W. Kern

Spin parity analysis of the

Abstract We have carried out a study of the reaction π − p → ƒ 1 (1285) π − p at 18 GeV / c , with ƒ 1 (1285) → K + K 0 π − This reaction is almost entirely mediated by the natural-parity exchange, presumably ƒ 2 (1270) or ϱ exchange. We find evidence for two possible resonances - a JPC = 1++ state at 1.7 GeV / c2 and a broad JPC = 1−+ structure at 1.6–2.2 GeV/c2.

f_1(1285) \pi^-

Abstract We present a measurement of the polarization and decay asymmetry parameters of the Ξ − inclusively produced in the forward direction in K − p interactions at 5 GeV/ c . The Ξ − decay parameters have been determined to be α Ξ = −0.405 ± 0.029 and Φ Ξ = 14.7° ± 16.0° from a sample of 20 865 events. A linear rise of the Ξ − polarization has been seen with respect to the transverse momentum of the Ξ − , reaching a maximum of 49 ± 4% at P ⊥ ∼ 0.50 GeV/ c . The value of α Ξ is consistent with the world average prior to 1975, but below the value measured by two recent experiments.

system in the reaction

Abstract We have performed a partial-wave analysis of the K + K O S π − system produced in the reaction K − p → K + K 0 S π − Λ / Σ at 8 GeV/c. We present results of a preliminary analysis of approximately 2000 events in the KKπ mass range 1.24–1.64 GeV, with 0.0 2 . In the 1.28 GeV mass region, we observe a small J PG = 0 −+ contribution but little indication of a 1 ++ wave. We observe a large enhancement of events at the threshold of KK ∗ production. Above this threshold the J PG = 1 +− , 1 ++ and 0 −+ waves all contribute, and we see evidence for a 1 +− resonance below the KK ∗ threshold.

\pi^- p \to f_1(1285) \pi^- p

We have performed a partial wave analysis of the K+K0Sπ− system produced in the reaction π−p → K+K0π−n at GeV/c. We present the mass dependent fits to the PWA results for the waves JPG(isobar)=0−+(α0), 0−+(K*), 1++(α0) and 1++(K*).

at 18-GeV/c

We are studying the reaction pp→K+K°π−X and pp→Λpπ X. We present mass spectra for the systems produced in these reactions. The data respresent one‐half of the total data collected.

Measurement of decay parameters and polarization in inclusive Ξ− production from K−p interactions

This paper describes an experiment that will search for JPC hybrid mesons at the Brookhaven MPS‐II facility. Such explicitly exotic states are allowed in QCD, and are predicted to be in an accessible mass region by several models. The experiment will investigate the production of exotics in the reaction π−p→π−f1p. Expected rates and experimental sensitivity to possible hybrid states are discussed.

Preliminary partial-wave analysis of the K+KOs π− system produced in 8 GeV/c K−p interactions

This paper describes an experiment that will search for JPC hybrid mesons at the Brookhaven MPS‐II facility. Such explicitly exotic states are allowed in QCD, and are predicted to be in an accessible mass region by several models. The experiment will investigate the production of exotics in the reaction π−p→π−f1p. Expected rates and experimental sensitivity to possible hybrid states are discussed.

Mass dependent fits of the partial wave analysis of the K+K̄0π− system

We have carried out a sensitive (> or approx. =5 events/nb) search for narrow p-barp states at the BNL Multiparticle Spectrometer. We found no evidence of narrow p-barp states at 2020 and 2200 MeV in the reaction ..pi../sup -/p..-->..p..pi../sup -/p-barp at 16 GeV/c. We quote 2 upper limits of or approx. =5 s signals at 2020 and 2200 MeV.