# Helicity Amplitudes of the Lambda1670 and two Lambda1405 as dynamically generated resonances - Nuclear Theory

Helicity Amplitudes of the Lambda1670 and two Lambda1405 as dynamically generated resonances - Nuclear Theory - Download this document for free, or read online. Document in PDF available to download.

Abstract: We determine the helicity amplitudes A 1-2 and radiative decay widths in thetransition Lambda1670 to gamma Y Y=Lambda or Sigma^0. The Lambda1670 istreated as a dynamically generated resonance in meson-baryon chiral dynamics.We obtain the radiative decay widths of the Lambda1670 to gamma Lambda as 3\pm 2 keV and to gamma Sigma^0 as 120 \pm 50 keV. Also, the Q^2 dependence ofthe helicity amplitudes A 1-2 is calculated. We find that the K Xi component inthe Lambda1670 structure, mainly responsible for the dynamical generation ofthis resonance, is also responsible for the significant suppression of thedecay ratio Gamma {gamma Lambda}-Gamma {gamma Sigma^0}. A measurement of theratio would, thus, provide direct access to the nature of the Lambda1670. Tocompare the result for the Lambda1670, we calculate the helicity amplitudesA 1-2 for the two states of the Lambda1405. Also, the analytic continuationof Feynman parameterized integrals of more complicated loop amplitudes to thecomplex plane is developed which allows for an internally consistent evaluationof A 1-2.

Author: ** M. Doring, D. Jido, E. Oset**

Source: https://arxiv.org/