New N'(1720)3/2$^+$ resonance from combined studies of $\pi^+\pi^-p$ photo-/electroproduction
ORAL
Abstract
Observation of a new N’(1720)3/2$^+$ baryon state from combined analysis of the CLAS $\pi^+\pi^-p$ photo- and electroproduction data in the resonance region will be presented. This new resonance was discovered, in addition to several ``missing” resonances already observed and included in the PDG, from a global multi-channel analysis of exclusive meson photoproduction channels with decisive impact from the CLAS K$^+$Y data. Contributions from both the N(1720)3/2$^+$ PDG state of mass 1.74 GeV and the new N’(1720)3/2$^+$ state of mass 1.72 GeV, which have different decay widths to the $\pi\Delta$ and $\rho p$ final states, are needed in order to describe the $\pi^+\pi^-p$ photo- and electroproduction data with Q$^2$-independent resonance masses, total and partial hadronic decay widths of the new N’(1720)3/2$^+$ state, and all well-established resonances in the third resonance region. This provides strong evidence for the existence of the new N’(1720)3/2$^+$ resonance. The results on the Q$^2$ evolution of the resonance electroexcitation amplitudes of the N’(1720)3/2$^+$ have become available, offering insight into the structure of this new resonance for the first time.
–
Authors
-
Victor Mokeev
JLab, Thomas Jefferson National Accelerator Laboratory, Newport News, VA 23606, Jefferson Lab, Thomas Jefferson National Accelerator Facility