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2017

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Articles 61 - 90 of 95

Full-Text Articles in Nuclear

Particle Physics Model For The 17 Mev Anomaly In Beryllium Nuclear Decays, Jonathan L. Feng, Bartosz Fornal, Iftah Galon, Susan Gardner, Jordan Smolinsky, Tim M. P. Tait, Philip Tanedo Feb 2017

Particle Physics Model For The 17 Mev Anomaly In Beryllium Nuclear Decays, Jonathan L. Feng, Bartosz Fornal, Iftah Galon, Susan Gardner, Jordan Smolinsky, Tim M. P. Tait, Philip Tanedo

Physics and Astronomy Faculty Publications

The 6.8σ anomaly in excited 8Be nuclear decays via internal pair creation is fit well by a new particle interpretation. In a previous analysis, we showed that a 17 MeV protophobic gauge boson provides a particle physics explanation of the anomaly consistent with all existing constraints. Here we begin with a review of the physics of internal pair creation in 8Be decays and the characteristics of the observed anomaly. To develop its particle interpretation, we provide an effective operator analysis for excited 8Be decays to particles with a variety of spins and parities and show that …


Beam-Target Double-Spin Asymmetry In Quasielastic Electron Scattering Off The Deuteron With Clas, M. Mayer, S. E. Kuhn, K. P. Adhikari, Z. Akbar, S. Anefalos Pereira, G. Asryan, H. Avakian, R. A. Badui, J. Ball, N. A. Baltzell, S. Bueltmann, N. Guler, C. E. Hyde, M. Khachatryan, A. Klein, Y. Prok, F. Sabatie, B. Torayev, L. B. Weinstein Feb 2017

Beam-Target Double-Spin Asymmetry In Quasielastic Electron Scattering Off The Deuteron With Clas, M. Mayer, S. E. Kuhn, K. P. Adhikari, Z. Akbar, S. Anefalos Pereira, G. Asryan, H. Avakian, R. A. Badui, J. Ball, N. A. Baltzell, S. Bueltmann, N. Guler, C. E. Hyde, M. Khachatryan, A. Klein, Y. Prok, F. Sabatie, B. Torayev, L. B. Weinstein

Physics Faculty Publications

Background: The deuteron plays a pivotal role in nuclear and hadronic physics, as both the simplest bound multinucleon system and as an effective neutron target. Quasielastic electron scattering on the deuteron is a benchmark reaction to test our understanding of deuteron structure and the properties and interactions of the two nucleons bound in the deuteron.

Purpose: The experimental data presented here can be used to test state-of-the-art models of the deuteron and the two-nucleon interaction in the final state after two-body breakup of the deuteron. Focusing on polarization degrees of freedom, we gain information on spin-momentum correlations in …


Locality And Efficient Evaluation Of Lattice Composite Fields: Overlap-Based Gauge Operators, Andrei Alexandru, Ivan Horváth Jan 2017

Locality And Efficient Evaluation Of Lattice Composite Fields: Overlap-Based Gauge Operators, Andrei Alexandru, Ivan Horváth

Physics and Astronomy Faculty Publications

We propose a novel general approach to locality of lattice composite fields, which in case of QCD involves locality in both quark and gauge degrees of freedom. The method is applied to gauge operators based on the overlap Dirac matrix elements, showing for the first time their local nature on realistic path-integral backgrounds. The framework entails a method for efficient evaluation of such nonultralocal operators, whose computational cost is volume independent at fixed accuracy, and only grows logarithmically as this accuracy approaches zero. This makes computation of useful operators, such as overlap-based topological density, practical. The key notion underlying these …


Nuclear Structure Of 76Ge From Inelastic Neutron Scattering Measurements And Shell Model Calculations, Sharmistha Mukhopadhyay, Benjamin P. Crider, B. A. Brown, S. F. Ashley, Anagha Chakraborty, A. Kumar, Marcus T. Mcellistrem, Erin E. Peters, Francisco M. Prados-Estévez, Steven W. Yates Jan 2017

Nuclear Structure Of 76Ge From Inelastic Neutron Scattering Measurements And Shell Model Calculations, Sharmistha Mukhopadhyay, Benjamin P. Crider, B. A. Brown, S. F. Ashley, Anagha Chakraborty, A. Kumar, Marcus T. Mcellistrem, Erin E. Peters, Francisco M. Prados-Estévez, Steven W. Yates

Physics and Astronomy Faculty Publications

The low-lying, low-spin levels of 76Ge were studied with the (n,n′γ) reaction. Gamma-ray excitation function measurements were performed at incident neutron energies from 1.6 to 3.7 MeV, and γ-ray angular distributions were measured at neutron energies of 3.0 and 3.5 MeV. From these measurements, level spins, level lifetimes, γ-ray intensities, and multipole mixing ratios were determined. No evidence for a number of previously placed levels was found. Below 3.3 MeV, many new levels were identified, and the level scheme was re-evaluated. The B(E2) values support low-lying band structure. The 2 …


Inelastic Neutron Scattering Cross Section Measurements For 134,136Xe Of Relevance To Neutrinoless Double-Β Decay Searches, Erin E. Peters, T. J. Ross, S. H. Liu, Marcus T. Mcellistrem, Steven W. Yates Jan 2017

Inelastic Neutron Scattering Cross Section Measurements For 134,136Xe Of Relevance To Neutrinoless Double-Β Decay Searches, Erin E. Peters, T. J. Ross, S. H. Liu, Marcus T. Mcellistrem, Steven W. Yates

Chemistry Faculty Publications

Neutrinoless double-β decay (0νββ) searches typically involve large-scale experiments for which backgrounds can be complex. One possible source of background near the 0νββ signature in the observed spectra is γ rays arising from inelastic neutron scattering from the materials composing or surrounding the detector. In relation to searches for the 0νββ of 136Xe to 136Ba, such as the EXO-200 and KamLAND-Zen projects, inelastic neutron scattering γ-ray production cross sections for 136Xe and 134Xe are of importance for characterizing such γ rays that may inhibit the unambiguous identification of this yet-to-be-observed …


Charge-Dependent Directed Flow In Cu + Au Collisions At √SNn = 200 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, Renee H. Fatemi, Suvarna Ramachandran Jan 2017

Charge-Dependent Directed Flow In Cu + Au Collisions At √SNn = 200 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We present the first measurement of charge-dependent directed flow in Cu + Au collisions at √sNN = 200  GeV. The results are presented as a function of the particle transverse momentum and pseudorapidity for different centralities. A finite difference between the directed flow of positive and negative charged particles is observed that qualitatively agrees with the expectations from the effects of the initial strong electric field between two colliding ions with different nuclear charges. The measured difference in directed flow is much smaller than that obtained from the parton-hadron-string-dynamics model, which suggests that most of the electric charges, …


On Marie Curie And Me, Sharon L. Stephenson Jan 2017

On Marie Curie And Me, Sharon L. Stephenson

Physics and Astronomy Faculty Publications

When people discover I am a nuclear physicist, they often say, "Oh, like Marie Curie!" And yes, I am like Marie in that I have woman parts, I study nuclei, I have two children and a physicist husband. But had I lived in her time, I would not have been that rare female admitted to the Sorbonne. I could not have quietly made the top scores on the math and physics examinations. I am impulsive and thin-skinned, my occasional cleverness passing for deeper talent. I would probably have been a cleaning girl, pregnant at 15, unable to speak any language …


Investigation Of The Microsoft Kinect V2 Sensor As A Multi-Purpose Device For A Radiation Oncology Clinic, Evan Asher Silverstein Jan 2017

Investigation Of The Microsoft Kinect V2 Sensor As A Multi-Purpose Device For A Radiation Oncology Clinic, Evan Asher Silverstein

Wayne State University Dissertations

For a radiation oncology clinic, the number of devices available to assist in the workflow for radiotherapy treatments are quite numerous. Processes such as patient verification, motion management, or respiratory motion tracking can all be improved upon by devices currently on the market. These three specific processes can directly impact patient safety and treatment efficacy and, as such, are important to track and quantify. Most products available will only provide a solution for one of these processes and may be outside the reach of a typical radiation oncology clinic due to difficult implementation and incorporation with already existing hardware. This …


Monte-Carlo Event Generators For Jet Modification In D(P)-A And A-A Collisions, Michael Charles Kordell Ii Jan 2017

Monte-Carlo Event Generators For Jet Modification In D(P)-A And A-A Collisions, Michael Charles Kordell Ii

Wayne State University Dissertations

This work outlines methods to use jet simulations to study both initial and final state nuclear effects in heavy-ion collisions. To study the initial state of heavy-ion collisions, the production of jets and high momentum hadrons from jets, produced in deuteron ($d$)-$Au$ collisions at the relativistic heavy-ion collider (RHIC) and proton ($p$)-$Pb$ collisions at the large hadron collider (LHC) are studied as a function of \emph{centrality}, a measure of the impact parameter of the collision. A modified version of the event generator PYTHIA, widely used to simulate $p$-$p$ collisions, is used in conjunction with a nuclear Monte-Carlo event generator which …


Azimuthally-Differential Pion Femtoscopy Relative To The Second And Third Harmonic In Pb-Pb Collisions, Mohammad Saleh Jan 2017

Azimuthally-Differential Pion Femtoscopy Relative To The Second And Third Harmonic In Pb-Pb Collisions, Mohammad Saleh

Wayne State University Dissertations

Heavy-ion collisions at LHC energies create a hot and dense medium of deconned quarks

and gluons, known as the quark-gluon plasma (QGP) [56]. The QGP reball rst expands,

cools and then freezes out into a collection of nal-state hadrons. Correlations between the

free particles carry information about the space-time extent of the emitting source, and are

imprinted on the nal-state spectra due to a quantum-mechanical interference eect [18].

The correlation of two identical particles at small relative momentum, commonly known as

intensity, or Hanbury Brown-Twiss (HBT), interferometry, is an eective tool to study the

space-time structure of the emitting source …


Radiation Therapy Medical Physics Review – Delivery, Interactions, Safety, Feasibility, And Head To Head Comparisons Of The Leading Radiation Therapy Techniques, Cielle Collins Jan 2017

Radiation Therapy Medical Physics Review – Delivery, Interactions, Safety, Feasibility, And Head To Head Comparisons Of The Leading Radiation Therapy Techniques, Cielle Collins

Honors Theses and Capstones

Radiation therapy uses high energy radiation to kill cancer cells. Radiation therapy for cancer treatment can take the form of photon therapy (using x-rays and gamma rays), or charged particle therapy including proton therapy and electron therapy. Within these categories, numerous methods of delivery have been developed. For example, a certain type of radiation can be administered by a machine outside of the body, called external-beam radiation therapy, or by a “seed” placed inside of the body near cancer cells, called internal radiation therapy or brachytherapy. Approximately half of all cancer patients receive radiation therapy, and the form of radiation …


The Future Of The Iran Nuclear Deal: Pretty Bright From Its Verification Lens, Mutti Anggitta Jan 2017

The Future Of The Iran Nuclear Deal: Pretty Bright From Its Verification Lens, Mutti Anggitta

International Journal of Nuclear Security

This manuscript discusses the JCPOA’s verification mechanism, especially its four innovative additional safeguards measures: much broader monitoring of Iran’s nuclear program, access with a deadline and dispute resolution mechanism, the Procurement Channel, and the prohibition of weaponization activities. It considers the possible implications of such safeguards measures for the future of the deal and for the non-proliferation regime. This manuscript found that the four additional safeguards measures, if implemented with the Iran’s Comprehensive Safeguards Agreement and the Additional Protocol, would increase the effectiveness of monitoring and verification measures under the deal. In short, they will significantly contribute to the success …


A Study Of The Potential Applications Of Am241, And Determining The Feasibility Of Using Gamma Spectroscopy For Future Physical Validation, Eric A. Feissle Jan 2017

A Study Of The Potential Applications Of Am241, And Determining The Feasibility Of Using Gamma Spectroscopy For Future Physical Validation, Eric A. Feissle

Masters Theses

“Am241 is typically produced via Pu241 decay in a uranium fueled reactor. Presence of Am241 can be used as the age estimation tool for spent fuel, which is a focus of this thesis along with the interest of the measurement and the ratio of production rates of Am241’s activation products; Americium-242 and its first excited state of Americium-242m. MCNP models of the core and BEGe 3825 detector were built. These models were compared with established and physical measurements of gamma/x-ray standards that were available at the reactor. Thermal fluxes at 200 kW for potential foils centered in the source holder …


Target Mass Effects In Parton Quasi-Distributions, A. V. Radyushkin Jan 2017

Target Mass Effects In Parton Quasi-Distributions, A. V. Radyushkin

Physics Faculty Publications

We study the impact of non-zero (and apparently large) value of the nucleon mass M on the shape of parton quasi-distributions Q(y, p3), in particular on its change with the change of the nucleon momentum p3. We observe that the usual target-mass corrections induced by the M-dependence of the twist-2 operators are rather small. Moreover, we show that within the framework based on parametrizations by transverse momentum dependent distribution functions (TMDs) these corrections are canceled by higher-twist contributions. We identify a novel source of kinematic target-mass dependence of TMDs and build models corrected for …


First Measurement Of Unpolarized Semi-Inclusive Deep-Inelastic Scattering Cross Sections From A He 3 Target, X. Yan, K. Allada, K. Aniol, J. R. M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P. C. Bradshaw, P. Bosted, A. Camsonne, M. Canan Jan 2017

First Measurement Of Unpolarized Semi-Inclusive Deep-Inelastic Scattering Cross Sections From A He 3 Target, X. Yan, K. Allada, K. Aniol, J. R. M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P. C. Bradshaw, P. Bosted, A. Camsonne, M. Canan

Physics Faculty Publications

The unpolarized semi-inclusive deep-inelastic scattering (SIDIS) differential cross sections in 3He(e,e′π±)X have been measured for the first time in Jefferson Lab experiment E06-010 with a 5.9GeV e- beam on a 3He gas target. The experiment focuses on the valence quark region, covering a kinematic range 0.12<xbj<0.45,1<Q2<4(GeV/c)2,0.45<zh<0.65, and 0.05<Pt<0.55GeV/c. The extracted SIDIS differential cross sections of π± production are compared with existing phenomenological models while the 3He nucleus approximated as two protons and one neutron in a plane-wave picture, in multidimensional bins. Within …


Nonperturbative Evolution Of Parton Quasi-Distributions, A. V. Radyushkin Jan 2017

Nonperturbative Evolution Of Parton Quasi-Distributions, A. V. Radyushkin

Physics Faculty Publications

Using the formalism of parton virtuality distribution functions (VDFs) we establish a connection between the transverse momentum dependent distributions (TMDs) F(x,k2⊥) and quasi-distributions (PQDs) Q(y,p3) introduced recently by X. Ji for lattice QCD extraction of parton distributions f(x). We build models for PQDs from the VDF-based models for soft TMDs, and analyze the p3 dependence of the resulting PQDs. We observe a strong nonperturbative evolution of PQDs for small and moderately large values of p3 reflecting the transverse momentum dependence of TMDs. Thus, the study of PQDs on the lattice …


The Heavy Photon Search Beamline And Its Performance, N. Baltzell, H. Egiyan, M. Ehrhart, C. Field, A. Freyberger, F.-X. Girod, M. Holtrop, J. Jaros, G. Kalicy, T. Maruyama, H. Vance Jan 2017

The Heavy Photon Search Beamline And Its Performance, N. Baltzell, H. Egiyan, M. Ehrhart, C. Field, A. Freyberger, F.-X. Girod, M. Holtrop, J. Jaros, G. Kalicy, T. Maruyama, H. Vance

Physics Faculty Publications

The Heavy Photon Search (HPS) is an experiment to search for a hidden sector photon, aka a heavy photon or dark photon, in fixed target electroproduction at the Thomas Jefferson National Accelerator Facility (JLab). The HPS experiment searches for the e+e- decay of the heavy photon with bump hunt and detached vertex strategies using a compact, large acceptance forward spectrometer, consisting of a silicon microstrip detector (SVT) for tracking and vertexing, and a PbWO4 electromagnetic calorimeter for energy measurement and fast triggering. To achieve large acceptance and good vertexing resolution, the first layer of silicon detectors …


Photon Beam Asymmetry Σ For Η And Η′ Photoproduction From The Proton, P. Collins, B. G. Ritchie, M. Dugger, A. V. Anisovich, M. Doring, E. Klempt, V. A. Nikonov, D. Rönchen, D. Sadasivan, A. Sarantsev, M. J. Amaryan, A. Klein Jan 2017

Photon Beam Asymmetry Σ For Η And Η′ Photoproduction From The Proton, P. Collins, B. G. Ritchie, M. Dugger, A. V. Anisovich, M. Doring, E. Klempt, V. A. Nikonov, D. Rönchen, D. Sadasivan, A. Sarantsev, M. J. Amaryan, A. Klein

Physics Faculty Publications

Measurements of the linearly-polarized photon beam asymmetry Σ for photoproduction from the proton of η and η ′ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the γ p → η p reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the γ p → η ′ p reaction. For γ p → η p , the data reported here considerably extend the range of measurements to higher energies, and are …


Differential Cross Section Measurements For Γn→Π-P Above The First Nucleon Resonance Region, P. T. Mattione, D. S. Carman, I. I. Strakovsky, R. L. Workman, A. E. Kudryavtsev, A. Svarc, V. E. Tarasov, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, Z. W. Zhao Jan 2017

Differential Cross Section Measurements For Γn→Π-P Above The First Nucleon Resonance Region, P. T. Mattione, D. S. Carman, I. I. Strakovsky, R. L. Workman, A. E. Kudryavtsev, A. Svarc, V. E. Tarasov, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, Z. W. Zhao

Physics Faculty Publications

The quasifree γd→π-p(p) differential cross section has been measured with CLAS at photon beam energies Eγ from 0.445 to 2.510 GeV (corresponding to W from 1.311 to 2.366 GeV) for pion center-of-mass angles cosθπc.m. from -0.72 to 0.92. A correction for final state interactions has been applied to these data to extract the γn→π-p differential cross sections. These cross sections are quoted in 8428 (Eγ,cosθπc.m.) bins, a factor of nearly 3 increase in the world statistics for this channel in this kinematic range. These new data …


Measurements Of Ep → E′Π+Π-P′ Cross Sections With Clas At 1.40 Gev < W < 2.0 Gev And 2.0 Gev² < Q² < 5.0 Gev², E.L. Isupov, V.D. Burkert, D.S. Carman, R. W. Gothe, R. Hicks, B. S. Ishkhanov, V. I. Mokeev, K. P. Adhikari, S. Adhikari, D. Adikaram, M. J. Amaryan, G. Charles, A. Klein, Y. Prok, B. Torayev Jan 2017

Measurements Of Ep → E′Π+Π-P′ Cross Sections With Clas At 1.40 Gev < W < 2.0 Gev And 2.0 Gev² < Q² < 5.0 Gev², E.L. Isupov, V.D. Burkert, D.S. Carman, R. W. Gothe, R. Hicks, B. S. Ishkhanov, V. I. Mokeev, K. P. Adhikari, S. Adhikari, D. Adikaram, M. J. Amaryan, G. Charles, A. Klein, Y. Prok, B. Torayev

Physics Faculty Publications

This paper reports new exclusive cross sections for ep → e′π+π-p′ using the CLAS detector at Jefferson Laboratory. These results are presented for the first time at photon virtualities 2.0GeV2 2 < 5.0GeV2 in the center-of-mass energy range 1.4 GeV < W < 2.0 GeV, which covers a large part of the nucleon resonance region. Using a model developed for the phenomenological analysis of electroproduction data, we see strong indications that the relative contributions from the resonant cross sections at W < 1.74 GeV increase with Q2. These data considerably extend the kinematic reach of previous measurements. Exclusive ep → e′π+π-p′ cross section measurements are of particular importance for the extraction of resonance electrocouplings in the mass range above 1.6 GeV.


Photon Beam Asymmetry Σ In The Reaction →Γ P → Pω For Eγ = 1.152 To 1.876 Gev, P. Collins, B. G. Ritchie, M. Dugger, F. J. Klein, A. V. Anisovich, E. Klempt, V. A. Nikonov, A. Sarantsev, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao Jan 2017

Photon Beam Asymmetry Σ In The Reaction →Γ P → Pω For Eγ = 1.152 To 1.876 Gev, P. Collins, B. G. Ritchie, M. Dugger, F. J. Klein, A. V. Anisovich, E. Klempt, V. A. Nikonov, A. Sarantsev, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao

Physics Faculty Publications

Photon beam asymmetry Σ measurements for ω photoproduction in the reaction γ → p → ω p are reported for photon energies from 1.152 to 1.876 GeV. Data were taken using a linearly-polarized tagged photon beam, a cryogenic hydrogen target, and the CLAS spectrometer in Hall B at Jefferson Lab. The measurements obtained markedly increase the size of the database for this observable, extend coverage to higher energies, and resolve discrepancies in previously published data. Comparisons of these new results with predictions from a chiral-quark-based model and from a dynamical coupled-channels model indicate the importance of interferences between t-channel meson …


Measurement Of The Helicity Asymmetry E In Ω→Π+ΠˉΠᵒ Photoproduction, Z. Akbar, P. Roy, S. Park, V. Crede, A. V. Anisovich, I. Denisenko, E. Klempt, V. A. Nikonov, A. V. Sarantsev, K. P. Adhikari, M. J. Amaryan, G. Charles, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao Jan 2017

Measurement Of The Helicity Asymmetry E In Ω→Π+ΠˉΠᵒ Photoproduction, Z. Akbar, P. Roy, S. Park, V. Crede, A. V. Anisovich, I. Denisenko, E. Klempt, V. A. Nikonov, A. V. Sarantsev, K. P. Adhikari, M. J. Amaryan, G. Charles, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao

Physics Faculty Publications

The double-polarization observable E was studied for the reaction γp→pω using the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at the Thomas Jefferson National Accelerator Facility and the longitudinally polarized frozen-spin target (FROST). The observable was measured from the charged decay mode of the meson, ω→π+π-π0, using a circularly polarized tagged-photon beam with energies ranging from the ω threshold at 1.1 to 2.3 GeV. A partial-wave analysis within the Bonn-Gatchina framework found dominant contributions from the 3/2+ partial wave near threshold, which is identified with the subthreshold N(1720)3/2+ nucleon …


Extraction Of The Nuetron Electric Form Factor From Measurements Of Inclusive Double Spin Asymmetries, V. Sulkosky, G. Jin, E. Long, Y.W. Zhang, M. Mihovilovic, A. Kelleher, B. Anderson, D. W. Higinbotham, S. Ŝirca, K. Allada, M. Canan Jan 2017

Extraction Of The Nuetron Electric Form Factor From Measurements Of Inclusive Double Spin Asymmetries, V. Sulkosky, G. Jin, E. Long, Y.W. Zhang, M. Mihovilovic, A. Kelleher, B. Anderson, D. W. Higinbotham, S. Ŝirca, K. Allada, M. Canan

Physics Faculty Publications

Background: Measurements of the neutron charge form factor, GnE , are challenging because the neutron has no net charge. In addition, measurements of the neutron form factors must use nuclear targets which require accurately accounting for nuclear effects. Extracting GnE with different targets and techniques provides an important test of our handling of these effects.

Purpose: The goal of the measurement was to use an inclusive asymmetry measurement technique to extract the neutron charge form factor at a four-momentum transfer of 1(GeV/c)2 . This technique has very different systematic uncertainties than traditional exclusive …


Determination Of The Proton Spin Structure Functions For 0.05 < Q2 <5gev2 Using Clas, R. G. Fersch, N. Guler, P. Bosted, A. Deur, K. Griffioen, C. Keith, S E. Kuhn, R. Minehart, Y. Prok, K. P. Adhikari, S. Bültmann, S. Careccia, Gail Dodge, V. G. Lagerquist, L. B. Weinstein Jan 2017

Determination Of The Proton Spin Structure Functions For 0.05 < Q2 <5gev2 Using Clas, R. G. Fersch, N. Guler, P. Bosted, A. Deur, K. Griffioen, C. Keith, S E. Kuhn, R. Minehart, Y. Prok, K. P. Adhikari, S. Bültmann, S. Careccia, Gail Dodge, V. G. Lagerquist, L. B. Weinstein

Physics Faculty Publications

We present the results of our final analysis of the full data set of gp1 Q2, the spin structure function of the proton, collected using CLAS at Jefferson Laboratory in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.7 GeV were scattered from proton targets 15NH3 dynamically polarized along the beam direction) and detected with CLAS. From the measured double spin asymmetries, we extracted virtual photon asymmetries Ap1 and Ap2 and spin structure functions g p1 and gp2 over a wide kinematic range (0.05 GeV …


Measurement Of The Differential And Total Cross Sections Of The ᵧd→Kºʌ(P) Reaction Within The Resonance Region, N. Compton, C. E. Taylor, K. Hicks, P. Cole, N. Zachariou, Y. Ilieva, P. Nadel-Turonski, E. Klempt, V. A. Nikonov, A. V. Sarantsev, C. E. Hyde, M. Khachatryan, A. Klein, Y. Prok, B. Torayev, J. Zhang Jan 2017

Measurement Of The Differential And Total Cross Sections Of The ᵧd→Kºʌ(P) Reaction Within The Resonance Region, N. Compton, C. E. Taylor, K. Hicks, P. Cole, N. Zachariou, Y. Ilieva, P. Nadel-Turonski, E. Klempt, V. A. Nikonov, A. V. Sarantsev, C. E. Hyde, M. Khachatryan, A. Klein, Y. Prok, B. Torayev, J. Zhang

Physics Faculty Publications

We report the first measurement of differential and total cross sections for the γd →K0 Λ(p)reaction, using data from the CLAS detector at the Thomas Jefferson National Accelerator Facility. Data collected during two separate experimental runs were studied with photon-energy coverage 0.8-3.6 GeV and 0.5-2.6 GeV, respectively. The two measurements are consistent giving confidence in the method and determination of systematic uncertainties. The cross sections are compared with predictions from the KAON-MAID theoretical model (without kaon exchange), which deviate from the data at higher W and at forward kaon angles. These data, along with previously published cross sections for …


Nucleon-Nucleon Correlations, Short-Lived Excitations, And The Quarks Within, Or Hen, Gerald A. Miller, Eli Piasetzky, Lawrence B. Weinstein Jan 2017

Nucleon-Nucleon Correlations, Short-Lived Excitations, And The Quarks Within, Or Hen, Gerald A. Miller, Eli Piasetzky, Lawrence B. Weinstein

Physics Faculty Publications

This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon. The interpretation of measurements of the European Muon Collaboration (EMC) effect for valence quarks, a reduction in the deep inelastic scattering cross-section ratios for nuclei relative to deuterium, and its possible connection to nucleon-nucleon short-range correlations (SRCs) in nuclei are focused on. This review and new analysis (involving the amplitudes of non-nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and …


Target And Beam-Target Spin Asymmetries In Exclusive Pion Electroproduction For Q² > 1 Gev² . Ii. Ep→ Eπºp, Clas Collaboration, K. P. Adhikari, D. Adikaram, M. J. Amaryan, S. Bültmann, N. Guler, S E. Kuhn, A. Klein, S. Koirala, B. Torayev, J. Zhang, Z. W. Zhao Jan 2017

Target And Beam-Target Spin Asymmetries In Exclusive Pion Electroproduction For Q² > 1 Gev² . Ii. Ep→ Eπºp, Clas Collaboration, K. P. Adhikari, D. Adikaram, M. J. Amaryan, S. Bültmann, N. Guler, S E. Kuhn, A. Klein, S. Koirala, B. Torayev, J. Zhang, Z. W. Zhao

Physics Faculty Publications

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive π0 electroproduction reaction γ∗p→pπ0, expanding an analysis of the γ∗p→nπ+ reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are 1.1 < W < 3 GeV and 1 < Q2< 6 GeV2 . Results were obtained for about 5700 bins in W, Q2, cos(θ∗) , and ϕ∗. The beam-target asymmetries were found to generally be greater than zero, with …


Optimization Of The Rf Cavity Heat Load And Trip Rates For Cebaf At 12 Gev, H. Zhang, Y. Roblin, A. Freyberger, G. Krafft, B. Terzić Jan 2017

Optimization Of The Rf Cavity Heat Load And Trip Rates For Cebaf At 12 Gev, H. Zhang, Y. Roblin, A. Freyberger, G. Krafft, B. Terzić

Physics Faculty Publications

The Continuous Electron Beam Accelerator Facility at JLab has 200 RF cavities in the north linac and the south linac respectively after the 12 GeV upgrade. The purpose of this work is to simultaneously optimize the heat load and the trip rate for the cavities and to reconstruct the pareto-optimal front in a timely manner when some of the cavities are turned down. By choosing an efficient optimizer and strategically creating the initial gradients, the pareto-optimal front for no more than 15 cavities down can be re-established within 20 seconds.


Measurement Of Two-Photon Exchange Effect By Comparing Elastic E ± P Cross Sections, D. Rimal, D. Adikaram, B. A. Raue, L. B. Weinstein, J. Arrington, W. K. Brooks, M. Ungaro, K. P. Adhikari, A. V. Afanasev, Z. Akbar Jan 2017

Measurement Of Two-Photon Exchange Effect By Comparing Elastic E ± P Cross Sections, D. Rimal, D. Adikaram, B. A. Raue, L. B. Weinstein, J. Arrington, W. K. Brooks, M. Ungaro, K. P. Adhikari, A. V. Afanasev, Z. Akbar

Physics Faculty Publications

Background: The electromagnetic form factors of the proton measured by unpolarized and polarized electron scattering experiments show a significant disagreement that grows with the squared four-momentum transfer (Q2) . Calculations have shown that the two measurements can be largely reconciled by accounting for the contributions of two-photon exchange (TPE). TPE effects are not typically included in the standard set of radiative corrections since theoretical calculations of the TPE effects are highly model dependent, and, until recently, no direct evidence of significant TPE effects has been observed.

Purpose: We measured the ratio of positron-proton to electron-proton elastic-scattering cross …


Inclusive Neutrino Scattering Off The Deuteron At Low Energies In Chiral Effective Field Theory, A. Baroni, R. Schiavilla Jan 2017

Inclusive Neutrino Scattering Off The Deuteron At Low Energies In Chiral Effective Field Theory, A. Baroni, R. Schiavilla

Physics Faculty Publications

Cross sections for inclusive neutrino scattering off the deuteron induced by neutral and charge-changing weak currents are calculated from threshold up to 150 MeV energies in a chiral effective field theory including high orders in the power counting. Contributions beyond leading order (LO) in the weak current are found to be small, and increase the cross sections obtained with the LO transition operators by a couple of percent over the whole energy range 0–150 MeV. The cutoff dependence is negligible, and the predicted cross sections are within ∼2% of, albeit consistently larger than, corresponding predictions obtained in conventional meson-exchange frameworks.