排序方式: 共有12条查询结果,搜索用时 0 毫秒
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J. -E. Augustin G. Cosme F. Couchot B. Dudelzak F. Fulda B. Grelaud G. Grosdidier B. Jean-Marie S. Jullian D. Lalanne V. Lepeltier B. Louis F. Mané C. Paulot R. Riskalla Ph. Roy F. Rumpf G. Szklarz Z. Ajaltouni A. Falvard J. Jousset B. Michel J. C. Montret R. Baldini S. Calcaterra G. Capon D. Bisello G. Busetto S. Limentani M. Nigro L. Pescara M. Posocco P. Sartori L. Stanco DM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1987,36(3):369-376
The radiative decayJ/ψ → γ π+ π? has been studied using the 8.6 millionJ/ψ produced in the DM2 experiment at the DCIe +e? storage rings at Orsay. The π+ π? mass spectrum shows a cleanf 2 (1270) signal, and the possible presence of two other states at thef 2 (1720) andf 4 (2030) masses. For thef 2 (1270), the branching ratio BR(J/ψ →γf)xBR(f→π+ π?) is measured to be (7.50±0.30±1.12)×10?4, and the spin analysis prefers theJ=2 assignment, with helicity parametersx=0.83±0.06 andy=0.01±0.06. The existence of higher mass states is discussed. 相似文献
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D. Bisello G. Busetto A. Castro M. Nigro M. Penzo L. Pescara M. Posocco P. Sartori L. Stanco Z. Ajaltouni A. Falvard J. Jousset B. Michel J. C. Montret A. Antonelli R. Baldini A. Calcaterra G. Capon M. Schioppa J. -E. Augustin G. Cosme F. Couchot B. Dudelzak F. Fulda G. Grosdidier B. Jean-Marie S. Jullian D. Lalanne V. Lepeltier F. Manè C. Paulot R. Riskalla Ph. Roy G. Szklarz DM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,39(1):13-19
Thee + e ?→K + K ? cross section has been measured from about 750 events in the energy interval \(1350 \leqq \sqrt s \leqq 2400 MeV\) with the DM2 detector at DCI. TheK ± form factor |F F ±| cannot be explained by the ρ, ω, ? and ρ′(1600). An additional resonant amplitude at 1650 MeV has to be added as suggested by a previous experiment. 相似文献
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L. Stanco 《Zeitschrift fur Physik C Particles and Fields》1989,44(2):241-246
A discussion is given of a new method to isolate supersymmetric signals. As the presence of missing mass in the supersymmetric reactions is one of the biggest problems, the principal advantage of the new method proposed is its ability to offer an estimate of the mass of the produced superpartners. The technique has been successfully applied to the HERA environment, where errors of 10% on the mass values have been obtained, even starting from very few detected events. 相似文献
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The production of heavy flavours at HERA has been investigated with a new Monte Carlo generator, which describes the heavy quark production ine–p scattering via boson-gluon fusion. The program has been developed in the framework of the HERWIG Monte Carlo and, different from the existing generator AROMA from the Lund package, takes account of the initial state radiation associated with higher order QCD corrections. The
production at HERA energies has been studied in the two different approaches. As expected, large differences for the particle and energy flows have been found. 相似文献
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D. Bisello G. Busetto A. Castro M. Nigro L. Pescara M. Posocco P. Sartori L. Stanco A. Antonelli M. E. Biagini R. Baldini A. Calcaterra M. Schioppa J. E. Augustin G. Cosme F. Couchot F. Fulda G. Grosdidier B. Jean-Marie V. Lepeltier G. Szklarz DM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,48(1):23-28
Search for baryon pairs production ine + e ? annihilation at \(\sqrt s = 2386 MeV\) is reported. The data relate to a luminosity of 161 nb?1 collected by the DM2 experiment at DCI, the Orsay colliding ring. First measurements of directe + e ? annihilation into \(\Lambda \bar \Lambda \) and ofe + e ?→ \(p\bar p\) at this energy are presented. First observation of a goode + e ?→ \(n\bar n\) candidate is reported and upper limits are given fore + e ?→ \(n\bar n, \Lambda \bar \sum ^0 + c.c.\) and \(\Sigma ^0 \bar \Sigma ^0 \) . 相似文献
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A. Antonelli R. Baldini M. E. Biagini S. Calcaterra M. Schioppa D. Bisello G. Busetto A. Castro M. Nigro L. Pescara P. Sartori L. Stanco J. E. Augustin L. Ayach G. Cosme F. Couchot F. Fulda G. Grosdidier B. Jean-Marie V. Lepeltier G. Szklarz 《Zeitschrift fur Physik C Particles and Fields》1992,56(1):15-19
The cross sections fore + e ?→π + π ? π 0 ande + e ?→ωπ + π ? have been measured in the 1.35 ≦ \(\sqrt s \) ≦2.4 GeV range from 1900 nb?1 collected by DM2 at DCI. The second process proceeds via a resonant state at ≈- 1660 MeV/c2, ≈- 280 MeV/c2 wide. The first one is larger than a VDM extrapolation from the ω-? peaks and, although does not show any clear structure, is compatible with the presence of the above resonance. 相似文献
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D. Bisello G. Busetto A. Castro M. Nigro L. Pescara P. Sartori L. Stanco A. Antonelli R. Baldini M. E. Biagini M. Schioppa J. E. Augustin A. Calcaterra G. Cosme F. Couchot F. Fulda G. Grosdidier B. Jean-Marie V. Lepeltier F. Mane G. Szklarz 《Zeitschrift fur Physik C Particles and Fields》1991,52(2):227-230
The \(e^ + e^ - \to K_s^0 K^ \pm \pi ^ \mp \) andK + K ?π0 cross sections have been measured in the energy interval \(1350 \leqq \sqrt s \leqq 2400\) with the DM2 detector at DCI. The \(K_s^0 K^ \pm \pi ^ \mp \) cross section shows the contribution of an isoscalar vector meson at ≈1650 MeV/c2 in agreement with a previous experiment. The low statisticsK + K ?π0 measurement is consistent with the above result. 相似文献