Equations for T V V and T T P couplings are derived from dual amplitudes for the processes P + V + P + V and P + T+ P + P. The couplings are expressed in terms of other mesonic couplings, known from experiment. With the aid of these couplings we calculate the decay rates o f A,-WTP, f -p.rr.rr, K * * i K*mr and the electromagnetic decays A,, f i V y , and y y . The calculated rates for A,+on?r and f+pn.rr are smaller (by about a factor of 4) than the average experimental data. This discrepancy is analyzed in terms of a consistent picture for all the decays studied in this paper.
A model with dominant T W interaction, supplemented by experimental information from related processes, predicts the yet-unreported decay K**(1420)-r K*(890)lr?r to have a width of 7.5 MeV. A characteristic feature of the model is that the pion pair comes out predominantly in an isotopic spin T = 1 state.During the l a s t few years, several groups have reported measurements of the strong decays A,-wnn and f -4n, the latter proceeding a t least partially a s f -pn+n-. Although unfavored by phase-space limitation in comparison with the twobody decays of the tensor mesons, these decays turn out to be relatively frequent, the world ave r a g e being'r$(f -$8-n'n-)=6.2*1.5 MeV.In a recent paper,' a theoretical analysis of these decay modes was presented. The principal conclusion is that the TVV coupling appears to play the dominant role in this type of transitions, the major contribution to the decay amplitudes arising through the T -V + V-P + P + V chain. A generalization of the TVV interaction to a n SU(3)-symmetric form would then imply the occurrence of similar transitions of the strange tensor meson ~* * ( 1 4 2 0 ) , i.e., KC*(1420) -K*(890)nn decays of appropriate strength. In this note, we work out the expectations for the K**-K*nn transitions, arriving a t a predicted r a t e of 7.5 MeV when the average experimental width for A, -wan is used a s input.A survey of the reported1 K t * experiments r eveals that the K** -K3n transitions have not been analyzed in the past for the detection of the modes suggested here. Two recent experimental analyses, which had sought this mode, give figures differing by an order of magnitude. With limited statistics, Goldberg concludes3 that the K**--Kt-n'n-proc e s s occurs a t a r a t e of 4 * 1.3 MeV. On theother hand, preliminary r e s u l t s f r o m the Amsterdam-CERN-Nijmegen-Oxford collaboration give4 0. 6: : : ; MeV f o r this decay.Since we address ourselves to K** decays deriving from a TVV vertex, we have to consider a s possible modes Kt* -K*nn, K** -pKn, and K** -wKn. However, while the f i r s t mode h a s approximately 250 MeV of phase space available, the other two have only a margin of a few MeV and hence will be considerably inhibited and of no practical interest. In the r e s t of this note, we therefore r e s t r i c t our analysis to the K** -K*nn modes only. To be specific, l e t u s consider the decays of K**+; there a r e three channels available:Unlike the A,-wan decay, where the two pions a r e emitted in an isotopic-spin state T = 1, the pion pair in the (2a) transition can be in both T = O and T = 1 states, whereas in K**+ -~*'n+nO we have again a pure T = 1 pion pair.We now summarize the approach used in Ref. 2 to deal with the A, -wnn, f -pnn decays and then proceed to use the information extracted thereof for the Kt*-K*nn decays. The amplitude for T + V -P +P is calculated by including the contributions f r o m direct (s) and exchange ( t , u ) channels. The direct-channel contribution is dominated by an intermediate vector meson, while the t ...
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