Inclusive pion double charge exchange in /sup 4/He at intermediate energies

Technical Report · Sat Oct 01 04:00:00 EDT 1988

OSTI ID:6796933

Kinney, E R

A systematic experimental study of inclusive pion double charge exchange in /sup 4/He has been undertaken. The reaction /sup 4/He(..pi../sup +/,..pi../sup /minus//4p was observed at incident energies 120, 150, 180, 210, 240, and 270 MeV; the /sup 4/He(..pi../sup /minus//,..pi../sup +/)4n reaction was observed only at incident energies 180 and 240 MeV. At each incident energy, the doubly differential cross section was measured at three to five angles between 25/degree/ and 130/degree/ over the entire range of outgoing pion energies from 10 MeV up to the kinematic limit for the reaction in which the final state consists of the oppositely charged pion plus four free nucleons. The spectra of outgoing pions are strikingly different from those observed for the inclusive double charge exchange reaction in heavier nuclei. The forward-angle spectra from both the reactions in /sup 4/He exhibit a prominent peak at high outgoing pion energies. Interpretation of the peak as a four-nucleon resonance is ruled out by kinematic analysis. The results of a calculation, wherein the double charge exchange reaction is assumed to consist of two sequential single charge exchange interactions, are also presented and suggest that the high energy peak is naturally explained by this double scattering reaction mechanism. In spite of the qualitative success of the calculation, the double charge exchange reaction and its relation to other pion-nucleus processes is still not quantitatively understood. A large set of non-charge exchange and double charge exchange data with small relative uncertainty is now available for comparison to theoretical predictions. 152 refs., 123 figs., 11 tabs.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6796933
• Report Number(s): LA-11417-T; ON: TI89001457
• Country of Publication: United States
• Language: English

Related Subjects

651220* -- Nuclear Properties & Reactions
A=1-5
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
CHARGE EXCHANGE
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA ACQUISITION SYSTEMS
DATA ANALYSIS
DIFFERENTIAL CROSS SECTIONS
DISTRIBUTION
ELASTIC SCATTERING
ENERGY SPECTRA
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
HELIUM 4 TARGET
INTERACTIONS
MATHEMATICAL SPACE
MESON REACTIONS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
NUCLEAR REACTIONS
PARTICLE INTERACTIONS
PHASE SPACE
PION REACTIONS
PION-NUCLEON INTERACTIONS
SCATTERING
SPACE
SPECTRA
TARGETS