Download or read book Photoproduction of and 0 Hyperons Off Protons in the Nucleon Resonance Region Using CLAS at Jefferson Lab written by and published by . This book was released on 2002 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The differential cross section and hyperon recoil polarizations of the photoproduction of the ground state hyperons, ? p → K+ ? and ? p → K+ ?0 , have been measured with the CLAS at Jefferson Lab up to a photon energy in the lab of 2.325 GeV. The results for both channels show significantly larger cross section in the middle to forward angles than have been observed previously by the SAPHIR Collaboration. Both reactions show significantly more backward peaking in the angular distributions than has previously been possible to observe. The backward peaking hints that hyperon resonances in the u-channel play a significant role in the production mechanism. In addition, in the ? p → K+ ? reaction, a previously unobserved bump in the cross section was observed at forward angles, centered on a W of 1.95 GeV with a width of approximately ? = 100 MeV. In both ? p → K+ Y reactions the recoil polarization in the forward direction seems reasonably well reproduced by t-channel interferences in a Regge model calculation as well as hadrodynamic models that include kaon resonances in the t-channel. The recoil polarization for ? p → K+ ? shows a significant enhancement around a W of 1.9 GeV in the backward angles, which is a sign of resonance activity in this vicinity. The polarization of ? p → K+ ?0 at backward angles is, in contrast, less pronounced and mostly consistent with zero.
Download or read book Photoproduction Of Lambda And Sigma sup 0 Hyperons Off Protons in the Nucleon Resonance Region Using CLAS at Jefferson Lab written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The differential cross section and hyperon recoil polarizations of the photoproduction of the ground state hyperons, [gamma] p[yields] K[sup+][Lambda] and[gamma] p[yields] K[sup+][Sigma][sup 0], have been measured with the CLAS at Jefferson Lab up to a photon energy in the lab of 2.325 GeV. The results for both channels show significantly larger cross section in the middle to forward angles than have been observed previously by the SAPHIR Collaboration. Both reactions show significantly more backward peaking in the angular distributions than has previously been possible to observe. The backward peaking hints that hyperon resonances in the u-channel play a significant role in the production mechanism. In addition, in the[gamma] p[yields] K[sup+][Lambda] reaction, a previously unobserved bump in the cross section was observed at forward angles, centered on a W of 1.95 GeV with a width of approximately[Gamma]= 100 MeV. In both[gamma] p[yields] K[sup+] Y reactions the recoil polarization in the forward direction seems reasonably well reproduced by t-channel interferences in a Regge model calculation as well as hadrodynamic models that include kaon resonances in the t-channel. The recoil polarization for[gamma] p[yields] K[sup+][Lambda] shows a significant enhancement around a W of 1.9 GeV in the backward angles, which is a sign of resonance activity in this vicinity. The polarization of[gamma] p[yields] K[sup+][Sigma][sup 0] at backward angles is, in contrast, less pronounced and mostly consistent with zero.
Download or read book Photoproduction of Lambda and Sigma Hyperons Off Protons in the Nucleon Resonance Region Using CLAS at Jefferson Lab written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The differential cross section and hyperon recoil polarizations of the photoproduction of the ground state hyperons, [gamma] p 2!K [Lambda] and [gamma] p 2!K [Sigma]°, have been measured with the CLAS at Jefferson Lab up to a photon energy in the lab of 2.325 GeV. The results for both channels show significantly larger cross section in the middle to forward angles than have been observed previously by the SAPHIR Collaboration. Both reactions show significantly more backward peaking in the angular distributions than has previously been possible to observe. The backward peaking hints that hyperon resonances in the u-channel play a significant role in the production mechanism. In addition, in the [gamma] p 2!K+ [Lambda] reaction, a previously unobserved bump in the cross section was observed at forward angles, centered on a W of 1.95 GeV with a width of approximately [Gamma] = 100 MeV. In both [gamma] p 2!K+ Y reactions the recoil polarization in the forward direction seems reasonably well reproduced by t-channel interferences in a Regge model calculation as well as hadrodynamic models that include kaon resonances in the t-channel. The recoil polarization for [gamma] p 2!K+ [Lambda] shows a significant enhancement around a W of 1.9 GeV in the backward angles, which is a sign of resonance activity in this vicinity. The polarization of [gamma] p 2!K+ [Sigma]° at backward angles is, in contrast, less pronounced and mostly consistent with zero.
Download or read book Photoproduction of Lambda and Sigma0 Hyperons Off Protons in the Nucleon Resonance Region Using CLAS at Jefferson Lab written by John W. C. McNabb and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrophotoproduction Of Strangeness On Nucleons And Nuclei Proceedings Of The International Symposium written by Kazushige Maeda and published by World Scientific. This book was released on 2004-06-01 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains important papers on the strangeness production processes and strangeness nuclear physics resulting from electromagnetic interaction. Both experimentalists and theorists in the field present information on recent activities and discuss the prospects of related fields.
Download or read book Photoproduction of and 0 Hyperons Using Linearly Polarized Photons written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of polarization observables for the reactions $\vec{\gamma} p \rightarrow K+̂ \Lambda$ and $\vec{\gamma} p \rightarrow K+̂ \Sigma0̂$ have been performed. This is part of a programme of measurements designed to study the spectrum of baryon resonances. The accurate measurement of several polarization observables provides tight constraints for phenomenological fits. Beam-recoil observables for the $\vec{\gamma} p \rightarrow K+̂ \Sigma0̂$ reaction have not been reported before now. Furthermore, the measurements were carried out using linearly polarized photon beams and the CLAS detector at the Thomas Jefferson National Accelerator Facility. The energy range of the results is 1.71GeV.
Download or read book Study of the Hyperon Nucleon Interaction in Exclusive Lambda Photoproduction Off the Deuteron written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2003 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Eta Photoproduction from the Proton Using CLAS written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Differential cross sections for the reaction[gamma]p[yields] np have been measured for incident photon energies from 0.75 to 1.95 GeV. Data were taken using the CLAS spectrometer and tagged photon facility at Jefferson Lab. The data provide the first extensive measurements of angular distributions for this process above the S11 (1535) resonance in the range up to W= 2.1 GeV.
Download or read book Measurement of Excited Hyperons in Photoproduction at CLAS written by and published by . This book was released on 2014 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurement results of photoproduced excited hyperon states using the CLAS detector at Jefferson Lab are shown. The invariant mass distribution of the?(1405) has recently been shown to be different for each of the three Sigma pi channels that it decays to, showing that there is prominent interference between the isospin I=0 and I=1 isospin amplitudes. Measurements of the differential and total cross sections of the three hyperons?(1405),?°(1385), and Lambda(1520) are presented and compared. Prospects of future studies using a 12 GeV beam with the GlueX detector are briefly given.
Download or read book Electromagnetic Production of Hyperon Resonances written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of hyperon resonances has entered a new era of precision with advent of high-statistics photoproduction data from the CLAS detector at Jefferson Lab. These data have multi-particle final states, allowing clean identification of exclusive reactions associated with strange mesons and baryons. Examples of physics results are: evidence for isospin interference in the decay of the [Lambda](1405) resonance; a strong suggestion of meson cloud effects in the structure of the [Sigma](1385) resonance; data from K* photoproduction that will test the existence of the purported K0(800)$ meson. Properties of other hyperon resonances will also be studied in the near future.
Download or read book Photoproduction of Multiply Strange Hyperons at CLAS written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The activities of the California State University, Dominguez Hills (CSUDH) Hadronic Structure Laboratory, undertaken with the support of the U.S. Department of Energy's Office of Science under grant DE-FG02-07ER41525, are described. This grant was originally awarded in 2007, and then renewed in 2009 and 2012, before it expired in 2015. The work was performed primarily at the home institution on the CSUDH campus in Carson, CA. A significant portion of the work was carried out at the Thomas Jefferson National Accelerator Facility (JLab) in Newport News, VA. The work covered in this award involves the study of the structure of the proton, which is done indirectly by looking at the Xi particle. This is a particle with a spin and spatial structure similar to that of the proton, but with a different quark structure. Their properties are expected to be related due to SU(3) flavor symmetry. Additional work performed under this grant involved the construction of the High Threshold Cherenkov Counter, which was done by CSUDH undergraduate students in collaboration with JLab staff scientists.
Download or read book Eta Photoproduction from the Proton Using CLAS written by Michael Dugger and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Differential cross sections for the reaction {gamma}p {yields} np have been measured for incident photon energies from 0.75 to 1.95 GeV. Data were taken using the CLAS spectrometer and tagged photon facility at Jefferson Lab. The data provide the first extensive measurements of angular distributions for this process above the S11 (1535) resonance in the range up to W = 2.1 GeV.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoproduction of the Doubly strange Xi Hyperons written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on the first measurement of exclusive Xi- and Xi0 photoproduction. The Xi- states are produced in the reaction gamma p --> K+ K+ Xi-, and the Xi0 states in gamma p --> K+ K+ pi- Xi0. Identification is made by the unique mass measured as the missing mass of the K+ K+ (or K+ K+ pi- ) system using the CLAS detector at the Thomas Jefferson National Accelerator Facility. A systematic study of the excited Xi spectrum improves our understanding of the N* and Delta* states, since the Xi* states are related to them by SU(3) flavor symmetry. At the highest energies available at Jefferson Lab, we begin to find evidence for known excited Xi- states in the photoproduction process, and possibly new states at 1770 and 1860 MeV, although we do not have enough statistics to draw a strong conclusion. A search for the Xi5--(1862) pentaquark state seen by NA49 is made using the process gamma p -> K+ K+ pi+ X, but the result is inconclusive for lack of statistics.
Download or read book Photoproduction of the Rho 0 Meson on the Proton at Large Momentum Transfer written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The differential cross section, d[sigma]/dt, for p0 meson photoproduction on the proton above the resonance region was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The p0 channel was extracted from the measured two charged-pion cross sections by fitting the [pi]+[pi]- and p[pi]+ invariant masses. The low momentum transfer region shows the typical diffractive pattern expected from Reggeon exchange. The flatter behavior at large -t cannot be explained solely in terms of QCD-inspired two-gluon exchange models. The data indicate that other processes, like quark interchange, are important to fully describe p photoproduction.
Download or read book Photoproduction of the math mrow msub mi f mi mn 1 mn msub mrow mo mo mn 1285 mn mo mo mrow mrow math Meson written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The \fx\ meson with mass $1281.0 \pm 0.8$~MeV/$c^2$ and width $18.4 \pm 1.4$~MeV (FWHM) was measured for the first time in photoproduction from a proton target using CLAS at Jefferson Lab. Differential cross sections were obtained via the $\eta\pi^{+}\pi^{-}$, $K^+\bar{K}^0\pi^-$, and $K^-K^0\pi^+$ decay channels from threshold up to a center-of-mass energy of 2.8~GeV. The mass, width, and an amplitude analysis of the $\eta\pi^{+}\pi^{-}$ final-state Dalitz distribution are consistent with the axial-vector $J^P=1^+$ \fx\ identity, rather than the pseudoscalar $0^-$ \etax. The production mechanism is more consistent with $s$-channel decay of a high-mass $N^*$ state, and not with $t$-channel meson exchange. Decays to $\eta\pi\pi$ go dominantly via the intermediate $a_0^\pm(980)\pi^\mp$ states, with the branching ratio $\Gamma(a_0\pi \text{\small{ (no }} \bar{K} K\text{\small{)}}) / \Gamma(\eta\pi\pi \text{\small{ (all)}}) = 0.74\pm0.09$. The branching ratios $\Gamma(K \bar{K} \pi)/\Gamma(\eta\pi\pi) = 0.216\pm0.033$ and $\Gamma(\gamma\rho^0)/\Gamma(\eta\pi\pi) = 0.047\pm0.018$ were also obtained. The first is in agreement with previous data for the \fx, while the latter is lower than the world average.
