OBSERVATION OF A NEW ETA-PI0-PI-0 RESONANCE AT 1900 MEV/C2 IN 2-PHOTON SCATTERING

被引：11

作者：

KARCH, K

机构：

[1] Deutsches Elektronen Synchrotron DESY

[2] Harvard University5 5 Supported by the US Department of Energy, Cambridge, MA 02138

[3] Princeton University6 6 Supported by the US Department of Energy, contract No. DE-AC02-76ER03072 and by the National Science Foundation, Princeton, NJ 08544

[4] Universität Hamburg, I. Inst. fur Experimentalphysik7 7 Supported by the German Bundesministerium fur Forsch. und Technol, contract No. 054 HH 11P(7) and by the Deutsche Forschungsgemeinschaft.

[5] INFN, University of Firenze

[6] Department of Physics8 8 Supported by the US Department of Energy, contract No. DE-AC03-76SF00326 and by the National Science Foundation, grant No. PHY81-07396., HEPL, and Stanford Linear Accelerator Center9 9 Supported by the US Department of Energy, cont

[7] Carnegie-Mellon University10 10 Supported by the US Department of Energy, Pittsburgh, PA 15213

[8] University of California, Santa Cruz11 11 Supported by the National Science Foundation, Santa Cruz, CA 95064

[9] Universitat Erlangen-Nurnberg12 12 Supported by the German Bundesministerium fur Forsch. und Technol, D-8520 Erlangen

[10] University of Nijmegen and NIKHEF13 13 Supported by FOM-NWO.

[11] Universitat Wurzburg14 14 Supported by the German Bundesministerium fur Forschung und Technologie, D-8700 Würzburg

[12] Cracow Institute of Nuclear Physics

[13] California Institute, Technology15 15 Supported by the US Department of Energy, contract No. DE-AC03-81ER40050 and by the National Science Foundation, Pasadena, CA 91125

来源：

PHYSICS LETTERS B | 1990年 / 249卷 / 02期

关键词：

D O I：

10.1016/0370-2693(90)91268-G

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Using the Crystal Ball detector at the DORIS II e+e- storage ring, we measure the ηπ0π0 mass spectrum in the reaction e+e-→e+e-ηπ 0π0→e+e-6γ from the ηπ0π0 threshold to about 2500 MeV/c2. The spectrum is dominated by the η′, for which we determine Γγγ(η′)BR(η'→6γ)=0 .36±0.02±0.03 keV. In addition, we observe an enhancement in the cross section near 1900 MeV/c2 which we attribute to the two-photon production of a new resonance X(1900). The angular distributions and the invariant mass distribution of the ηπ0 subsystem are consistent with those expected for the hypothetical η2 meson with JPC=2-+. For this JP assignment the resonance parameters are M(X) = 1876 ±35±50 MeV/c2, Γtot(X)=228±90±34 MeV/c2 and Γγγ(X)BR(X→ηππ) = 0.9±0.2±0.3 keV. © 1990.

引用

页码：353 / 358

页数：6

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