J. O. Dickey

A study of the reaction π−p → π+π−n at 100 and 175 GeV/c

Abstract The reaction π−p → π+π−n was studied at 100 and 175 GeV/c incident beam momenta. The ϱ0 region cross section was 0.934 μb at 100 GeV/c and 0.229 μb at 175 GeV/c. Spherical harmonic moments in the Gottfried-Jackson frame are presented as a function of mass and proton-neutron four-momentum transfer. The pion Regge trajectory is calculated. Decay distributions are presented for the ϱ in the helicity and Gottfried-Jackson frames. The apparatus and analysis are discussed.

D and E mesons and possible KKK enhancements

Results are presented from the study of multikaon final states in the reactions r−p→K0K±r∓X, K0K+KX at 50 and 100 GeV/c. Here X is semi‐inclusive, because a specific forward topology and an interaction registering in the counters sourrounding the target are required. The D(1285) meson is seen in the dr mode, while the E(1420) meson is observed in both the dr and the KK modes. In addition, there are two possible enhancements in the three kaon final state. The first (M∠1840 MeV) is associated with the K0f mode and is consistent with being the charmed D0. The second, a K state (M = 2003±14 MeV, G = 87±43 MeV), decays into KA2.

Study of K * − ( 890 ) and K * − ( 1430 ) production in the reaction K − p → K ¯ 0 π − p at 100 and 175 GeV/ c

The reaction K/sup -/p..-->..K/sup 0/..pi../sup -/p has been studied at 100 and 175 GeV/c and the reaction ..pi../sup -/p..-->..K/sup 0/K/sup -/p at 50, 100, and 175 GeV/c. Both reactions are dominated by production of resonances, K((890), K((1430) and A/sub 2/(1320), A/sub 2/(2040), respectively. Production cross sections, t distributions, and decay-angular distributions are studied. Isoscalar natural-parity exchange is dominant. The energy dependence of the K( and A/sub 2/ resonance production between 10 and 175 GeV/c is well described by a Regge-pole model. Our data on A/sub 2/ corrects that in an earlier paper.

Study of K/sup -/(890) and K/sup -/(1430) production in the reaction K/sup -/p. -->. K/sup 0/. pi. /sup -/p at 100 and 175 GeV/c

The reaction K/sup -/p..-->..K/sup 0/..pi../sup -/p has been studied at 100 and 175 GeV/c and the reaction ..pi../sup -/p..-->..K/sup 0/K/sup -/p at 50, 100, and 175 GeV/c. Both reactions are dominated by production of resonances, K((890), K((1430) and A/sub 2/(1320), A/sub 2/(2040), respectively. Production cross sections, t distributions, and decay-angular distributions are studied. Isoscalar natural-parity exchange is dominant. The energy dependence of the K( and A/sub 2/ resonance production between 10 and 175 GeV/c is well described by a Regge-pole model. Our data on A/sub 2/ corrects that in an earlier paper.