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Full-Text Articles in Physics
Ruling Out Color Transparency In Quasielastic ¹²C(E,E'P) Up To Q² Of 14.2 (Gev/C)², D. Bhetuwal, J. Matter, H. Szumila-Vance, F. Hauenstein, C. Yero, J. Zhang, Et Al., Hall C. Collaboration
Ruling Out Color Transparency In Quasielastic ¹²C(E,E'P) Up To Q² Of 14.2 (Gev/C)², D. Bhetuwal, J. Matter, H. Szumila-Vance, F. Hauenstein, C. Yero, J. Zhang, Et Al., Hall C. Collaboration
Physics Faculty Publications
Quasielastic 12C(e,e'p) scattering was measured at spacelike 4-momentum transfer squared Q2 = 8, 9.4, 11.4, and 14.2 (GeV/c)2, the highest ever achieved to date. Nuclear transparency for this reaction was extracted by comparing the measured yield to that expected from a plane-wave impulse approximation calculation without any final state interactions. The measured transparency was consistent with no Q2 dependence, up to proton momenta of 8.5 GeV/c, ruling out the quantum chromodynamics effect of color transparency at the measured Q2 scales in exclusive (e, e'p) reactions. These results impose strict constraints on models of color …
Measurement Of Deeply Virtual Compton Scattering Off 4He With The Cebaf Large Acceptance Spectrometer At Jefferson Lab, Clas Collaboration, R. Dupré, Mohammad Hattawy, N. A. Batzell, Stephen Bültmann, Bayram Torayev, Moskov Amaryan, Dilini L. Bulumulla, M. Mayer, David C. Payette, Yelena Prok, Jiwan Poudel, Lawrence B. Weinstein, B. Yale, N. Zachariou, J. Zhang, Et Al.
Measurement Of Deeply Virtual Compton Scattering Off 4He With The Cebaf Large Acceptance Spectrometer At Jefferson Lab, Clas Collaboration, R. Dupré, Mohammad Hattawy, N. A. Batzell, Stephen Bültmann, Bayram Torayev, Moskov Amaryan, Dilini L. Bulumulla, M. Mayer, David C. Payette, Yelena Prok, Jiwan Poudel, Lawrence B. Weinstein, B. Yale, N. Zachariou, J. Zhang, Et Al.
Physics Faculty Publications
We report on the measurement of the beam spin asymmetry in the deeply virtual Compton scattering off 4He using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab using a 6 GeV longitudinally polarized electron beam incident on a pressurized 4He gaseous target. We detail the method used to ensure the exclusivity of the measured reactions, in particular the upgrade of CLAS with a radial time projection chamber to detect the low-energy recoiling 4He nuclei and an inner calorimeter to extend the photon detection acceptance at forward angles. Our results confirm the theoretically predicted enhancement of the …
Constraining 1 + 𝒥 → 2 Coupled-Channel Amplitudes In A Finite Volume, Raúl A. Briceño, Jozef J. Dudek, Luka Leskovec
Constraining 1 + 𝒥 → 2 Coupled-Channel Amplitudes In A Finite Volume, Raúl A. Briceño, Jozef J. Dudek, Luka Leskovec
Physics Faculty Publications
Whether one is interested in accessing the excited spectrum of hadrons or testing the standard model of particle physics, electroweak transition processes involving multihadron channels in the final state play an important role in a variety of experiments. Presently the primary theoretical tool with which one can study such reactions is lattice QCD, which is defined in a finite spacetime volume. In this work, we investigate the feasibility of implementing existing finite-volume formalism in realistic lattice QCD calculation of reactions in which a stable hadron can transition to one of several two-hadron channels under the action of an external current. …
Photoproduction Of The F₂(1270) Meson Using The Clas Detector, Krishna P. Adhikari, Moskov J. Amaryan, Dilini Bulumulla, Mohammad Hattawy, G. Gavalian, Charles E. Hyde, Yelena Prok, J. Zhang, Et Al., Clas Collaboration
Photoproduction Of The F₂(1270) Meson Using The Clas Detector, Krishna P. Adhikari, Moskov J. Amaryan, Dilini Bulumulla, Mohammad Hattawy, G. Gavalian, Charles E. Hyde, Yelena Prok, J. Zhang, Et Al., Clas Collaboration
Physics Faculty Publications
The quark structure of the f2(1270) meson has, for many years, been assumed to be a pure quark-antiquark (qq⁻) resonance with quantum numbers JPC = 2++. Recently, it was proposed that the f2(1270) is a molecular state made from the attractive interaction of two 𝜌 mesons. Such a state would be expected to decay strongly to final states with charged pions due to the dominant decay 𝜌 → π+π-, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction 𝛾p …
Differential Cross Sections For Λ (1520) Using Photoproduction At Clas, K. P. Adhikari, M.J. Amaryan, G. Gavalian, M. Hattawy, Y. Prok, Et. Al., The Clas Collaboration
Differential Cross Sections For Λ (1520) Using Photoproduction At Clas, K. P. Adhikari, M.J. Amaryan, G. Gavalian, M. Hattawy, Y. Prok, Et. Al., The Clas Collaboration
Physics Faculty Publications
The reaction 𝛾p → K+Λ (1520) using photoproduction data from the CLAS g12 experiment at Jefferson Lab is studied. The decay of Λ(1520) into two exclusive channels, Σπ+π- and Σ-π+, is studied from the detected K+, π+, and π- particles. A good agreement is established for the Λ(1520) differential cross sections with the previous CLAS measurements. The differential cross sections as a function of center-of-mass angle are extended to higher photon energies. Newly added are the differential cross sections as a function of invariant four-momentum transfer t, …
Photoproduction Of Η Mesons Off The Proton For 1.2 < EΓ < 4.7 Gev Using Clas At Jefferson Laboratory, K. P. Adhikari, M. J. Amaryan, G. Gavalian, M. Hattawy, M. Khachatryan, J. Poudel, Y. Prok, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration
Photoproduction Of Η Mesons Off The Proton For 1.2 < EΓ < 4.7 Gev Using Clas At Jefferson Laboratory, K. P. Adhikari, M. J. Amaryan, G. Gavalian, M. Hattawy, M. Khachatryan, J. Poudel, Y. Prok, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration
Physics Faculty Publications
Photoproduction cross sections are reported for the reaction γp→pη using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The η mesons are detected in their dominant charged decay mode, η→π+π−π0, and results on differential cross sections are presented for incident photon energies between 1.2 and 4.7 GeV. These new η photoproduction data are consistent with earlier CLAS results but extend the energy range beyond the nucleon resonance region into the Regge regime. The normalized angular distributions are also compared with the experimental results from several other experiments, and with predictions of η-MAID 2018 and the latest solution of the …
Measurement Of The Q² Dependence Of The Deuteron Spin Structure Function G1 And Its Moments At Low Q² With Clas, Clas Collaboration, K. P. Adhikari, L. El Fassi, S E. Kuhn, M. J. Amaryan, S. Bültmann, G. Charles, Gail Dodge, N. Guler, C. E. Hyde, A. Klein, D. Payette, J. Poudel, Y. Prok, L. B. Weinstein, J. Zhang, Z. W. Zhao
Measurement Of The Q² Dependence Of The Deuteron Spin Structure Function G1 And Its Moments At Low Q² With Clas, Clas Collaboration, K. P. Adhikari, L. El Fassi, S E. Kuhn, M. J. Amaryan, S. Bültmann, G. Charles, Gail Dodge, N. Guler, C. E. Hyde, A. Klein, D. Payette, J. Poudel, Y. Prok, L. B. Weinstein, J. Zhang, Z. W. Zhao
Physics Faculty Publications
We measured the g1 spin structure function of the deuteron at low Q2, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W ≈ 1.9 GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γd1 and the spin polarizability γd0 are precisely determined down to a minimum Q2 of 0.02 GeV2 for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a …
Measurement Of Target And Double-Spin Asymmetries For The Ep → Eπ+(N) Reaction In The Nucleon Resonance Region At Low Q², Clas Collaboration, K. P. Adhikari, S E. Kuhn, D. Adikaram, M. J. Amaryan, S. Bültmann, Gail Dodge, N. Guler, L. B. Weinstein
Measurement Of Target And Double-Spin Asymmetries For The Ep → Eπ+(N) Reaction In The Nucleon Resonance Region At Low Q², Clas Collaboration, K. P. Adhikari, S E. Kuhn, D. Adikaram, M. J. Amaryan, S. Bültmann, Gail Dodge, N. Guler, L. B. Weinstein
Physics Faculty Publications
We report measurements of target- and double-spin asymmetries for the exclusive channel →e→p → eπ+(n) in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH3 target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3, and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low Q2 range from 0.0065 to 0.35(GeV/c)2. The Q2 access was made possible by a custom-built Cherenkov detector …