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Articles 31 - 60 of 106

Full-Text Articles in Elementary Particles and Fields and String Theory

Graded Quivers, Generalized Dimer Models And Toric Geometry, Sebastián Franco, Azeem Hasan Nov 2019

Graded Quivers, Generalized Dimer Models And Toric Geometry, Sebastián Franco, Azeem Hasan

Publications and Research

The open string sector of the topological B-model on CY (m+2)-folds is described by m-graded quivers with superpotentials. This correspondence extends to general m the well known connection between CY (m+2)-folds and gauge theories on the world-volume of D(5-2m)-branes for m = 0, ..., 3. We introduce m-dimers, which fully encode the m-graded quivers and their superpotentials, in the case in which the CY (m+2)-folds are toric. Generalizing the well known m = 1,2 cases, m-dimers significantly simplify the connection between geometry and m-graded quivers. A key …

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Unitarity Of The Infinite-Volume Three-Particle Scattering Amplitude Arising From A Finite-Volume Formalism, Raúl A. Briceño, Maxwell T. Hansen, Stephen R. Sharpe, Adam P. Szczepaniak Sep 2019

Unitarity Of The Infinite-Volume Three-Particle Scattering Amplitude Arising From A Finite-Volume Formalism, Raúl A. Briceño, Maxwell T. Hansen, Stephen R. Sharpe, Adam P. Szczepaniak

Physics Faculty Publications

Hansen and Sharpe [Phys. Rev. D 92, 114509 (2015)] derived a relation between the scattering amplitude of three identical bosons,M3, and a real function referred to as the divergence-free K matrix and denoted Kdf;3. The result arose in the context of a relation between finite-volume energies and Kdf;3, derived to all orders in the perturbative expansion of a generic low-energy effective field theory. In this work we set aside the role of the finite volume and focus on the infinite-volume relation between Kdf;3 and M3. We show that, for any …

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Spacetime Groups, Ian M. Anderson, Charles G. Torre Jan 2019

Spacetime Groups, Ian M. Anderson, Charles G. Torre

Publications

A spacetime group is a connected 4-dimensional Lie group G endowed with a left invariant Lorentz metric h and such that the connected component of the isometry group of h is G itself. The Newman-Penrose formalism is used to give an algebraic classification of spacetime groups, that is, we determine a complete list of inequivalent spacetime Lie algebras, which are pairs (g,η), with g being a 4-dimensional Lie algebra and η being a Lorentzian inner product on g. A full analysis of the equivalence problem for spacetime Lie algebras is given which leads to a completely algorithmic solution to the …

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Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato Jan 2019

Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato

Physics Faculty Publications

Motivated by recently observed tension between O(α2s) calculations of very large transverse momentum dependence in both semi-inclusive deep inelastic scattering and Drell-Yan scattering, we repeat the details of the calculation through an O(α2s) transversely differential cross section. The results confirm earlier calculations, and provide further support to the observation that tension exists with current parton distribution and fragmentation functions.

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Challenges With Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato, B. Wang Dec 2018

Challenges With Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato, B. Wang

Physics Faculty Publications

We survey the current phenomenological status of semi-inclusive deeply inelastic scattering at moderate hard scales and in the limit of very large transverse momentum. As the transverse momentum becomes comparable to or larger than the overall hard scale, the differential cross sections should be calculable with fixed order perturbative QCD (pQCD) methods, while small transverse momentum (transverse-momentum-dependent factorization) approximations should eventually break down. We find large disagreement between HERMES and COMPASS data and fixed order calculations done with modern parton densities, even in regions of kinematics where such calculations should be expected to be very accurate. Possible interpretations are suggested.

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Nonthermal Dark Matter From Early Matter Domination, Jacek Ksawery Osinski Nov 2018

Nonthermal Dark Matter From Early Matter Domination, Jacek Ksawery Osinski

Shared Knowledge Conference

Dark matter (DM) production in the early universe traditionally assumes a standard thermal history where the universe is in a radiation-dominated phase after the end of inflation until matter-radiation equality. However, the presence of additional scalar fields (which is a generic prediction of explicit string constructions) can lead to an epoch of early matter domination (EMD) that ends before the onset of big bang nucleosynthesis. Such an EMD phase has important cosmological consequences and renders thermal production of DM irrelevant. We present three scenarios for DM production involving an era of EMD: evaporation of primordial black holes into DM, DM …

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Search For A Dark Photon In Electroproduced E + E − Pairs With The Heavy Photon Search Experiment At Jlab, P. H. Adrian, N. A. Baltzell, M. Battaglieri, M. Bondí, S. Boyarinov, S. Bueltmann, G. Kalicy, H. Szumila-Vance, L. B. Weinstein, Heavy Photon Search Collaboration Nov 2018

Search For A Dark Photon In Electroproduced E + E − Pairs With The Heavy Photon Search Experiment At Jlab, P. H. Adrian, N. A. Baltzell, M. Battaglieri, M. Bondí, S. Boyarinov, S. Bueltmann, G. Kalicy, H. Szumila-Vance, L. B. Weinstein, Heavy Photon Search Collaboration

Physics Faculty Publications

The Heavy Photon Search experiment took its first data in a 2015 engineering run using a 1.056 GeV, 50 nA electron beam provided by CEBAF at the Thomas Jefferson National Accelerator Facility, searching for a prompt, electroproduced dark photon with a mass between 19 and 81  MeV/c2. A search for a resonance in the e+e− invariant mass distribution, using 1.7 days (1170  nb−1) of data, showed no evidence of dark photon decays above the large QED background, confirming earlier searches and demonstrating the full functionality of the experiment. Upper limits on the square …

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Event Engineering Studies For Heavy Flavor Production And Hadronization In High Multiplicity Hadron-Hadron And Hadron-Nucleus Collisions, Yan-Qing Ma, Prithwish Tribedy, Raju Venugopalan, Kazuhiro Watanabe Oct 2018

Event Engineering Studies For Heavy Flavor Production And Hadronization In High Multiplicity Hadron-Hadron And Hadron-Nucleus Collisions, Yan-Qing Ma, Prithwish Tribedy, Raju Venugopalan, Kazuhiro Watanabe

Physics Faculty Publications

Heavy flavor measurements in high multiplicity proton-proton and proton-nucleus collisions at collider energies enable unique insights into their production and hadronization mechanism because experimental and theoretical uncertainties cancel in ratios of their cross sections relative to minimum bias events. We explore such event engineering using the color glass condensate (CGC) effective field theory to compute short-distance charmonium cross sections. The CGC is combined with heavy-quark fragmentation functions to compute D-meson cross sections; for the J/ψ, hadronization is described employing nonrelativistic QCD (NRQCD) and an improved color evaporation model. Excellent agreement is found between the CGC computations and the LHC heavy …

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Photoproduction Of K+ K- Meson Pairs On The Proton, S. Lombardo, M. Battaglieri, A. Celentano, A. D'Angelo, R. De Vita, A. Filippi, D. I. Glazier, M. Khachatryan, A. Klein, Y. Prok, The Clas Collaboration Sep 2018

Photoproduction Of K+ K- Meson Pairs On The Proton, S. Lombardo, M. Battaglieri, A. Celentano, A. D'Angelo, R. De Vita, A. Filippi, D. I. Glazier, M. Khachatryan, A. Klein, Y. Prok, The Clas Collaboration

Physics Faculty Publications

The exclusive reaction γp → pK+K− was studied in the photon energy range 3.0–3.8 GeV and momentum transfer range 0.6 < −t< 1.3 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. In this kinematic range the integrated luminosity was approximately 20 pb−1. The reaction was isolated by detecting the K+ and the proton in CLAS, and reconstructing the K− via the missing-mass technique. Moments of the dikaon decay angular distributions were extracted from the experimental data. Besides the dominant contribution of the ϕ meson in the P wave, …

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First Measurement Of Ξ− Polarization In Photoproduction, J. Bono, L. Guo, K. P. Adhikari, M. J. Amaryan, G. Charles, G. Gavalian, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao Aug 2018

First Measurement Of Ξ− Polarization In Photoproduction, J. Bono, L. Guo, K. P. Adhikari, M. J. Amaryan, G. Charles, G. Gavalian, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao

Physics Faculty Publications

Despite decades of studies of the photoproduction of hyperons, both their production mechanisms and their spectra of excited states are still largely unknown. While the parity-violating weak decay of hyperons offers a means of measuring their polarization, which could help discern their production mechanisms and identify their excitation spectra, no such study has been possible for doubly strange baryons in photoproduction, due to low production cross sections. However, by making use of the reaction γ p → K+K+Ξ−, we have measured, for the first time, the induced polarization, P, and the transferred polarization from circularly polarized …

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Finite-Volume Effects Due To Spatially Nonlocal Operators, Raúl A. Briceño, Juan V. Guerrero, Maxwell T. Hansen, Christopher J. Monahan Jul 2018

Finite-Volume Effects Due To Spatially Nonlocal Operators, Raúl A. Briceño, Juan V. Guerrero, Maxwell T. Hansen, Christopher J. Monahan

Physics Faculty Publications

Spatially nonlocal matrix elements are useful lattice-QCD observables in a variety of contexts, for example in determining hadron structure. To quote credible estimates of the systematic uncertainties in these calculations, one must understand, among other things, the size of the finite-volume effects when such matrix elements are extracted from numerical lattice calculations. In this work, we estimate finite- volume effects for matrix elements of nonlocal operators, composed of two currents displaced in a spatial direction by a distance ξ. We find that the finite-volume corrections depend on the details of the matrix element. If the external state is the lightest …

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One-Loop Evolution Of Parton Pseudo-Distribution Functions On The Lattice, Anatoly Radyushkin Jul 2018

One-Loop Evolution Of Parton Pseudo-Distribution Functions On The Lattice, Anatoly Radyushkin

Physics Faculty Publications

We incorporate recent calculations of one-loop corrections for the reduced Ioffe-time pseudo-distribution m(v, z(3)(2) thorn to extend the leading-logarithm analysis of lattice data obtained by Orginos et al. We observe that the one-loop corrections contain a large term reflecting the fact that effective distances involved in the most important diagrams are much smaller than the nominal distance z(3). The large correction in this case may be absorbed into the evolution term, and the perturbative expansion used for extraction of parton densities at the μ ≈ 2 GeV scale is under control. The extracted parton distribution is rather close to global …

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Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. Park, M. Guidal, R. W. Gothe, B. Pire, G. Charles, C. E. Hyde, S E. Kuhn, J. Poudel, Y. Prok May 2018

Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. Park, M. Guidal, R. W. Gothe, B. Pire, G. Charles, C. E. Hyde, S E. Kuhn, J. Poudel, Y. Prok

Physics Faculty Publications

We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, ep → e'nπ+, above the resonance region at backward pion center-of-mass angles. The ϕ∗ π-dependent cross sections were measured, from which we extracted three combinations of structure functions of the proton. Our results are compatible with calculations based on nucleon-to-pion transition distribution amplitudes (TDAs). These non-perturbative objects are defined as matrix elements of threequark-light-cone-operators and characterize partonic correlations with a particular emphasis on baryon charge distribution inside a nucleon.

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Primordial Black Hole Atoms, David Zwick, Tyler Hanover, Brian Nepper Apr 2018

Primordial Black Hole Atoms, David Zwick, Tyler Hanover, Brian Nepper

STEM Student Research Symposium Posters

Primordial black holes are thought to have been formed at the early stages of the universe in the presence of non-homogeneous density distributions of dark matter. We are working under the assumption that dark matter consists of elementary low mass particles, specifically, spin 1/2 fermions. We further assume that dark matter is electrically neutral, thus its main interaction is gravitational. We investigate dark matter spin 1/2 fermions in orbit around a black hole atom and consider mass ranges for which the quantum description is appropriate. Solutions to the Dirac equation are utilized to describe the radial mass distribution of primordial …

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Anomalous Electromagnetic Transport In Compact Stars, Efrain J. Ferrer, Vivian De La Incera Mar 2018

Anomalous Electromagnetic Transport In Compact Stars, Efrain J. Ferrer, Vivian De La Incera

Publications and Research

We study the anomalous electromagnetic transport properties of a quark-matter phase that can be realized in the presence of a magnetic field in the low-temperature/moderate-high-density region of the Quantum Chromodynamics (QCD) phase map. In this so-called Magnetic Dual Chiral Density Wave phase, an inhomogeneous condensate is dynamically induced producing a nontrivial topology, a consequence of the asymmetry of the lowest Landau level modes of the quasiparticles in this phase. The nontrivial topology manifests in the electromagnetic effective action via a chiral anomaly term θFµνF˜µν, with an axion field θ given by the phase of the Dual …

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Prompt Photon-Jet Angular Correlations At Central Rapidities In P + A Collisions, Sanjin Benić, Adrian Dumitru Jan 2018

Prompt Photon-Jet Angular Correlations At Central Rapidities In P + A Collisions, Sanjin Benić, Adrian Dumitru

Publications and Research

Photon-jet azimuthal correlations in proton-nucleus collisions are a promising tool for gaining information on the gluon distribution of the nucleus in the regime of nonlinear color fields. We compute such correlations from the process $g → q\bar{q}γ$ in the rapidity regime where both the projectile and target light-cone momentum fractions are small. By integrating over the phase space of the quark which emits the photon, subject to the restriction that the photon picks up most of the transverse momentum (to pass an isolation cut), we effectively obtain a g + A → qγ process. For nearly back-to-back photon-jet configurations we …

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Numerical Study Of The Relativistic Three-Body Quantization Condition In The Isotropic Approximation, Raúl A. Briceño, Maxwell T. Hansen, Stephen R. Sharpe Jan 2018

Numerical Study Of The Relativistic Three-Body Quantization Condition In The Isotropic Approximation, Raúl A. Briceño, Maxwell T. Hansen, Stephen R. Sharpe

Physics Faculty Publications

We present numerical results showing how our recently proposed relativistic three-particle quantization condition can be used in practice. Using the isotropic (generalized s-wave) approximation, and keeping only the leading terms in the effective range expansion, we show how the quantization condition can be solved numerically in a straightforward manner. In addition, we show how the integral equations that relate the intermediate three-particle infinite-volume scattering quantity, Kdf,3, to the physical scattering amplitude can be solved at and below threshold. We test our methods by reproducing known analytic results for the 1/L expansion of the threshold state, the volume …

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Isoscalar Ππ; Kk; Ηη Scattering And The Σ; F0; F2 Mesons From Qcd, Raul A. Briceño, Jozef J. Dudek, Robert G. Edwards, David J. Wilson Jan 2018

Isoscalar Ππ; Kk; Ηη Scattering And The Σ; F0; F2 Mesons From Qcd, Raul A. Briceño, Jozef J. Dudek, Robert G. Edwards, David J. Wilson

Physics Faculty Publications

We present the first lattice QCD study of coupled isoscalar ππ;K ¯K; ηη S- and D-wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the light quark mass corresponding to mπ ∼ 391 MeV. In the JP = 0+ sector we find analogues of the experimental σ and f0 (980) states, where the σ appears as a stable bound-state below ππ threshold, and, similar to what is seen in experiment, the f0 (980) manifests itself as a dip in the ππ cross section in the vicinity of the …

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Introduction To The Usu Library Of Solutions To The Einstein Field Equations, Ian M. Anderson, Charles G. Torre Dec 2017

Introduction To The Usu Library Of Solutions To The Einstein Field Equations, Ian M. Anderson, Charles G. Torre

Tutorials on... in 1 hour or less

This is a Maple worksheet providing an introduction to the USU Library of Solutions to the Einstein Field Equations. The library is part of the DifferentialGeometry software project and is a collection of symbolic data and metadata describing solutions to the Einstein equations.

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Lattice Qcd Exploration Of Parton Pseudo-Distribution Functions, Kostas Orginos, Anatoly Radyushkin, Joseph Karpie, Savvas Zafeiropoulos Nov 2017

Lattice Qcd Exploration Of Parton Pseudo-Distribution Functions, Kostas Orginos, Anatoly Radyushkin, Joseph Karpie, Savvas Zafeiropoulos

Physics Faculty Publications

We demonstrate a new method of extracting parton distributions from lattice calculations. The starting idea is to treat the generic equal-time matrix element M(Pz(3), z(3)(2)) as a function of the Ioffe time nu = Pz(3) and the distance z(3). The next step is to divide M(Pz(3), z(3)(2)) by the rest-frame density M(0, z(3)(2)). Our lattice calculation shows a linear exponential z(3)-dependence in the rest-frame function, expected from the Z(z(3)(2)) factor generated by the gauge link. Still, we observe that the ratio M (Pz(3), z(3)(2))/M(Pz(3), z(3)(2)) has a Gaussian-type behavior with respect to z(3) for 6 values of P used in …

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Miniclean Dark Matter Experiment, Juijen Wang Sep 2017

Miniclean Dark Matter Experiment, Juijen Wang

Physics & Astronomy ETDs

Particle Dark Matter is a hypothesis accounting for a number of observed astrophysical phenomena such as the anomalous galactic rotation curves. From these astronomical observation, about 23% of the universe appears to consist of dark matter. Among the possible candidates for dark matter, a plausible one is a Weakly Interacting Massive Particle (WIMP). A particle with the required properties is beyond the standard model of particle physics. The MiniCLEAN experiment is single-phase liquid-argon detector instrumented with 92 photomultiplier tubes placed inside the cryogenic liquid with 4-pi coverage of a 500 kg (150 kg) target (fiducial) mass. For this experiment, PMT …

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Searching For Signals Of Dark Matter Decay, Gardner R. Marshall, William Hester Jun 2017

Searching For Signals Of Dark Matter Decay, Gardner R. Marshall, William Hester

Journal of the South Carolina Academy of Science

Dark matter is believed to make up approximately eighty-three percent of the matter in the universe. Despite its apparent abundance, it has not yet been directly detected, and it is not known what types of particles it is composed of. Efforts to understand what dark matter is made of and how it fits into the Standard Model of particle physics is currently an important and active area of research. In this paper we investigate a method of studying dark matter indirectly by using terrestrial neutrino telescopes to search for signs of dark matter decay. In particular, we study leptonically decaying …

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What Are The Low-Q And Large-X Boundaries Of Collinear Qcd Factorization Theorems?, E. Moffat, W. Melnitchouk, T. C. Rogers, N. Sato May 2017

What Are The Low-Q And Large-X Boundaries Of Collinear Qcd Factorization Theorems?, E. Moffat, W. Melnitchouk, T. C. Rogers, N. Sato

Physics Faculty Publications

Familiar factorized descriptions of classic QCD processes such as deeply inelastic scattering (DIS) apply in the limit of very large hard scales, much larger than nonperturbative mass scales and other nonperturbative physical properties like intrinsic transverse momentum. Since many interesting DIS studies occur at kinematic regions where the hard scale, Q ∼ 1-2 GeV, is not very much greater than the hadron masses involved, and the Bjorken scaling variable xbj is large, xbj ≳ 0.5, it is important to examine the boundaries of the most basic factorization assumptions and assess whether improved starting points are needed. Using an …

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Pion Distribution Amplitude And Quasidistributions, A. V. Radyushkin Mar 2017

Pion Distribution Amplitude And Quasidistributions, A. V. Radyushkin

Physics Faculty Publications

We extend our analysis of quasidistributions onto the pion distribution amplitude. Using the formalism of parton virtuality distribution amplitudes, we establish a connection between the pion transverse momentum dependent distribution amplitude Ψ(x, k2⊥) and the pion quasidistribution amplitude (QDA) Qπ(y, p3). We build models for the QDAs from the virtuality-distribution-amplitude-based models for soft transverse momentum dependent distribution amplitudes, and analyze the p3 dependence of the resulting QDAs. As there are many models claimed to describe the primordial shape of the pion distribution amplitude, we present the p3-evolution …

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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 …

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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 …

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Probing Dark Matter-Neutrino Connection Via Indirect Detection Experiments, Bradley Knockel Nov 2016

Probing Dark Matter-Neutrino Connection Via Indirect Detection Experiments, Bradley Knockel

Physics & Astronomy ETDs

Various evidence reveals that dark matter is a primary component of this universe. The amount of dark matter is known, but its identity is a mystery. To determine its properties, efforts to detect and produce dark matter are underway. Dark matter annihilations throughout the galaxy may produce photons, neutrinos, and cosmic rays. Neutrino and photon detectors may then indirectly detect dark matter by detecting these annihilation products. The annihilation rate, dark matter mass, and dark matter scattering rate off of matter affect the signals received at Earth. These signals can therefore probe the identity of dark matter, especially if dark …

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Measurement And Modeling Of Cosmic Ray Exposure For Supercdms Dark Matter Detectors., Kameron Mccall, John Orrell, Jared Yamaoka Oct 2016

Measurement And Modeling Of Cosmic Ray Exposure For Supercdms Dark Matter Detectors., Kameron Mccall, John Orrell, Jared Yamaoka

STAR Program Research Presentations

Dark matter is an unknown type of matter that composes roughly 27% of the observable universe and, as cosmological structure models suggest, the earth should be passing through a “dark halo” of this unknown matter present in the Milky Way galaxy. As we pass through this halo, the Super Cryogenic Dark Matter Search (SuperCDMS) experiment aims to directly detect dark -matter particles. Though many dark matter particle candidates exist, SuperCDMS focuses on the detection of particles called WIMPS (weakly interacting massive particles) as predicted by super-symmetric theories beyond the standard model. Due to the high-sensitivity of the germanium detectors employed, …

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An Apparatus For Studying Electrical Breakdown In Liquid Helium At 0.4 K And Testing Electrode Materials For The Neutron Electric Dipole Moment Experiment At The Spallation Neutron Source, T. M. Ito, J. C. Ramsey, W. Yao, D. H. Beck, V. Cianciolo, S. M. Clayton, Christopher B. Crawford, S. A. Currie, B. W. Filippone, W. C. Griffith, M. Makela, R. Schmid, G. M. Seidel, Z. Tang, D. Wagner, W. Wei, S. E. Williamson Apr 2016

An Apparatus For Studying Electrical Breakdown In Liquid Helium At 0.4 K And Testing Electrode Materials For The Neutron Electric Dipole Moment Experiment At The Spallation Neutron Source, T. M. Ito, J. C. Ramsey, W. Yao, D. H. Beck, V. Cianciolo, S. M. Clayton, Christopher B. Crawford, S. A. Currie, B. W. Filippone, W. C. Griffith, M. Makela, R. Schmid, G. M. Seidel, Z. Tang, D. Wagner, W. Wei, S. E. Williamson

Physics and Astronomy Faculty Publications

We have constructed an apparatus to study DC electrical breakdown in liquid helium at temperatures as low as 0.4 K and at pressures between the saturated vapor pressure and ∼600 Torr. The apparatus can house a set of electrodes that are 12 cm in diameter with a gap of 1–2 cm between them, and a potential up to ±50 kV can be applied to each electrode. Initial results demonstrated that it is possible to apply fields exceeding 100 kV/cm in a 1 cm gap between two electropolished stainless steel electrodes 12 cm in diameter for a wide range of pressures …

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Measurements Of Dⁿ² And Aⁿ¹: Probing The Neutron Spin Structure, D. Flay, M. Posik, D. S. Parno, K. Allada, M. Canan, C. Hyde, Jefferson Lab Hall A Collaboration Jan 2016

Measurements Of Dⁿ² And Aⁿ¹: Probing The Neutron Spin Structure, D. Flay, M. Posik, D. S. Parno, K. Allada, M. Canan, C. Hyde, Jefferson Lab Hall A Collaboration

Physics Faculty Publications

We report on the results of the E06-014 experiment performed at Jefferson Lab in Hall A, where a precision measurement of the twist-3 matrix element d2 of the neutron dⁿ2 was conducted. The quantity dⁿ2 represents the average color Lorentz force a struck quark experiences in a deep inelastic electron scattering event off a neutron due to its interaction with the hadronizing remnants. This color force was determined from a linear combination of the third moments of the 3He spin structure functions, g1 and g2, after nuclear corrections had been applied to these …

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