BACKWARD K~;;p ELASTIC SCATTERING AND 0 PRODUCTION

Conference · Tue Aug 01 04:00:00 EDT 1978

OSTI ID:1014060

Alston-Garnjost, M; Hamilton, R; Kenny, R; Nicholson, H; Lazarus, D; Pollard, D; Tripp, R

A high precision measurement of the momentum dependence of backward {sup -}p elastic scattering from 476 to 1077 MeV/c incident momentum has been performed at the Brookhaven National Laboratory Alternating Gradient Synchrotron. With the same apparatus they have also measured the 0{sup o} production of pions in the reaction K{sup -}p {yields} {Sigma}{sup -}{pi}{sup +}. The forward and backward angular distributions decomposed into partial waves are particularly simple since the Legendre polynomials are either {+-}1, and the spin-flip amplitude is absent. The forward elastic cross section is well determined through the total cross section using the optical theorem and dispersion relations. The backward elastic cross section has been found by bubble chamber experiments to quite small, generally an order of magnitude smaller than the forward cross section. This is easily understood; the many absorption channels present make the amplitudes largely imaginary so that even and odd parity states cancel in their contributions to backward scattering. For this reason a small resonant amplitude will be expected to reveal itself most prominently in the backward direction. If a resonance has too small an elasticity to be seen in the elastic channel, but has a large branching fraction into {Sigma}{pi} then it should be observed at 0{sup o} in this reaction.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Physics Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1014060
• Report Number(s): LBL-7985
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
ABSORPTION
AMPLITUDES
ANGULAR DISTRIBUTION
BNL
BUBBLE CHAMBERS
CROSS SECTIONS
DISPERSION RELATIONS
ELASTIC SCATTERING
ELASTICITY
HIGH ENERGY PHYSICS
LEGENDRE POLYNOMIALS
MESONS
OPTICAL THEOREM
PARITY
PARTIAL WAVES
PIONS
SCATTERING
SPIN FLIP
TOTAL CROSS SECTIONS