Scattering of 22-Mev Positive Pions by Protons
Abstract
The differential cross section for the reaction π++p-->π++p was measured in the angular interval 45° to 135° in the center-of-mass system at a pion energy of 21.5+/-3.5 Mev in the laboratory system. The pion beam was formed by a magnetic-focusing selection of pions produced from polyethylene at an angle of 0° in the reaction p+p-->π++d. The production target was placed in the strong-focused 340-Mev proton beam electrostatically deflected from the Berkeley synchrocyclotron. The pion beam entered liquid hydrogen contained in a Styrofoam scattering target at 25.0 Mev, with an energy spread of +/-0.6 Mev, and left at 18.0 Mev. Scattered pions were detected in an emulsion stack placed 1 inch from the beam edge and 78 inch from the liquid hydrogen. The data, consisting of 41 acceptable events, were analyzed by a maximum-likelihood method to obtain the following best values for the pion-proton scattering phase shifts at a relative momentum, η=0.49:α3=-0.048+/-0.007, α33=+0.013+/-0.013, α31=0.000+/-0.016.
- Publication:
-
Physical Review
- Pub Date:
- April 1956
- DOI:
- 10.1103/PhysRev.102.251
- Bibcode:
- 1956PhRv..102..251W