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961.
The functional formulation of the Hubbard model is critically analyzed. Conditions to be satisfied by the transformed problem to maintain the fermion character of the original system are given. 相似文献
962.
The asymptotic behavior of the power fluctuations of a propagation mode coupled to a finite number of guided modes is obtained. The departure from an exponential power distribution is quantitatively shown by evaluating the variance. 相似文献
963.
P.L. Frabetti G. Bellini T. Bettinazzi M. Di Corato E. Meroni S. Micheletti F. Palombo F. Ragusa P.G. Rancoita G. Vegni L. Chernenko Yu. Ivanshin I. Pisarev S. Sychkov A. Tjapkin V. Vishniakov O. Zaimidoroga P.F. Manfredi 《Nuclear Physics B》1979,158(1):57-70
In the frame of a systematic study of hadron-nucleus interactions performed at the Serpukhov accelerator (CERN-IHEP 5th experiment), semicoherent elastic scattering on carbon was investigated with 25 and 40 GeV/c incident pions.The experimental data were obtained with a counter technique, looking at the coincidence between the scattered pion and the 4.44 MeV photon from the JP = 2+ carbon excited state detected by a NaI counter.The value obtained for the integrated cross section at 40 GeV/c in the 0.0032 ? |t| ? 0.27 (GeV/c)2 four-momentum transfer range isσ = 1.16 ± 0.11 mb.According to the theoretical models, this t-range at 40 GeV/c covers more than 99% of the angular distribution, so the above value almost corresponds to the total semicoherent elastic cross section. 相似文献
964.
965.
966.
W. Beusch E. Polgar D. Websdale K. Freudenreich F.X. Gentit P. Muhlemann J. Pernegr W. Wetzel P. Astbury J.G. Lee M. Letheren G. Bellini M. Di Corato F. Palombo P.G. Rancoita G. Vegni 《Physics letters. [Part B]》1975,55(1):97-100
In the reaction π? + A → π+π?π? + A at 15.1 GeV/c the coherently produced 3π mass spectrum has a broad peak around 1.1 GeV which consists mainly of a JP = 1+ state and of a smaller fraction of 0-. Comparing the observed dependence of the production of these diffractive states on the atomic weight A of the target nuclei with the optical model, we have studied the absorption of the produced states in nuclear matter. We have found the following values of the absorption cross-sections: σ2(0-) = 49?7+9 mb and σ2(1+) = 15.8?1.3+1.5 mb. 相似文献
967.
Francesco Paolo Di Stefano 《Annali dell'Universita di Ferrara》1978,24(1):25-35
Summary In this paper we define a new kind of blowing-up, as a functor from the category of real analytic spaces to the category of
real semianalytic spaces, in such a way that orientability is preserved. Then we prove an existence theorem for ?oriented
blowing-ups? of real analytic spaces.
Riassunto In questo articolo si definisce un nuovo tipo blowing-up, come un funtore dalla categoria degli spazi analitici reali alla categoria degli spazi semianalitici reali, in modo tale che l'orientabilità sia preservata. Si dimostra quindi un teorema di esistenza per blowing-ups orientati di spazi analitici reali.相似文献
968.
Routine food analysis requires methods that are non-destructive, rapid and easy to use. Pulsed low-resolution NMR satisfies all these conditions and is increasingly being applied to determine the water, oil and protein content of a number of foodstuffs. 相似文献
969.
The power losses due to coupling errors between source and fibre or two fibres are evaluated by means of a geometrical analysis of the coupling between an emitting and a detecting surfac. The theory is apllied to actual cases of separation, displacement and misalignment between a uniformly emitting lambertian source and fibre, and between two fibres. Good agreement is obtained with experimental results found in the literature. 相似文献
970.
Agnello M Beer G Benussi L Bertani M Bianco S Botta E Bressani T Busso L Calvo D Camerini P Cerello P Dalena B De Mori F D'Erasmo G Di Santo D Fabbri FL Faso D Feliciello A Filippi A Filippini V Fiore EM Fujioka H Gianotti P Grion N Lucherini V Marcello S Maruta T Mirfakhrai N Morra O Nagae T Olin A Outa H Pace E Palomba M Pantaleo A Panzarasa A Paticchio V Piano S Pompili F Rui R Simonetti G So H Tomassini S Toyoda A Wheadon R Zenoni A;FINUDA Collaboration 《Physical review letters》2005,94(21):212303
We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the e(+)e(-) collider DAPhiNE. Almost monochromatic K(-)'s produced through the decay of phi(1020) mesons are used to observe K(-) absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state K(-)pp through its two-body decay into a Lambda hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as 115(+6)(-5)(stat)(+3)(-4)(syst) MeV and 67(+14)(-11)(stat)(+2)(-3)(syst) MeV, respectively. 相似文献