# 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

@article{Metag2021ObservationOA,
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},
year={2021}
}
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…

## References

SHOWING 1-10 OF 29 REFERENCES
Photoproduction of $\pi^{0}_{}$$\eta on protons and the \Delta(1700)D33 -resonance • Physics • 2009 Total and differential cross-sections for the reaction \ensuremath \gamma p\rightarrow\pi^0\eta p have been measured with the Crystal Ball/TAPS detector using the tagged photon facility at the MAMI Search for the N(1685) in \eta\pi-Photoproduction The nucleon-like member N(1685) of the speculative baryon antidecuplet denotes one possible explanation for the narrow peak-structure around W = 1.68 GeV observed in the total cross section of Photoproduction of \eta$$\pi$ pairs off nucleons and deuterons
Abstract.Quasi-free photoproduction of $\pi\eta$-pairs has been investigated from threshold up to incident photon energies of 1.4 GeV, respectively up to photon-nucleon invariant masses up to 1.9
Photoproduction of π0π0 - and π0π+ -pairs off the proton from threshold to the second resonance region
Precise total cross-sections and invariant-mass distributions have been measured for photoproduction of pion pairs off the proton producing $\ensuremath p\pi^0\pi^0$ and $\ensuremath n\pi^+\pi^0$
Progress towards understanding baryon resonances.
• Physics, Medicine
Reports on progress in physics. Physical Society
• 2013
Recent results from photo- and electroproduction experiments provide intriguing indications for new states and shed light on the structure of some of the known nucleon excitations, and an overview of theoretical approaches are given.
Triangle singularity and a possible ϕp resonance in the Λc+→π0ϕp decay
• Physics
• 2017
Abstract We study the Λ c + → π 0 ϕ p decay by considering a triangle singularity mechanism. In this mechanism, the Λ + c decays into the K ⁎ Σ ⁎ ( 1385 ) , the Σ ⁎ ( 1385 ) decays into the π 0 Σ (or
The Crystal Barrel Collaboration
The three reactions pp! … 0 … 0 … 0 , … 0 … 0 · and … 0 ·· in proton-antiproton annihilation in ∞ight at 900 MeV=c are used to search for isoscalar 0 ++ and 2 ++ mesons in the mass range 1000i 2000
Data on I-s and I-c in (gamma)over-right-arrowp -> p pi(0)pi(0) reveal cascade decays of N(1900) via N(1520)pi
Photoproduction of two neutral pions off the proton is studied using linearly polarized photons, and the polarization observables I-s and I-c are measured for the first time. These two observables
Measurement of the helicity asymmetry E for the reaction \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} \gamma p\rig
A measurement of the double-polarization observable E for the reaction \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb}
First measurement of helicity-dependent cross sections in π0η photoproduction from quasi-free nucleons
Abstract The helicity-dependent cross sections for the photoproduction of π 0 η pairs have been measured for the first time. The experiment was performed at the tagged photon facility of the Mainz