Comparison of 20 exclusive reactions at large [ital t]

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.49.58· OSTI ID:5340110

White, C; Appel, R; Barton, D S; Bunce, G; Carroll, A S; Courant, H; Fang, G; Gushue, S; Heller, K J; Heppelmann, S; Johns, K; Kmit, M; Lowenstein, D I; Ma, X; Makdisi, Y I; Marshak, M L; Russell, J J; Shupe, M ^[1]

---

1. Brookhaven National Laboratory, Upton, New York, 11973 (United States) Pennsylvania State University, University Park, Pennsylvania 16802 (United States) University of Massachusetts, Dartmouth, N. Dartmouth, Massachusetts 02747 (United States) University of Minnesota, Minneapolis, Minnesota 55455 New York University, Neww York, New York 10003 (United States)

We report a study of 20 exclusive reactions measured at the AGS at 5.9 GeV/[ital c] incident momentum, 90[degree] center of mass. This experiment confirms the strong quark flow dependence of two-body hadron-hadron scattering at large angle. At 9.9 GeV/[ital c] an upper limit had been set for the ratio of cross sections for ([ital [bar p]p][r arrow][ital [bar p]p])/([ital pp][r arrow][ital pp]) at 90[degree] c.m. with the ratio less than 4%. The present experiment was performed at lower energy to gain sensitivity, but was still within the fixed angle scaling region. A ratio [ital R]([ital [bar p]p]/[ital pp])[approx]1/40 was measured at 5.9 GeV/[ital c], 90[degree] c.m. in comparison to a ratio near 1.7 for small angle scattering. In addition, many other reactions were measured, often for the first time at 90[degree] c.m. in the scaling region, using beams of [pi][sup [plus minus]], [ital K][sup [plus minus]], [ital p] and [ital [bar p]] on a hydrogen target. There are similar large differences in cross sections for other reactions: [ital R]([ital K][sup [minus]][ital p][r arrow][pi][sup +][Sigma][sup [minus]]/[ital K][sup [minus]][ital p][r arrow][pi][sup [minus]][Sigma][sup +])[approx]1/12, for example. The relative magnitudes of the different cross sections are consistent with the dominance of quark interchange in these 90[degree] reactions, and indicate that pure gluon exchange and quark-antiquark annihilation diagrams are much less important. The angular dependence of several elastic cross sections and the energy dependence at a fixed angle of many of the reactions are also presented.

• OSTI ID: 5340110
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 49:1; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

662340* -- Hadron Interactions-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CROSS SECTIONS
ELASTIC SCATTERING
ENERGY DEPENDENCE
EXCLUSIVE INTERACTIONS
HADRON-HADRON INTERACTIONS
IMPACT PARAMETER
INELASTIC SCATTERING
INTERACTIONS
MANY-BODY PROBLEM
MOMENTUM TRANSFER
PARTICLE INTERACTIONS
QUARK-ANTIQUARK INTERACTIONS
SCATTERING
TWO-BODY PROBLEM