Quantum Monte Carlo Calculations of Pion Inelastic Scattering

We show that the neutron and proton transition densities predicted by recent quantum Monte Carlo calculations for light nuclei are consistent with pion inelastic scattering. This provides a microscopic understanding of the enhancement factors for quadrople excitations, which were needed to describe pion inelastic scattering within the nuclear shell model of Cohen and Kurath. PACS numbers: 21.60.Ka, 25.80.Ek Typeset using REVTEX 1 Quantum Monte Carlo (QMC) methods have been successfully developed to predict the properties of low-lying states of light nuclei starting with realistic twoand three-nucleon potentials [1]. While the reproduction of the energy spectra is the essential first step in such an effort, the dynamical content of the resulting nuclear wave functions must be tested against various reactions. This has been achieved so far mainly by considering electroweak processes [2,3]. In this paper we report on an additional test by using pion inelastic scattering. Let us first briefly review the status of our understanding of pion inelastic scattering at medium energies( 120 MeV < Elab < 300 MeV). Because of the excitation of the ∆ resonance, the pion-nucleus interactions in this energy region are dominanted by the strong absorption mechanism. Consequently, the pion-nucleus inelastic scattering leading to discrete final nuclear states can be described by the distorted wave impulse approximation (DWIA). This has been well established [4–13] in very extensive investigations of the data from meson factories. Following the momentum-space approach [7], the inelastic scattering amplitude can be written as Tfi(~k ′ 0, ~k0) = ∫