排序方式: 共有10条查询结果,搜索用时 15 毫秒
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I. V. Ajinenko Y. A. Belokopitov A. A. Borovikov P. V. Chliapnikov Z. C. Garutchava L. N. Gerdyukov S. A. Gumenuk V. V. Kniazev A. I. Kurnosenko L. V. Orekhova L. P. Petrovikh V. N. Riadovikov A. G. Tomaradse V. A. Uvarov A. P. Vorobjev N. S. Amaglobely Ch. S. Chochiachvili M. Barth E. A. De Wolf M. Van Immerseel F. Verbeure CERN - USSR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1984,25(2):103-114
We present final results on inclusive production ofK *+(890),K *+(1430) andK *?(890) in \(\bar K^ + p\) interactions at 32 GeV/c, based on a statistics of ~27 events/μb. Total cross sections,p T -andx-dependence of inclusive distributions are compared with experiments at other energies and with the Lund fragmentation model. Spin density matrix elements of theK *+(890) are also discussed. The results suggest that “recombination” of both initial state valence quarks \(\bar s\) andu of theK + intoK *+(890), responsible in the Lund model for ~45% of theK *+(890) cross section, is strongly suppressed. 相似文献
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A. A. Minaenko T. M. Bryukhanova N. A. Kruglov A. M. Moiseev E. A. Starchenko M. N. Ukhanov R. Barloutaud C. Cochet A. Givernaud C. Lewin M. L. Turluer U. Gensch H. J. Grabosch W. Lohmann J. MacNaughton F. Mandl France Collaboration Soviet Union CERN Collaboration Soviet Union Collaboration 《Zeitschrift fur Physik C Particles and Fields》1984,26(1):27-35
The inclusive production of γ's and πp0's inK ? p-interactions at 32 GeV/c is studied. About 30.000 γ's coming from a Mirabelle bubble chamber experiment with a sensitivity of 6.5 ev/μb have been used for the analysis. Inclusive and topological cross sections of γ's are measured. The γ invariant differential distributions and their scaling properties are investigated. The inclusive cross section of πp0-production is determined and the πp0 invariant differential distributions are evaluated and compared to those of πp±. 相似文献
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K. Zuber C. F. Liang P. Paris J. Styczen J. Zuber P. Kleinheinz B. Rubio G. de Angelis H. Gabelmann A. Huck J. Blomqvist The ISOLDE collaboration CERN 《Zeitschrift für Physik A Hadrons and Nuclei》1987,327(3):357-358
The β-decay of146Dy80 was studied by γ-ray and conversion electron spectroscopy following on-line mass separation. 58 % of the β-decay proceeding to a group of levels close to 2 MeV excitation is attributed to GT-decay of (πh 11 2/2 )0+ pairs populating (πh11/2νh9/2νj 0 ?2 )1+ states in146Tb81. The total decay strength is significantly higher than found in148Dy82 decay, which arises from GT-transitions involving the ν-holes. 相似文献
4.
Virkus T Thomsen HD Uggerhøj E Uggerhøj UI Ballestrero S Sona P Mangiarotti A Ketel TJ Dizdar A Kartal S Pagliarone C;CERN NA Collaboration 《Physical review letters》2008,100(16):164802
Experimental results for the restricted energy loss of pairs created from 1-178 GeV photons in a thin Au target and subsequently passing a CCD detector are presented. It is shown that pairs--when detected close to the creation vertex--suffer a reduced energy loss due to the internal screening of the charges constituting the pair. Furthermore, the ability to measure directly the energy of the pair by calorimetry enables a comparison with theory as a function of energy. The observed phenomenon is in good qualitative agreement with general expectations from the Chudakov effect but indicates a quantitative disagreement with either of two mutually disagreeing theories. 相似文献
5.
K. -L. Kratz H. Gabelmann B. Pfeiffer P. Möller ISOLDE Collaboration CERN 《Zeitschrift für Physik A Hadrons and Nuclei》1988,330(2):229-230
Beta-decay properties of neutron-rich35Br isotopes confirm the predicted smooth onset of quadrupole deformation for Z<37 already below N=60. The observed increase of the energy of the first 2+ state in the N=56 nucleus92Kr may indicate octupole softness. 相似文献
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M. J. G. Borge D. G. Burke F. Calaprice O. C. Jonsson G. Løvhøiden R. A. Naumann K. Nybø G. Nyman H. L. Ravn T. F. Thorsteinsen The ISOLDE Collaboration CERN Geneva Switzerland 《Zeitschrift für Physik A Hadrons and Nuclei》1986,325(4):429-434
Neutron-rich isotopes of radon, produced by spallation reactions in a ThC2 target and selected chemically, were mass-separated and used as samples for radiation counting experiments. Assignments of the activities to radon isotopes were confirmed by genetic relationships to the previously known francium daughters. The halflife for the new isotope227Rn is 23±1 s and that for226Rn is 7.4±0.1 min. X-rays,γ-rays, and conversion electrons from the223Rn activity were measured. The decay patterns ofK X-rays and known gamma transitions in the223Fr daughter yield a halflife of 23.2± 0.4 min for223Rn, in contrast to the value of 43± 5 min reported earlier. Energies, intensities, and likely multipolarities for the most prominent gamma transitions in the223Rn→223Fr decay are presented. 相似文献
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J. Lohmüller H. H. Bertschat H. Granzer H. Haas G. Schatz ISOLDE Collaboration PPE Division CERN CH- Geneva- Switzerland W. -D. Zeitz 《Surface science》1996,360(1-3):213-220
Chemisorption and desorption of isolated bromine adatoms on the Si(100)-(2 × 1) surface were investigated with nuclear methods. Br adsorption sites at low coverages of 10−3 monolayers (ML) were characterised by measuring the nuclear quadrupole interaction with perturbed γγ-angular correlation (PAC) of 77Br→77Se probe atoms. Below room temperature, two distinct adsorption sites for Br are revealed by PAC. One of them disappears after isochronal annealing above 300 K. The more stable probe-atom state is associated with single Br atoms saturating a dangling bond of the surface, while the less stable state is attributed to adsorption of Br at a bridge site. The potential barrier between the two adsorption sites is estimated to be 0.9(1) eV. At temperatures above 550 K, the fraction of atoms on distinct sites decreases, presumably due to surface diffusion. By measuring the γ-activity of the sample, complete desorption of the 77Br atoms was observed above 620 K. 相似文献
8.
A. Breakstone R. Campanini H. B. Crawley G. M. Dallavalle M. M. Deninno K. Doroba D. Drijard F. Fabbri A. Firestone H. G. Fischer H. Frehse W. Geist G. Giacomelli R. Gokieli M. Gorbics P. Hanke M. Heiden W. Herr D. Isenhower E. E. Kluge J. W. Lamsa T. Lohse W. T. Meyer G. Mornacchi T. Nakada M. Panter A. Putzer K. Rauschnabel B. Rensch F. Rimondi M. Schmelling G. P. Siroli J. D. Skeens R. Sosnowski M. Szczekowski O. Ullaland D. Wegener R. Yeung Ames Collaboration Bologna Collaboration CERN Collaboration Dortmund Collaboration Heidelberg Collaboration Warsaw Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,43(3):522-522
Data are presented for the first time on inclusive Pomeron-Pomeron interactions which produce a central systemX (composed mainly of multimeson states) in proton-proton collisions at \(\sqrt s \) at the CERN ISR. The systemX has a Feynman-x distribution which is sharply peaked atx f=0, is inconsistent with any significant contributions from Reggeon exchange processes, and has an invariant mass dependence in good agreement with the predicted formM x ?2 . Kaon production is about 15% of pion production, nearly independent ofM x, while proton-antiproton production averages about 5% of pion production and increases withM x. The structure of the central systemX develops into a jetlike shape, asM x increases, as would be expected from a model of Pomeron fragmentation. The shape of thex f(π) distribution in the center of mass of theX system (although not proving existence) is consistent with asoft partonic substructure of the Pomeron. 相似文献
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G. T. Ewan P. Hoff B. Jonson K. -L. Kratz P. O. Larsson G. Nyman H. L. Ravn W. Ziegert The ISOLDE collaboration CERN 《Zeitschrift für Physik A Hadrons and Nuclei》1984,318(3):309-314
Improved production yields of short-lived halogens were obtained from a ThO2 target, irradiated with 600 MeV protons, in combination with a negative surface ionization source. Mass-separated samples were studied by decay spectroscopy. Production yields of radioactive isotopes of chlorine, bromine, iodine and astatine are presented. Half-lives and relative neutron emission probabilities were measured for the heavy bromine isotopes89?92Br. Normalizing to earlier publishedP n values for89Br, the results are:89Br (4.30±0.14s,P n =13.6±0.8%),90Br (1.92±0.06s,P n =24.8±1.5%),91Br (0.53 ±0.03 s,P n =30.1 ±2.1%), and92Br (0.31 ±0.02 s,P n =34.6±2.5%). Energy spectra ofβ-delayed neutrons were measured. 相似文献
10.
Andersen KK Andersen SL Esberg J Knudsen H Mikkelsen R Uggerhøj UI Sona P Mangiarotti A Ketel TJ Ballestrero S;CERN NA 《Physical review letters》2012,108(7):071802
We report the first observation of a shoulder in the radiation spectrum from GeV electrons in a structured target consisting of two thin and closely spaced foils. The position of the shoulder depends on the target spacing and is directly connected to the finite formation length of a low-energy photon emitted by an ultrarelativistic electron. With the present setup it is possible to control the separation of the foils on a μm scale and hence measure interference effects caused by the macroscopic dimensions of the formation length. Several theoretical groups have predicted this effect using different methods. Our observations have a preference for the modified theory by Blankenbecler but disagree with the results of Baier and Katkov. 相似文献
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