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 Spectroscopic Study of Capital Lambda hypernuclei Beyond the P shell written by Victor Manuel Rodriguez and published by . This book was released on 2006 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectroscopic Investigation of P Shell Lambda Hypernuclei by the e E K Reaction written by and published by . This book was released on 2014 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypernuclear spectroscopy is a powerful tool to investigate Lambda-N interaction. Compared with other Lambda hypernuclei productions, electroproduction via the (e, e'K+) reaction has the advantage of exciting states deeply inside of the hypernucleus and achieving sub-MeV energy resolution. The E05-115 experiment, which was successfully performed in 2009, is the third generation hypernuclear experiment in JLab Hall C.A new splitter magnet and electron spectrometer were installed, and beam energy of 2.344 GeV was selected in this experiment. These new features gave better field uniformity, optics quality and made the tilt method more effective in improving yield-to-background ratio. The magnetic optics of the spectrometers were carefully studied with GEANT simulation, and corrections were applied to compensate for the fringe field cross talk between the compact spectrometer magnets. The non-linear least chi-squared method was used to further calibrate the spectrometer with the events from Lambda, Sigma0 and B12Lambda and uniform magnetic optics as well as precise kinematics were achieved. Several p-shell Lambda hypernuclear spectra, including B12[Lambda], Be10[Lambda], He7[Lambda], were obtained with high energy resolution and good accuracy. For B12[Lambda], eight peaks were recognized with the resolution of ~540keV (FWHM), and the ground state binding energy was obtained as 11.529 ± 0.012(stat.) ± 0.110(syst.) MeV. Be10[Lambda], twelve peaks were recognized with the resolution of ~520keV (FWHM), and the binding energy of the ground state was determined as 8.710 ± 0.059(stat.) ± 0.114(syst.) MeV. For He7[Lambda], three peaks were recognized with the resolution of ~730keV, and the ground state binding energy was obtained as 5.510 ± 0.050(stat.) ± 0.120(syst.) MeV. Compared with the published data of B12[Lambda] from the JLab Hall A experiment, four extra peaks were fitted and interpreted thanks to the highest ever energy resolution and sufficient statistics. The determined binding energy of Be10[Lambda] provides new information on charge symmetry breaking effect in the Lambda-N interaction. Compared with the results of He7Lambda from the E01-011 experiment, the ground state position is consistent with 4 times more statistics, and two extra peaks corresponding to excited states were recognized.

Download or read book P SHELL Lambda HYPERNUCLEI AND THE Lambda N EFFECTIVE INTERACTION written by and published by . This book was released on 2000 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Empirical data on the spectra of light hypernuclei, especially the data from recent [gamma]-ray experiments, is used to constrain the parameters which govern the P{sub N}s{sub {Lambda}} and p{sub N}p{sub {Lambda}}j two-body matrix elements that enter into shell-model calculations.

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 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 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 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 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 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 High Precision Hypernuclear Spectroscopy Study by the e e K Reaction written by and published by . This book was released on 2002 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Jefferson Lab experiment E89009 is the first experiment to study hypernuclear spectroscopy by (e,e' K+) reaction. The 12 / LambdaB spectrum was observed from carbon target with the best energy resolution ever achieved from direct measurement of hypernuclear spectrum. The comparisons of the 12 / LambdaB spectrum with theoretical predictions were provided in terms of excitation strength and level separations. The overall excitation is in accord with theoretical calculations. The binding energies of p-shell and s-shell Lambda states were extracted. The photo-production cross section of the 12 / LambdaB ground state was also extracted. The experiment is also the pioneer in detecting scattered electrons at near zero degrees. The benefit and lessons learned from this method was also discussed.

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 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 High Energy Physics Index written by and published by . This book was released on 1992 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1992-05 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 1596 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 1058 pages. Available in PDF, EPUB and Kindle. Book excerpt: