hla

Physics Faculty Publications

Using a q+ atomic force microscopy at low temperature, a sexiphenyl molecule is slid across an atomically flat Ag(111) surface along the direction parallel to its molecular axis and sideways to the axis. Despite identical contact area and underlying surface geometry, the lateral force required to move the molecule in the direction parallel to its molecular axis is found to be about half of that required to move it sideways. The origin of the lateral force anisotropy observed here is traced to the one-dimensional shape of the molecule, which is further confirmed by molecular dynamics simulations. We also demonstrate that …


Two- And Three-Nucleon Contact Interactions And Ground-State Energies Of Light- And Medium-Mass Nuclei, R. Schiavilla, L. Girlanda, A. Gnech, A. Kievsky, A. Lovato, L. E. Marcucci, M. Piarulli, M. Viviani Jan 2021

Two- And Three-Nucleon Contact Interactions And Ground-State Energies Of Light- And Medium-Mass Nuclei, R. Schiavilla, L. Girlanda, A. Gnech, A. Kievsky, A. Lovato, L. E. Marcucci, M. Piarulli, M. Viviani

Physics Faculty Publications

Classes of two-nucleon (2N) contact interactions are developed in configuration space at leading order (LO), next-to-leading order (NLO), and next-to-next-to-next-to-leading order (N3LO) by fitting the experimental singlet np scattering length and deuteron binding energy at LO, and np and pp scattering data in the laboratory-energy ranges 0–15 MeV at NLO and 0–25 MeV at N3LO. These interactions are regularized by including two Gaussian cutoffs, one for T=0 and the other for T=1 channels. The cutoffs are taken to vary in the ranges R0=(1.5–2.3) fm and R1=(1.5–3.0) fm. The 780 (1100) data points up to …


Laser Chirping In Inverse Compton Sources At High Electron Beam Energies And High Laser Intensities, Balŝa Terzić, Jeffrey Mckaig, Erik Johnson, Tabin Dharanikota, Geoffrey A. Krafft Jan 2021

Laser Chirping In Inverse Compton Sources At High Electron Beam Energies And High Laser Intensities, Balŝa Terzić, Jeffrey Mckaig, Erik Johnson, Tabin Dharanikota, Geoffrey A. Krafft

Physics Faculty Publications

The onset of nonlinear effects, such as ponderomotive broadening, increases the radiation bandwidth and thereby places a stringent limitation on the laser intensity used in inverse Compton sources. Recently, we have shown that a judicious longitudinal laser frequency modulation ("chirping") can perfectly compensate for this ponderomotive broadening and restore the narrow band property of scattered radiation in the Thomson regime, when electron recoil during the collision with the laser can be neglected. Consequently, using QED, the laser chirping has been extended to the Compton regime, where electron recoil is properly accounted for. Here we present a new, semiclassical model for …


Simulating Electron Impact Ionization Using A General Particle Tracer (Gpt) Custom Element, J.T. Yoskowitz, G.A. Krafft, S.B. Van Der Geer, J. Grames, R.M. Soto, C.A.V. Lizarraga Jan 2021

Simulating Electron Impact Ionization Using A General Particle Tracer (Gpt) Custom Element, J.T. Yoskowitz, G.A. Krafft, S.B. Van Der Geer, J. Grames, R.M. Soto, C.A.V. Lizarraga

Physics Faculty Publications

A new C++ custom element has been developed with the framework of General Particle Tracer (GPT) to simulate electron impact ionization of residual gas molecules. The custom element uses Monte-Carlo routines to determine both the ion production rate and the secondary electron kinetic energy based on user-defined gas densities and theoretical values for the ionization cross section and the secondary electron differential cross section. It then uses relativistic kinematics to track the secondary electron, the scattered electron, and the newly formed ion after ionization. The ion production rate and the secondary electron energy distribution determined by the custom element have …


Environmental Modifications Of Atomic Properties: The Ground And 1s2p Excited States Of Compressed Helium, N. C. Pyper, T. C. Naginey, Colm T. Whelan Jan 2021

Environmental Modifications Of Atomic Properties: The Ground And 1s2p Excited States Of Compressed Helium, N. C. Pyper, T. C. Naginey, Colm T. Whelan

Physics Faculty Publications

Atoms remaining as recognizably distinct constituents of bulk condensed phases can have properties modified from those of the isolated species. Dense helium bubbles at high pressures are a common form of radiation damage degrading the mechanical and electrical properties of host materials. Detailed knowledge is critical for predicting their long term performance. Modifications of the ground and first singlet excited states of confined compressed helium are investigated using an entirely non-empirical theory based on the results of ab initio self-consistent field calculations with corrections for the effects of electron correlation. For finite sized portions representing bulk condensed fcc and bcc …


Optical-Depth Scaling Of Light Scattering From A Dense And Cold Atomic 87Rb Gas, K. J. Kemp, S. J. Roof, M. D. Havey, I. M. Sokolov, D. V. Kupriyanov, W. Guerin Jan 2020

Optical-Depth Scaling Of Light Scattering From A Dense And Cold Atomic 87Rb Gas, K. J. Kemp, S. J. Roof, M. D. Havey, I. M. Sokolov, D. V. Kupriyanov, W. Guerin

Physics Faculty Publications

We report investigation of near-resonance light scattering from a cold and dense atomic gas of 87Rb atoms. Measurements are made for probe frequencies tuned near the F=2→ F'=3 nearly closed hyperfine transition, with particular attention paid to the dependence of the scattered light intensity on detuning from resonance, the number of atoms in the sample, and atomic sample size. We find that, over a wide range of experimental variables, the optical depth of the atomic sample serves as an effective single scaling parameter which describes well all the experimental data.


Novel Observation Of Isospin Structure Of Short-Range Correlations In Calcium Isotopes, D. Nguyen, Z. Ye, Lawrence Weinstein, X. Zheng, P. Zhu, R. Zielinski, Et Al., Jefferson Lab Hall A Collaboration Jan 2020

Novel Observation Of Isospin Structure Of Short-Range Correlations In Calcium Isotopes, D. Nguyen, Z. Ye, Lawrence Weinstein, X. Zheng, P. Zhu, R. Zielinski, Et Al., Jefferson Lab Hall A Collaboration

Physics Faculty Publications

Short-range correlations (SRCs) have been identified as being responsible for the high-momentum tail of the nucleon momentum distribution, n(k). Hard, short-range interactions of nucleon pairs generate the high-momentum tail and imprint a universal character on n(k) for all nuclei at large momentum. Triple coincidence experiments have shown a strong dominance of np pairs, but these measurements involve large final-state interactions. This paper presents the results from Jefferson Lab experiment E08014 which measured inclusive electron scattering cross section from Ca isotopes. By comparing the inclusive cross section from 48Ca to 40Ca in a kinematic region dominated by SRCs …


Sources And Characteristics Of Size-Resolved Particulate Organic Acids And Methanesulfonate In A Coastal Megacity: Manila, Philippines, Connor Stahl, Melliza Templonuevo Cruz, Paola Angela Bañaga, Grace Betito, Rachel A. Braun, Mojtaba Azadi Aghdam, Maria Obiminda L. Cambaliza, Genevieve Rose Lorenzo, Alexander B. Macdonald, Miguel Ricardo A. Hilario, Preciosa Corazon Pabroa, John Robin Yee, James Bernard Simpas, Armin Sorooshian Jan 2020

Sources And Characteristics Of Size-Resolved Particulate Organic Acids And Methanesulfonate In A Coastal Megacity: Manila, Philippines, Connor Stahl, Melliza Templonuevo Cruz, Paola Angela Bañaga, Grace Betito, Rachel A. Braun, Mojtaba Azadi Aghdam, Maria Obiminda L. Cambaliza, Genevieve Rose Lorenzo, Alexander B. Macdonald, Miguel Ricardo A. Hilario, Preciosa Corazon Pabroa, John Robin Yee, James Bernard Simpas, Armin Sorooshian

Physics Faculty Publications

A 16-month (July 2018–October 2019) dataset of size-resolved aerosol composition is used to examine the sources and characteristics of five organic acids (oxalate, succinate, adipate, maleate, phthalate) and methanesulfonate (MSA) in Metro Manila, Philippines. As one of the most polluted megacities globally, Metro Manila offers a view of how diverse sources and meteorology impact the relative amounts and size distributions of these species. A total of 66 sample sets were collected with a Micro-Orifice Uniform Deposit Impactor (MOUDI), of which 54 sets were analyzed for composition. Organic acids and MSA surprisingly were less abundant than in other global regions that …


Long-Range Aerosol Transport And Impacts On Size-Resolved Aerosol Composition In Metro Manila, Philippines, Rachel A. Braun, Mojtaba Azadi Aghdam, Paola Angela Bañaga, Grace Betito, Maria Obiminda L. Cambaliza, Melliza Templonuevo Cruz, Genevieve Rose Lorenzo, Alexander B. Macdonald, James Bernard Simpas, Connor Stahl, Armin Sorooshian Jan 2020

Long-Range Aerosol Transport And Impacts On Size-Resolved Aerosol Composition In Metro Manila, Philippines, Rachel A. Braun, Mojtaba Azadi Aghdam, Paola Angela Bañaga, Grace Betito, Maria Obiminda L. Cambaliza, Melliza Templonuevo Cruz, Genevieve Rose Lorenzo, Alexander B. Macdonald, James Bernard Simpas, Connor Stahl, Armin Sorooshian

Physics Faculty Publications

This study analyzes long-range transport of aerosol and aerosol chemical characteristics based on instances of high- and low-aerosol-loading events determined via ground-based size-resolved aerosol measurements collected at the Manila Observatory in Metro Manila, Philippines, from July to October 2018. Multiple data sources, including models, remote sensing, and in situ measurements, are used to analyze the impacts of long-range aerosol transport on Metro Manila and the conditions at the local and synoptic scales facilitating this transport. Through the use of case studies, evidence of long-range transport of biomass burning aerosol and continental emissions is identified in Metro Manila. Long-range transport of …


Measurement Of The Single-Spin Asymmetry A⁰ʸ In Quasi-Elastic ³He↑(E,E'N) Scattering At 0.4 < Q2 < 1.0 Gev/C2, E. Long, Y.W. Zhang, M. Mihovilovic, M. Canan, S. Golge, L. Zhu Jan 2020

Measurement Of The Single-Spin Asymmetry A⁰ʸ In Quasi-Elastic ³He↑(E,E'N) Scattering At 0.4 < Q2 < 1.0 Gev/C2, E. Long, Y.W. Zhang, M. Mihovilovic, M. Canan, S. Golge, L. Zhu

Physics Faculty Publications

Due to the lack of free neutron targets, studies of the structure of the neutron are typically made by scattering electrons from either ²H or ³He targets. In order to extract useful neutron information from a ³He target, one must understand how the neutron in a ³He system differs from a free neutron by taking into account nuclear effects such as final state interactions and meson exchange currents. The target single spin asymmetry A⁰ʸ is an ideal probe of such effects, as any deviation from zero indicates effects beyond plane wave impulse approximation. New measurements of the target single spin …


Photoproduction Of Η Mesons Off The Proton For 1.2 < EΓ < 4.7 Gev Using Clas At Jefferson Laboratory, K. P. Adhikari, M. J. Amaryan, G. Gavalian, M. Hattawy, M. Khachatryan, J. Poudel, Y. Prok, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration Jan 2020

Photoproduction Of Η Mesons Off The Proton For 1.2 < EΓ < 4.7 Gev Using Clas At Jefferson Laboratory, K. P. Adhikari, M. J. Amaryan, G. Gavalian, M. Hattawy, M. Khachatryan, J. Poudel, Y. Prok, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration

Physics Faculty Publications

Photoproduction cross sections are reported for the reaction γp→pη using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The η mesons are detected in their dominant charged decay mode, η→π+π−π0, and results on differential cross sections are presented for incident photon energies between 1.2 and 4.7 GeV. These new η photoproduction data are consistent with earlier CLAS results but extend the energy range beyond the nucleon resonance region into the Regge regime. The normalized angular distributions are also compared with the experimental results from several other experiments, and with predictions of η-MAID 2018 and the latest solution of the …


Drift Chamber Calibration And Particle Identification In The P-349 Experiment, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Glowacz, D. Grzonka, Florian Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink, J. Zmeskal Jan 2019

Drift Chamber Calibration And Particle Identification In The P-349 Experiment, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Glowacz, D. Grzonka, Florian Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink, J. Zmeskal

Physics Faculty Publications

The goal of the P-349 experiment is to test whether 3.5 GeV/c antiprotons produced in high-energy proton-proton collisions are polarized in view of the preparation of a polarized antiproton beam. In this article, we present the details of the ongoing analysis focused on the drift chambers calibration and particle identification with DIRC.


Measurement Of The Beam Spin Asymmetry Of →Ep → E'P'Η In The Deep-Inelastic Regime With Clas, B. Zhao, A. Kim, K. Joo, I . Bedlinskiy, W. Kim, V. Kubarovsky, M. Ungaro, G. Gavalian, A. Klein, S. E. Kuhn, Clas Collaboration Jan 2019

Measurement Of The Beam Spin Asymmetry Of →Ep → E'P'Η In The Deep-Inelastic Regime With Clas, B. Zhao, A. Kim, K. Joo, I . Bedlinskiy, W. Kim, V. Kubarovsky, M. Ungaro, G. Gavalian, A. Klein, S. E. Kuhn, Clas Collaboration

Physics Faculty Publications

The beam spin asymmetry of the exclusive pseudoscalar channel ep→e′p′η was measured for the first time in the deep-inelastic regime (W > 2 GeV/c2 and Q2 > 1 GeV2 /c2) using a longitudinally polarized 5.78 GeV electron beam at Jefferson Lab with the CEBAF Large Acceptance Spectrometer. The data were accumulated in 144 four-dimensional bins of Q2, xB, −t and ϕ over a wide kinematic range, where ϕ is the azimuthal angle between the lepton and hadron scattering planes, The measured azimuthal dependence with large amplitudes of the sin ϕ moments is …


Argon Metastable And Resonant Level Densities In Ar And Ar/Cl² Discharges Used For The Processing Of Bulk Niobium, Jeremy Peshl, Roderick Mcneill, Charles I. Sukenik, Milka Nikolić, Svetozar Popović, Leposava Vŭsković Jan 2019

Argon Metastable And Resonant Level Densities In Ar And Ar/Cl² Discharges Used For The Processing Of Bulk Niobium, Jeremy Peshl, Roderick Mcneill, Charles I. Sukenik, Milka Nikolić, Svetozar Popović, Leposava Vŭsković

Physics Faculty Publications

A comparative analysis of two popular spectroscopy techniques is conducted in a coaxial cylindrical capacitively coupled discharge designed for the plasma processing of superconducting radio frequency (SRF) cavities. The density of the metastable and resonant levels in Ar is measured in both Ar and Ar/Cl2 discharges to properly characterize the unique discharge system and aid in the development of a cavity etching routine. The first method, deemed the “branching fraction method,” utilizes the sensitivity of photon reabsorption of radiative decay to measure the lower state (metastable and resonant) densities by taking ratios of spectral lines with a common upper …


Current-Driven Production Of Vortex-Antivortex Pairs In Planar Josephson Junction Arrays And Phase Cracks In Long-Range Order, Francisco Estellés-Duart, Miguel Ortuño, Andrés M. Somoza, Valerii M. Vinokur, Alex Gurevich Oct 2018

Current-Driven Production Of Vortex-Antivortex Pairs In Planar Josephson Junction Arrays And Phase Cracks In Long-Range Order, Francisco Estellés-Duart, Miguel Ortuño, Andrés M. Somoza, Valerii M. Vinokur, Alex Gurevich

Physics Faculty Publications

Proliferation of topological defects like vortices and dislocations plays a key role in the physics of systems with long-range order, particularly, superconductivity and superfluidity in thin films, plasticity of solids, and melting of atomic monolayers. Topological defects are characterized by their topological charge reflecting fundamental symmetries and conservation laws of the system. Conservation of topological charge manifests itself in extreme stability of static topological defects because destruction of a single defect requires overcoming a huge energy barrier proportional to the system size. However, the stability of driven topological defects remains largely unexplored. Here we address this issue and investigate numerically …


Catalysis Of Stark-Tuned Interactions Between Ultracold Rydberg Atoms, A. L. Win, W. D. Williams, T. J. Carroll, C. I. Sukenik Sep 2018

Catalysis Of Stark-Tuned Interactions Between Ultracold Rydberg Atoms, A. L. Win, W. D. Williams, T. J. Carroll, C. I. Sukenik

Physics Faculty Publications

We have experimentally investigated a catalysis effect in the resonant energy transfer between ultracold 85Rb Rydberg atoms. We studied the time dependence of the process, 34p + 34p → 34s + 35s, and observed an enhancement of 34s state population when 34d state atoms are added. We have also performed numerical model simulations, which are in qualitative agreement with experiment and indicate that the enhancement arises from a redistribution of p-state atoms due to the presence of the d-state atoms.


Compensation Of Non-Linear Bandwidth Broadening By Laser Chirping In Thomson Sources, C. Maroli, V. Petrillo, I. Drebot, L, Serafini, B. Terzić, G. A. Krafft Aug 2018

Compensation Of Non-Linear Bandwidth Broadening By Laser Chirping In Thomson Sources, C. Maroli, V. Petrillo, I. Drebot, L, Serafini, B. Terzić, G. A. Krafft

Physics Faculty Publications

A new laser chirping prescription is derived by means of the phase-stationary method for an inci- dent Gaussian laser pulse in conjunction with a Li enard-Wiechert calculation of the scattered radia- tion flux and spectral brilliance. This particularly efficient laser chirp has been obtained using the electric field of the laser and for electrons and radiation on axis. The frequency modulation is some- what reduced with respect to that proposed in the previous literature, allowing the application of this procedure to lasers with larger values of the parameter a0. Numerical calculations have been performed using mildly focused and …


Electron- And Positron-Impact Ionization Of Inert Gases, R. I. Campeanu, H. R. J. Walters, Colm T. Whelan Jun 2018

Electron- And Positron-Impact Ionization Of Inert Gases, R. I. Campeanu, H. R. J. Walters, Colm T. Whelan

Physics Faculty Publications

Triple-differential cross sections (TDCS) are presented for the electron and positron impact ionization of inert gas atoms in a range of geometries where a number of significant few body effects compete to define the shape of the TDCS. Using both positrons and electrons as projectiles has opened up the possibility of performing complementary studies which could effectively isolate competing interactions which cannot be separately detected in an experiment with a single projectile. A comparison is presented between theory and the recent experiments of [Gavin, deLucio, and DuBois, Phys. Rev. A95, 062703 (2017)] for e± and contrasted with the …


Light Scattering From An Atomic Gas Under Conditions Of Quantum Degeneracy, V. M. Porozova, L. V. Gerasimov, M. D. Havey Jan 2018

Light Scattering From An Atomic Gas Under Conditions Of Quantum Degeneracy, V. M. Porozova, L. V. Gerasimov, M. D. Havey

Physics Faculty Publications

Elastic light scattering from a macroscopic atomic sample existing in the Bose-Einstein condensate phase reveals a unique physical configuration of interacting light and matter waves. However, the joint coherent dynamics of the optical excitation induced by an incident photon is influenced by the presence of incoherent scattering channels. For a sample of sufficient length the excitation transports as a polariton wave and the propagation Green's function obeys the scattering equation which we derive. The polariton dynamics could be tracked in the outgoing channel of the scattered photon as we show via numerical solution of the scattering equation for one-dimensional geometry. …


Angular Distribution Of Single-Photon Superradiance In A Dilute And Cold Atomic Ensemble, A. S. Kuraptsev, I. M. Sokolov, M. D. Havey Aug 2017

Angular Distribution Of Single-Photon Superradiance In A Dilute And Cold Atomic Ensemble, A. S. Kuraptsev, I. M. Sokolov, M. D. Havey

Physics Faculty Publications

On the basis of a quantum microscopic approach we study the dynamics of the afterglow of a dilute Gaussian atomic ensemble excited by pulsed radiation. Taking into account the vector nature of the electromagnetic field we analyze in detail the angular and polarization distribution of single-photon superradiance of such an ensemble. The dependence of the angular distribution of superradiance on the length of the pulse and its carrier frequency as well as on the size and the shape of the atomic clouds is studied. We show that there is substantial dependence of the superradiant emission on the polarization and the …


Transverse Parton Momenta In Single Inclusive Hadron Production In E+E- Annihilation Process., M. Boglione, J. O. Gonzalez-Hernandez, R. Taghavi Jan 2017

Transverse Parton Momenta In Single Inclusive Hadron Production In E+E- Annihilation Process., M. Boglione, J. O. Gonzalez-Hernandez, R. Taghavi

Physics Faculty Publications

We study the transverse momentum distributions of single inclusive hadron production in e+e annihilation processes. Although the only available experimental data are scarce and quite old, we find that the fundamental features of transverse momentum dependent (TMD) evolution, historically addressed in Drell–Yan processes and, more recently, in Semi-inclusive deep inelastic scattering processes, are visible in e+e annihilations as well. Interesting effects related to its non-perturbative regime can be observed.

We test two different parameterizations for the p⊥ dependence of the cross section: the usual Gaussian distribution and a power-law model. We find the latter …


Coincidence Charged-Current Neutrino-Induced Deuteron Disintegration For 2H216O, J. W. Van Orden, T. W. Donnelly, O. Moreno Jan 2017

Coincidence Charged-Current Neutrino-Induced Deuteron Disintegration For 2H216O, J. W. Van Orden, T. W. Donnelly, O. Moreno

Physics Faculty Publications

Semi-inclusive charge-changing neutrino reactions on targets of heavy water are investigated with the goal of determining the relative contributions to the total cross section of deuterium and oxygen in kinematics chosen to emphasize the former. The study is undertaken for conditions where the typical neutrino beam energies are in the few GeV region, and hence relativistic modeling is essential. For this, the previous relativistic approach for the deuteron is employed, together with a spectral function approach for the case of oxygen. Upon optimizing the kinematics of the final-state particles assumed to be detected (typically a muon and a proton) it …


Dynamics Of Optically-Generated Carriers In Si (100) And Si (111) Substrate-Grown Gaas/Algaas Core-Shell Nanowires, Ramon M. Delos Santos, Jasher John Ibañes, Maria Herminia Balgos, Rafael Jaculbia, Jessica Pauline Afalla, Michelle Bailon-Somintac, Elmer Estacio, Arnel Salvador, Armando Somintac, Christopher Que, Satoshi Tsuzuki, Kohji Yamamoto, Masahiko Tani Aug 2015

Dynamics Of Optically-Generated Carriers In Si (100) And Si (111) Substrate-Grown Gaas/Algaas Core-Shell Nanowires, Ramon M. Delos Santos, Jasher John Ibañes, Maria Herminia Balgos, Rafael Jaculbia, Jessica Pauline Afalla, Michelle Bailon-Somintac, Elmer Estacio, Arnel Salvador, Armando Somintac, Christopher Que, Satoshi Tsuzuki, Kohji Yamamoto, Masahiko Tani

Physics Faculty Publications

GaAs/Al0.1Ga0.9As core-shell nanowires (CSNWs), with average lateral size of 125 nm, were grown on gold nanoparticle-activated Si (100) and Si (111) substrates via molecular beam epitaxy. Room temperature-photoluminescence (RT-PL) from the samples showed bulk-like GaAs and Al0.1Ga0.9As bandgap emission peaks at 1.43 and 1.56 eV, respectively. Higher PL emission intensity of the sample on Si (111) compared to that on Si (100) is attributed to uniform Al0.1Ga0.9As shell passivation of surface states on Si (111)-grown CSNWs. Carrier dynamics in two different temporal regimes were studied. In the sub-nanosecond time scale (300–500 ps), time-resolved radiative recombination efficiency of carriers was examined. …


Longitudinal Target-Spin Asymmetries For Deeply Virtual Compton Scattering, E. Seder, A. Biselli, S. Bültmann, A. Klein, S. E. Kuhn, Y. Prok, Clas Collaboration Jan 2015

Longitudinal Target-Spin Asymmetries For Deeply Virtual Compton Scattering, E. Seder, A. Biselli, S. Bültmann, A. Klein, S. E. Kuhn, Y. Prok, Clas Collaboration

Physics Faculty Publications

A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for e p → e'p'ɣ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t, and ɸ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into …


Measurement Of The Target-Normal Single-Spin Asymmetry In Quasielastic Scattering From The Reaction ³He↑(E, E'), Y. W. Zhang, E. Long, M. Mihoviloviĉ, G. Gin, M Canan, S. Golge, R. Schiavilla Jan 2015

Measurement Of The Target-Normal Single-Spin Asymmetry In Quasielastic Scattering From The Reaction ³He↑(E, E'), Y. W. Zhang, E. Long, M. Mihoviloviĉ, G. Gin, M Canan, S. Golge, R. Schiavilla

Physics Faculty Publications

We report the first measurement of the target single-spin asymmetry, Ay, in quasielastic scattering from the inclusive reaction ³He↑(e, e') on a ³He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero Ay can arise from the interference between the one-and two-photon exchange processes which is sensitive to the details of the substructure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at Q2 = 0.13, 0.46, and 0.97 GeV2. These measurements demonstrate, for the first …


Direct Observation Of Quark-Hadron Duality In The Free Neutron F2 Structure Function, I. Niculescu, G. Niculescu, W. Melnitchouk, J. Arrington, M. E. Christy, S. Kuhn Jan 2015

Direct Observation Of Quark-Hadron Duality In The Free Neutron F2 Structure Function, I. Niculescu, G. Niculescu, W. Melnitchouk, J. Arrington, M. E. Christy, S. Kuhn

Physics Faculty Publications

Using the recently published data from the BONuS(Barely Off-shell Nucleon Structure) experiment at Jefferson Lab, which utilized a spectator tagging technique to extract the inclusive electron-free neutron scattering cross section, we obtain the first direct observation of quark-hadron duality in the neutron F2 structure function. The data are used to reconstruct the lowest few (N = 2, 4, and 6) moments of F2 in the three prominent nucleon resonance regions, as well as the moments integrated over the entire resonance region. Comparison with moments computed from global parametrizations of parton distribution functions suggest that quark-hadron duality holds locally …


Measurements Of Population Densities Of Metastable And Resonant Levels Of Argon Using Laser Induced Fluorescence, M. Nikolic, J. Newton, C. I. Sukenik, L. Vuskovic, S. Popovic Jan 2015

Measurements Of Population Densities Of Metastable And Resonant Levels Of Argon Using Laser Induced Fluorescence, M. Nikolic, J. Newton, C. I. Sukenik, L. Vuskovic, S. Popovic

Physics Faculty Publications

We present a new approach to measure population densities of Ar I metastable and resonant excited states in low temperature Ar plasmas at pressures higher than 1 Torr. This approach combines the time resolved laser induced fluorescence technique with the kinetic model of Ar. The kinetic model of Ar is based on calculating the population rates of metastable and resonant levels by including contributions from the processes that affect population densities of Ar I excited states. In particular, we included collisional quenching processes between atoms in the ground state and excited states, since we are investigating plasma at higher pressures. …