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Full-Text Articles in Physics
Counting Linearly Polarized Gluons With Lattice Qcd, Shuai Zhao
Counting Linearly Polarized Gluons With Lattice Qcd, Shuai Zhao
Physics Faculty Publications
We outline an approach to calculate the transverse-momentum-dependent distribution of linearly polarized gluons inside an unpolarized hadron on the lattice with the help of large momentum effective theory. To achieve this purpose, we propose calculating a Euclidean version of the degree of polarization for a fast-moving hadron on the lattice, which is ultraviolet finite, and no soft function subtraction is needed. It indicates a practical way to explore the distribution of the linearly polarized gluons in a proton and the linearly polarized gluon effects in hadron collisions on the lattice.
Nuclear Magnetic Quadrupole Moment Of ¹⁷⁵Lu And Parity-Violating Polarization Degree Of Levels In ¹⁷⁵Luoh⁺, Igor Kurchavov, Daniel Maison, Leonid Skripnikov, Matt Grau, Alexander Petrov
Nuclear Magnetic Quadrupole Moment Of ¹⁷⁵Lu And Parity-Violating Polarization Degree Of Levels In ¹⁷⁵Luoh⁺, Igor Kurchavov, Daniel Maison, Leonid Skripnikov, Matt Grau, Alexander Petrov
Physics Faculty Publications
A calculation is performed of the parity-violating polarizations in the external electric field, which are associated with the electron electric dipole moment (eEDM) and magnetic quadrupole moment (MQM) of the 175Lu nucleus, as well as the determination of the rovibrational structure for the 175LuOH+ cation. Beyond the bending of the molecule, the slight effect of the stretching of the distance between Lu and OH is taken into account. This study is required for the preparation of the experiment and for the extraction of the eEDM and MQM values of 175Lu from future measurements.
Measurement Of The Helicity Asymmetry E For The 𝛾p → P𝛑⁰ Reaction In The Resonance Region, C. W. Kim, N. Zachariou, M. Bashkanov, W. J. Briscoe, S. Fegan, V. L. Kashevarov, K. Nikonov, A. Sarantsev, A. Schmidt, I. I. Strakovsky, D. P. Watts, R. L. Workman, P. Achenbach, Z. Akbar, M. J. Amaryan, G. Angelini, W. R. Armstrong, H. Atac, L. Baashen, M. Zurek, Et Al., The Clas Collaboration
Measurement Of The Helicity Asymmetry E For The 𝛾p → P𝛑⁰ Reaction In The Resonance Region, C. W. Kim, N. Zachariou, M. Bashkanov, W. J. Briscoe, S. Fegan, V. L. Kashevarov, K. Nikonov, A. Sarantsev, A. Schmidt, I. I. Strakovsky, D. P. Watts, R. L. Workman, P. Achenbach, Z. Akbar, M. J. Amaryan, G. Angelini, W. R. Armstrong, H. Atac, L. Baashen, M. Zurek, Et Al., The Clas Collaboration
Physics Faculty Publications
The double-spin-polarization observable E for 𝛾→ p→ → p𝛑⁰ has been measured with the CEBAF Large Acceptance Spectrometer (CLAS) at photon beam energies E𝛾 from 0.367 to 2.173 GeV (corresponding to center-of-mass energies from 1.240 to 2.200 GeV) for pion center-of-mass angles, cos θc.m.𝛑⁰, between - 0.86 and 0.82. These new CLAS measurements cover a broader energy range and have smaller uncertainties compared to previous CBELSA data and provide an important independent check on systematics. These measurements are compared to predictions as well as new global fits from The George Washington University, Mainz, and Bonn-Gatchina …
Beam-Recoil Transferred Polarization In K+Y Electroproduction In The Nucleon Resonance Region With Clas12, D. S. Carman, A. D'Angelo, L. Lanza, V. I. Mokeev, K. P. Adhikari, M. J. Amaryan, W. R. Armstrong, H. Atac, H. Avakian, C. Ayerbe Gayoso, N. A. Baltzell, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, A. Bianconi, A. S. Biselli, M. Bondi, S. Boiarinov, V. Ziegler
Beam-Recoil Transferred Polarization In K+Y Electroproduction In The Nucleon Resonance Region With Clas12, D. S. Carman, A. D'Angelo, L. Lanza, V. I. Mokeev, K. P. Adhikari, M. J. Amaryan, W. R. Armstrong, H. Atac, H. Avakian, C. Ayerbe Gayoso, N. A. Baltzell, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, A. Bianconi, A. S. Biselli, M. Bondi, S. Boiarinov, V. Ziegler
Physics Faculty Publications
Beam-recoil transferred polarizations for the exclusive electroproduction of K + Λ and K + Σ0 final states from an unpolarized proton target have been measured using the CLAS12 spectrometer at Jefferson Laboratory. The measurements at beam energies of 6.535 and 7.546 GeV span the range of four-momentum transfer Q2 from 0.3 to 4.5 GeV2 and invariant energy W from 1.6 to 2.4 GeV, while covering the full center-of-mass angular range of the K+. These new data extend the existing hyperon polarization data from CLAS in a similar kinematic range but from a significantly larger dataset. …
Testing For Directionality In The Planck Polarization And Lensing Data, Majd Ghrear, Emory F. Bunn, Dagoberto Contreras, Douglas Scott
Testing For Directionality In The Planck Polarization And Lensing Data, Majd Ghrear, Emory F. Bunn, Dagoberto Contreras, Douglas Scott
Physics Faculty Publications
In order to better analyse the polarization of the cosmic microwave background (CMB), which is dominated by emission from our Galaxy, we need tools that can detect residual foregrounds in cleaned CMB maps. Galactic foregrounds introduce statistical anisotropy and directionality to the polarization pseudo-vectors of the CMB, which can be investigated by using the D statistic of Bunn and Scott. This statistic is rapidly computable and capable of investigating a broad range of data products for directionality. We demonstrate the application of this statistic to detecting foregrounds in polarization maps by analysing the uncleaned Planck 2018 frequency maps. For the …
Polarization Analysis Of P̄ Produced In Pa Collisions, D. Grzonka, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Glowacz, F. Hauenstein, T. Horn, K. Kilian
Polarization Analysis Of P̄ Produced In Pa Collisions, D. Grzonka, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Glowacz, F. Hauenstein, T. Horn, K. Kilian
Physics Faculty Publications
A quite simple procedure for the generation of a polarized antiproton beam could be worked out if antiprotons are produced with some polarization. In order to investigate this possibility measurements of the polarization of produced antiprotons have been started at a CERN/PS test beam. The polarization will be determined from the asymmetry of the elastic antiproton scattering at a liquid hydrogen target in the CNI region for which the analyzing power is well known. The data are under analysis and an additional measurement is done in 2018. Details on the experiment and the ongoing data analysis will be given.
The Us Electron Ion Collider Accelerator Designs, A. Seryi, S.V. Benson, S.A. Bogacz, P.D. Brindza, M.W. Brucker, A. Camsonne, E. Daly, P.V. Degtiarenko, Y.S. Derbenev, M. Diefenthaler, J. Dolbeck, R. Ent, R. Fair, D. Fazenbaker, Y. Furletova, B.R. Gamage, D. Gaskell, R.L. Geng, P. Ghoshal, R.C. York, Et Al.
The Us Electron Ion Collider Accelerator Designs, A. Seryi, S.V. Benson, S.A. Bogacz, P.D. Brindza, M.W. Brucker, A. Camsonne, E. Daly, P.V. Degtiarenko, Y.S. Derbenev, M. Diefenthaler, J. Dolbeck, R. Ent, R. Fair, D. Fazenbaker, Y. Furletova, B.R. Gamage, D. Gaskell, R.L. Geng, P. Ghoshal, R.C. York, Et Al.
Physics Faculty Publications
With the completion of the National Academies of Sciences Assessment of a US Electron-Ion Collider, the prospects for construction of such a facility have taken a step forward. This paper provides an overview of the two site-specific EIC designs: JLEIC (Jefferson Lab) and eRHIC (BNL) as well as brief overview of ongoing EIC R&D.
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
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 …
Laser Pulsing In Linear Compton Scattering, G. A. Krafft, E. Johnson, K. Deitrick, B. Terzić, R. Kelmar, T. Hodges, J. R. Delayen
Laser Pulsing In Linear Compton Scattering, G. A. Krafft, E. Johnson, K. Deitrick, B. Terzić, R. Kelmar, T. Hodges, J. R. Delayen
Physics Faculty Publications
Previous work on calculating energy spectra from Compton scattering events has either neglected considering the pulsed structure of the incident laser beam, or has calculated these effects in an approximate way subject to criticism. In this paper, this problem has been reconsidered within a linear plane wave model for the incident laser beam. By performing the proper Lorentz transformation of the Klein-Nishina scattering cross section, a spectrum calculation can be created which allows the electron beam energy spread and emittance effects on the spectrum to be accurately calculated, essentially by summing over the emission of each individual electron. Such an …
Peppo: Using A Polarized Electron Beam To Produce Polarized Positrons, A. Adeyemi, G.L Gueye, P.A. Adderly, M. L. Stutzman, M. M. Ali, H. Areti, J. F. Benesch, L. S. Cardman, J. Clark, S. Covert, S. Golge, C. Hyde
Peppo: Using A Polarized Electron Beam To Produce Polarized Positrons, A. Adeyemi, G.L Gueye, P.A. Adderly, M. L. Stutzman, M. M. Ali, H. Areti, J. F. Benesch, L. S. Cardman, J. Clark, S. Covert, S. Golge, C. Hyde
Physics Faculty Publications
An experiment demonstrating a new method for producing polarized positrons has been performed at the CEBAF accelerator at Jefferson Laboratory. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e+/e− pairs originating from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a 1.0 mm tungsten pair-production target. This paper describes preliminary results of measurements using an 8.2 MeV/c electron beam with polarization 84% to generate positrons in the range of 3.1 to 6.2 MeV/c with polarization as high as ∼80%.
Semi-Inclusive Charged-Current Neutrino-Nucleus Reactions, O. Moreno, T. W. Donnelly, J. W. Van Orden, W. P. Ford
Semi-Inclusive Charged-Current Neutrino-Nucleus Reactions, O. Moreno, T. W. Donnelly, J. W. Van Orden, W. P. Ford
Physics Faculty Publications
The general, universal formalism for semi-inclusive charged-current (anti) neutrino-nucleus reactions is given for studies of any hadronic system, namely, either nuclei or the nucleon itself. The detailed developments are presented with the former in mind and are further specialized to cases where the final-state charged lepton and an ejected nucleon are presumed to be detected. General kinematics for such processes are summarized, and then explicit expressions are developed for the leptonic and hadronic tensors involved and for the corresponding responses according to the usual charge, longitudinal and transverse projections, keeping finite the masses of all particles involved. In the case …
J/Ѱ Polarization In P+P Collisions At √S = 200 Gev In Star, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, S. Bültmann
J/Ѱ Polarization In P+P Collisions At √S = 200 Gev In Star, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, S. Bültmann
Physics Faculty Publications
We report on a polarization measurement of inclusive J/Ѱ mesons in the di-electron decay channel at mid-rapidity at 2 < pT < 6 GeV/c in p + p collisions at √s = 200 GeV. Data were taken with the STAR detector at RHIC. The J/Ѱ polarization measurement should help to distinguish between different models of the J/Ѱ production mechanism since they predict different pT dependences of the J/Ѱ polarization. In this analysis, J/Ѱ is studied in the helicity frame. The polarization parameter λθ measured at RHIC becomes smaller towards high pT, indicating more longitudinal J/Ѱ polarization as pT increases. The result is compared with predictions of presently available models.
Single Spin Asymmetry An In Polarized Proton–Proton Elastic Scattering At √S = 200 Gev, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, C. D. Anson, D. Arkhipkin, E. Aschenauer, S. Bültmann, I. Koralt, D. Plyku
Single Spin Asymmetry An In Polarized Proton–Proton Elastic Scattering At √S = 200 Gev, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, C. D. Anson, D. Arkhipkin, E. Aschenauer, S. Bültmann, I. Koralt, D. Plyku
Physics Faculty Publications
We report a high precision measurement of the transverse single spin asymmetry AN at the center of mass energy √s = 200 GeV in elastic proton–proton scattering by the STAR experiment at RHIC. The AN was measured in the four-momentum transfer squared t range 0.003 ⩽ | t | ⩽ 0.035 ( GeV / c ) 2 , the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of AN and its t-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the …
First Measurement Of Beam-Recoil Observables CX And CZ In Hyperon Photoproduction, M. J. Amaryan, H. Bagdasaryan, H. Bektasoglu, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, J. Lachniet, M. R. Niroula, R. A. Niyazov, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration
First Measurement Of Beam-Recoil Observables CX And CZ In Hyperon Photoproduction, M. J. Amaryan, H. Bagdasaryan, H. Bektasoglu, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, J. Lachniet, M. R. Niroula, R. A. Niyazov, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration
Physics Faculty Publications
Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions →γ + p → K+ + →Λ and →γ+p → K+ + →Σ0. The data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS) detector at the Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85 < cos θc.m.K+ < +0.95. For the Λ, the polarization transfer coefficient along the photon momentum axis, Cz, was found to be near unity for a wide range of energy and kaon production angles. The associated transverse polarization coefficient Cx is smaller than Cz by a roughly …
Differential Cross Sections For 𝛾 + P → K⁺ + Y For Λ And Σ⁰ Hyperons, H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, S. Bültmann, G. E. Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. V. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., Clas Collaboration
Differential Cross Sections For 𝛾 + P → K⁺ + Y For Λ And Σ⁰ Hyperons, H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, S. Bültmann, G. E. Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. V. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., Clas Collaboration
Physics Faculty Publications
High-statistics cross sections for the reactions 𝛾 + p → K⁺ + Λ and 𝛾 + p → K⁺ + Σ⁰ have been measured using CLAS at Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85 < cos θ Kc.m. < +0.95. In the K⁺ + Λ channel we confirm a resonance-like structure near W=1.9 GeV at backward kaon angles. The position and width of this structure change with angle, indicating that more than one resonance is likely playing a role. The K⁺ + Λ channel at forward angles and all energies is well described by a t-channel scaling characteristic of Regge exchange, whereas the same scaling applied to the K⁺ + Σ⁰ channel is less successful. Several existing theoretical models are compared to the data, but none provide a good representation of the results.
Beam-Helicity Asymmetries In Double-Charged-Pion Photoproduction On The Proton, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, Gail Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. Klein, S. E. Kuhn, L. M. Qin, W. Roberts, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang, Et Al., Clas Collaboration
Beam-Helicity Asymmetries In Double-Charged-Pion Photoproduction On The Proton, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, Gail Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. Klein, S. E. Kuhn, L. M. Qin, W. Roberts, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang, Et Al., Clas Collaboration
Physics Faculty Publications
Beam-helicity asymmetries for the two-pion-photoproduction reaction 𝛾⃗p → p π+π- have been studied for the first time in the resonance region for center-of-mass energies between 1.35 and 2.30 GeV. The experiment was performed at Jefferson Lab with the CEBAF Large Acceptance Spectrometer using circularly polarized tagged photons incident on an unpolarized hydrogen target. Beam-helicity-dependent angular distributions of the final-state particles were measured. The large cross-section asymmetries exhibit strong sensitivity to the kinematics and dynamics of the reaction. The data are compared with the results of various phenomenological model calculations, and show that these models currently do not …
Complete Angular Distribution Measurements Of Two-Body Deuteron Photodisintegration Between 0.5 And 3 Gev, H. Bagdasaryan, H. Bektasoglu, G. E. Dodge, T. A. Forest, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, F. Sabatié, S. Stepanyan, L. B. Weinstein, J. Yun, Et Al., The Clas Collaboration
Complete Angular Distribution Measurements Of Two-Body Deuteron Photodisintegration Between 0.5 And 3 Gev, H. Bagdasaryan, H. Bektasoglu, G. E. Dodge, T. A. Forest, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, F. Sabatié, S. Stepanyan, L. B. Weinstein, J. Yun, Et Al., The Clas Collaboration
Physics Faculty Publications
Nearly complete angular distributions of the two-body deuteron photodisintegration differential cross section have been measured using the CEBAF Large Acceptance Spectrometer detector and the tagged photon beam at the Thomas Jefferson National Accelerator Facility. The data cover photon energies between 0.5 and 3.0 GeV and center-of-mass proton scattering angles 10°–160°. The data show a persistent forward-backward angle asymmetry over the explored energy range, and are well described by the nonperturbative quark gluon string model.
Renormalons As Dilation Modes In The Functional Space, A. Babansky, I. Balitsky
Renormalons As Dilation Modes In The Functional Space, A. Babansky, I. Balitsky
Physics Faculty Publications
There are two possible sources of the factorial large-order behavior of a typical perturbative series. First, the number of different Feynman diagrams may be large; second, there may be abnormally large diagrams known as renormalons. It is well known that the large combinatorial number of diagrams is described by instanton-type solutions of the classical equations. We demonstrate that, from the functional-integral viewpoint, the renormalons do not correspond to a particular configuration but manifest themselves as dilatation modes in the functional space.