Observation of a structure in the $$M_{p\eta }$$ invariant mass distribution near 1700 $$\hbox {MeV}/\hbox {c}^2$$ in the $$\gamma \mathbf {p \rightarrow p \pi ^0 \eta } $$ reaction

  title={Observation of a structure in the \$\$M\_\{p\eta \}\$\$ invariant mass distribution near 1700 \$\$\hbox \{MeV\}/\hbox \{c\}^2\$\$ in the \$\$\gamma \mathbf \{p \rightarrow p \pi ^0 \eta \} \$\$ reaction},
  author={V. Metag and M. Nanova and J. L. Hartmann and Ph. Mahlberg and F. Afzal and Clara Bartels and D. E. Bayadilov and Richard A. Beck and Mathias Becker and Eva Blanke and K-Th. Brinkmann and S. Ciupka and Volker Crede and Manuel Dieterle and H. Dutz and Daniel Elsner and Frank Frommberger and Anatoly Gridnev and Manuela Gottschall and M. Gruner and Christian Hammann and J{\"u}rgen Hannappel and Wolfgang Hillert and Jens Hoff and Ph. Hoffmeister and Ch. Honisch and Thomas Jude and Hartmut Kalinowsky and Felix Kalischewski and Irakli Keshelashvili and B. Ketzer and P. Klassen and Frank Klein and Karsten Koop and P. Kroenert and B. Krusche and M. Lang and I. I. Lopatin and F. Messi and W. Meyer and B. Mitlas'oczky and Jonas Muller and J. Mullers and V. A. Nikonov and V. Novinsky and Radek Novotny and Daniela Piontek and Gerhard Reicherz and Laura Richter and Tigran Rostomyan and Stefan Runkel and B. Salisbury and Andrey V. Sarantsev and Dimitri Schaab and Ch. Schmidt and Hartmut Schmieden and Joachim Schultes and Tobias Seifen and Vahe Sokhoyan and Claudia Sowa and Kathrin Spieker and Niklas Stausberg and Annika Thiel and Ulrike Thoma and T. Triffterer and Marcel Urban and G. Urff and H. van Pee and Marc Wagner and Dirk Walther and Ch. Wendel and Dominik Werthmuller and U. Wiedner and A. S. Wilson and A. Winnebeck and Lilian Witthauer and Y. Wunderlich},
  journal={The European Physical Journal A},
The reaction γp → pπη has been studied with the CBELSA/TAPS detector at the electron stretcher accelerator ELSA in Bonn for incident photon energies from threshold up to 3.1 GeV. This paper has been motivated by the recently claimed observation of a narrow structure in the MNη invariant mass distribution at a mass of 1678 MeV. The existence of this structure cannot be confirmed in the present work. Instead, for Eγ = 1400 1500 MeV and the cut Mpπ0 ≤ 1190 MeV a statistically significant structure… 


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