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71.
We have measured the polarization of ∧ and Ξ? hyperons produced inclusively by a Σ? beam of 340 GeV/c momentum in nuclear targets, using samples of 9.5 million ∧ decays and 880000 Ξ? decays. The large statistics allowed a two-dimensional analysis as functions ofx F andp t . The polarization w.r.t. the production normal is mainly positive for ∧ and negative for Ξ?. The positive sign of the ∧ polarization is opposite to predictions. Atp t >1 Gev/c, the ∧ polarization decreases to zero or even negative values, in sharp contrast to the plateau abovep t <1 GeV/c observed in inclusive ∧ production by protons. No such effect is observed for the Ξ? polarization, and its sign is as expected. 相似文献
72.
R. Albrecht T. C. Awes C. Baktash P. Beckmann F. Berger R. Bock G. Claesson G. Clewing L. Dragon A. Eklund R. L. Ferguson A. Franz S. Garpman R. Glasow H. ?. Gustafsson H. H. Gutbrod J. Idh P. Jacobs K. H. Kampert B. W. Kolb P. Kristiansson I. Y. Lee H. L?hner I. Lund F. E. Obenshain A. Oskarsson I. Otterlund T. Peitzmann S. Persson F. Plasil A. M. Poskanzer M. Purschke H. G. Ritter S. Saini R. Santo H. R. Schmidt T. Siemiarczuk S. P. Sorenseh E. Stenlund M. Tincknell G. R. Young WA -Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,45(4):529-537
Charged pion yields and transverse energies of baryons are measured for the reaction16O+Cu, Ag, Au at 60 and 200A GeV bombarding energy in the target fragmentation region employing the Plastic Ball detector. Only little dependence of the measured quantities on the bombarding energy is found. The data are compared with the multi-chain fragmentation model of Ranft. As a result it turns out that a leading order formation zone cascade is not sufficient to explain the baryon yield and the transverse energies of baryons in the target fragmentation region. 相似文献
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74.
W A Korfmacher T A Getek E B Hansen C E Cerniglia S Abou-Khalil A A Yunis 《Journal of chromatographic science》1990,28(5):236-238
The thermospray (TS) liquid chromatographic-mass spectrometric analysis of the antibiotic chloramphenicol and three related compounds is presented. The three additional compounds are dehydrochloramphenicol, aminodehydrochloramphenicol, and nitrophenylaminopropanediol. Baseline separation of the four compounds is achieved. The TS mass spectrum of each of the four compounds includes a prominent [MH]+ ion plus some fragment ion peaks. 相似文献
75.
M. Bonesini E. Bonvin P. S. L. Boóth D. Bortoletto L. J. Carroll A. J. Cass D. Cavalli G. Costa M. Donnat P. A. Dorsaz D. N. Edwards J. R. Fischer L. Fluri D. Frame F. Gianotti S. Jack J. N. Jackson M. Kelly M. N. Kienzle-Focacci R. Lucock J. G. Lynch L. Mandelli M. Martin L. Mathys A. Maxwell M. Mazzanti J. J. Myerscough P. J. Negus S. Pensotti-Rancoita L. Perini D. Perrin G. Polesello W. H. Range L. Rosselet S. W. Snow M. Tamborini A. S. Thompson R. M. Turnbull J. Wells M. Werlen WA -Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,37(4):535-544
The inclusive cross sections for prompt photon production by π? and π+ on protons have been measured with a beam momentum of 280 GeV/c using a fine grained electromagnetic calorimeter and the CERN Omega spectrometer. The transverse momentum and Feynmanx F ranges covered are 4.0<p T <7.0GeV/c and ?0.45<x F <0.55 respectively. A quantitative comparison of the prompt photon cross section with next-to-leading order QCD predictions using Duke and Owens structure functions is performed. 相似文献
76.
R. Albrecht T. C. Awes C. Baktash P. Beckmann F. Berger R. Bock G. Claesson L. Dragon R. L. Ferguson A. Franz S. Garpmann R. Glasow H. A. Gustafsson H. H. Gutbrod K. H. Kampert B. W. Kolb P. Kristiansson I. Y. Lee H. Lohner I. Lund F. E. Obenshain A. Oskarsson I. Otterlund T. Peitzmann S. Persson F. Plasil A. M. Poskanzer M. Purschke H. G. Ritter R. Santo H. R. Schmidt T. Siemiarczuk S. P. Sorensen E. Stenlund G. R. Young WA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,38(1):3-14
Results based on calorimetric measurements are presented from reactions of 60A GeV and 200A GeV16O projectiles with C, Cu, Ag, and Au nuclei. Minimum-bias cross sections are discussed. Energy spectra measured at zero degrees and transverse-energy distributions for the pseudorapidity range 2.4≦η≤5.5 are shown. An analysis of the average transverse energy in terms of the number of participating nucleons and the number of binary nucleon-nucleon collisions is presented. Estimates of nuclear stopping and of attained energy densities are made. 相似文献
77.
The branching ratios for the reaction pathways of 39 polychlorinate dibenzo-p-dioxins (PCDDs) under oxygen negative chemical ionization/atmospheric pressure ionization mass spectrometric conditions were measured. These results demonstrated that the PCDDs could be separated into 14 groups by this technique. These results were compared with those reported previously for 14 PCDDs using oxygen negative chemical ionization mass spectrometry. 相似文献
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79.
J O Lay T A Getek D W Kelly W Slikker W A Korfmacher 《Rapid communications in mass spectrometry : RCM》1989,3(3):72-75
Two conjugated metabolites of methapyrilene hydrochloride isolated from mouse-hepatocytes were examined by mass spectrometry using fast-atom bombardment (FAB) and thermospray ionization. The major metabolite, methapyrilene glucuronide, was identified based on a prominent peak due to the protonated molecule as well as the loss of the dimethylamine and sugar moieties. Identification of the second metabolite was complicated by large signals associated with the biological sample matrix. The complementary nature of the fragmentation observed in the mass spectra using FAB and thermospray ionization allowed this metabolite to be identified as the desmethylmethapyrilene glucuronide. The fragmentation observed using FAB ionization was not greatly affected by the presence of the glucuronide moiety. While loss of the sugar moiety indicated a glucuronide, additional fragmentation confirmed the presence of the underlying ethylenediamine substructure which is characteristic of this class of antihistamines. 相似文献
80.
T. A. Armstrong I. J. Bloodworth J. N. Carney B. R. French B. Ghidini J. B. Kinson V. Lenti A. Palano I. C. Print H. R. Shaylor G. Vassiliadis O. Villalobos Baillie M. E. Votruba G. Zito R. Zitoun WA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1987,34(1):23-31
We have analyzed theK 1 0 K ± π? system in the reactions π+/pp→π+/p(K 1 0 K ± π?)p. A spin-parity analysis of theK 1 0 K ± π? system in the “4C” channel confirms the existence of the 1++ E meson which decays mainly throughK * \(\bar K\) . The data allow the presence of a 0?+ wave at a level of 14% of theE/ι signal. The production ofD andE mesons in the channels where theK 1 0 K ± π? system is produced along with a π0 or π+π? system is suppressed. 相似文献