Download or read book Spectroscopic Study of the Lambda Hypernuclei by the e e K Reaction written by and published by . This book was released on 2002 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypernuclear spectroscopy study via the (e,e'K+) reaction has been carried out for the first time, establishing a new technique to study Lambda hypernuclei. The high quality electron beam at Jefferson Lab made it possible to measure Lambda hypernuclear spectra with an energy resolution better than 1 MeV (FWHM). The present experiment was designed to make full use of the virtual photon flux, which peaks at very forward angles, by detecting scattered electrons at 0 degrees. Scattered positive kaons were also detected near 0 degrees, where the cross section of the kaon photo-production is maximized. This unique kinematical configuration was realized with the HyperNuclear Spectrometer System (HNSS), which consisted of the Short-Orbit Spectrometer, the Enge Split-Pole Spectrometer, and the splitter magnet. The $12top{Λ}$B mass spectrum was measured in the 12C(e,e'K+)$12top{Λ}$ reaction with 0.9 MeV (FWHM) energy resolution. The averaged binding energy of the $12top{Λ}$B ground state doublet was obtained to be 11.7 ± 0.1 (statistical) ± 0.3 (systematic) MeV, which is consistent with emulsion data. The general spectral structure of the 12C(e,e'K+) $12top{Λ}$B reaction was found to be similar to that of the 12C(?+,K+)$12top{Λ}$C reaction, showing characteristic peaks corresponding to sLambda and pLambda orbits, as well as a few core-excited states. The cross section of the $12top{Λ}$B ground state doublet was derived to be 117 ± 13 (statistical) ± 14 (systematic) nb/sr. The theoretical prediction of the cross section was consistent with the present result, validating DWIA calculation for hypernuclear yields. The present study proved the effectiveness of the (e,e'K+) reaction for future Lambda hypernuclear spectroscopy studies.

Download or read book Spectroscopic Study of Light Lambda Hypernuclei Via the e E K Reaction written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypernuclear production through the (e, e'K+) reaction makes it possible to realize sub-MeV high-resolution spectroscopy of  hypernuclei thanks to the availability of high quality primary beams. It is in contrast to the (K?, L?) and (L+, K+) reactions which use secondary beams of pions and kaons. Even though hypernuclear cross sections are much smaller than those from meson beams, the (e, e?K+) reaction has advantageous features for  hypernuclear production. A goal of the present study is to further explore and establish (e, e?K+) spectroscopy as a tool to investigate  hypernuclei, succeeding the pioneering experiment JLab E89-009, which was successfully carried out previously. A 1.8 GeV electron beam hit targets at the entrance of the splitter magnet in JLab?s Hall C.A positive kaon and a scattered electron were deflected by the splitter magnet to opposite directions and guided to the high resolution kaon spectrometer (HKS) and the scattered electron spectrometer (Enge), respecti.

Download or read book Spectroscopic Study of the Lambda Hypernuclei by the e E K Reaction written by Toshinobu Miyoshi and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypernuclear spectroscopy study via the (e, e'K+) reaction has been carried out for the first time, establishing a new technique to study Lambda hypernuclei. The high quality electron beam at Jefferson Lab made it possible to measure Lambda hypernuclear spectra with an energy resolution better than 1 MeV (FWHM). The present experiment was designed to make full use of the virtual photon flux, which peaks at very forward angles, by detecting scattered electrons at 0 degrees. Scattered positive kaons were also detected near 0 degrees, where the cross section of the kaon photo-production is maximized. This unique kinematical configuration was realized with the HyperNuclear Spectrometer System (HNSS), which consisted of the Short-Orbit Spectrometer, the Enge Split-Pole Spectrometer, and the splitter magnet. The Lambda12B mass spectrum was measured in the 12C(e, e'K+)Lambda12B reaction with 0.9 MeV (FWHM) energy resolution. The averaged binding energy of the Lambda12B ground state doublet was obtained to be 11.7 " 0.1 (statistical) " 0.3 (systematic) MeV, which is consistent with emulsion data. The general spectral structure of the 12C(e, e'K+) Lambda12B reaction was found to be similar to that of the 12C(Lambda+, K+)Lambda12C reaction, showing characteristic peaks corresponding to sLambda and pLambda orbits, as well as a few core-excited states. The cross section of the Lambda12B ground state doublet was derived to be 117 " 13 (statistical) " 14 (systematic) nb/sr. The theoretical prediction of the cross section was consistent with the present result, validating DWIA calculation for hypernuclear yields. The present study proved the effectiveness of the (e, e'K+) reaction for future Lambda hypernuclear spectroscopy studies.

Download or read book Spectroscopic Research of Lambda Hypernuclei Up to Medium heavy Mass Region with the e E K Reaction written by and published by . This book was released on 2014 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2009 (August-November), the E05-115 experiment was carried out at JLab to investigate L hypernuclei in the wide mass region up to A = 52 ($7\atop{{u039B}}$He, $10\atop{{u039B}}$Be, $12\atop{{u039B}}$B and $52\atop{{u039B}}$V) with the (e, e'K+) reaction. This is the first attempt to investigate a medium heavy L hypernucleus with the (e, e'K+) reaction. Experimentally, it is difficult to measure heavier L hypernuclei as background rates of particles which originate from electromagnetic processes are roughly in proportion to Z2 (Z: target proton number) in the (e, e'K+) experiment. To perform the experiment, many experimental techniques have been developed and introduced such as optimization of the electron spectrometer configuration (tilt method), clean kaon identification, particle tracking under high multiplicity environment, precise energy scale calibration and so on. In the present thesis, experimental results of the elementary process of p(e, e'K+)L, L hypernuclei of $7\atop{{u039B}}$He, $10\atop{{u039B}}$Be, $12\atop{{u039B}}$B and $52\atop{{u039B}}$V are shown. Elementary processes of the electroproduction of L and [Sigma]0, p(e, e'K+)L, [Sigma]0 were used for the absolute energy scale calibration of our spectrometer systems. A careful Monte Carlo simulation shows that the binding energy can be obtained with a systematic error of 0.11 MeV with our energy scale calibration method. A study of the elementary process of L is important to understand L hypernuclei as it is essential for theoretical calculations of L hypernuclei. The differential cross section of the p(e, e'K+)L reaction at the small K+ scattering angle (theta-CM/gamma-K approx. 15.5°), the small Q2 (approx 0.01 [GeV/c]2) and the total energy of W = 1.92 GeV, where no experimental data exists was obtained to be 235 ± 13$+28\atop{-24}$ nb/sr. The ground state (1/2+) binding energy of $7\atop{[Lambda]}$He was already measured in JLab E01-011 (2005). In the present work, the binding energy of 1/2+ state was determined to be B[Lambda] = 5.55 ± 0.10 ±0.11 MeV with five times more statistic and smaller systematic errors than those of the previous experiment. The ground state binding energy is important to test the phe- nomenologically introduced CSB (Charge Symmetry Breaking) LN interaction for A = 7, T = 1 hypernuclear systems. In addition, a peak which is interpreted as 3/2+ and 5/2+ states was measured to be B[Lambda] = 3.65 ± 0.20 ±0.11 MeV with sufficient statistic for the first time. Only three events of the ground state of $10\atop{[Lambda]}$ Be had been observed in the emulsion experiments. The present experiment is the first spectroscopic measurement of 10/L-Be, and the detailed structures have been successfully measured for the first time. About three times better energy resolution was achieved in the present experiment (0.78 MeV in FWHM) than that of the mirror L hy- pernucleus, $10\atop{[Lambda]}$B (2.2 MeV in FWHM) which was measured in the ([pi]+, K+) experiment at KEK. The result of the ground state binding energy was obtained to be B[Lambda] = 8.55 ± 0.07 ± 0.11 MeV which serves also to discuss about the CSB effect in the LN interaction. $12\atop{[Lambda]}$B has been measured with the world best energy resolution of 0:5 MeV (FWHM) among the reaction spectroscopy of L hypernuclei. The results of $12\atop{[Lambda]}$B are compared with the experimental results in the previous experiments to confirm the consistency. Furthermore, the obtained ground state binding energies of $12\atop{[Lambda]}$B (B[Lambda]= 11.38 ± 0.02 ± 0.11 MeV) and $52\atop{[Lambda]}$V (B[Lambda] = 21.88 ± 0.59 ± 0.11 MeV) indicate that the reported value of 12/L-C which has been used as a reference of binding energy measurements for the ([pi]+, K+) experiments would be shallower by ~ 0.5 MeV. A pilot study for investigation in the medium-heavy mass region with the (e, e'K

Download or read book Spectroscopy of Medium heavy Lambda Hypernuclei Via the pi Kappa Reaction written by Dideaki Hotchi and published by . This book was released on 2000 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectroscopic Study of Lambda Hypernuclei Beyon the P Shell written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hypernuclear Spectroscopy of 12lambdaB by the e E K Reactions written by Joerg Reinhold and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The first Lambda-hypernuclear spectroscopy study using an electron beam has been carried out at Jefferson Lab. The hypernuclear spectrometer system (HNSS) was used to measure spectra from the 12C (e, e'K+) 12Lambda B reaction with close to 1 MeV resolution, the best energy resolution obtained so far in hypernuclear spectroscopy with magnetic spectrometers. This paper describes the HNSS and preliminary results for the 12Lambda B system. A program of hypernuclear physics experiments is planned for the future with much higher yield and even better energy resolution.

Download or read book Spectroscopy of the Hypernuclei 13 subscript Lambda C 14 subscript Lambda N and 18 subscript Lambda O with the K symbol for Pi Strangeness Exchange Reaction written by Stephen M. Bart and published by . This book was released on 1983 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Resolution Spectroscopy of the Lambda B 12 Hypernucleus Produced by the e E K Reaction written by E. V. Hungerford and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The first electroproduction experiment of a hypernucleus was undertaken at the Thomas Jefferson National Acceleration Facility. The (e, e'K+) reaction was used on a natC target resulting in the observation of the 12LB hypernucleus. The excitation spectrum is presented and discussed.

Download or read book High Resolution Spectroscopy of the B 12 Lambda Hypernucleus Produced by the e E prime K Reaction written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High energy CW electron beams at new accelerator facilities allow electromagnetic production and precision study of hypernuclear structure, and we report here on the first experiment demonstrating the usefulness of the (e, e'K+) reaction. This experiment is also the first to take advantage of the enhanced virtual photon flux available when electrons are scattered at approximately zero degrees. The observed resolution, ~900 keV, of the 12B(hypernuclear) spectrum is the best yet attained using magnetic spectrometers. The positions of the major excitations are in agreement with theoretical predictions and the previous binding energy measurements.

Download or read book A Study of Hypernuclei Using the Pi K Reaction written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The (.pi./sup plus/, K/sup plus/) reaction was used to study lambda hypernuclear states from 9Be, 12C, 13C, 16O, 28Si, 4°Ca, 51V, and 89Y targets. Ground state excitations were seen for all targets as well as clear indications for the .lambda. populating bound shell model single-particle states. The data will be compared with DWBA calculations of Dover and Millener. 10 refs., 2 figs., 1 tab.

Download or read book The Production and Decay of Hypernuclei written by and published by . This book was released on 1990 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypernuclei have been studied for the last 35 years using several techniques. Since 1970, the {sup A}Z (K−, [pi]−) {sub {Lambda}}{sup A}Z strangeness-exchange reaction has been used at CERN, BNL, and KEK to produce hypernuclei and study their spectroscopic properties. These studies also include experiments where decay gamma rays and hypernuclear weak decay products are detected in coincidence with hypernuclear production. Recent experiments at BNL and KEK have proven the utility of the {sup A}Z ([pi], K) {sub {Lambda}}{sup A}Z reaction to study hypernuclear spectroscopy. Although I have no hope of covering this field in much detail, I write this paper as an introduction to the subject and highlights some of the recent experimental developments. 37 refs., 6 figs., 2 tabs.

Download or read book Experimental Study of Hypernuclei Electroproduction by High Precision Spectroscopy written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Jlab experiment E01-011, carried out in 2005 in JLab Hall C, is the second generation of the hypernuclear spectroscopy experiments by the (e, e'K+) reaction. The (e, e'K+) reaction is complimentary to the associated production reactions (K-, [pi]- ), ([pi]+, K+) since, due to a larger momentum transfer to a hyperon, excitations of both spin-non-flip and spin-flip states are possible. The experiment uses high quality and continuous primary electron beam to produce neutron rich hypernuclei on various targets by the electroproduction. The experimental setup consists of splitter magnet, high resolution kaon spectrometer (HKS) and electron spectrometer (Enge) implemented in new configuration, the so called 'Tilt Method'. Production data was taken on multiple targets: CH2, 6Li, 7Li, 9Be, 10B, 12C and 28Si. In present study the analysis of CH2, 12C and 28Si is presented. The elementary processes of p(e, e'K+)[Lambda]/[Sigma] from CH2 data were used for calibration of the spectrometer optics and kinematics. The hypernuclear spectra of 12[Lambda]B was obtained with ground state resolution of 0.47 ± 0.07 MeV (FWHM), the best ever achieved. Feasibility of the electroproduction reaction to study medium to heavy targets has been proven with the first high resolution beyond p-shell hypernuclear spectra from 28[Lambda]Al hypernuclei. The obtained results of the E01-011 experiment confirmed that hypernuclear spectroscopy by the (e, e'K+) reaction is a very useful technique.

Download or read book High Resolution Spectroscopy of 12B Hypernuclei by the e E K Reaction written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Jefferson Laboratory experiment E89-009 used the reaction (e, e' K+) to produce 12/[Lambda]B hypernuclei from a carbon target. The scattered electrons were tagged at 0 degrees to take advantage of the increased virtual photon flux at forward angles, and the electroproduced kaons were also detected at small angles, H" degrees, to minimize the momentum transfer. To do this, a splitter magnet was used to bend the scattered electrons into an Enge split-pole spectrometer and the kaons into a short orbit spectrometer. In addition to increasing the production rate, tagging the scattered electrons at 0 degrees minimizes the optical aberrations on the focal plane of the Enge split-pole spectrometer. In this experiment, the spectroscopy of the 12/[Lambda]B hypernuclei was studied and excellent energy resolution was achieved, H"918 keV. The differential cross section of the ground state doublet was also calculated.

Download or read book A Study of Heavy Hypernuclei Using the Pi K Reaction written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The (.pi., K) reaction was used to study lambda hypernuclear states in /sub .lambda./9Be, /sub .lambda./12C, /sub .lambda./13C, /sub .lambda./16O, /sub .lambda./28Si, /sub .lambda./4°Ca, /sub .lambda./51V and /sub .lambda./89Y. The results show that the (.pi.+, K+) reaction is ideally suited for populating lambda single particle states in heavy nuclei. 14 refs., 3 figs.

Download or read book Observation Of Lambda hypernuclei in the Reaction 12C Pi K written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The observation of .lambda.-hypernuclear levels in /sub .lambda./12C by associated production through the (.pi., K) reaction is reported. Spectrometers used in the measurements are discussed. The /sub .lambda./12C excitation energy spectra were recorded at laboratory scattering angles of 5.6°, 10.3°, and 15.2°. The spectra show two major peaks - one attributed to the ground state, and one about 11 MeV higher in excitation. The peak near 11 MeV excitation energy is believed to be almost entirely composed of a multiplet of three J/sup .pi./ = 2 states. Relativistic DWBA calculations imply support for the expectation that higher spin states are preferentially populated in the (.pi.+, K+) reaction, compared to the (K−, .pi.−) reaction in which lower spin states are excited. 29 refs., 40 figs.

Download or read book Production Of Lambda Lambda Hypernuclei in the K K Reaction written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Very little data exists on doubly strange .lambda lambda. hypernuclei; only the ground states of /sub .lambda lambda./He6 and /sub .lambda lambda./Be1° have been seen in emulsion experiments. With existing K− beam lines and magnetic spectrometer systems at CERN and Brookhaven, and the prospect of much higher K− intensities at an eventual kaon factory, one is invited to consider the possibility that discrete states of .lambda lambda. hypernuclei may be observed directly in the (K−, K) reaction on nuclear targets. Some DWBA estimates of the relevant cross sections are reported.