Evidence for the N′(1720)3/2+ nucleon resonance from combined studies of CLAS π+π−p photo- and electroproduction data

Autor: R. W. Gothe, B. S. Ishkhanov, K. Joo, D. S. Carman, Latifa Elouadrhiri, Arjun Trivedi, E. Golovatch, Eugene Pasyuk, N. Markov, V. I. Mokeev, Volker D. Burkert, K. Hicks, E. L. Isupov
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Physics Letters B, Vol 805, Iss, Pp-(2020)
Physics Letters
ISSN: 0370-2693
Popis: 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 $N'(1720)3/2^+$ 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 $N'(1720)3/2^+$ 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 $N'(1720)3/2^+$ 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.
Comment: accepted for publication in Phys. Lett. B
Databáze: OpenAIRE
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