Measurement of the pp. -->. pi. d spin correlation parameters A/sub SL/ and A/sub LL/ at energies between 500 and 800 MeV

Technical Report · Thu Nov 01 04:00:00 EST 1984

DOI:https://doi.org/10.2172/6211132· OSTI ID:6211132

Barlow, D B

Angular distributions of the spin correlation parameters A/sub SL/ and A/sub LL/ for the inelastic reaction pp..--> pi..d have been measured at pion center-of-mass angles between 40 and 130/sup 0/, at energies of 500, 650, and 800 MeV. Additional measurements of A/sub LL/(THETA) were made at 600, 700, and 750 MeV. The reaction was studied using an incident beam of either longitudinally polarized protons. Both the final state pion and deuteron were detected in a two-armed detector system. The momenta of particles detected in the deuteron arm were analyzed with a magnetic spectrometer which allowed the deuterons to be distinguished from particles produced by quasi-free, three-body, or other background reactions. A/sub SL/ was found to be negative (approx. = -0.5) at 500 MeV. It became increasingly more negative as energy increased, going down to as low as -0.88 at forward angles at 800 MeV. A/sub SL/ showed only a slight angular dependence in the entire energy range. The angular distribution of A/sub LL/ was found to be almost flat at 500 (approx. = -0.5) and 600 MeV (approx. = -0.4). As energy increased A/sub LL/ became less negative and began to peak at theta/sub cm/ = 90/sup 0/. At 800 MeV A/sub LL/ was positive at almost all measured angles and had a well defined peak at theta/sub cm/ = 90/sup 0/ which reached a maximum of about +0.4. The data were compared to several partial wave analyses and to theoretical calculations based on unified theories of NN..-->..NN, ..pi..d..--> pi..d, and NN..--> pi..d reactions. In general these later calculations were found to be unsuccessful in fitting our data. Partial wave analyses, which included the present data, fitted the data reasonably well and did not indicate the need for any unusual (dibaryon like) structures in any of the partial waves. 52 references.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6211132
• Report Number(s): LA-10289-T; ON: DE85005314
• Country of Publication: United States
• Language: English

Related Subjects

651225* -- Nuclear Properties & Reactions
A=1-5
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
BARYON REACTIONS
BARYON RESONANCES
BARYON-BARYON INTERACTIONS
BARYONS
BEAMS
BOSONS
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
DATA
DEUTERONS
DIBARYON RESONANCES
DISTRIBUTION
ELEMENTARY PARTICLES
ENERGY DEPENDENCE
ENERGY RANGE
EXPERIMENTAL DATA
FERMIONS
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
HADRONS
HYDROGEN 1 TARGET
INFORMATION
INTERACTIONS
MESONS
MEV RANGE
MEV RANGE 100-1000
MULTIPLE PRODUCTION
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEON-NUCLEON INTERACTIONS
NUMERICAL DATA
PARTIAL WAVES
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PIONIZATION
PIONS
POLARIZATION-ASYMMETRY RATIO
POLARIZED BEAMS
POLARIZED TARGETS
PROTON REACTIONS
PROTON-NUCLEON INTERACTIONS
PROTON-PROTON INTERACTIONS
PSEUDOSCALAR MESONS
RESONANCE PARTICLES
TARGETS