Evidence for the $N^{\prime }(1720)3/2^{+}$ Nucleon Resonance from Combined Studies of CLAS ${\pi }^{+}{\pi }^{-}p$ Photo- and Electroproduction Data

Abstract

The analysis of the nine 1-fold differential cross sections for the ${\gamma }_{r,v}p\to {\pi }^{+}{\pi }^{-}p$ photo- and electroproduction reactions obtained with the CLAS detector at Jefferson Laboratory was carried out with the goal to establish the contributing resonances in the mass range from 1.6~GeV to 1.8~GeV. In order to describe the photo- and electroproduction data with $Q^2$-independent resonance masses and hadronic decay widths in the $Q^2$ range below 1.5~GeV${}^2$, it was found that an $N^{\prime }(1720)3/2^{+}$ state is required in addition to the already well-established nucleon resonances. This work demonstrates that the combined studies of ${\pi }^{+}{\pi }^{-}p$ photo- and electroproduction data are vital for the observation of this resonance. The contributions from the $N^{\prime }(1720)3/2^{+}$ state and the already established $N(1720)3/2^{+}$ state with a mass of 1.745~GeV are well separated by their different hadronic decays to the $\pi \Delta$ and $\rho p$ final states and the different $Q^2$-evolution of their photo-/electroexcitation amplitudes. The $N^{\prime }(1720)3/2^{+}$ state is the first recently established baryon resonance for which the results on the $Q^2$-evolution of the photo-/electrocouplings have become available. These results are important for the exploration of the nature of the ``missing'' baryon resonances.

arXiv commentaccepted for publication in Phys. Lett. B

References in corpus (24)

• Differential Cross Sections for gamma + p --> K+ + Y for Lambda and Sigma0 Hyperons
• Progress Toward Understanding Baryon Resonances
• Nucleon resonances within a dynamical coupled-channels model of pi N and gamma N reactions
• Additional Strange Hadrons from QCD Thermodynamics and Strangeness Freeze-out in Heavy Ion Collisions
• Electroexcitation of nucleon resonances
• Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab
• First Measurement of Beam-Recoil Observables Cx and Cz in Hyperon Photoproduction
• A study of the $P_{11}(1440)$ and $D_{13}(1520)$ resonances from CLAS data on $ep\to e^{\prime }{\pi }^{+}{\pi }^{-}{p}^{\prime }$
• Hybrid Baryons in QCD
• Measurement of $ep\to e^{{}^{\prime }}p{\pi }^{+}{\pi }^{-}$ and baryon resonance analysis
• Masses of ground and excited-state hadrons
• Strange and nonstrange baryon spectra in the relativistic interacting quark-diquark model with a Gürsey and Radicati-inspired exchange interaction
• New Results from the Studies of the $N(1440)1/2^{+}$, $N(1520)3/2^{-}$, and $\Delta (1620)1/2^{-}$ Resonances in Exclusive $ep\to e^{\prime }{p}^{\prime }{\pi }^{+}{\pi }^{-}$ Electroproduction with the CLAS Detector
• Differential cross sections and recoil polarizations for the reaction gamma p -> K+ Sigma0
• Model Analysis of the $ep\to e{p}^{\prime }{\pi }^{+}{\pi }^{-}$ Electroproduction Reaction on the Proton
• Photoproduction Reactions and Non-Strange Baryon Spectroscopy
• Strong evidence for nucleon resonances near 1900\,MeV
• Measurements of $ep\to e^{\prime }{\pi }^{+}{\pi }^{-}{p}^{\prime }$ Cross Sections with CLAS at $1.40<W<2.0$ GeV and $2.0<Q^2<5.0$ GeV${}^2$
• First results on nucleon resonance photocouplings from the $\gamma p\to {\pi }^{+}{\pi }^{-}p$ reaction
• Nucleon resonance contributions to unpolarised inclusive electron scattering
• Spectrum and structure of octet and decuplet baryons and their positive-parity excitations
• Recent results on the nucleon resonance spectrum and structure from the CLAS detector
• Measurements of the ${\gamma }_{v}p\to p^{\prime }{\pi }^{+}{\pi }^{-}$ cross section with the CLAS detector for $0.4$ GeV${}^2$ $<Q^2<$ $1.0$ GeV${}^2$ and $1.3$ GeV $<W<$ $1.825$ GeV
• Nucleon Resonance Physics

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• Electromagnetic Transition Form Factors of Baryon Resonances
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• Nucleon resonances with higher spins in soft-wall AdS/QCD
• Coupled-channel analysis of pion- and eta-electroproduction with the Jülich-Bonn-Washington model
• Resonant contributions to inclusive nucleon structure functions from exclusive meson electroproduction data
• Beam-Recoil Transferred Polarization in $K^{+}Y$ Electroproduction in the Nucleon Resonance Region with CLAS12
• $\Lambda$ and $\Sigma$ Excitations and the Quark Model
• Differential cross sections for Λ(1520) using photoproduction at CLAS
• Resonant contributions to polarized proton structure functions
• Polarized proton structure in the resonance region