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 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 Hypernuclear Spectroscopy written by Pavlo Baturin and published by LAP Lambert Academic Publishing. This book was released on 2011-03 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the main tasks of nuclear physics is the study of subatomic particles and their interactions. The nucleon-nucleon interactions have been extensively studied over the last decades and have been supported with plenty of experimental data. The discovery of a new quantum number, strangeness, and a new type of particles that contain it, hyperons, spurred a renewed interest in science. New classes of interactions, hyperon-nucleon, and hyperon- hyperon, evolved. One of the best ways to study such interactions is to place a hyperon inside a nucleus, where it serves as a probe of the internal structure and might manifest properties that cannot be seen in an ordinary nucleus. This book presents the high resolution spectroscopy of light to medium hypernuclei recently obtained in Jefferson Laboratory. The main emphasis is given to the physics of the core-excited states. The described analysis techniques allowed achieving high quality missing mass spectra with energy resolution of 400- 500 keV, an unprecedented value in the history of hypernuclear reaction spectroscopy.
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 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 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 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 Proceedings of TRIUMF KEK Workshop on Hypernuclear Physics at KAON written by and published by . This book was released on 1989 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Using the e E K Reaction written by and published by . This book was released on 2006 with total page 44607 pages. Available in PDF, EPUB and Kindle. Book excerpt: A pioneering experiment in Lambda 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 7Li targets using the (e, e' K+)reaction. The 12B hypernuclear spectrum was previously published. This experiment is now reported in more detail, with improved results for the 12B hypernuclear spectrum. In addition, unpublished results of the 7He hypernuclear 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.
Download or read book Open Problems and Future Prospects for Hypernuclear Physics written by and published by . This book was released on 1992 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: We appraise the current status of our knowledge of hypernuclear structure physics, and emphasize the unsolved problems. The prospects for significant advances in high resolution hypernuclear spectroscopy with CW electron beams at CEBAF or intense pion beams at the proposed PILAC facility at LPF are discussed. These facilities could greatly extend our understanding of strangeness S = -1 hypernuclear systems. For S = -2 systems, new events have been seen in a (K−, K) hybrid counter-emulsion experiment at KEK in Japan. We give a theoretical interpretation of one of these events, as well as some further possibilities for the exploration of?? hypernuclear spectroscopy via?−-atoms. We mention some possible enhancements of (K−, K+) or (K−, K°) cross sections to discrete states, due to?N-?? configuration mixing in a shell model description of S = -2 hypernuclei. Finally, we explore the possibilities for producing multi-strange nuclei or droplets of strange quark matter (s̀̀trangelets̀̀) in relativistic heavy ion collisions.
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 Investigation of High precision Lambda Hypernuclear Spectroscopy Via the e E K Reaction written by and published by . This book was released on 2011 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of [Lambda] hypernuclear structure is very interesting in point of the understanding of the interaction between [Lambda] and nucleon ([Lambda]-N interaction) and its strange structure itself due to the containment of a [Lambda] hyperon which has a strangeness as a new degree of freedom. In the several way to study the Lamda hypernuclei, the (e, e'K+) reaction spectroscopy is a powerful tool for the precise investigation of [Lambda] hypernuclear structure. The purpose of the preset thesis is the establishment of the experimental design with the efficient data analysis method for the (e, e'K+) hypernuclear spectroscopic experiment in the wide mass region (from A=7 to A=52). It is very challenging to perform the (e, e'K+) spectroscopic experiment with such a heavy target, because of the huge electron background due to the bremsstrahlung process. In the experiment, it is required to obtain the necessary hypernuclear yield, suppressing the background event ratio. We achieved these requirements by newly constructing the high resolution electron spectrometer (HES) and splitter magnet (SPL) dedicated to the (e, e'K+) spectroscopic experiment. The HES consists of two quadrupole magnets and a dipole magnets (Q-Q-D) with a momentum resolution of dp/p = 3x10-4 at p = 0.84 GeV/c. It was used being vertically tilted by 6.5 degree so as to optimize signal to noise ratio and hypernuclear yield. The SPL is a dipole magnet. The experimental target was placed at the entrance of this magnet. The role of the SPL is to separate four kind of particles; scattered kaons, photons created by the bremsstrahlung, the post beam and scattered electrons. In addition, since the SPL is a part of the kaon and electron spectrometers. We designed the magnet shape carefully considering these points. The experiment was performed with 2.344 GeV/c electron beam from CEBAF at Jefferson Lab. The experimental setup consists of the HES, SPL and HKS (high momentum resolution kaon spectrometer). The HKS is also a Q-Q-D type spectrometer with the momentum resolution of dp/p = 2x10-4 at p = 1.2 GeV/c. In the data analysis, the particle momentum calibration was the most important procedure. At the initial point, the particle momentum was obtained from the calculated magnetic field map of the spectrometer whose accuracy is an order of 10-2. The initial momentum was calibrated by two step, the the magnetic field map improvement and the calibration with known masses of [Lambda]/[sigma]0 which were observed by the CH2 target data. As a result of the calibration, the momentum resolutions of HKS and HES were estimated as 4x10-4 and 6x10-4, respectively. Though these values are the double of the designed value, it was achieved to obtain the [Lambda]/[sigma]0 peaks with the same order of the designed energy from the original calculated magnetic field. The cross section was calculated with the several estimated factors. The averaged p([gamma]*, K+)[Lambda] cross section in the HKS acceptance, (0.90
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 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.
