High Resolution Spectroscopy ofBΛ12by Electroproduction

An experiment measuring electroproduction of hypernuclei has been performed in Hall A at Jefferson Lab on a $^{12}$C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a Ring Imaging CHerenkov detector (RICH) were added to the Hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed \lam{12}{B} spectrum shows for the first time identifiable strength in the core-excited region between the ground-state {\it s}-wave $\Lambda$ peak and the 11 MeV {\it p}-wave $\Lambda$ peak.

Spectroscopy of A=9 hyperlithium with the (e,e′K+) reaction

Experiments with the High Resolution Kaon Spectrometer at JLab Hall C and the new spectroscopy ofΛ12Bhypernuclei

Since the pioneering experiment E89-009 studying hypernuclear spectroscopy using the (e, e’K+) reaction was completed, two additional experiments, E01-011 and E05-115, were performed at Jefferson Lab. These later experiments used a modified experimental design, the "tilt method", to dramatically suppress the large electromagnetic background, and allowed for a substantial increase in luminosity. Additionally, a new kaon spectrometer, HKS (E01-011), a new electron spectrometer, HES, and a new splitting magnet (E05-115) were added to produce new data sets of precision, high-resolution hypernuclear spectroscopy. All three experiments obtained a spectrum for 12B-Lambda, which is the most charact…

Spectroscopy of the neutron-rich hypernucleusHeΛ7from electron scattering

The missing mass spectroscopy of the HeΛ7 hypernucleus was performed using the Li7(e, e ′K+)HeΛ7 reaction at the Thomas Jefferson National Accelerator Facility Hall C. The Λ- binding energy of the ground-state (1/2+) was determined with a smaller error than that of the previous measurement, being BΛ=5.55±0.10stat.±0.11sys.MeV. The experiment also provided new insight into charge symmetry breaking in p-shell hypernuclear systems. Finally, a peak at BΛ=3.65±0.20stat. ±0.11sys.MeV was observed and assigned as a mixture of 3/2+ and 5/2+ states, confirming the "gluelike" behavior of Λ, which makes an unstable state in He6 stable against neutron emission.

High Resolution Λ Hypernuclear Spectroscopy with Electron Beams

T. Gogami1 ∗, P. Achenbach2, A. Ahmidouch3, I. Albayrak4, D. Androic5, A. Asaturyan6, R. Asaturyan6, O. Ates4, P. Baturin7, R. Badui7, W. Boeglin7, J. Bono7, E. Brash8, P. Carter8, C. Chen4, A. Chiba1, E. Christy4, S. Danagoulian3, R. De Leo10, D. Doi1, M. Elaasar11, R. Ent9, Y. Fujii1, M. Fujita1, M. Furic5, M. Gabrielyan7, L. Gan12, F. Garibaldi13, D. Gaskell9, A. Gasparian3, O. Hashimoto1, T. Horn9, B. Hu14, Ed. V. Hungerford21, M. Jones9, H. Kanda1, M. Kaneta1, S. Kato19, M. Kawai1, D. Kawama1, H. Khanal7, M. Kohl4, A. Liyanage4, W. Luo14, K. Maeda1, A. Margaryan6, P. Markowitz7, T. Maruta1, A. Matsumura1, V. Maxwell7, A. Mkrtchyan6, H. Mkrtchyan6, S. Nagao1, S. N. Nakamura1, A. Narayan…

Spectroscopy ofLiΛ9by electroproduction

Background: In the absence of accurate data on the free two-body hyperon-nucleon interaction, the spectra of hypernuclei provides information on the details of the effective hyperon-nucleon interaction.Purpose: To obtain a high-resolution binding-energy spectrum for the ${}^{9}\mathrm{Be}(e,{e}^{\ensuremath{'}}{K}^{+})_{\ensuremath{\Lambda}}^{9}\mathrm{Li}$ reaction.Method: Electroproduction of the hypernucleus $_{\ensuremath{\Lambda}}^{9}\mathrm{Li}$ has been studied for the first time with sub-MeV energy resolution in Hall A at Jefferson Lab on a $^{9}\mathrm{Be}$ target. In order to increase the counting rate and to provide unambiguous kaon identification, two superconducting septum magn…