V. Sulkosky,1, 2, 3 C. Peng,4, 5 J.-P. Chen,2 A. Deur⇤,3, 2 S. Abrahamyan,6 K. A. Aniol,7 D. S. Armstrong,1 T. Averett,1 S. L. Bailey,1 A. Beck,8 P. Bertin,9 F. Butaru,10 W. Boeglin,11 A. Camsonne,9 G. D. Cates,3 C. C. Chang,12 Seonho Choi,10 E. Chudakov,2 L. Coman,11 J. C Cornejo,7 B. Craver,3 F. Cusanno,13 R. De Leo,14 C. W. de Jager†,2 J. D. Denton,15 S. Dhamija,16 R. Feuerbach,2 J. M. Finn†,1 S. Frullani†,17, 18 K. Fuoti,1 H. Gao,4 F. Garibaldi,17, 18 O. Gayou,8 R. Gilman,2, 19 A. Glamazdin,20 C. Glashausser,19 J. Gomez,2 J.-O. Hansen,2 D. Hayes,21 B. Hersman,22 D. W. Higinbotham,2 T. Holmstrom,1, 15 T. B. Humensky,3 C. E. Hyde,21 H. Ibrahim,21, 23 M. Iodice,13 X. Jiang,19 L. J. Kaufman,24 A. Kelleher,1 K. E. Keister,1 W. Kim,25 A. Kolarkar,16 N. Kolb,26 W. Korsch,16 K. Kramer,1, 4 G. Kumbartzki,19 L. Lagamba,14 V. Lainé,2, 9 G. Laveissiere,9 J. J. Lerose,2 D. Lhuillier,27 R. Lindgren,3 N. Liyanage,3, 2 H.-J. Lu,28 B. Ma,8 D. J. Margaziotis,7 P. Markowitz,11 K. McCormick,19 M. Meziane,4 Z.-E. Meziani,10 R. Michaels,2 B. Moffit,1 P. Monaghan,8 S. Nanda,2 J. Niedziela,24 M. Niskin,11 R. Pandolfi,29 K. D. Paschke,24 M. Potokar†,30 A. Puckett,3 V. A. Punjabi,31 Y. Qiang,8 R. Ransome,19 B. Reitz,2 R. Roché,32 A. Saha†,2 A. Shabetai,19 S. Širca,33 J. T. Singh,3 K. Slifer,10 R. Snyder,3 P. Solvignon†,10 R. Stringer,4 R. Subedi,34 W. A. Tobias,3 N. Ton,3 P. E. Ulmer,21 G. M. Urciuoli,13 A. Vacheret,27 E. Voutier,35 K. Wang,3 L. Wan,8 B. Wojtsekhowski,36 S. Woo,25 H. Yao,10 J. Yuan,19 X. Zhan,8 X. Zheng,5 and L. Zhu8

In the original PDF online version of this article, the references 22–26 were missing.

The spin-structure functions g_1 and g_2, and the spin-dependent partial cross-section \sigma_{TT} have been extracted from the polarized cross-sections differences, \Delta \sigma_{||}(\nu,Q^2) and \Delta \sigma_{\perp}(\nu,Q^2) measured for the 3He(e,e')X reaction at Jefferson Lab. Polarized electrons with energies from 1.147 to 4.404 GeV were scattered at angles of 6^o and 9^o from a longitudinally or transversely polarized 3He target. The data cover the kinematic regions of the quasi-elastic, resonance and beyond. From the extracted spin-structure functions, the first moments \Gamma_1(Q^2), \Gamma_2(Q^2) and I_{TT}(Q^2) are evaluated with high precision for the neutron in the Q^2 range from 0.035 to 0.24 GeV^2. Finally, these low Q^2 results are used to test chiral perturbation theory calculations.

Measurements of elastic electron scattering data within the past decade have highlighted two-photon exchange contributions as a necessary ingredient in theoretical calculations to precisely evaluate hydrogen elastic scattering cross sections. This correction can modify the cross section at the few percent level. In contrast, dispersive effects can cause significantly larger changes from the Born approximation. The purpose of this experiment is to extract the carbon-12 elastic cross section around the first diffraction minimum, where the Born term contributions to the cross section are small to maximize the sensitivity to dispersive effects. The analysis uses the LEDEX data from the high resolution Jefferson Lab Hall A spectrometers to extract the cross sections near the first diffraction minimum of 12C at beam energies of 362 MeV and 685 MeV. The results are in very good agreement with previous world data, although with less precision. The average deviation from a static nuclear charge distribution expected from linear and quadratic fits indicate a 30.6 contribution of dispersive effects to the cross section at 1 GeV. The magnitude of the dispersive effects near the first diffraction minimum of 12C has been confirmed to be large with a strong energy dependence and could account for a large fraction of the magnitude for the observed quenching of the longitudinal nuclear response. These effects could also be important for nuclei radii extracted from parity-violating asymmetries measured near a diffraction minimum.

This Article is brought to you for free and open access by the Physics at ODU Digital Commons. It has been accepted for inclusion in Physics Faculty Publications by an authorized administrator of ODU Digital Commons. For more information, please contact digitalcommons@odu.edu. Repository Citation Urciuoli, G. M.; Hayes, D.; Hyde, C. E.; Ibrahim, H. F.; Ulmer, P.E.; and Jefferson Lab Hall A Collaboration, "Spectroscopy of Li-9 (Lambda) by Electroproduction" (2015). Physics Faculty Publications. 152. https://digitalcommons.odu.edu/physics_fac_pubs/152

In the absence of accurate data on the free two-body hyperon-nucleon interaction, the spectra of hypernuclei can provide information on the details of the effective hyperon-nucleon interaction. Electroproduction of the hypernucleus Lambda-9Li has been studied for the first time with sub-MeV energy resolution in Hall A at Jefferson Lab on a 9Be target. In order to increase the counting rate and to provide unambiguous kaon identification, two superconducting septum magnets and a Ring Imaging CHerenkov detector (RICH) were added to the Hall A standard equipment. The cross section to low-lying states of Lambda-9Li is concentrated within 3 MeV of the ground state and can be fitted with four peaks. The positions of the doublets agree with theory while a disagreement could exist with respect to the relative strengths of the peaks in the doublets. A Lambda separation energy of 8.36 +- 0.08 (stat.) +- 0.08 (syst.) MeV was measured, in agreement with an earlier experiment.

The characteristics of the Jefferson Lab electron beam, together with those of the experimental equipment, offer a unique opportunity to study hypernuclear spectroscopy via electromagnetic induced (e,e′K+) reactions. Experiment 94-107 started a systematic study on 1p-shell targets, C12, Be9 and O16. For C12 for the first time measurable strength in the core-excited part of the spectrum between the ground state and the p state was shown in the BΛ12 spectrum. For O16 a high-quality NΛ16 spectrum was produced for the first time with sub-MeV energy resolution. A very precise Λ binding energy value for NΛ16, calibrated against the elementary (e,e′K+) reaction on hydrogen, has also been obtained. Preliminary data on the LiΛ9 spectrum shows some disagreement in strength for the second and third doublet with respect to the theory.

The (2)H(e,e'p)n cross section at a momentum transfer of 3.5 (GeV/c)(2) was measured over a kinematical range that made it possible to study this reaction for a set of fixed missing momenta as a function of the neutron recoil angle θ(nq) and to extract missing momentum distributions for fixed values of θ(nq) up to 0.55  GeV/c. In the region of 35°≤θ(nq)≤45° recent calculations, which predict that final-state interactions are small, agree reasonably well with the experimental data. Therefore, these experimental reduced cross sections provide direct access to the high momentum component of the deuteron momentum distribution in exclusive deuteron electrodisintegration.

High precision measurements of induced and transferred recoil proton polarization in d(polarized gamma, polarized p})n have been performed for photon energies of 277--357 MeV and theta_cm = 20 degrees -- 120 degrees. The measurements were motivated by a longstanding discrepancy between meson-baryon model calculations and data at higher energies. At the low energies of this experiment, theory continues to fail to reproduce the data, indicating that either something is missing in the calculations and/or there is a problem with the accuracy of the nucleon-nucleon potential being used.

S. Riordan, 2, 3 S. Abrahamyan, B. Craver, A. Kelleher, A. Kolarkar, J. Miller, G.D. Cates, N. Liyanage, B. Wojtsekhowski, ∗ A. Acha, K. Allada, B. Anderson, K.A. Aniol, J.R.M. Annand, J. Arrington, T. Averett, A. Beck, 8 M. Bellis, W. Boeglin, H. Breuer, J.R. Calarco, A. Camsonne, J.P. Chen, E. Chudakov, L. Coman, B. Crowe, F. Cusanno, D. Day, P. Degtyarenko, P.A.M. Dolph, C. Dutta, C. Ferdi, C. Fernández-Ramı́rez, R. Feuerbach, 5 L.M. Fraile, G. Franklin, S. Frullani, S. Fuchs, F. Garibaldi, N. Gevorgyan, R. Gilman, 8 A. Glamazdin, J. Gomez, K. Grimm, J.-O. Hansen, J.L. Herraiz, D.W. Higinbotham, R. Holmes, T. Holmstrom, D. Howell, C.W. de Jager, X. Jiang, M.K. Jones, J. Katich, L.J. Kaufman, M. Khandaker, J.J. Kelly, † D. Kiselev, W. Korsch, J. LeRose, R. Lindgren, P. Markowitz, D.J. Margaziotis, S. May-Tal Beck, 8 S. Mayilyan, K. McCormick, Z.-E. Meziani, R. Michaels, B. Moffit, S. Nanda, V. Nelyubin, T. Ngo, D.M. Nikolenko, B. Norum, L. Pentchev, C.F. Perdrisat, E. Piasetzky, R. Pomatsalyuk, D. Protopopescu, A.J.R. Puckett, V.A. Punjabi, X. Qian, Y. Qiang, B. Quinn, I. Rachek, R.D. Ransome, P.E. Reimer, B. Reitz, J. Roche, G. Ron, O. Rondon, G. Rosner, A. Saha, M.M. Sargsian, B. Sawatzky, J. Segal, M. Shabestari, A. Shahinyan, Yu. Shestakov, J. Singh, S. Širca, P. Souder, S. Stepanyan, V. Stibunov, V. Sulkosky, S. Tajima, W.A. Tobias, J.M. Udias, G.M. Urciuoli, B. Vlahovic, H. Voskanyan, K. Wang, F.R. Wesselmann, J.R. Vignote, S.A. Wood, J. Wright, H. Yao, and X. Zhu

The electric form factor of the neutron was determined from studies of the reaction 3 He ! ð ~e; e 0 n Þ pp in quasielastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the Q 2 range over which it is known, we find G nE ¼ 0 : 0236 (cid:1) 0 : 0017 ð stat Þ (cid:1) 0 : 0026 ð syst Þ , 0 : 0208 (cid:1) 0 : 0024 (cid:1) 0 : 0019 , and 0 : 0147 (cid:1) 0 : 0020 (cid:1) 0 : 0014 for Q 2 ¼ 1 : 72 , 2.48, and 3 : 41 GeV 2 , respectively.

The electric form factor of the neutron was determined from studies of the reaction 3He(e,e'n)pp in quasielastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the Q2 range over which it is known, we find G(E)(n)=0.0236±0.0017(stat)±0.0026(syst), 0.0208±0.0024±0.0019, and 0.0147±0.0020±0.0014 for Q(2)=1.72, 2.48, and 3.41 GeV2, respectively.

An experimental study of the (16)O(e,e'K(+))(Lambda)(16)N reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K(+))Lambda, Sigma(0) exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76+/-0.16 MeV was obtained for (Lambda)(16)N with better precision than previous measurements on the mirror hypernucleus (Lambda)(16)O. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p(1/2) and p(3/2) hole states of the (15)N core nucleus.

K. Slifer, 2 O.A. Rondón, A. Aghalaryan, A. Ahmidouch, R. Asaturyan, F. Bloch, W. Boeglin, P. Bosted, C. Carasco, R. Carlini, J. Cha, J.P. Chen, M.E. Christy, L. Cole, L. Coman, D. Crabb, S. Danagoulian, D. Day, J. Dunne, M. Elaasar, R. Ent, H. Fenker, E. Frlez, D. Gaskell, L. Gan, J. Gomez, B. Hu, J. Jourdan, M. K. Jones, C. Keith, C.E. Keppel, M. Khandaker, A. Klein, L. Kramer, Y. Liang, J. Lichtenstadt, R. Lindgren, D. Mack, P. McKee, D. McNulty, 15 D. Meekins, H. Mkrtchyan, R. Nasseripour, I. Niculescu, K. Normand, B. Norum, D. Pocanic, Y. Prok, B. Raue, J. Reinhold, J. Roche, D. Kiselev (nee Rohe), 16 N. Savvinov, B. Sawatzky, M. Seely, I. Sick, C. Smith, G. Smith, S. Stepanyan, L. Tang, S. Tajima, G. Testa, W. Vulcan, K. Wang, G. Warren, 7 F.R. Wesselmann, 12 S. Wood, C. Yan, L. Yuan, J. Yun, M. Zeier, and H. Zhu