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1.
Brick DH Widgoff M Beilliere P Lutz P Narjoux JL Gelfand N Alyea ED Bloomer M Bober J Busza W Cole B Frank TA Fuess TA Grodzins L Hafen ES Haridas P Huang D Huang HZ Hulsizer R Kistiakowsky V Ledoux RJ Milstene C Noguchi S Oh SH Pless IA Steadman S Stoughton TB Suchorebrow V Tether S Trepagnier PC Wadsworth BF Wu Y Yamamoto RK Cohn HO Calligarich E Castoldi C Dolfini R Introzzi G Ratti S Badiak M DiMarco R Jacques PF Kalelkar M Plano RJ Stamer PE Brucker EB Koller EL Alexander G Grunhaus J 《Physical review D: Particles and fields》1990,41(3):765-773
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The production of ?0 and f mesons in πN→π+π?N reactions in the momentum range 4 to 17 GeV/c is investigated in a model-independent way by imposing in full the positivity of the density matrix. The results so obtained are used in order to determine the effective Regge trajectories for unnatural and natural parity exchanges and are compared to results obtained in different analyses. 相似文献
3.
B. Niczyporuk Z. Jakubowski T. Zełudziewicz G. Folger B. Lurz H. Vogel U. Volland H. Wegener J. K. Bienlein R. Graumann H. -J. Trost M. Schmitz F. H. Heimlich R. Nernst A. Schwarz U. Strohbusch P. Zschorsch K. W. Chen A. C. König D. J. Schotanus M. Coles A. Engler R. W. Kraemer D. Marlow F. Messing C. Rippich S. Youssef A. Fridman G. Alexander A. Av-Shalom G. Bella J. Grunhaus W. Langguth M. Scheer LENA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1983,17(3):197-202
A search for the decays γ→ρπ, γ→J/ψX and γ→γa (whereX is undetermined and a is an axion) has been completed using the LENA detector at the DORIS storage ring. No evidence for any of these processes was found. For these decay modes we set branching fraction upper limits (90% C.L.) of 2.1×10?3, 2.0×10?2 and 9.1×10?4, respectively. 相似文献
4.
H. Braun D. Evrard A. Fridman J. -P. Gerber A. Givernaud J. Grunhaus R. Kahn G. Maurer A. Michalon B. Schiby R. Strub C. Voltolini 《Zeitschrift für Physik A Hadrons and Nuclei》1971,247(2):107-116
A study of a 150000-picture exposure of ¯pd at 5.5 GeV/c yielded 152 events satisfying the hypothesis ¯pd→p s π+2π?π0. For the events with proton spectator in the momentum range 100–280 MeV/c we obtained the cross section of 0.11±0.02 mb. Assuming the validity of the impulse approximation we estimate a cross section of 0.43±0.06 mb for the reaction ¯pn→ π+2π?π0. The rate for single ? meson production and an upper limit for double ? production are given. A modified multiperipheral Regge model was used in order to describe the general features of the data. 相似文献
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B. Niczyporuk Z. Jakubowski G. Nowak G. Folger B. Lurz U. Volland H. Wegener J. K. Bienlein R. Graumann H. -J. Trost M. Schmitz F. H. Heimlich R. Nernst A. Schwarz U. Strohbusch P. Zschorsch K. W. Chen A. C. König D. J. Schotanus M. Coles A. Engler R. W. Kraemer D. Marlow F. Messing C. Rippich S. Youssef A. Fridman G. Alexander A. Av-Shalom G. Bella J. Grunhaus M. Scheer LENA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1982,15(4):299-309
The rationR=σ(e + e ?→hadrons)/σ(e + e ?→ µ+ µ?) was measured with the LENA detector at DORIS in a scan between 7.40 and 7.48 GeV and between 8.67 and 9.43 GeV center of mass energies. Corrected for QED radiative effects,R is found to be constant with an average value ofR=3.37 ±0.06stat±0.23syst. No narrow resonances withΓ ee (Γ had/Γ tot)?0.30 keV (95% C.L.) and no steps have been observed. Based on this value ofR, revised values for υ(1S) resonance parameters are presented. 相似文献
7.
J.D. Dowell J. Garvey M. Jobes I.R. Kenyon J. Mawson T. McMahon I.F. Corbett S. Dagan R.J. Esterling M.R. Jane N.H. Lipman P.J. Litchfield K.C.T.O. Sumorok G. Alexander I. Bar-Nir Y. Gnat J. Grunhaus E.H. Bellamy D.H. Thomas 《Nuclear Physics B》1976,108(1):30-44
The reaction π?p → ωn has been studied at 8 and 12 GeV/c incident momenta with the CERN Omega spectrometer using a neutron time of flight trigger. The differential cross sections and the ω-decay density matrix elements are presented as functions of the momentum transfer squared ?t in the range of 0.02 to 0.80 GeV2. The data are used to evaluate the intercept and slope of both the natural and unnatural parity exchange trajectories. Regge exchange amplitude factorisation tests involving the reaction πN → ωN are investigated. 相似文献
8.
Brick DH Widgoff M Beilliere P Lutz P Narjoux JL Gelfand N Alyea ED Bloomer M Bober J Busza W Cole B Frank TA Fuess TA Grodzins L Hafen ES Haridas P Huang D Huang HZ Hulsizer R Kistiakowsky V Ledoux RJ Milstene C Noguchi S Oh SH Pless IA Steadman S Stoughton TB Suchorebrow V Tether S Trepagnier PC Wadsworth BF Wu Y Yamamoto RK Cohn HO Calligarich E Corti G Dolfini R Gianini G Introzzi G Ratti S Badiak M DiMarco R Jacques PF Kalelkar M Plano RJ Stamer PE Brucker EB Koller EL Alexander G 《Physical review D: Particles and fields》1992,45(3):734-742
9.
B. Niczyporuk T. Zeludziewicz K. W. Chen R. Hartung G. Folger B. Lurz H. Vogel U. Volland H. Wegener J. K. Bienlein R. Graumann J. Krüger M. Leißner M. Schmitz F. H. Heimlich R. Nernst A. Schwarz U. Strohbusch H. -J. Trost P. Zschorsch A. Engler R. W. Kraemer F. Messing C. Rippich B. Stacey S. Youssef A. Fridman G. Alexander A. Av-Shalom G. Bella Y. Gnat J. Grunhaus E. Hörber W. Langguth M. Scheer LENA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1981,9(1):1-8
Charged hadron production ine + e ? annihilation is studied in the 7 to 10 GeV CM energy region and at the Υ (9.46) and Υ′ (10.01) resonances with the LENA detector at DORIS. The statistical moments of the charged multiplicities are studied. The data show KNO scaling behaviour and suggest the presence of long range correlations. An average charged multiplicityrise of Δn(Υ)=0.55±0.19 and Δn(Υ′)=1.26±0.29 over the continuum is observed for the Υ and Υ′ direct decays. The jet structure of the Υ and Υ′ direct decays is investigated using the charged particles. The polar angular distributions of the jet axis behave like 1+α(T) cos2θ with 〈α(T)〉Υ=0.7±0.3 and 〈α(T)〉Υ′=0.6±0.4. The 〈α(T)〉Υ value is in agreement with the QCD vector gluon assignment and excludes scalar gluons by more than four standard deviations. 相似文献
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S. Toaff S. Dado J. Goldberg L. Berny G. Alexander O. Benary J. Grunhaus S. Dagan A. Levy D. Lissauer Y. Oren Y. Eisenberg B. Haber U. Karshon D. Revel E.E. Ronat R. Yaari G. Yekutieli 《Nuclear Physics B》1978,146(2):368-380
Cross sections for various channels in 3 prong + V0 final states of K?n interactions are obtained at 8.25 GeV/c. An energy dependence study of the quasi two-body reactions Σ?(1385) + vector meson and ΛB? seem to imply the presence of cuts in the Regge exchange formalism, whereas the reaction Δ(1236) 1 (890) does not require such cuts. Upper limits of 1 and 2 μb are found for the reactions K?n → ΛA1 and K?n → ΛA2. 相似文献