Spin Dependence of High-P⊥2 Elastic p-p Scattering
Abstract
We measured dσdt for p↑+p↑-->p+p from P⊥2=4.50 to 5.09 (GeV/c)2 at 11.75 GeV/c. We used a 59%-polarized proton beam and a 71%-polarized proton target with both spins oriented perpendicular to the scattering plane. In these large-P⊥2 hard-scattering events, spin effects are very large and the ratio (dσdt)↑↑:(dσdt)↑↓ grows rapidly with increasing P⊥2, reaching a value of 4 at 90° (c.m.). Thus, hard elastic scattering, which is presumably due to the direct scattering of the protons' constituents, may only occur when the two incident protons' spins are parallel.
- Publication:
-
Physical Review Letters
- Pub Date:
- November 1978
- DOI:
- 10.1103/PhysRevLett.41.1257
- Bibcode:
- 1978PhRvL..41.1257C