Production and Decay Properties of the $D(1285)$ Meson in $K^- p$ Interactions at 4.2-{GeV}/$c$

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gurtu, A. ; Gavillet, P. ; Armenteros, R. ; et al.
Nucl.Phys.B 151 (1979) 181-192, 1979.
Inspire Record 133183 DOI 10.17182/hepdata.34791

We have studied the production and decay of the D(1285) meson in the reaction K − p→ Λ D at an incident K − momentum of 4.2 GeV/ c . The cross section for this reaction is 11 ± 3 μ b and the branching ratios D→ KK π /D → ηππ and D → 4 π /D → ηππ are found to be 0.42 ± 0.15 and 0.7 ± 0.5, respectively. The proportion of D → ηπ + π − going through the intermediate δ ± π ∓ states is 0.72 ± 0.15. Forward and backward exchange mechanisms are found to contribute in the ratio 3 : 2.

1 data table

ABOUT 60 PCT OF THE D(1285) PRODUCTION OCCURS IN THE FORWARD HEMISPHERE.


Backward Production of a Spin Parity 1+ $K \rho$ Resonance at 1.28-{GeV}

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gavillet, P. ; Diaz, J. ; Dionisi, C. ; et al.
Phys.Lett.B 76 (1978) 517-522, 1978.
Inspire Record 130237 DOI 10.17182/hepdata.27442

A ( K π π ) + mass enhancement is observed in the reactions K − p → Ξ −K o + π + π o − when events with a small (K − → Ξ − ) four momentum transfer squared are selected. The signal is also visible in the reaction K − p → Ξ − π + + neutrals. The enhancement, centered at 1.28 GeV, is seen to decay preferentially into Kϱ with spin-parity J P = 1 + . The cross section for K − p→ Ξ − C + (1.28) with C + → K ϱ at 4.15 GeV/c incident K − momentum is (6.2 ± 0.6) μ b.

1 data table

ASSUMING ISOSPIN HALF FOR C(1280)+ AND C(1400)+. FOR C(1280)+, D(SIG)/DU HAS SLOPE OF 1.60 +- 0.30 GEV**-2. THESE AXIAL VECTOR RESONANCES ARE HERE ENCODED AS QLOW(1240)+ AND QHIGH(1340)+.