Pion-nucleus inelastic scattering: Reaction contributions and nuclear spin determinations

Journal Article · Mon Jun 01 00:00:00 EDT 1981 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.23.2661· OSTI ID:6438061

Siciliano, E R; Walker, G E

Formulas for pion-nucleus inelastic scattering are presented in a form that may suggest experiments to isolate various contributions to the reaction, including S-wave, P-wave spin and nonspin flip, and effects of nucleon Fermi motion. Adopting a form of the distorted wave impulse appoximation, we obtain an expression for inelastic cross sections that clearly separate the pion laboratory energy (E), three-momentum transfer (q), and scattering angle (theta) dependences. The result is similar to the separation of longitudinal and transverse form factors in inelastic electron scattering. By varying the energy of the incident pion, but working at fixed q, one can determine whether a given nuclear excitation has natural or unnatural parity. By working at fixed theta, and varying E and thus q, one can isolate different reaction contributions: spin, scalar, and ''convection current.'' We also discuss the potential usefulness of studying the energy dependence of angle-integrated differential cross sections at fixed energy loss. The predictions of our formulas are in good agreement with recent data on natural and unnatural parity excitations in /sup 12/C(..pi..,..pi..')/sup 12/C*. Thus, this approach may be useful in analyzing future data in which the final nuclear spin is uncertain. Future experiments with selective q, E, and theta variations to separate nuclear structure from reaction-mechanism uncertainties are suggested.

• Research Organization: Meson Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
• OSTI ID: 6438061
• Journal Information: Phys. Rev. C; (United States), Vol. 23:6
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ELECTRON REACTIONS
INELASTIC SCATTERING
PION REACTIONS
DIFFERENTIAL CROSS SECTIONS
DISTORTED WAVE THEORY
FERMI STATISTICS
FORM FACTORS
IMPULSE APPROXIMATION
MEV RANGE 100-1000
NUCLEAR STRUCTURE
P WAVES
PARITY
PHASE SHIFT
S WAVES
SPIN
ANGULAR MOMENTUM
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
ENERGY RANGE
HADRON REACTIONS
LEPTON REACTIONS
MESON REACTIONS
MEV RANGE
NUCLEAR REACTIONS
PARTIAL WAVES
PARTICLE PROPERTIES
SCATTERING
653001* - Nuclear Theory- Nuclear Structure
Moments
Spin
& Models
653003 - Nuclear Theory- Nuclear Reactions & Scattering