Hypernuclear spectroscopy with electron beam at JLab Hall C

Nuclear Physics A, 2008

Hypernuclear production by the (e, e K + ) reaction has unique advantages in hypernuclear spectroscopy of the S = −1 regime. The second-generation spectroscopy experiment on 12 C, 7 Li and 28 Si targets has been recently carried out at JLab Hall C with a new experimental configuration (Tilt method) and also using a new high-resolution kaon spectrometer (HKS). The experiment is described and preliminary results are presented together with the empasis of significance of the (e, e K + ) reaction for Λ hypernuclear spectroscopy and its future prospects.

Nuclear Physics A, 2005

Encouraged by the success of the first hypernuclear spectroscopy through the (e, e K + ) reaction (JLab E89-009), a new improved experiment with a newly developed High resolution Kaon Spectrometer (HKS) and a new configuration of the electron spectrometer is planned at the JLab Hall C.

Nuclear Physics A, 2010

Since the 1st generation experiment, E89-009, which was successfully carried out as a pilot experiment of (e,e'K+) hypernuclear spectroscopy at JLab Hall C in 2000, precision hypernuclear spectroscopy by the (e,e'K+) reactions made considerable progress. It has evolved to the 2nd generation experiment, E01-011, in which a newly constructed high resolution kaon spectrometer (HKS) was installed and the "Tilt method" was adopted in order to suppress large electromagnetic background and to run with high luminosity. Preliminary high-resolution spectra of 7 Λ He and 28 Λ Al together with that of 12 Λ B that achieved resolution better than 500 keV(FWHM) were obtained. The third generation experiment, E05-115, has completed data taking with an experimental setup combining a new splitter magnet, high resolution electron spectrometer (HES) and the HKS used in the 2nd generation experiment. The data were accumulated with targets of Nuclear Physics A 835 (2010) 121-128 0375-9474/$ -see front matter 7 Li, 9 Be, 10 B, 12 C and 52 Cr as well as with those of CH 2 and H 2 O for calibration. The analysis is under way with particular emphasis of determining precision absolute hypernuclear masses.

Nuclear Physics A, 2013

Experiment E94-107 at Jefferson Lab is designed to perform hypernuclear high resolution spectroscopy by electroproduction of strangeness on four 1p-shell targets: 12 C, 9 Be, 16 O, 7 Li. The hypernuclear spectroscopy provides fundamental information to understand the effective Λ-Nucleon interaction. The first part of the experiment on C and 9 Be targets has been performed in January and April-May 2004 in the experimental Hall A. The second part of the experiment (16 O and 7 Li targets) is scheduled on June 2005. Two septum magnets and a Ring Imaging Cherenkov detector (RICH) are added to the existing apparatus, to have reasonable counting rates and excellent particle identification respectively, as required for the experiment. A description of the apparatus, particularly of the RICH detector, and the preliminary analysis results, showing interesting information respect to the theoretical models for the studied hypernuclei, are presented here.

JPS Conf. Proc. 8, 021010 (2015) Proceedings of the 2nd International Symposium on Science at J-PARC, 2015

Abstract: (Physical Society of Japan) JLab E05-115 which is an experiment for Λ hypernuclear spectroscopy with electron beams was carried out at Jefferson Lab (JLab) in 2009. In the experiment, 7ΛHe, 9ΛLi, 10ΛBe, 12ΛB and 52ΛV were measured by new magnetic spectrometer systems (SPL+HES+HKS) which were necessary for spectroscopy with high energy resolution of sub-MeV (FWHM). This is the first attempt to measure a Λ hypernucleus with up to medium–heavy mass region by the (e,e′K+) reaction, overcoming high rate and high multiplicity conditions due to electromagnetic background particles. An overview of the hypernuclear experiments at JLab Hall-C and preliminary binding energy spectrum of 10ΛBe are shown.

Physical Review C, 2006

A pioneering experiment in Λ hypernuclear spectroscopy, undertaken at the Thomas Jefferson National Accelerator Facility (Jlab), was recently reported. The experiment used the high-precision, continuous electron beam at Jlab, and a special arrangement of spectrometer magnets to measure the spectrum from nat C and 7 Li targets using the (e, e ′ K + ) reaction. The 12 Λ B spectrum was previously published. This experiment is now reported in more detail, with improved results for the 12 Λ B spectrum. In addition, unpublished results of the 7 Λ He spectrum are also shown. This later spectrum indicates the need for a more detailed few-body calculation of the hypernucleus and the reaction process. The success of this experiment demonstrates that the (e, e ′ K + ) reaction can be effectively used as a high resolution tool to study hypernuclear spectra, ant its use should be vigorously pursued.