Pion inelastic scattering to the first three excited states of lithium-6

Technical Report · Mon Oct 01 04:00:00 EDT 1984

OSTI ID:6246982

Kiziah, R R

Using the Energetic Pion Channel and Spectrometer system at the Clinton P. Anderson Meson Physics Facility, differential cross sections were measured for ..pi../sup +/ inelastic scattering to the 3/sup +/, T=0, 2.185-MeV, 0/sup +/, T=1, 3.563-MeV, and 2/sup +/, T=0, 4.25-MeV states of /sup 6/Li at incident pion energies of 120 and 180 MeV and laboratory scattering angles between 15/sup 0/ and 47/sup 0/. Excitation functions were measured at a constant momentum transfer of approximately 109 MeV/c for incident pion energies from 100 to 260 MeV. The constant momentum transfer corresponds to the maxima of the angular distributions for ..pi../sup +/ inelastic scattering to the 3.563-MeV level. Microscopic calculations using the distorted-wave impulse approximation (DWIA) agree well with the measured angular distributions and excitation functions for the 2.185- and 4.25-MeV levels. However, microscopic DWIA calculations do not adequately reproduce the measured angular distributions for the 3.563-MeV level and fail to reproduce the observed anomalous excitation function. The shape of the 3.563-MeV excitation function is similar to that previously observed for ..pi../sup + -/ inelastic scattering to the 1/sup +/, T=1, 15.11-MeV state of /sup 12/C. The same mechanism may be responsible for the observed excitation functions of both ..delta..S=..delta..T=1 transitions. A possible mechanism is the direct excitation of ..delta.. particle-nucleon hole (..delta..-h) components in the final state wave functions. Within the ..delta..-h model interpretation, the peak of the 3.563-MeV excitation function is reproduced with an estimated probability amplitude for the ..delta..-h component of the 3.563-MeV state with respect to the ground state of 0.01 less than or equal to ..beta.. less than or equal to 0.13, a range of values of ..beta.. consistent with the range estimated for the 15.11-MeV level of /sup 12/C (0.026 less than or equal to ..beta.. less than or equal to 0.096).

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6246982
• Report Number(s): LA-10257-T; ON: DE85005319
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALKALI METAL ISOTOPES
ANGULAR DISTRIBUTION
BARYON RESONANCES
BARYONS
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA
DELTA-1236 RESONANCES
DIFFERENTIAL CROSS SECTIONS
DISTORTED WAVE THEORY
DISTRIBUTION
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
EXCITATION FUNCTIONS
EXPERIMENTAL DATA
FERMIONS
FUNCTIONS
HADRON REACTIONS
HADRONS
IMPULSE APPROXIMATION
INELASTIC SCATTERING
INFORMATION
ISOTOPES
LIGHT NUCLEI
LITHIUM 6
LITHIUM 6 TARGET
LITHIUM ISOTOPES
MESON REACTIONS
MEV RANGE
MEV RANGE 100-1000
N RESONANCES
NUCLEAR REACTIONS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
PION PLUS REACTIONS
PION REACTIONS
RESONANCE PARTICLES
SCATTERING
STABLE ISOTOPES
TARGETS
THEORETICAL DATA