About 15 000 K − Φp events have been collected in the CERN Ω′ spectrometer. A partial-wave decomposition of the K − Φ system is performed. The 1 + SO + wave is dominant. The 0 − P0 + and 2 − P0 + waves are important and show resonant behaviour at ∼ 1.83 GeV (Γ ∼ 0.25 GeV) and ∼ 1.73 GeV (Γ ∼ 0.22 GeV) respectively. The first one can be interpreted as the second radial excitation of the kaon while the second one can be identified as one of the two L mesons.
No description provided.
PARTIAL WAVE AMPLITUDE SHOWING POSSIBLE EXISTENCE OF L MESON AT 1.73 GEV (WIDTH = 0.22 GEV) AND RADIAL EXCITATION OF THE KAON AT 1.83 GEV (WIDTH = 0.25 GEV).
We present experimental results on a number of K − p reactions at 14.3 GeV/ c that have three bodies in the final state. The final states are K − ω p , K − π p , Λπ + π − , Λ K + K − , Λp p , K ∗ − ω p , Λ(1520) K + K − and Λ(1520) p p . Whenever, with one exception explained by the Zweig rule, there is a K − or a proton in the final state, there is a diffractive-like threshold enhancement in the mass spectrum of the two recoiling particles. These enhancements account for a large fraction of the events in all but the Λπ + π − final state, where they cannot occur, and which is dominated by resonance production. We find evidence for the Q 1 (1300) decaying into K − ω .
THE DIFFRACTION DISSOCIATION CROSS SECTIONS ARE FOR DIFFRACTIVE THRESHOLD ENHANCEMENTS IN THE TWO-BODY MASS SPECTRA (WITHIN 500 MEV CM ENERGY OF THRESHOLD).
We discuss the structure of the momentum transfer distributions for the diffractive dissociation processes p → n π + , p → Δ ++ π − and K − → K 890 ∗0 π − . In the near-threshold mass region a clear break of slope is found around t ′KK ∼ 0.25 GeV 2 for the two baryonic channels, whereas no comparable structure is seen for the mesonic system. The K → K ∗ π differential cross section exhibits a nearly exponential behaviour up to t ′ pp ∼ 0.6 GeV 2 , falling over three orders of magnitude. The slope variations and breaks are strongly correlated both to the mass region considered and to the decay angle of the fragmentation system.
No description provided.
A partial-wave analysis has been performed of the diffractively produced low-mass ( K ̄ 0 π − π 0 ) system in the reaction K − p → ( K ̄ 0 π − π 0 ) p at 10 and 16 GeV/ c . Thus information complementary to that derived from the K − p → (K − π + π − )p) channel is obtained. The presence of the K ϱ decay mode, besides the dominant K ∗ (890)π mode, for the state J P = 1 + , is confirmed. It is also confirmed that for this 1 + state the assumption of factorization of the amplitude into “production” and “decay” does not hold: the two decay modes K ∗ π and K ϱ have different polarisation properties (helicity is approximately conserved in the t -channel for the first, in the s -channel for the second). The assumption that the ( K ̄ 0 π − π 0 ) system has isospin I = 1 2 has been tested and found to hold. From the cross sections for the various J P states, assuming I = 1 2 , the cross sections for the (K − π + π − ) system are predicted and compared with the experimental ones. In general, agreement is found.
No description provided.
No description provided.
We have studied the reactions K − p → K − π + π − p and K − p → K 0 π − π 0 p at 14.3 GeV/ c using respectively 15 992 and 3723 events. Partial-wave analysis of the region 1.0 < m (K ππ ) < 1.7 GeV have been made using a modified version of the method developed at the University of Illinois.
No description provided.