排序方式: 共有17条查询结果,搜索用时 15 毫秒
1.
E. Bonvin R. Bopp L. J. Carroll A. J. Cass S. U. Chung M. Donnat P. A. Dorsaz M. E. Feliks L. Fluri J. N. Jackson M. N. Kienzle-Focacci J. G. Lynch M. Martin L. Mathys P. J. Negus L. Perini R. Poultney W. H. Range L. Rosselet S. W. Snow A. S. Thompson R. M. Turnbull M. Werlen WA -Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,41(4):591-598
A search for pairs of highp T prompt photons produced in hydrogen by a 280 GeV/c incidentπ - beam has been carried out using a fine-grained electromagnetic calorimeter and the Omega spectrometer at the CERN SPS. Clear evidence for the existence of such events is found with a six standard deviation signal forp T >3.0 GeV/c. The cross-sections are consistent with beyond leading order QCD calculations. A discussion on the determination of α s is also presented. 相似文献
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M. Bonesini E. Bonvin R. Bopp L. J. Carroll A. J. Cass D. Cavalli G. Costa S. U. Chung M. Donnat P. A. Dorsaz M. Feliks J. R. Fischer L. Fluri F. Gianotti S. Jack J. N. Jackson M. N. Kienzle-Focacci J. G. Lynch L. Mandelli M. Martin L. Mathys A. Maxwell M. Mazzanti P. J. Negus S. Pensotti-Rancoita L. Perini D. Perrin R. W. Poultney W. H. Range L. Rosselet S. W. Snow A. S. Thompson R. M. Turnbull J. Wells M. Werlen WA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,44(1):71-78
The structure of events associated with the production of direct photons in π? p, π+ p andpp reactions of 280 GeV/c has been studied using data from the WA 70 experiment at the CERN SPS. Results are presented on the distributions of the fractional momenta of the colliding partons and on the fragmentation of the recoil jet and a comparison is made with predictions using the structure functions of Duke and Owens in the Lund Monte Carlo with string fragmentation. 相似文献
3.
M. Bonesini E. Bonvin P. S. L. Booth R. Bopp L. J. Carroll A. J. Cass D. Cavalli S. U. Chung G. Costa M. Donnat P. A. Dorsaz E. Durieux M. E. J. Feliks J. R. Fischer L. Fluri 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 P. J. Negus L. Perini D. Perrin G. Polesello R. Poultney W. H. Range L. Rosselet S. W. Snow A. S. Thompson R. M. Turnbull M. Werlen WA -Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,42(4):527-532
The inclusive cross sections for η production by the interactions of 280 GeV/c momentum π?, π+, and proton beams in hydrogen have been measured. The kinematical range covered is ?0.45<x F <0.45, and 4.0<P T <7.0 GeV/c for Feynmanx F and transverse momentum respectively. The η to π0 cross section ratios are given for the three reactions. The ratio of π? p to π+ p cross sections for η production in the above kinematic ranges is 1.22±0.08±0.11. 相似文献
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M. Bonesini E. Bonvin P. S. L. Booth L. J. Carroll A. J. Cass D. Cavalli G. Cecchet 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 A. S. Thompson R. M. Turnbull J. Wells M. Werlen WA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,38(3):371-382
The inclusive cross sections for production of prompt photons and π0 s by 280 GeV/c protons incident on a liquid hydrogen target, have been measured forp T in the range 4.0 to 6.5 GeV/c and for |x F |<0.45. A quantitative comparison of the prompt photon cross section with next-to-leading order QCD predictions using Duke and Owens structure functions is performed. Phenomenological fits to the π0 and prompt photon cross sections are given. 相似文献
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E. Bonvin R. Bopp L. J. Carroll A. J. Cass M. Donnat P. A. Dorsaz E. Durieux M. E. J. Feliks L. Pluri J. N. Jackson M. N. Kienzle-Focacci J. G. Lynch M. Martin L. Mathys P. J. Negus R. Poultney W. H. Range L. Rosselet S. W. Snow A. S. Thompson R. M. Turnbull M. Werlen 《Zeitschrift fur Physik C Particles and Fields》1991,51(2):163-166
The production of charged hadrons accompanying the highp
T
photons in the reactions –
pX at 280 GeV/c has been studied using data from the WA70 experiment at the CERN SPS. The energy distribution of these hadrons cannot be explained by direct photon processes and their hadrons background alone. The rate of bremsstrahlung processes has been estimated on the assumption that the hadronic excess results from such processes alone. 相似文献
9.
Mouaddab M Foucat L Donnat JP Renou JP Bonny JM 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2007,189(1):151-155
A method is described for the absolute quantification of double-quantum filtered spectra of spin-3/2 nuclei ((23)Na). The method was tested on a model system, a cationic exchange resin for which the number of Na(+) binding sites was quantitatively controlled. The theoretical and experimental approaches were validated on samples with different Na(+) concentrations. An excellent agreement between the results obtained by double-quantum and single-quantum acquisitions was found. This method paves the way for absolute quantification of both bound and free fractions of Na(+), which are determining factors in the characterization of salted/brined/dried food products. 相似文献
10.
The structural and electronic transport properties of La1−x
Ce
x
MnO3 (x=0.0–1.0) have been studied. All the samples exhibit orthorhombic crystal symmetry and the unit cell volume decreases with
Ce doping. They also make a metal-insulator transition (MIT) and transition temperature increases with increase in Ce concentration
up to 50% doping. The system La0.5Ce0.5MnO3 also exhibits MIT instead of charge-ordered state as observed in the hole doped systems of the same composition. 相似文献