排序方式: 共有52条查询结果,搜索用时 31 毫秒
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T. Eichten H. Faissner F.J. Hasert S. Kabe W. Krenz J. Von Krogh J. Morfin K. Schultze G.H. Bertrand-Coremans J. Sacton W. Van Doninck P. Vilain D.C. Cundy D. Haidt M. Jaffre S. Natali P. Musset J.B.M. Pattison W.G. Scott 《Physics letters. [Part B]》1973,46(2):274-280
The v and nucleon total cross-sections have been determined as a function of energy using a sample of 2500 v and 950 event. The results are compared with predictions of scaling and charge symmetry hypotheses. 相似文献
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J. Blietschau H. Deden F.J. Hasert W. Krenz D. Lanske J. Morfin M. Pohl K. Schultze H. Schumacher H. Weerts L.C. Welch G. Bertrand-Coremans M. Dewit H. Mulkens J. Sacton W. Van Doninck D. Haidt A.G. Michette 《Nuclear Physics B》1978,133(2):205-219
About 200 and 60 candidates for electron neutrino and antineutrino interactions, respectively, have been analyzed in the heavy liquid bubble chamber Gargamelle exposed to the CERN PS neutrino beam. Evidence for scaling has been found for these interactions, with slopes of the cross sections in good agreement with those obtained for muon neutrino and antineutrino events in the same chamber. No evidence appears for oscillations of neutrinos or antineutrinos, which would induce in the present experiment an excess of electron or positron events. The corresponding limits are given as functions of the mixing parameter, for the finite mass Majorana neutrinos. The possibility of a multiplicative law for the lepton number has also been investigated. A search for isolated electron-positron pairs revealed no excess in the forward direction, in contradiction to the expectation for muonic neutrino and antineutrino decays. The corresponding limits on the c.m. half lifetimes are given. 相似文献
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W. Bartel T. Canzler D. Cords P. Dittmann R. Eichler R. Felst D. Haidt S. Kawabata H. Krehbiel B. Naroska L.H. ONeill J. Olsson P. Steffen W.L. Yen E. Elsen M. Helm A. Petersen C. Yanagisawa 《Physics letters. [Part B]》1980,91(1):142-147
Topological distributions of charged and neutral hadrons from the reaction e+e? → multihadrons are studied at √s of about 30 GeV. An excess of planar events is observed at a rate which cannot be explained by statistical fluctuations in the standard two-jet process. The planar events, mostly consisting of a slim jet on one side and a broader jet on the other, are shown actually to possess three-jet structure by demonstrating that the broader jet itself consists of two collinear jets in its own rest system. Detailed agreement between data and predictions is obtained if the process is taken into account. This strongly suggests gluon bremsstrahlung as the origin of the planar three-jet events. By comparison of the data with the qq?g-model we obtain a value for the strong coupling constant of αS(q2 = 0.17 ± 0.04. 相似文献
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W. Bartel D. Cords P. Dittmann R. Eichler R. Felst D. Haidt H. Krehbiel K. Meier B. Naroska L.H. ONeill P. Steffen H. Wenninger E. Elsen A. Petersen P. Warming G. Weber S. Bethke C. Yanagisawa 《Physics letters. [Part B]》1982,113(2):190-194
The reaction e+e- → e+e-η' has been observed in the JADE experiment at PETRA, by detecting the final state π+π-γ, resulting from the decay η' → γ?0. The cross section was measured at an average beam energy of 17.15 GeV to be σ(e+e- → e+e-η') = 2.2 ± 0.2 (stat.) ± 0.4(syst.) nb, yielding the radiative width Γη'γγ= 5.0 ± 0.5(stat.) ± 0.9 (syst.) keV. 相似文献
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W. Bartel L. Becker C. Bowdery D. Cords R. Felst D. Haidt H. Junge G. Knies H. Krehbiel P. Laurikainen R. Meinke B. Naroska J. Olsson E. Pietarinen D. Schmidt P. Steffen M. Zachara S. Yamada 《Physics letters. [Part B]》1984,146(6):437-442
The forward-backward charge asymmetry for the process hadrons has been measured using the JADE detector at PETRA. An asymmetry of (?22.8 ± 6.0 ± 2.5)% was observed at an average center of mass energy of 34.6 GeV. For comparison, an asymmetry of ?25.2% is expected on the basis of the standard Glashow-Salam-Weinberg model. 相似文献
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F.J. Hasert W. Krenz J. Von Krogh D. Lanske J. Morfin K. Schultze H. Weerts G.H.B. Coremans H. Mulkens J. Sacton W. Van Doninck D.C. Cundy D. Haidt P. Musset A. Norton J.B.M. Pattison F. Romano A. Rousset A.J. Segar 《Physics letters. [Part B]》1975,59(5):485-489
A study is presented of single πo production in neutrino and antineutrino interactions in Gargamelle filled with freon CF3Br. Limits on the neutral to charged current cross-section ratios and are found to be at 68% confidence level. 相似文献
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H. Deden F.J. Hasert W. Krenz J. Von Krogh D. Lanske J. Morfin K. Schultze H. Weerts G.H. Bertrand-Coremans J. Sacton W. Van Doninck P. Vilain D.C. Cundy D. Haidt M. Jaffre S. Natali J.B.M. Pattison W.G. Scott 《Nuclear Physics B》1975,85(2):269-288
High-energy exclusive and inclusive cross sections are discussed in terms of their dependence on the transverse-position variables (impact parameters) of incident and outgoing particles. The objective is to clarify the points of conflict and agreement of various models with each other and with intuitive ideas based on macroscopic collisions. First the impact parameter representation of states and amplitudes is reviewed. New impact parameter conservation laws and sum rules are derived from Lorentz invariance. The generalized optical theorem of Mueller is extended to give the impact parameter distribution of produced particles. Mueller-Regge behaviour is shown to imply three-dimensional limiting fragmentation in (impact parameter, rapidity)- space and a specific linear structure of the final-state particle density in the central region of this space. The predictions of weak- and strong-coupling multiperipheral models, the φ3 ladder eikonal model and the dual resonance model are presented, with emphasis on the dependence of average multiplicity on impact parameter and the dependence of mean square impact parameter on multiplicity. Special techniques for strong-coupling multiperipheral models are used to study the breakdown of the random-walk impact-parameter structure of the weak-coupling case, and to show explicitly that the average multiplicity is a decreasing function of impact parameter in the strongly coupled ABFST model. 相似文献
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