Experimental study of the $$P_{11}(1440)$$ and $$D_{13}(1520)$$ resonances from $$\mathrm{CLAS}$$ data on $$ep \rightarrow e'π^{+} π^{-} p'$$

Journal Article · Thu Sep 13 04:00:00 EDT 2012 · Phys. Rev. C

DOI:https://doi.org/10.1103/PhysRevC.86.035203· OSTI ID:1052992

Mokeev, V I; Elouadrhiri, L; Fedotov, G V; Golovatch, E N; Gothe, R W; Ishkhanov, B S; Isupov, E L

The transition helicity amplitudes from the proton ground state to the $$P_{11}(1440)$$ and $$D_{13}(1520)$$ excited states ($$\gamma_{v}pN^*$$ electrocouplings) were determined from the analysis of nine independent one-fold differential $$\pi^{+} \pi^{-} p$$ electroproduction cross sections off a proton target, taken with CLAS at photon virtualities $$0.25 < \mathrm{GeV}^2 < Q^2 < 0.60 \mathrm{GeV}^2$$. The phenomenological reaction model was employed for separation of the resonant and non-resonant contributions to the final state. The $$P_{11}(1440)$$ and $$D_{13}(1520)$$ electrocouplings were obtained from the resonant amplitudes parametrized within the framework of a unitarized Breit-Wigner ansatz. They are consistent with results obtained in the previous CLAS analyses of the $$\pi^+n$$ and $$\pi^0p$$ channels. The successful description of a large body of data in dominant meson-electroproduction channels off protons with the same $$\gamma_{v}pN^*$$ electrocouplings offers clear evidence for the reliable extraction of these fundamental quantities from meson-electroproduction data. This analysis also led to the determination of the long-awaited hadronic branching ratios for the $$D_{13}(1520)$$ decay into $$\Delta\pi$$ (24%-32%) and $$N\rho$$ (8%-17%).

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1052992
• Report Number(s): JLAB-PHY-12-1530; DOE/OR/23177-2139; arXiv:1205.3948
• Journal Information: Phys. Rev. C, Journal Name: Phys. Rev. C Journal Issue: 03 Vol. 86
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS