Measurement of the doubly differential cross section for. pi. /sup -/p. -->. pi. /sup +/. pi. /sup -/n near threshold

Technical Report · Thu May 01 04:00:00 EDT 1980

DOI:https://doi.org/10.2172/5335495· OSTI ID:5335495

Walter, J B

The doubly differential cross sections for the ..pi../sup +/ from the reaction ..pi../sup -/p ..-->.. ..pi../sup +/..pi../sup -/n were measured at about twenty points for each of five energies between 245 MeV and 356 MeV. The experiment was carried out at the Clinton P. Anderson Meson Physics Facility, where a double focusing magnetic spectrometer detected the ..pi../sup +/ mesons produced in a liquid hydrogen target. The measurements were normalized by comparison with ..pi../sup -/p elastic scattering measured with the same apparatus. These are the first such measurements in this energy range, and have an accuracy between 4.7% and 39%. The integrated reaction cross section was determined at each energy with an accuracy of about 5%. These agree with but are an improvement over previous measurements in this energy range. Comparison of the extrapolated threshold value of the mean square modulus of the matrix element with the soft pion calculations favors the symmetry breaking mechanism of Weinberg (xi = 0). It also demonstrates the futility of attempting to determine the symmetry breaking parameter xi from a single measurement of the integrated reaction cross section.

• Research Organization: Los Alamos Scientific Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36; AS02-76ER02197
• OSTI ID: 5335495
• Report Number(s): LA-8377-T
• Country of Publication: United States
• Language: English

Related Subjects

645103* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Strong Interactions & Baryon & Meson Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCELERATORS
ANGULAR DISTRIBUTION
BOSONS
CROSS SECTIONS
DATA
DATA ACQUISITION
DATA FORMS
DIFFERENTIAL CROSS SECTIONS
DISTRIBUTION
ELASTIC SCATTERING
ELEMENTARY PARTICLES
ENERGY RANGE
EXPERIMENTAL DATA
GRAPHS
HADRON-HADRON INTERACTIONS
HADRONS
INFORMATION
INTERACTIONS
ISOLATED VALUES
LAMPF LINAC
LINEAR ACCELERATORS
LOW-ENERGY THEOREM
MESON FACTORIES
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
MEV RANGE
MEV RANGE 100-1000
NUMERICAL DATA
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PION-NUCLEON INTERACTIONS
PION-PROTON INTERACTIONS
PIONS
PIONS PLUS
PSEUDOSCALAR MESONS
SCATTERING
SYMMETRY BREAKING
TABLES