Download or read book Update of High Resolution e E K Hypernuclear Spectroscopy at Jefferson Lab s Hall A written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Updated results of the experiment E94-107 hypernuclear spectroscopy in Hall A of the Thomas Jefferson National Accelerator Facility (Jefferson Lab), are presented. The experiment provides high resolution spectra of excitation energy for 12B_\Lambda, 16N_\Lambda, and 9Li_\Lambda hypernuclei obtained by electroproduction of strangeness. A new theoretical calculation for 12B_\Lambda, final results for 16N_\Lambda, and discussion of the preliminary results of 9Li_\Lambda are reported.

Download or read book High Resolution Hypernuclear Spectroscopy at Jefferson Lab Hall A written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 reactions. Experiment 94-107 started a systematic study on 1p-shell targets, $Ĉ$, ${̂9}Be$ and $Ô$. For $Ĉ$ 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 $_̂{\Lambda}B$ spectrum. A high-quality $_̂{\Lambda}N$ spectrum was produced for the first time with sub-MeV energy resolution. A very precise $\Lambda$ binding energy value for $_̂{\Lambda}N$, calibrated against the elementary $(e, e'K+̂)$ reaction on hydrogen, has also been obtained. ${̂9}_{\Lambda}Li$ spectrum shows some disagreement in strength for the second and third doublet with respect to the theory.

Download or read book Recent Results on High Resolution Hypernuclear Spectroscopy by Electroproduction at Jefferson Lab Hall A written by G. Chang and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The first ''systematic'' study of 1 p shell hypernuclei with electromagnetic probes has started in Hall A at Jefferson Lab . The aim is to perform hypernuclear high resolution spectroscopy by the electroproduction of strangeness on four 1p-shell targets: 12C, 9Be, 16O, 7Li. The first part of the experiment on 12C and 9Be has been performed in 2004, the second part (16O and 7Li) is scheduled for June 2005. To overcome the major experimental difficulties, namely the low counting rate and the challenging Particle IDentification (PID), two septum magnets and a Ring Imaging CHerenkov (RICH) detector had to be added to the existing apparatus. After underlining the particular role the electroproduction reaction plays in hypernuclear physics we describe the challenging modifications of the Hall A apparatus. Preliminary results on 12C and 9Be are presented.

Download or read book Hypernuclear Spectroscopy in JLab s Hall A written by C. C. Chang and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented from a new experiment (E94-107) in Hall A of the Thomas Jefferson National Accelerator Facility (JLab) producing Boron-12-lambda using electroproduction, (e, e{prime}K+). In the hypernuclear missing-mass spectrum the experiment achieves very good energy resolution (640 keV FWHM) by exploiting the characteristics of the High Resolution spectrometer pair and the exceptional beam quality available at JLab. The spectrometers were used with the addition an INFN provided pair of septum magnets to reach the desired small angles. Also, the Hall A standard complement of equipment was further augmented by the addition of a Ring Imaging Cherenkov detector (RICH) to achieve the best possible kaon identification.

Download or read book High Resolution Hypernuclear Spectroscopy written by F. Garibaldi and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypernuclear spectroscopy provides fundamental information for understanding the effective?-Nucleon interaction. Jefferson Laboratory experiment E94-107 was designed to perform high resolution hypernuclear spectroscopy by electroproduction of strangeness in four 1p-shell nuclei: 12C, 9Be, 16O, and 7Li. The first part of the experiment on 12C and 9Be has been performed in January and April-May 2004 in Hall A at Jefferson Lab. Significant modifications were made to the standard Hall A apparatus for this challenging experiment: two septum magnets and a RICH detector have been added to get reasonable counting rates and excellent particle identification, as required for the experiment. A description of the apparatus and the preliminary analysis results are presented here.

Download or read book Electron Induced Hypernuclear Spectroscopy Results in Hall A at Jefferson Lab written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The characteristics of the Jefferson LAB electron beam, together with those of the experimental equipments, offer a unique opportunity to study hypernuclear spectroscopy via electromagnetic induced reactions. Results are presented on 12C, 16O and 9Be targets. In the hypernuclear missing-mass spectrum the experiment achieves sub-MeV energy resolution by exploiting the characteristics of the High Resolution Spectrometer pair and the beam quality available at JLab. These studies have provided, among other things, the first quantitative information on core-excited states in hypernuclei, as well as the precise determination of Lambda binding energy in the Lambda16N hypernucleus. For the experiment on oxygen, a waterfall target has been employed, allowing simultaneous measurement of the elementary reaction on protons: a crucial measurement to disentangle the contribution of the elementary reaction from the measured hypernuclear production cross section, yielding direct access to the nucleus-hypernucleus transition structure.

Download or read book Experiments with the High Resolution Kaon Spectrometer at Jlab Hall C and the New Spectroscopy of 1 2 Lambda B Hypernuclei written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the pioneering experiment, E89-009 studying hypernuclear spectroscopy using the $(e, e{̂\prime}K+̂)$ 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 were added to produce precision, high-resolution hypernuclear spectroscopy. These two experiments, E01-011 and E05-115, resulted in two new data sets, producing sub-MeV energy resolution in the spectra of ${}{̂7}_{\Lambda}\text{He}$, ${}_̂{\Lambda}\text{B}$ and ${}{̂28}_{\Lambda} \text{Al}$ and ${}{̂7}_{\Lambda}\text{He}$, ${}_̂{\Lambda}\text{Be}$, ${}_̂{\Lambda}\text{B}$ and ${}{̂52}_{\Lambda}\text{V}$. All three experiments obtained a ${}_̂{\Lambda}\text{B}$, spectrum, which is the most characteristic $p$-shell hypernucleus and is commonly used for calibration. Independent analyses of these different experiments demonstrate excellent consistency and provide the clearest level structure to date of this hypernucleus as produced by the $(e, e{̂\prime}K+̂)$ reaction. This paper presents details of these experiments, and the extraction and analysis of the observed ${}_̂{\Lambda}\text{B}$ spectrum.

Download or read book Hypernuclear Spectroscopy Via e E K in JLab s Hall A written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented from a new experiment (E94-107) in Hall A of the Thomas Jefferson National Accelerator Facility (JLab) producing {12/Lambda} B, {16/Lambda}N, and {9/Lambda}Li using electroproduction, (e, e'K+). In the hypernuclear missing-mass spectrum the experiment achieves very good energy resolution (670 keV FWHM) by exploiting the characteristics of the High Resolution spectrometer pair and the exceptional beam quality available at JLab. The spectrometers were used with the addition an INFN provided pair of septum magnets to reach the desired small angles. Also, the Hall A standard complement of equipment was further augmented by the addition of a Ring Imaging Cherenkov detector (RICH) to achieve the best possible kaon identification.

Download or read book Hypernuclear Spectroscopy Program at JLab Hall C written by and published by . This book was released on 2008 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: DOI: http://dx.doi.org/10.1016/j.nuclphysa.2008.01.029 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 12C, 7Li and 28Si 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? hypernuclear spectroscopy and its future prospects.

Download or read book Hypernuclear Physics Programs Via Electroproduction in Hall C at Jefferson Lab written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypernuclei with strangeness -1 have been intensively studied both theoretically and experimentally using hadronic probes and reactions, (K, [pi]) and ([pi], K), for many years since the first discovery of such formation in the earlier nuclear emulsion and bubble chamber experiments. Many recent review papers exist on the status of hypernuclear physics, such as the recent one written by B.F. Gibson and Ed V. Hungerford in which one can find detailed discussion on all aspects of hypernuclear physics and more complete reference list. The unique feature of this field can be summarized, in general, into three categories: (1) Strong Interaction Involving Strangeness, (2) Weak Interaction with [Delta]S = -1, and (3) Medium Modifications. For strong interaction, it is commonly believed that a hyperon can be treated as an ''impurity'' to probe deep interior of the nuclear medium to explore fundamental issues such as the changes in size and shape due to the short range feature of YN interactions, limit of conventional nuclear model (shell or cluster) in solving for many body systems with new degree of freedom, spin dependent forces (spin-spin, spin-orbital, tensor), new symmetry and explicit QCD effect in nuclear media. Many of such issues are impossible or very difficult to be studied in the ordinary nuclear physics. The keys for success in this part of field includes good energy resolution and wide ranged spectroscopy. Until now, many important issues are still unresolved or remained to be resolved in more consistent and satisfactory fashion, such as spin dependent forces. This is due to luck of high quality experimental facilities. Recent experiments at KEK using ([pi][sup +], K[sup +]) reaction with a dedicated new SKS spectrometer have demonstrated the importance of improving the energy resolution. New structures were found as resolution improved only from 3 MeV to 2 MeV.

Download or read book written by and published by . This book was released on 1942 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hypernuclear Spectroscopy with Electron Beam at JLab Hall C written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypernuclear spectroscopy with electron beam at JLab Hall C has been studied since 2000. The first experiment, JLab E89-009, used Short Orbit Spectrometer (SOS) as a kaon arm and a split-pole type spectrometer (ENGE) as an electron arm. E89-009 employed zero-degree tagging method, which tags scattered electrons at zero-degree and the kaon arm also covered zero-degree. This method obtains maximum yield of hypernuclei but sufferers from high rate background of electrons from bremsstrahlung and positrons from pair-creation. Nevertheless, this experiment demonstrated the possibility of the (e, e' K) reaction for hypernuclear spectroscopy by obtaining a hypernuclear mass spectrum with an energy resolution of better than 1 MeV (FWHM) [1][2]. However, poor signal to noise ratio and poor statistics requires us to improve the experimental setup. Therefore, E01-011 experiment was proposed based on the success of the JLab E01-011 experiment. Improvements of E01-011 from E09-009 can be summarized as: 1. Employed newly constructed high resolution kaon spectrometer (HKS) as a kaon arm. 2. Employed so-called 'tilt-method' for the electron arm. With the newly constructed HKS, having 2-10-4 momentum resolution, we expect an energy resolution of 400 keV (FWHM). The 'tilt-method' means the electron arm is tilted vertically to the splitter dispersive plane to avoid background electrons from bremsstrahlung and moeller scattering. The setup allowed us to use up to a few tens beam. The experiment was performed in 2005 and final result will be shown shortly. The third experiment, JLab E05-115 experiment was proposed as a natural extension of E01-011 experiment and will be performed in 2009. Improvements of experimental setup are, 1. Employed newly constructed high resolution electron spectrometer (HES) as a electron arm, 2. Employed a new charge-separation magnet (Splitter), fully customized for hypernuclear experiment at Hall C. With the third generation experimental setup, we can study variety of targets up to medium-heavy ones such as 52Cr. This talk mainly focuses on the current status of the E05-115 experiment.

Download or read book A New Hypernuclear Experiment with the High Resolution Kaon Spectrometer HKS at JLAB Hall C written by Satoshi Nakamura and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As a natural extension of the first successful hypernuclear spectroscopy through the (e, e'K+) reaction (JLAB-E89-009), a new experiment with a newly developed High Resolution Kaon Spectrometer (HKS) and new configuration of the electron spectrometer was proposed. The high performance of the HKS and the new electron spectrometer configuration (tilt method) enables us to improve the energy resolution by a factor of 2, the hypernuclear yield by a factor of 50 and the signal to noise ratio by a factor of 10.

Download or read book First Experiment on Spectroscopy of Lambda Hypernuclei by Electroproduction at Jlab written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The first experiment in Lambda-hypernuclear spectroscopy using the high precision electron beam at Jefferson laboratory (Jlab) has been carried out. The hypernuclear spectrometer system (HNSS) was used to measure spectra from the 12C(e, e(prime)K)12{sub {Lambda}}B reaction with sub-1 MeV resolution, the best energy resolution obtained thus far in hypernuclear spectroscopy with magnetic spectrometers. This paper describes the HNSS and the preliminary results for the 12{sub {Lambda}}B system. The experimental spectrum is consistent with the expected strong spin-flip excitations of unnatural parity states. A program of hypernuclear physics experiments is planned for the future with much higher yield and even better energy resolution.

Download or read book Proceedings of The IX International Conference on Hypernuclear and Strange Particle Physics written by Josef Pochodzalla and published by Springer Science & Business Media. This book was released on 2008-06-27 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the IX International Conference on Hypernuclear and Strange Particle Physics (HYP 2006). This conference series is devoted to the progress of our knowledge about strangeness flavor in hadron and nuclear physics. Besides the traditional topics such as hadron structure, hypernuclear spectroscopy and weak decay of hypernuclei, a particular focus of this conference was on the properties of strange mesons and their binding in nuclear systems.

Download or read book Feasibility Test Run of C 12 e E K sup Reaction at Thomas Jefferson National Accelerator Facility written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The high quality and high duty factor (100%) electron beam at Jefferson Lab offers an opportunity to broaden their view of hypernuclear physics by studying the (e, e[prime]K[sup +]) reaction with high resolution. The present data represent a feasibility study of such a reaction on a carbon target. The test run was carried out during experiments E91-16 (Electroproduction of Kaons and Light Hypernuclei) and E93-18 (Kaon Electroproduction on p(e, e[prime]K[sup +])Y). These two experiments used liquid deuterium and hydrogen targets, respectively. There exist data on an aluminum target for the background calibration of the liquid targets which are suitable also for a feasibility study of electroproduction of hypernuclei. These data are still under analysis. The goal of this test run is to evaluate issues concerned with the electroproduction of hypernuclei. These issues include: (1) the quasi-free production rate, which had not been measured previously, (2) random coincidence background, (3) keon identification over a possibly large hadronic background, and (4) possible evaluation of the production rate of the bound hypernuclear structures. This test run will supply significant knowledge for running high quality hypernuclear experiments at Jefferson Lab. The spectroscopy of hypernuclei has been studied mainly in two ways: the strangeness-exchange reaction (K[sup -], [pi][sup -]), and associated strangeness production ([pi][sup +], K[sup +]). The (e, e[prime]K[sup +]) reaction has the advantage of exciting both natural- and unnatural-parity states and the possibility of obtaining good energy resolution. The cross section for the (e, e[prime]K[sup +]) reaction is about a hundred times smaller than for the corresponding hadronic production reactions but it is compensated for by the availability of high intensity and high duty factor electron beams. In order to optimize the production rate, the kinematic setting requires both the scattered electron and kaon to be detected at very forward angles. The test run was not optimized for hypernuclear production, but it serves as an important technical evaluation for future hypernuclear programs at Jefferson Lab. The first high-resolution spectroscopy experiment on p-shell lambda hypernuclei is tentatively scheduled to run in 1999 in Hall C at Jefferson Lab.

Download or read book Future Hypernuclear Program at JLAB Hall C written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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. The introduction of the HKS will improve by a factor of two, the energy resolution which was limited by the previous kaon spectrometer. The hypernuclear yield and the signal to noise ratio will be also improved by a factor of 50 and 10, respectively.