Beam-Target Helicity Asymmetry E In K0Λ And K0Σ0 Photoproduction On The Neutron,
2018
GAC R&D Center Silicon Valley Inc.
Beam-Target Helicity Asymmetry E In K0Λ And K0Σ0 Photoproduction On The Neutron, D. H. Ho, R. A. Schumacher, A. D’Angelo, A. Deur, J. Fleming, C. Hanretty, T. Kageya, F. J. Klein, E. Klempt, M. M. Lowry, H. Lu, V. A. Nikonov, P. Peng, A. M. Sandorfi, A. V. Sarantsev, I. I. Strakovsky, N. K. Walford, X. Wei, R. L. Workman, K. P. Adhikari, S. Adhikari, D. Adikaram, Z. Akbar, J. Ball, L. Barion, M. Bashkanov, C. D. Bass, M. Battaglieri, I. Bedlinskiy, A. S. Biselli, Wesley P. Gohn
Physics and Astronomy Faculty Publications
We report the first measurements of the E beam-target helicity asymmetry for the γ→ n→ → K0Λ and K0Σ0 channels in the energy range 1.70 ≤ W ≤ 2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees is used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the …
All Tree Level Scattering Amplitudes In Chern-Simons Theories With Fundamental Matter,
2018
Tel Aviv University, Israel
All Tree Level Scattering Amplitudes In Chern-Simons Theories With Fundamental Matter, Karthik Inbasekar, Sachin Jain, Pranjal Nayak, V. Umesh
Physics and Astronomy Faculty Publications
We show that Britto-Cachazo-Feng-Witten (BCFW) recursion relations can be used to compute all tree level scattering amplitudes in terms of 2 → 2 scattering amplitude in U(N) 𝒩 = 2 Chern-Simons (CS) theory coupled to matter in the fundamental representation. As a by-product, we also obtain a recursion relation for the CS theory coupled to regular fermions, even though in this case standard BCFW deformations do not have a good asymptotic behavior. Moreover, at large N, 2 → 2 scattering can be computed exactly to all orders in ’t Hooft coupling as was done in earlier works …
Nonperturbatively Renormalized Glue Momentum Fraction At The Physical Pion Mass From Lattice Qcd,
2018
Michigan State University
Nonperturbatively Renormalized Glue Momentum Fraction At The Physical Pion Mass From Lattice Qcd, Yi-Bo Yang, Ming Gong, Jian Liang, Huey-Wen Lin, Keh-Fei Liu, Dimitra Pefkou, Phiala Shanahan
Physics and Astronomy Faculty Publications
We present the first nonperturbatively renormalized determination of the glue momentum fraction ⟨x⟩g in the nucleon, based on lattice-QCD simulations at the physical pion mass using the cluster-decomposition error reduction technique. We provide the first practical strategy to renormalize the gauge energy-momentum tensor nonperturbatively in the regularization-independent momentum-subtraction (RI/MOM) scheme and convert the results to the MS¯ scheme with one-loop matching. The simulation results show that the cluster-decomposition error reduction technique can reduce the statistical uncertainty of its renormalization constant by a factor of O(300) in calculations using a typical state-of-the-art lattice volume, and the nonperturbatively …
Perturbative Representation Of Ultrashort Nonparaxial Elegant Laguerre-Gaussian Fields,
2018
University of Nebraska - Lincoln
Perturbative Representation Of Ultrashort Nonparaxial Elegant Laguerre-Gaussian Fields, Andrew Vikartofsky, Anthony F. Starace, Liang-Wen Pi
Anthony F. Starace Publications
An analytical method for calculating the electromagnetic fields of a nonparaxial elegant Laguerre-Gaussian (LG) vortex beam is presented for arbitrary pulse duration, spot size, and LG mode. This perturbative approach provides a numerically tractable model for the calculation of arbitrarily high radial and azimuthal LG modes in the nonparaxial regime, without requiring integral representations of the fields. A key feature of this perturbative model is its use of a Poisson-like frequency spectrum, which allows for the proper description of pulses of arbitrarily short duration. This model is thus appropriate for simulating laser-matter interactions, including those involving short laser pulses.
Measurement Of Unpolarized And Polarized Cross Sections For Deeply Virtual Compton Scattering On The Proton At Jefferson Laboratory With Clas,
2018
Rensselaer Polytechnic Institute
Measurement Of Unpolarized And Polarized Cross Sections For Deeply Virtual Compton Scattering On The Proton At Jefferson Laboratory With Clas, N. Hirlinger Saylor, B. Guegan, V. D. Burkert, L. Elouadrhiri, M. Garçon, F. X. Girod, M. Guidal, H. S. Jo, V. Kubarovsky, S. Niccolai, P. Stoler, K. P. Adhikari, S. Adhikari, Z. Akbar, M. J. Amaryan, S. Anefalos Pereira, J. Ball, I. Balossino, N. A. Baltzell, L. Barion, M. Battaglieri, V. Batourine, I. Bedlinskiy, A. S. Biselli, S. Boiarinov, W. J. Briscoe, W. K. Brooks, S. Bültmann, F. Cao, S. Carman, Wesley P. Gohn
Physics and Astronomy Faculty Publications
This paper reports the measurement of polarized and unpolarized cross sections for the ep → e′ p′ γ reaction, which is composed of deeply virtual Compton scattering (DVCS) and Bethe-Heitler (BH) processes, at an electron beam energy of 5.88 GeV at the Thomas Jefferson National Accelerator Facility using the Large Acceptance Spectrometer CLAS. The unpolarized cross sections and polarized cross section differences have been measured over broad kinematics, 0.10 < xB < 0.58, 1.0 < Q2 < 4.8GeV2, and 0.09 < −t < 2.00GeV2. The results are found to be consistent with previous CLAS data, and these new data are discussed in …
Quark Spins And Anomalous Ward Identity,
2018
University of Kentucky
Quark Spins And Anomalous Ward Identity, Jian Liang, Yi-Bo Yang, Terrence Draper, Ming Gong, Keh-Fei Liu
Physics and Astronomy Faculty Publications
We calculate the intrinsic quark spin contribution to the total proton spin using overlap valence quarks on three ensembles of 2 + 1-flavor RBC/UKQCD domain-wall configurations with different lattice spacings. The lowest pion mass of the ensembles is around 171 MeV, which is close to the physical point. With overlap fermions and a topological charge derived from the overlap operator, we verify the anomalous Ward identity between nucleon states with momentum transfer. Both the connected and the disconnected insertions of the axial-vector current are calculated. For the disconnected-insertion part, the cluster-decomposition error reduction technique is utilized for the lattice with …
Event Engineering Studies For Heavy Flavor Production And Hadronization In High Multiplicity Hadron-Hadron And Hadron-Nucleus Collisions,
2018
Old Dominion University
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 …
Short Range Correlations And The Isospin Dependence Of Nuclear Correlation Functions,
2018
Old Dominion University
Short Range Correlations And The Isospin Dependence Of Nuclear Correlation Functions, R. Cruz-Torres, A. Schmidt, G. A. Miller, L. B. Weinstein, N. Barnea, R. Weiss, E. Piasetzky, O. Hen
Physics Faculty Publications
Pair densities and associated correlation functions provide a critical tool for introducing many-body correlations into a wide-range of effective theories. Ab initio calculations show that two-nucleon pairdensities exhibit strong spin and isospin dependence. However, such calculations are not available for all nuclei of current interest. We therefore provide a simple model, which involves combining the short and long separation distance behavior using a single blending function, to accurately describe the two nucleon correlations inherent in existing ab initio calculations. We show that the salient features of the correlation function arise from the features of the two-body short-range nuclear interaction, and …
Harmonic Decomposition Of Three-Particle Azimuthal Correlations At Energies Available At The Bnl Relativistic Heavy Ion Collider,
2018
AGH University of Science and Technology, Poland
Harmonic Decomposition Of Three-Particle Azimuthal Correlations At Energies Available At The Bnl Relativistic Heavy Ion Collider, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, 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, A. Behera, 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, D. Brown, Renee H. Fatemi, Suvarna Ramachandran
Physics and Astronomy Faculty Publications
We present measurements of three-particle correlations for various harmonics in Au+Au collisions at energies ranging from √sNN = 7.7 to 200 GeV using the STAR detector. The quantity ⟨cos(mϕ1 + nϕ2 − (m + n)ϕ3)⟩, with ϕ being the azimuthal angles of the particles is evaluated as a function of √sNN, collision centrality, transverse momentum, pT, pseudorapidity difference, Δη, and harmonics (m and n). These data provide detailed information on global event properties such as the three-dimensional structure of the initial …
Top Tagging: An Analytical Perspective,
2018
University of Manchester
Top Tagging: An Analytical Perspective, Mrinal Dasgupta, Marco Guzzi, Jacob Rowling, Gregory Soyez
Faculty Articles
In this paper we study aspects of top tagging from first principles of QCD. We find that the method known as the CMS top tagger becomes collinear unsafe at high pt and propose variants thereof which are IRC safe, and hence suitable for analytical studies, while giving a comparable performance to the CMS tagger. We also develop new techniques to identify three-pronged jet substructure, based on adaptations of the Y-splitter method and its combination with grooming. A novel feature of our studies, relative to previous calculations of two-pronged substructure, is our use of triple-collinear splitting functions combined with all-order resummation, …
Baryons And Interactions In Magnetic Fields,
2018
CUNY Graduate Center
Baryons And Interactions In Magnetic Fields, Amol Deshmukh
Dissertations, Theses, and Capstone Projects
The QCD external field problem allows one to probe the rich behavior of strongly interacting systems under external conditions, including the modification of hadron structure and interactions due to external electromagnetic fields. These dynamics, moreover, are likely relevant to describe the physics in the interiors of magnetars and in non-central heavy-ion collisions, for which large magnetic fields upwards of $10^{19}$ Gauss are conceivable. Additionally motivated by lattice QCD calculations in external fields, we study the behavior of single- and two-baryon (specifically, two-nucleon) systems in large magnetic fields. The dependence of single-baryon energies on magnetic fields is explored using chiral dynamics. …
Photoproduction Of K+ K- Meson Pairs On The Proton,
2018
Old Dominion University
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, …
Longitudinal Double-Spin Asymmetries For Dijet Production At Intermediate Pseudorapidity In Polarized Pp Collisions At √S = 200 Gev,
2018
Creighton University
Longitudinal Double-Spin Asymmetries For Dijet Production At Intermediate Pseudorapidity In Polarized Pp Collisions At √S = 200 Gev, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, Renee H. Fatemi, Suvarna Ramachandran
Physics and Astronomy Faculty Publications
We present the first measurements of the longitudinal double-spin asymmetry ALL for dijets with at least one jet reconstructed within the pseudorapidity range 0.8 < η < 1.8. The dijets were measured in polarized pp collisions at a center-of-mass energy √s = 200 GeV. Values for ALL are determined for several distinct event topologies, defined by the jet pseudorapidities, and span a range of parton momentum fraction x down to x ∼ 0.01. The measured asymmetries are found to be consistent with the predictions of global analyses that incorporate the results of previous RHIC measurements. They will provide new constraints on Δg(x) in this poorly constrained region when included in …
Steady-State Method To Measure The In-Plane Thermal Conductivity Of Thin Sheet Materials,
2018
Coe College
Steady-State Method To Measure The In-Plane Thermal Conductivity Of Thin Sheet Materials, Evgeny Pakhomenko, Andrew James Wildridge, Abraham Mathew Koshy, Souvik Das, Andreas Jung
The Summer Undergraduate Research Fellowship (SURF) Symposium
A new generation of silicon pixel detectors is required to cope with the unprecedented luminosities at the high-luminosity phase of the Large Hadron Collider (HL-LHC) in 2025. The HL-LHC provides a high radiation, high interaction rate environment for the innermost detector region of the CMS detector. This can lead to an uncontrolled increase in temperature of the detector that can destroy the silicon pixels. Moreover, too high operating temperature can add noise to the data obtained from the detector and can slow the read out cheap down. Therefore, the Phase II upgrade to the Compact Muon Solenoid (CMS) experiment requires …
Effect Of Self-Bias On Cylindrical Capacitive Discharge For Processing Of Inner Walls Of Tubular Structures-Case Of Srf Cavities,
2018
Old Dominion University
Effect Of Self-Bias On Cylindrical Capacitive Discharge For Processing Of Inner Walls Of Tubular Structures-Case Of Srf Cavities, J. Upadhyay, J. Peshl, S. Popović, A.-M. Valente-Feliciano, L. Vušković
Physics Faculty Publications
Cylindrical capacitive discharge is a convenient medium for generating reactive ions to process inner walls superconductive radio-frequency (SRF) cavities. These cavities, used in particle accelerators, presents a three-dimensional structure made of bulk Niobium, with axial cylindrical symmetry. Manufactured cavity walls are covered with Niobium oxides and scattered particulates, which must be removed for desired SRF performance. Cylindrical capacitive discharge in a mixture of Ar and Cl2 is a sole and natural non-wet acid choice to purify the inner surfaces of SRF cavities by reactive ion etching. Coaxial cylindrical discharge is generated between a powered inner electrode and the grounded …
High-Brilliance, High-Flux Compact Inverse Compton Light Source,
2018
Old Dominion University
High-Brilliance, High-Flux Compact Inverse Compton Light Source, K. E. Deitrick, G. A. Krafft, B. Terzić, J. R. Delayen
Physics Faculty Publications
The Old Dominion University Compact Light Source (ODU CLS) design concept is presented-a compact Inverse Compton Light Source (ICLS) with flux and brilliance orders of magnitude beyond conventional laboratory-scale sources and greater than other compact ICLS designs. This concept utilizes the physics of inverse Compton scattering of an extremely low emittance electron beam by a laser pulse of rms length of approximately two-thirds of a picosecond (2/3 ps). The accelerator is composed of a superconducting radio frequency (SRF) reentrant gun followed by four double-spoke SRF cavities. After the linac are three quadrupole magnets to focus the electron beam to the …
First Measurement Of Ξ− Polarization In Photoproduction,
2018
Old Dominion University
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 …
Azimuthal Anisotropy In Cu+Au Collisions At √SNn = 200 Gev,
2018
AGH University of Science and Technology, Poland
Azimuthal Anisotropy In Cu+Au Collisions At √SNn = 200 Gev, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, 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, K. Barish, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, Renee H. Fatemi, Suvarna Ramachandran
Physics and Astronomy Faculty Publications
The azimuthal anisotropic flow of identified and unidentified charged particles has been systematically studied in Cu+Au collisions at √sNN = 200 GeV for harmonics n = 1–4 in the pseudorapidity range |η| < 1. The directed flow in Cu+Au collisions is compared with the rapidity-odd and, for the first time, the rapidity-even components of charged particle directed flow in Au+Au collisions at √sNN = 20 GeV. The slope of the directed flow pseudorapidity dependence in Cu+Au collisions is found to be similar to that in Au+Au collisions, with the intercept shifted toward positive pseudorapidity values, i.e., the Cu-going direction. The mean transverse momentum projected onto the spectator plane ⟨px⟩ in Cu+Au collision also exhibits approximately linear dependence on pseudorapidity with the intercept …
Exclusive Photoproduction Of Π0 Up To Large Values Of Mandlestam Variables S, T, And U With Clas,
2018
Old Dominion University
Exclusive Photoproduction Of Π0 Up To Large Values Of Mandlestam Variables S, T, And U With Clas, M. C. Kunkel, M. J. Amaryan, I. I. Strakovsky, J. Ritman, G. R. Goldstein, K. P. Adhikari, S. Adhikari, H. Avakian, J. Ball, I. Balossino, L. Barion, M. Battaglieri, V. Batourine, I. Bedlinskiy, A. S. Biselli, S. Boiarinov, W. J. Briscoe, W. K. Brooks, S. Bültmann, V. D. Burkert, F. Cao, D. S. Carman, A. Celentano, G. Charles, T. Chetry, G. Ciullo, L. Clark, P. L. Cole, M. Contalbrigo, O. Cortes, Wesley P. Gohn
Physics and Astronomy Faculty Publications
Exclusive photoproduction cross sections have been measured for the process γp → pπ0[e+e−(γ)] with the Dalitz decay final state using tagged photon energies in the range of Eγ = 1.275–5.425 GeV. The complete angular distribution of the final state π0, for the entire photon energy range up to large values of t and u, has been measured for the first time. The data obtained show that the cross section dσ/dt, at mid to large angles, decreases with energy as s−6.89±0.26. This is …
Compton Scattering From The Deuteron Above Pion-Production Threshold,
2018
Nikhef, The Netherlands
Compton Scattering From The Deuteron Above Pion-Production Threshold, B. Strandberg, J. R. M. Annand, W. Briscoe, J. Brudvik, F. Cividini, L. Clark, E. J. Downie, K. England, G. Feldman, K. G. Fissum, D. I. Glazier, K. Hamilton, K. Hansen, L. Isaksson, R. Al Jebali, Michael A. Kovash, S. Lipschutz, M. Lundin, M. Meshkian, D. G. Middleton, L. S. Myers, D. O'Donnell, G. O'Rielly, B. Oussena, M. F. Preston, B. Schröder, B. Seitz, I. Strakovsky, M. Taragin
Physics and Astronomy Faculty Publications
The electromagnetic polarizabilities of the nucleon are fundamental nucleon-structure observables that characterize its response to external electromagnetic fields. The neutron polarizabilities can be accessed from Compton-scattering data on light nuclear targets. Recent measurements of the differential cross section for Compton scattering on the deuteron below the pion-production threshold have decreased the uncertainties in the neutron polarizabilities, yet the proton polarizabilities remain known substantially more accurately. As the sensitivity of the cross section to the polarizabilities increases with incident photon energy, measurements above the pion threshold may offer a way for an improved determination of the neutron polarizabilities. In this Rapid …
